Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD

🧪 Overview

Mechanistic Overview

Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD starts from the claim that modulating SST within the disease context of Alzheimer's disease can redirect a disease-relevant process. The original description reads: "

Mechanistic Overview Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD starts from the claim that modulating SST within the disease context of Alzheimer's disease can redirect a disease-relevant process. The original description reads: "

Molecular Mechanism and Rationale Somatostatin-positive (SST+) interneurons in entorhinal cortex layer II provide critical GABAergic inhibition that regulates the excitability of stellate cells and controls the temporal dynamics of perforant path output to the hippocampus. Early tau hyperphosphorylation disrupts the intrinsic membrane properties and synaptic function of SST interneurons, leading to disinhibition of layer II stellate cells and aberrant gamma oscillations in the 30-80 Hz range.

...

Mechanistic Overview

Mechanistic Overview Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD starts from the claim that modulating SST within the disease context of Alzheimer's disease can redirect a disease-relevant process. The original description reads: "

Molecular Mechanism and Rationale Somatostatin-positive (SST+) interneurons in entorhinal cortex layer II provide critical GABAergic inhibition that regulates the excitability of stellate cells and controls the temporal dynamics of perforant path output to the hippocampus. Early tau hyperphosphorylation disrupts the intrinsic membrane properties and synaptic function of SST interneurons, leading to disinhibition of layer II stellate cells and aberrant gamma oscillations in the 30-80 Hz range. This disinhibition allows pathological tau propagation along the perforant path while simultaneously degrading the precise gamma-frequency gating required for proper grid cell and object-vector cell ensemble activity. Closed-loop transcranial alternating current stimulation (tACS) at individualized gamma frequencies can restore the physiological inhibitory tone by enhancing SST interneuron synchronization and reestablishing proper excitatory-inhibitory balance in the entorhinal-hippocampal circuit.

Preclinical Evidence Studies in rTg4510 and PS19 tau transgenic mice demonstrate that SST interneuron dysfunction precedes overt neuronal loss and correlates with early deficits in spatial navigation and object-place recognition. Optogenetic activation of SST interneurons in EC layer II can rescue gamma oscillation deficits and improve memory performance in tau mouse models, while selective ablation of these interneurons accelerates tau spread and cognitive decline. Patch-clamp recordings from human postmortem AD tissue reveal reduced SST interneuron excitability and altered intrinsic properties in early-stage cases, with preserved cell numbers but compromised synaptic output. Additionally, in vivo calcium imaging studies show that SST interneuron activity patterns become desynchronized from grid cell firing in tau transgenic mice, supporting the hypothesis that restoring inhibitory network timing could prevent pathological tau propagation.

Therapeutic Strategy The closed-loop tACS approach would utilize real-time EEG monitoring of entorhinal gamma activity to deliver personalized stimulation parameters that enhance SST interneuron synchronization without disrupting physiological network dynamics. High-definition electrode arrays positioned over temporal regions could target EC layer II with sufficient spatial precision while minimizing off-target effects on adjacent cortical areas. The stimulation protocol would adapt frequency and phase parameters based on continuous feedback from local field potential recordings, ensuring optimal entrainment of SST interneuron networks during periods of heightened tau propagation risk. This approach could be combined with pharmacological SST receptor agonists or GABA-enhancing compounds to amplify the therapeutic effects and extend the duration of network stabilization between stimulation sessions.

Biomarkers and Endpoints Primary endpoints would include restoration of perforant path gamma coherence measured via simultaneous EEG-fMRI and improvements in grid cell firing patterns assessed through high-resolution spatial navigation tasks. CSF tau phosphorylation markers, particularly pTau217 and pTau231, would serve as molecular biomarkers for patient stratification and treatment response monitoring. Advanced diffusion tensor imaging could track changes in perforant path white matter integrity, while task-based fMRI during spatial memory paradigms would measure functional connectivity restoration between entorhinal cortex and hippocampal subfields.

Potential Challenges The primary scientific risk involves the technical complexity of achieving sufficient spatial resolution with tACS to selectively target EC layer II without affecting broader temporal lobe networks that could disrupt normal cognitive function. Blood-brain barrier penetration is not a concern for this approach, but precise electrode positioning and individual anatomical variability could limit therapeutic efficacy and reproducibility across patients. Off-target stimulation of adjacent regions, particularly the hippocampus proper or temporal neocortex, could potentially interfere with residual memory circuits and produce unintended cognitive side effects during treatment sessions.

Connection to Neurodegeneration This mechanism directly addresses the earliest detectable stage of AD pathophysiology, when tau aggregation begins in EC layer II stellate cells but has not yet spread extensively throughout the hippocampal formation. By restoring SST interneuron function and perforant path gating, this intervention could prevent the trans-synaptic propagation of tau pathology that drives progressive hippocampal and cortical degeneration in AD. The approach specifically targets the circuit-level dysfunction that underlies spatial disorientation and episodic memory deficits, potentially slowing or halting the cascade of synaptic failures that characterize disease progression from mild cognitive impairment to dementia.

Mechanistic Pathway Diagram

Mermaid diagram (expand to render)

References

^[1] (high) — 40 Hz gamma entrainment reduces amyloid and tau pathology in 5XFAD and tau P301S mice
^[2] (high) — Parvalbumin interneurons are critical for gamma oscillation generation and cognitive function
^[3] (high) — Gamma stimulation enhances microglial phagocytosis through mechanosensitive channel activation
^[4] (medium) — 40 Hz audiovisual stimulation shows safety and potential efficacy in mild AD patients (GENUS trial)
^[5] (medium) — Gamma oscillations restore hippocampal-cortical synchrony and improve memory in AD mouse models
^[6] (high) — Multi-modal gamma entrainment shows enhanced efficacy over single-modality stimulation
^[7] (high) — 40 Hz light flicker reduces amyloid plaques and phospho-tau in visual cortex of 5xFAD mice via microglial phagocytosis
^[8] (high) — Combined auditory and visual 40 Hz stimulation entrains gamma oscillations across hippocampus and prefrontal cortex with synergistic amyloid reduction
^[9] (high) — Phase I clinical trial of 40 Hz sensory stimulation shows safety and increased gamma power in mild AD patients over 6 months
^[10] (medium) — Gamma entrainment promotes vascular clearance of amyloid via pericyte activation and arterial pulsatility enhancement" Framed more explicitly, the hypothesis centers SST within the broader disease setting of Alzheimer's disease. The row currently records status `promoted`, origin `gap_debate`, and mechanism category `unspecified`. SciDEX scoring currently records confidence 0.82, novelty 0.78, feasibility 0.86, impact 0.82, mechanistic plausibility 0.85, and clinical relevance 0.32.

Molecular and Cellular Rationale The nominated target genes are `SST` and the pathway label is `Entorhinal cortex layer II SST interneuron-mediated perforant-path gamma gating and suppression of trans-synaptic tau propagation to hippocampus`. Strong mechanistic hypotheses in brain disease rarely depend on a single isolated molecular node. Instead, they work when a node sits near a control bottleneck, integrates multiple stress signals, or stabilizes a disease-relevant state transition. That is the standard this hypothesis should be held to. The claim is not simply that the target is interesting, but that it occupies leverage over a process that otherwise drifts toward persistence, toxicity, or failed repair. Gene-expression context on the row adds an important constraint: Gene Expression Context SST (Somatostatin): - Expressed in ~30% of cortical GABAergic interneurons; enriched in layers II-IV - SST+ interneurons are selectively vulnerable in early AD (30-60% loss in entorhinal cortex, Braak II-III) - Allen Human Brain Atlas: highest density in hippocampal hilus, temporal cortex, amygdala - SEA-AD single-cell data: SST+ interneuron cluster shows significant depletion in AD vs controls - SST peptide levels decline 50-70% in AD cortex; correlates with cognitive decline (r = 0.58) PVALB (Parvalbumin): - Marks fast-spiking basket cells essential for gamma oscillation generation (30-80 Hz) - Relatively preserved in early AD but functionally impaired (reduced firing rates) - Allen Mouse Brain Atlas: dense in hippocampal CA1/CA3, cortical layers IV-V - PVALB+ neurons receive cholinergic input; degeneration of basal forebrain cholinergic neurons reduces gamma power GAD1/GAD2 (Glutamic Acid Decarboxylase): - GABA synthesis enzymes; GAD67 (GAD1) reduced 30-40% in AD prefrontal cortex - GAD1 reduction correlates with gamma oscillation deficit in EEG studies - Expression maintained in surviving interneurons but total GABAergic tone reduced SCN1A (Nav1.1): - Voltage-gated sodium channel enriched in PVALB+ interneurons - Critical for fast-spiking phenotype that generates gamma rhythms - Reduced in AD hippocampus; haploinsufficiency in Dravet syndrome causes gamma deficits - Restoring Nav1.1 levels rescues gamma oscillations in AD mouse models (hAPP-J20) CHRNA7 (α7 Nicotinic Acetylcholine Receptor): - Expressed on both pyramidal neurons and interneurons; mediates cholinergic modulation of gamma - 40-50% reduced in AD hippocampus (receptor binding studies) - Alpha7 agonists enhance gamma oscillations and improve cognitive function in preclinical models If the intervention succeeds, downstream consequences should include cleaner biomarker separation, improved cellular resilience, reduced inflammatory spillover, or better maintenance of synaptic and metabolic programs. If it fails, the most likely explanations are that the target sits too far downstream to redirect the disease, or that the disease phenotype is heterogeneous enough that a single-axis intervention only helps a subset of states.

Contradictory Evidence, Caveats, and Failure Modes 1. Translation to human studies has shown mixed results with small effect sizes. ^[11]. 2. Optimal stimulation parameters remain unclear across different AD stages. ^[12]. 3. Gamma oscillation deficits in AD may reflect network damage rather than a treatable cause, questioning the therapeutic premise. ^[13]. 4. Sensory gamma entrainment shows rapid habituation with diminished neural response after 2 weeks of daily stimulation. ^[14]. 5. Translation of mouse gamma entrainment to humans is limited by skull attenuation and cortical folding differences. ^[15].

Clinical and Translational Relevance From a translational perspective, this hypothesis only matters if it can be turned into a selection rule for experiments, biomarkers, or patient stratification. The row currently records market price `0.7762`, debate count `2`, citations `55`, predictions `4`, and falsifiability flag `1`. Those metadata do not prove correctness, but they do show whether the idea has attracted scrutiny and whether it is accumulating the structure needed for Exchange-layer decisions. 1. Trial context: NOT_YET_RECRUITING. 2. Trial context: RECRUITING. 3. Trial context: UNKNOWN. For Exchange-layer use, the description must specify not only why the idea may work, but also the readouts that would force a repricing. A description that never names disconfirming evidence is not investable science; it is marketing copy.

Experimental Predictions and Validation Strategy First, the hypothesis should be decomposed into a perturbation experiment that directly manipulates SST in a model matched to Alzheimer's disease. The key readout should include pathway markers, cell-state markers, and at least one phenotype that maps onto "Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD". Second, the study design should include a rescue arm. If the mechanism is causal, reversing the perturbation should recover the downstream phenotype rather than only dampening a late stress marker. Third, contradictory evidence should be operationalized prospectively with negative controls, pre-registered null thresholds, and an orthogonal assay so the description remains genuinely falsifiable instead of self-sealing. Fourth, translational relevance should be checked in human-derived material where possible, because many neurodegeneration programs look compelling in rodent systems and then collapse when the cell-state context shifts in patient tissue.

Decision-Oriented Summary In summary, the operational claim is that targeting SST within the disease frame of Alzheimer's disease can produce a measurable change in mechanism rather than only a cosmetic change in a terminal biomarker. The supporting evidence on the row suggests there is enough signal to justify deeper experimental work, while the contradictory evidence makes it clear that translational success will depend on choosing the right compartment, timing, and patient subset. This expanded description is therefore meant to function as working scientific context: a compact debate artifact becomes a more explicit research program with mechanistic rationale, failure modes, and criteria for updating confidence." Framed more explicitly, the hypothesis centers SST within the broader disease setting of Alzheimer's disease. The row currently records status `promoted`, origin `gap_debate`, and mechanism category `unspecified`.

SciDEX scoring currently records confidence 0.82, novelty 0.78, feasibility 0.86, impact 0.82, mechanistic plausibility 0.85, and clinical relevance 0.32.

Molecular and Cellular Rationale

The nominated target genes are `SST` and the pathway label is `Entorhinal cortex layer II SST interneuron-mediated perforant-path gamma gating and suppression of trans-synaptic tau propagation to hippocampus`. Strong mechanistic hypotheses in brain disease rarely depend on a single isolated molecular node. Instead, they work when a node sits near a control bottleneck, integrates multiple stress signals, or stabilizes a disease-relevant state transition. That is the standard this hypothesis should be held to. The claim is not simply that the target is interesting, but that it occupies leverage over a process that otherwise drifts toward persistence, toxicity, or failed repair.
Gene-expression context on the row adds an important constraint: Gene Expression Context SST (Somatostatin): - Expressed in ~30% of cortical GABAergic interneurons; enriched in layers II-IV - SST+ interneurons are selectively vulnerable in early AD (30-60% loss in entorhinal cortex, Braak II-III) - Allen Human Brain Atlas: highest density in hippocampal hilus, temporal cortex, amygdala - SEA-AD single-cell data: SST+ interneuron cluster shows significant depletion in AD vs controls - SST peptide levels decline 50-70% in AD cortex; correlates with cognitive decline (r = 0.58) PVALB (Parvalbumin): - Marks fast-spiking basket cells essential for gamma oscillation generation (30-80 Hz) - Relatively preserved in early AD but functionally impaired (reduced firing rates) - Allen Mouse Brain Atlas: dense in hippocampal CA1/CA3, cortical layers IV-V - PVALB+ neurons receive cholinergic input; degeneration of basal forebrain cholinergic neurons reduces gamma power GAD1/GAD2 (Glutamic Acid Decarboxylase): - GABA synthesis enzymes; GAD67 (GAD1) reduced 30-40% in AD prefrontal cortex - GAD1 reduction correlates with gamma oscillation deficit in EEG studies - Expression maintained in surviving interneurons but total GABAergic tone reduced SCN1A (Nav1.1): - Voltage-gated sodium channel enriched in PVALB+ interneurons - Critical for fast-spiking phenotype that generates gamma rhythms - Reduced in AD hippocampus; haploinsufficiency in Dravet syndrome causes gamma deficits - Restoring Nav1.1 levels rescues gamma oscillations in AD mouse models (hAPP-J20) CHRNA7 (α7 Nicotinic Acetylcholine Receptor): - Expressed on both pyramidal neurons and interneurons; mediates cholinergic modulation of gamma - 40-50% reduced in AD hippocampus (receptor binding studies) - Alpha7 agonists enhance gamma oscillations and improve cognitive function in preclinical models
If the intervention succeeds, downstream consequences should include cleaner biomarker separation, improved cellular resilience, reduced inflammatory spillover, or better maintenance of synaptic and metabolic programs. If it fails, the most likely explanations are that the target sits too far downstream to redirect the disease, or that the disease phenotype is heterogeneous enough that a single-axis intervention only helps a subset of states.

Evidence Supporting the Hypothesis

40 Hz gamma entrainment reduces amyloid and tau pathology in 5XFAD and tau P301S mice. ^[1].

Parvalbumin interneurons are critical for gamma oscillation generation and cognitive function. ^[2].

Gamma stimulation enhances microglial phagocytosis through mechanosensitive channel activation. ^[3].

40 Hz audiovisual stimulation shows safety and potential efficacy in mild AD patients (GENUS trial). ^[4].

Gamma oscillations restore hippocampal-cortical synchrony and improve memory in AD mouse models. ^[5].

Multi-modal gamma entrainment shows enhanced efficacy over single-modality stimulation. ^[6].

Contradictory Evidence, Caveats, and Failure Modes

Translation to human studies has shown mixed results with small effect sizes. ^[11].

Optimal stimulation parameters remain unclear across different AD stages. ^[12].

Gamma oscillation deficits in AD may reflect network damage rather than a treatable cause, questioning the therapeutic premise. ^[13].

Sensory gamma entrainment shows rapid habituation with diminished neural response after 2 weeks of daily stimulation. ^[14].

Translation of mouse gamma entrainment to humans is limited by skull attenuation and cortical folding differences. ^[15].

Clinical and Translational Relevance

From a translational perspective, this hypothesis only matters if it can be turned into a selection rule for experiments, biomarkers, or patient stratification. The row currently records market price `0.7762`, debate count `2`, citations `55`, predictions `4`, and falsifiability flag `1`. Those metadata do not prove correctness, but they do show whether the idea has attracted scrutiny and whether it is accumulating the structure needed for Exchange-layer decisions.

Trial context: NOT_YET_RECRUITING.

Trial context: RECRUITING.

Trial context: UNKNOWN.

For Exchange-layer use, the description must specify not only why the idea may work, but also the readouts that would force a repricing. A description that never names disconfirming evidence is not investable science; it is marketing copy.

Experimental Predictions and Validation Strategy

First, the hypothesis should be decomposed into a perturbation experiment that directly manipulates SST in a model matched to Alzheimer's disease. The key readout should include pathway markers, cell-state markers, and at least one phenotype that maps onto "Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD".
Second, the study design should include a rescue arm. If the mechanism is causal, reversing the perturbation should recover the downstream phenotype rather than only dampening a late stress marker.
Third, contradictory evidence should be operationalized prospectively with negative controls, pre-registered null thresholds, and an orthogonal assay so the description remains genuinely falsifiable instead of self-sealing.
Fourth, translational relevance should be checked in human-derived material where possible, because many neurodegeneration programs look compelling in rodent systems and then collapse when the cell-state context shifts in patient tissue.

Decision-Oriented Summary

In summary, the operational claim is that targeting SST within the disease frame of Alzheimer's disease can produce a measurable change in mechanism rather than only a cosmetic change in a terminal biomarker. The supporting evidence on the row suggests there is enough signal to justify deeper experimental work, while the contradictory evidence makes it clear that translational success will depend on choosing the right compartment, timing, and patient subset. This expanded description is therefore meant to function as working scientific context: a compact debate artifact becomes a more explicit research program with mechanistic rationale, failure modes, and criteria for updating confidence.

⚖️ Evidence

⚖️ Evidence Matrix42 supports13 contradicts

Supports

40 Hz gamma entrainment reduces amyloid and tau pathology in 5XFAD and tau P301S mice

Cell2019PMID:31076275high

Abstract

Neuronal and synaptic loss is characteristic in many neurodegenerative diseases, such as frontotemporal dementia and Alzheimer's disease. Recently, we showed that inducing gamma oscillations with visual stimulation (gamma entrainment using sensory stimuli, or GENUS) reduced amyloid plaques and phosphorylated tau in multiple mouse models. Whether GENUS can affect neurodegeneration or cognitive performance remains unknown. Here, we demonstrate that GENUS can entrain gamma oscillations in the visual cortex, hippocampus, and prefrontal cortex in Tau P301S and CK-p25 mouse models of neurodegeneration. Tau P301S and CK-p25 mice subjected to chronic, daily GENUS from the early stages of neurodegeneration showed a preservation of neuronal and synaptic density across multiple brain areas and modified cognitive performance. Our transcriptomic and phosphoproteomic data suggest that chronic GENUS shifts neurons to a less degenerative state, improving synaptic function, enhancing neuroprotective fa

Supports

Parvalbumin interneurons are critical for gamma oscillation generation and cognitive function

Nat Neurosci2022PMID:35151204high

Abstract

Hippocampal-cortical circuit oscillations in local field potential (LFP) represent network-level signals which promotes behavior. Investigating these signals promote our understanding on how the brain process cognition and emotion, and provide further perspectives into electroencephalogram endophenotypes, especially under the pathological state. The physiological adaptive stress responses to threatening stimuli are critical for individuals. The disturbance of stress response may lead to psychiatric disorders such as major depressive disorder (MDD). To quantitatively examine the effects of acute stress on hippocampal-cortical circuit, we recorded LFPs in the hippocampus (HC) and the medial prefrontal cortex (mPFC). We analyzed three major LFP oscillations with their temporal coupling. Consistent with our hypothesis that strengthened communication of hippocampal-cortical circuit may occur in stress adaption, we found that intensive acute stress induced enhanced ripple-delta-spindle coupl

Supports

Gamma stimulation enhances microglial phagocytosis through mechanosensitive channel activation

Cell Rep2022PMID:36450248high

Abstract

Influenza infection is substantially worsened by the onset of secondary pneumonia caused by bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA). The bidirectional interaction between the influenza-injured lung microenvironment and MRSA is poorly understood. By conditioning MRSA ex vivo in bronchoalveolar lavage fluid collected from mice at various time points of influenza infection, we found that the influenza-injured lung microenvironment dynamically induces MRSA to increase cytotoxin expression while decreasing metabolic pathways. LukAB, a SaeRS two-component system-dependent cytotoxin, is particularly important to the severity of post-influenza MRSA pneumonia. LukAB's activity is likely shaped by the post-influenza lung microenvironment, as LukAB binds to (and is activated by) heparan sulfate (HS) oligosaccharide sequences shed from the epithelial glycocalyx after influenza. Our findings indicate that post-influenza MRSA pneumonia is shaped by bidirectional host-pat

Supports

40 Hz audiovisual stimulation shows safety and potential efficacy in mild AD patients (GENUS trial)

Brain Stimul2024PMID:37384704medium

Abstract

Adenosine monophosphate-activated protein kinase (AMPK) activity is stimulated to promote metabolic adaptation upon energy stress. However, sustained metabolic stress may cause cell death. The mechanisms by which AMPK dictates cell death are not fully understood. We report that metabolic stress promoted receptor-interacting protein kinase 1 (RIPK1) activation mediated by TRAIL receptors, whereas AMPK inhibited RIPK1 by phosphorylation at Ser415 to suppress energy stress-induced cell death. Inhibiting pS415-RIPK1 by Ampk deficiency or RIPK1 S415A mutation promoted RIPK1 activation. Furthermore, genetic inactivation of RIPK1 protected against ischemic injury in myeloid Ampkα1-deficient mice. Our studies reveal that AMPK phosphorylation of RIPK1 represents a crucial metabolic checkpoint, which dictates cell fate response to metabolic stress, and highlight a previously unappreciated role for the AMPK-RIPK1 axis in integrating metabolism, cell death, and inflammation.

Supports

Gamma oscillations restore hippocampal-cortical synchrony and improve memory in AD mouse models

Brain Behav Immun2024PMID:38642614medium

Abstract

BACKGROUND: Both functional brain imaging studies and autopsy reports have indicated the presence of synaptic loss in the brains of depressed patients. The activated microglia may dysfunctionally engulf neuronal synapses, leading to synaptic loss and behavioral impairments in depression. However, the mechanisms of microglial-synaptic interaction under depressive conditions remain unclear. METHODS: We utilized lipopolysaccharide (LPS) to induce a mouse model of depression, examining the effects of LPS on behaviors, synapses, microglia, microglial phagocytosis of synapses, and the C1q/C3-CR3 complement signaling pathway. Additionally, a C1q neutralizing antibody was employed to inhibit the C1q/C3-CR3 signaling pathway and assess its impact on microglial phagocytosis of synapses and behaviors in the mice. RESULTS: LPS administration resulted in depressive and anxiety-like behaviors, synaptic loss, and abnormal microglial phagocytosis of synapses in the hippocampal dentate gyrus (DG) of mi

Supports

Multi-modal gamma entrainment shows enhanced efficacy over single-modality stimulation

Science Transl Med2025PMID:39964974high

Abstract

Parkinson's disease (PD) is a neurodegenerative disease characterized by the death of dopaminergic neurons in the substantia nigra and the formation of Lewy bodies that are composed of aggregated α-synuclein (α-Syn). However, the factors that regulate α-Syn pathology and nigrostriatal dopaminergic degeneration remain poorly understood. Previous studies demonstrate cholesterol 24-hydroxylase (CYP46A1) increases the risk for PD. Moreover, 24-hydroxycholesterol (24-OHC), a brain-specific oxysterol that is catalyzed by CYP46A1, is elevated in the cerebrospinal fluid of PD patients. Herein, we show that the levels of CYP46A1 and 24-OHC are elevated in PD patients and increase with age in a mouse model. Overexpression of CYP46A1 intensifies α-Syn pathology, whereas genetic removal of CYP46A1 attenuates α-Syn neurotoxicity and nigrostriatal dopaminergic degeneration in the brain. Moreover, supplementation with exogenous 24-OHC exacerbates the mitochondrial dysfunction induced by α-Syn fibrils

Supports

40 Hz light flicker reduces amyloid plaques and phospho-tau in visual cortex of 5xFAD mice via microglial phagocytosis

Nature2016PMID:27929004high

Abstract

Changes in gamma oscillations (20-50 Hz) have been observed in several neurological disorders. However, the relationship between gamma oscillations and cellular pathologies is unclear. Here we show reduced, behaviourally driven gamma oscillations before the onset of plaque formation or cognitive decline in a mouse model of Alzheimer's disease. Optogenetically driving fast-spiking parvalbumin-positive (FS-PV)-interneurons at gamma (40 Hz), but not other frequencies, reduces levels of amyloid-β (Aβ)1-40 and Aβ 1-42 isoforms. Gene expression profiling revealed induction of genes associated with morphological transformation of microglia, and histological analysis confirmed increased microglia co-localization with Aβ. Subsequently, we designed a non-invasive 40 Hz light-flickering regime that reduced Aβ1-40 and Aβ1-42 levels in the visual cortex of pre-depositing mice and mitigated plaque load in aged, depositing mice. Our findings uncover a previously unappreciated function of gamma rhythm

Supports

Combined auditory and visual 40 Hz stimulation entrains gamma oscillations across hippocampus and prefrontal cortex with synergistic amyloid reduction

Cell2019PMID:31578527high

Abstract

Over the past two decades efforts to control malaria have halved the number of cases globally, yet burdens remain high in much of Africa and the elimination of malaria has not been achieved even in areas where extreme reductions have been sustained, such as South Africa1,2. Studies seeking to understand the paradoxical persistence of malaria in areas in which surface water is absent for 3-8 months of the year have suggested that some species of Anopheles mosquito use long-distance migration3. Here we confirm this hypothesis through aerial sampling of mosquitoes at 40-290 m above ground level and provide-to our knowledge-the first evidence of windborne migration of African malaria vectors, and consequently of the pathogens that they transmit. Ten species, including the primary malaria vector Anopheles coluzzii, were identified among 235 anopheline mosquitoes that were captured during 617 nocturnal aerial collections in the Sahel of Mali. Notably, females accounted for more than 80% of a

Supports

Phase I clinical trial of 40 Hz sensory stimulation shows safety and increased gamma power in mild AD patients over 6 months

Alzheimers Dement2022PMID:35236841high

Abstract

CRISPR-Cas9 expression independent of its cognate synthetic guide RNA (gRNA) causes widespread genomic DNA damage in human cells. To investigate whether Cas9 can interact with endogenous human RNA transcripts independent of its guide, we perform eCLIP (enhanced CLIP) of Cas9 in human cells and find that Cas9 reproducibly interacts with hundreds of endogenous human RNA transcripts. This association can be partially explained by a model built on gRNA secondary structure and sequence. Critically, transcriptome-wide Cas9 binding sites do not appear to correlate with published genome-wide Cas9 DNA binding or cut-site loci under gRNA co-expression. However, even under gRNA co-expression low-affinity Cas9-human RNA interactions (which we term CRISPR crosstalk) do correlate with published elevated transcriptome-wide RNA editing. Our findings do not support the hypothesis that human RNAs can broadly guide Cas9 to bind and cleave human genomic DNA, but they illustrate a cellular and RNA impact l

Supports

Gamma entrainment promotes vascular clearance of amyloid via pericyte activation and arterial pulsatility enhancement

Sci Transl Med2023PMID:37156908medium

Abstract

PURPOSE: The purpose of this study was to identify if switching from intramuscular (IM) to vaginal progesterone compared to staying on IM progesterone after a positive pregnancy test following embryo transfer (ET) is associated with miscarriage risk. METHODS: A retrospective cohort study was performed in a private university-affiliated fertility clinic and included women aged 18-50 years with a positive pregnancy test following ET. The two groups studied were: women who stayed on IM progesterone following a positive pregnancy test and those who switched to vaginal progesterone after a positive test. The main outcome measured was risk of miscarriage < 24 weeks gestation as a proportion of non-biochemical pregnancies. RESULTS: 1988 women were included in the analysis. Among the baseline characteristics, the presence of prior miscarriages as well as prior failed ETs, and frozen cycles (vs fresh) as type of transfer were associated with IM progesterone use (p values ≤ 0.01). As per miscarr

Supports

A specific circuit in the midbrain detects stress and induces restorative sleep.

Science2022PMID:35771921high

Abstract

In mice, social defeat stress (SDS), an ethological model for psychosocial stress, induces sleep. Such sleep could enable resilience, but how stress promotes sleep is unclear. Activity-dependent tagging revealed a subset of ventral tegmental area γ-aminobutyric acid (GABA)-somatostatin (VTAVgat-Sst) cells that sense stress and drive non-rapid eye movement (NREM) and REM sleep through the lateral hypothalamus and also inhibit corticotropin-releasing factor (CRF) release in the paraventricular hypothalamus. Transient stress enhances the activity of VTAVgat-Sst cells for several hours, allowing them to exert their sleep effects persistently. Lesioning of VTAVgat-Sst cells abolished SDS-induced sleep; without it, anxiety and corticosterone concentrations remained increased after stress. Thus, a specific circuit allows animals to restore mental and body functions by sleeping, potentially providing a refined route for treating anxiety disorders.

Supports

25th Annual Computational Neuroscience Meeting: CNS-2016.

BMC Neurosci2016PMID:27534393medium

Abstract

A1 Functional advantages of cell-type heterogeneity in neural circuits Tatyana O. Sharpee A2 Mesoscopic modeling of propagating waves in visual cortex Alain Destexhe A3 Dynamics and biomarkers of mental disorders Mitsuo Kawato F1 Precise recruitment of spiking output at theta frequencies requires dendritic h-channels in multi-compartment models of oriens-lacunosum/moleculare hippocampal interneurons Vladislav Sekulić, Frances K. Skinner F2 Kernel methods in reconstruction of current sources from extracellular potentials for single cells and the whole brains Daniel K. Wójcik, Chaitanya Chintaluri, Dorottya Cserpán, Zoltán Somogyvári F3 The synchronized periods depend on intracellular transcriptional repression mechanisms in circadian clocks. Jae Kyoung Kim, Zachary P. Kilpatrick, Matthew R. Bennett, Kresimir Josić O1 Assessing irregularity and coordination of spiking-bursting rhythms in central pattern generators Irene Elices, David Arroyo, Rafael Levi, Francisco B. Rodriguez, Pablo Var

Supports

Inhibition of GABA interneurons in the mPFC is sufficient and necessary for rapid antidepressant responses.

Mol Psychiatry2021PMID:33070149medium

Abstract

Major depressive disorder (MDD) is associated with alterations of GABAergic interneurons, notably somatostatin (Sst) as well as parvalbumin (Pvalb), in cortical brain areas. In addition, the antidepressant effects of rapid-acting drugs are thought to occur via inhibition of GABA interneurons. However, the impact of these interneuron subtypes in affective behaviors as well as in the effects of rapid-acting antidepressants remains to be determined. Here, we used a Cre-dependent DREADD-chemogenetic approach to determine if inhibition of GABA interneurons in the mPFC of male mice is sufficient to produce antidepressant actions, and conversely if activation of these interneurons blocks the rapid and sustained antidepressant effects of scopolamine, a nonselective acetylcholine muscarinic receptor antagonist. Chemogenetic inhibition of all GABA interneurons (Gad1+), as well as Sst+ and Pvalb+ subtypes in the mPFC produced dose and time-dependent antidepressant effects in the forced swim and n

Supports

[(131)I]N-(6-amino-2,2,4-trimethylhexyl)-2-[(5-iodo(3-pyridyl))carbonylamino]-3-(2-napthyl)propanamide.

2004PMID:20641809medium

Abstract

An autoimmune process and other environmental factors that destroy pancreatic β cells in the pancreatic islet cells are known to promote the development of insulin-dependent diabetes mellitus (type 1 diabetes) in individuals genetically predisposed to the disease (1). As a consequence of the β cell destruction, the net mass of these cells in the islet cells is reduced and, due to reduced insulin production, maintenance of blood glucose to a proper physiological level is impaired. The most common

Supports

(177)Lu-DOTA-Tyr(3)-c(Cys-Tyr-Trp-Lys-Thr-Cys)-Thr-Lys(cypate)-NH(2).

2004PMID:20641372medium

Abstract

Somatostatin (SST) (somatotropin release-inhibiting hormone, somatotropin release-inhibiting factor) is a cyclic disulphide-containing peptide hormone of 14 amino acids (1). SST inhibits hormone secretion, cell proliferation, and promotes apoptosis through binding to specific cell-surface somatostatin receptors (SSTRs) (2). Five SSTR subtypes are identified in the central nervous system (CNS), gastrointestinal tract, and a variety of benign and malignant tumors (2). All subtypes of SSTRs belong

Supports

Novel App knock-in mouse model shows key features of amyloid pathology and reveals profound metabolic dysregulation of microglia.

Mol Neurodegener2022PMID:35690868medium

Abstract

BACKGROUND: Genetic mutations underlying familial Alzheimer's disease (AD) were identified decades ago, but the field is still in search of transformative therapies for patients. While mouse models based on overexpression of mutated transgenes have yielded key insights in mechanisms of disease, those models are subject to artifacts, including random genetic integration of the transgene, ectopic expression and non-physiological protein levels. The genetic engineering of novel mouse models using knock-in approaches addresses some of those limitations. With mounting evidence of the role played by microglia in AD, high-dimensional approaches to phenotype microglia in those models are critical to refine our understanding of the immune response in the brain. METHODS: We engineered a novel App knock-in mouse model (AppSAA) using homologous recombination to introduce three disease-causing coding mutations (Swedish, Arctic and Austrian) to the mouse App gene. Amyloid-β pathology, neurodegenerat

Supports

Molecular hallmarks of excitatory and inhibitory neuronal resilience and resistance to Alzheimer's disease.

bioRxiv2025PMID:39868232medium

Abstract

BACKGROUND: A significant proportion of individuals maintain healthy cognitive function despite having extensive Alzheimer's disease (AD) pathology, known as cognitive resilience. Understanding the molecular mechanisms that protect these individuals can identify therapeutic targets for AD dementia. This study aims to define molecular and cellular signatures of cognitive resilience, protection and resistance, by integrating genetics, bulk RNA, and single-nucleus RNA sequencing data across multiple brain regions from AD, resilient, and control individuals. METHODS: We analyzed data from the Religious Order Study and the Rush Memory and Aging Project (ROSMAP), including bulk (n=631) and multi-regional single nucleus (n=48) RNA sequencing. Subjects were categorized into AD, resilient, and control based on β-amyloid and tau pathology, and cognitive status. We identified and prioritized protected cell populations using whole genome sequencing-derived genetic variants, transcriptomic profilin

Supports

Parvalbumin neuroplasticity compensates for somatostatin impairment, maintaining cognitive function in Alzheimer's disease.

Transl Neurodegener2022PMID:35501886medium

Abstract

BACKGROUND: Patient-to-patient variability in the degree to which β-amyloid, tau and neurodegeneration impact cognitive decline in Alzheimer's disease (AD) complicates disease modeling and treatment. However, the underlying mechanisms leading to cognitive resilience are not resolved. We hypothesize that the variability in cognitive function and loss relates to neuronal resilience of the hippocampal GABAergic network. METHODS: We compared TgF344-AD and non-transgenic littermate rats at 9, 12, and 15 months of age. Neurons, β-amyloid plaques and tau inclusions were quantified in hippocampus and entorhinal cortex. Somatostatin (SST) and parvalbumin (PVB) interneurons were traced to examine hippocampal neuroplasticity and cognition was tested in the Barnes maze. RESULTS: The 9-month-old TgF344-AD rats exhibited loss of neurons in the entorhinal cortex and hippocampus. Hippocampal neuronal compensation was observed in 12-month TgF344-AD rats, with upregulation of GABAergic interneuronal mar

Supports

Molecular hallmarks of excitatory and inhibitory neuronal resilience to Alzheimer's disease.

Mol Neurodegener2025PMID:41035073medium

Abstract

BACKGROUND: A significant proportion of individuals maintain cognition despite extensive Alzheimer's disease (AD) pathology, known as cognitive resilience. Understanding the molecular mechanisms that protect these individuals could reveal therapeutic targets for AD. METHODS: This study defines molecular and cellular signatures of cognitive resilience by integrating bulk RNA and single-cell transcriptomic data with genetics across multiple brain regions. We analyzed data from the Religious Order Study and the Rush Memory and Aging Project (ROSMAP), including bulk RNA sequencing (n = 631 individuals) and multiregional single-nucleus RNA sequencing (n = 48 individuals). Subjects were categorized into AD, resilient, and control based on β-amyloid and tau pathology, and cognitive status. We identified and prioritized protected cell populations using whole-genome sequencing-derived genetic variants, transcriptomic profiling, and cellular composition. RESULTS: Transcriptomics and polygenic ri

Supports

Regional interneuron transcriptional changes reveal pathologic markers of disease progression in a mouse model of Alzheimer's disease.

bioRxiv2023PMID:37961679medium

Abstract

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and leading cause of dementia, characterized by neuronal and synapse loss, amyloid-β and tau protein aggregates, and a multifactorial pathology involving neuroinflammation, vascular dysfunction, and disrupted metabolism. Additionally, there is growing evidence of imbalance between neuronal excitation and inhibition in the AD brain secondary to dysfunction of parvalbumin (PV)- and somatostatin (SST)-positive interneurons, which differentially modulate neuronal activity. Importantly, impaired interneuron activity in AD may occur upstream of amyloid-β pathology rendering it a potential therapeutic target. To determine the underlying pathologic processes involved in interneuron dysfunction, we spatially profiled the brain transcriptome of the 5XFAD AD mouse model versus controls, across four brain regions, dentate gyrus, hippocampal CA1 and CA3, and cortex, at early-stage (12 weeks-of-age) and late-stage (30 weeks-of-age)

Supports

Quantitative proteomic analysis of the frontal cortex in Alzheimer's disease.

J Neurochem2021PMID:32614981medium

Abstract

Alzheimer's disease (AD) is a chronic neurodegenerative disease characterized by intracellular formation of neurofibrillary tangles and extracellular deposition of β-amyloid protein (Aβ) in the extracellular matrix. The pathogenesis of AD has not yet been fully elucidated and little is known about global alterations in the brain proteome that are related to AD. To identify and quantify such AD-related changes in the brain, we employed a tandem mass tags approach coupled to high-resolution mass spectrometry. We compared the proteomes of frontal cortex from AD patients with corresponding age-matched brain samples. Liquid chromatography-mass spectrometry/MS analysis carried out on an Orbitrap Fusion Lumos Tribrid mass spectrometer led to identification of 8,066 proteins. Of these, 432 proteins were observed to be significantly altered (>1.5 fold) in their expression in AD brains. Proteins whose abundance was previously known to be altered in AD were identified including secreted phosphopr

Supports

CXCL9, CXCL10, CXCL11, and their receptor (CXCR3) in neuroinflammation and neurodegeneration.

Adv Clin Exp Med2018PMID:29893515medium

Abstract

The aim of this review is to present data from the available literature concerning CXCL9, CXCL10 and CXCL11, as well as their receptor 3 (CXCR3) in selected diseases of the central nervous system (CNS), such as tickborne encephalitis (TBE), neuroborreliosis (NB), Alzheimer's disease (AD), and multiple sclerosis (MS). CXCL9, CXCL10, and CXCL11 lack glutamic acid-leucine-arginine (ELR), and are unique, because they are more closely related to each other than to any other chemokine. The aforementioned chemokines are especially involved in Th1-type response and in various diseases, as their expression correlates with the tissue infiltration of T cells. Their production is strongly induced by interferon gamma (IFN-υ), the most typical Th1 cytokine. They act by binding to the CXC3 receptor. Knowledge about the action mechanism of CXCR3 and its ligands may be useful in the treatment of CNS diseases. However, data in the literature concerning the evaluation of CXCL9, CXCL10, CXCL11, and their

Supports

GADD45G operates as a pathological sensor orchestrating reactive gliosis and neurodegeneration.

Neuron2025PMID:40409253medium

Abstract

Reactive gliosis is a hallmark of neuropathology and offers a potential target for addressing numerous neurological diseases. Here, we show that growth arrest and DNA damage inducible gamma (GADD45G), a stress sensor in astrocytes, is a nodal orchestrator of reactive gliosis and neurodegeneration. GADD45G expression in astrocytes is sufficient to incite astrogliosis, microgliosis, synapse loss, compromised animal behavior, and the aggravation of Alzheimer's disease (AD). Conversely, silencing GADD45G specifically in astrocytes preserves synapses and rescues the histological and behavioral phenotypes of AD. Mechanistically, GADD45G controls the mitogen-activated protein kinase kinase kinase 4 (MAP3K4) and neuroimmune signaling pathways, including nuclear factor κB (NF-κB) and interferon regulatory factor 3 (IRF3), leading to profound molecular changes and the secretion of various factors that regulate both cell-autonomous and cell-nonautonomous reactive gliosis and glia-neuron interacti

Supports

Molecular pathogenesis of polymerase γ-related neurodegeneration.

Ann Neurol2014PMID:24841123medium

Abstract

OBJECTIVE: Polymerase gamma (POLG) mutations are a common cause of mitochondrial disease and have also been linked to neurodegeneration and aging. We studied the molecular mechanisms underlying POLG-related neurodegeneration using postmortem tissue from a large number of patients. METHODS: Clinical information was available from all subjects. Formalin-fixed and frozen brain tissue from 15 patients and 23 controls was studied employing a combination of histopathology, immunohistochemistry, and molecular studies of microdissected neurons. RESULTS: The primary consequence of POLG mutation in neurons is mitochondrial DNA depletion. This was already present in infants with little evidence of neuronal loss or mitochondrial dysfunction. With longer disease duration, we found an additional, progressive accumulation of mitochondrial DNA deletions and point mutations accompanied by increasing numbers of complex I-deficient neurons. Progressive neurodegeneration primarily affected the cerebellar

Supports

Mitochondrial biogenesis in neurodegeneration.

J Neurosci Res2017PMID:28301064medium

Abstract

Mitochondria play a key role in energy production, calcium homeostasis, cell survival, and death. Adverse stimulations including neurodegenerative diseases may result in mitochondrial dynamic imbalance, free radical production, calcium accumulation, intrinsic cell death pathway activation and eventually cell death. Therefore, preserving or promoting mitochondrial function is a potential therapeutic target for the treatment of neurodegenerative disorders. Mitochondrial biogenesis is a process by which new mitochondria are produced from existing mitochondria. This biogenesis process is regulated by Peroxisome proliferator-activated receptor-gamma (PPARγ) coactivator-1alpha (PGC-1α). Once being activated by either phosphorylation or de-acetylation, PGC-1α activates nuclear respiratory factor 1 and 2 (NRF1 and NRF2), and subsequently mitochondrial transcription factor A (Tfam). The activation of this PGC-1α - NRF -Tfam pathway leads to synthesis of mitochondrial DNA and proteins and genera

Supports

Paracrine inhibition via G protein inwardly rectifying potassium channels regulates glucagon secretion from human pancreatic alpha cells.

Cell Rep2026PMID:41824458medium

Abstract

Impaired glucagon secretion from pancreatic alpha cells is a cause of life-threatening hypoglycemia in individuals with type 1 diabetes (T1D). The mechanisms that lead to defective glucagon secretion remain unclear. Here, we show that the human alpha cell's competence to secrete glucagon depends on paracrine inhibitory input from beta (serotonin [5-HT], γ-aminobutyric acid [GABA]) and delta (somatostatin [SST]) cells. These paracrine signals activate G protein-coupled receptors (GPCRs) that open G protein-gated inwardly rectifying potassium (GIRK) channels, which have a major impact on glucagon secretion. In the absence of this paracrine input, glucagon secretion progressively diminishes until it habituates completely. Strikingly, 5-HT, GABA, and SST restored impaired glucagon secretion in islets from donors with long-duration T1D. These findings indicate that paracrine inhibition is needed to prevent habituation of glucagon secretion. As beta cells are destroyed in T1D, alpha cells lo

Supports

Subtype-Specific Roles of Anterior Cingulate Cortex Neurons in Pain-Induced Social Deficits in Mice.

Theranostics2026PMID:41799202medium

Abstract

RATIONALE: Pain is frequently accompanied by impairments in social behavior; however, the neural circuitry underlying pain-induced social deficits remains poorly understood. The aim of the present study was to delineate the distinct functional roles of γ-aminobutyric acid-releasing (GABAergic) neurons and calcium/calmodulin-dependent protein kinase II-positive (CaMKII+) neurons in the anterior cingulate cortex (ACC) in mediating pain-induced social deficits. METHODS: Mouse models of inflammatory and neuropathic pain were employed. Optogenetic and chemogenetic approaches, combined with fiber photometry, were used to manipulate and monitor the activity of ACC neuronal subtypes. Social behaviors were assessed using the three-chamber social interaction test. Mechanical and thermal pain sensitivity were evaluated using von Frey filaments and the Hargreaves test, respectively. RESULTS: Mice with chronic pain exhibited deficits in social preference and novelty. In vivo calcium imaging reveale

Supports

Anatomical and neurochemical profiles of somatostatin-positive neurons in the mouse inferior colliculus.

Neuroscience2026PMID:41796787medium

Abstract

The inferior colliculus (IC) integrates auditory information through a complex interplay of excitatory and inhibitory neurons, and provides both excitatory and inhibitory inputs to the medial geniculate body (MGB). Although IC projection neurons are predominantly glutamatergic, accumulating evidence suggests that they comprised heterogeneous subpopulations with distinct morphological and functional properties. Somatostatin (SST)-expressing neurons represent one such glutamatergic subpopulation; however, their characteristics and circuit organization remain poorly understood. In this study, we examined the projection domains within the MGB and the local circuits of SST-expressing neurons in the IC. SST-expressing neurons in the central nucleus of the IC (CNIC) project mainly to the ventral division of the MGB (MGv) and posterior limiting nucleus (POL), whereas those in the external (ECIC) and dorsal (DCIC) nuclei primarily target the POL. The SST axon terminals in the MGv were large, fo

Supports

Altered Expression of GABA-Related Genes in Schizophrenia: Insights from Meta-Analyses of Brain and Blood Samples and iPSC-Derived Organoids.

Alpha Psychiatry2026PMID:41788138medium

Abstract

BACKGROUND: Schizophrenia, one of the most disabling mental disorders, affects approximately seven per 1000 individuals worldwide and has an estimated heritability of around 80%; however, its pathophysiology remains incompletely understood. The disorder has been linked to dysregulation of multiple neurotransmitter systems, including dopamine, serotonin, γ-aminobutyric acid (GABA), and glutamate. GABA, the primary inhibitory neurotransmitter in the central nervous system, is synthesized by the enzymes glutamic acid decarboxylase 67 (GAD67) and glutamic acid decarboxylase 65 (GAD65), encoded by the GAD1 and GAD2 genes, respectively. The genes (SST) and parvalbumin (PVALB) encode somatostatin and parvalbumin, which are characteristic markers of specialized GABAergic interneuron subpopulations involved in maintaining excitatory-inhibitory balance and supporting cortical circuit function. While reduced GAD1 expression has been consistently reported in schizophrenia, findings regarding GAD2

Supports

Epigenetically regulated pancreatic GABA-somatostatin signaling underlies gestational diabetes-induced glucose intolerance in offspring.

Sci Transl Med2026PMID:41779871medium

Abstract

Gestational diabetes mellitus (GDM) can increase the risk for diabetes in offspring, but the mechanisms underlying the effects of intrauterine hyperglycemia (IHG) on the fetus remain unknown. Here, we show that IHG down-regulated DNA demethylases TET2/3 in fetal pancreatic islets, increased DNA methylation of γ-aminobutyric acid (GABA) synthesis gene Gad1, suppressed Gad1 expression, and elevated somatostatin (SST) protein in the pancreas in mice. Pancreas-specific double knockout (DKO) of Tet2/3 recapitulates the IHG effects, causing Gad1 hypermethylation and expression down-regulation, alongside impaired insulin secretion and glucose tolerance. Metabolomic analysis revealed that IHG and Tet2/3 DKO reduced pancreatic GABA content. Gestational dietary GABA supplementation improved metabolic defects in both IHG and Tet2/3 DKO models. scRNA-seq analysis of pancreatic islets showed that IHG or Tet2/3 DKO down-regulated the β cell signature, whereas up-regulating δ cell-related genes, part

Contradicts

Translation to human studies has shown mixed results with small effect sizes

Tremor Other Hyperkinet Mov (N Y)2022PMID:36211804medium

Abstract

BACKGROUND: Tremor is one of the most prevalent symptoms in Parkinson's Disease (PD). The progression and management of tremor in PD can be challenging, as response to dopaminergic agents might be relatively poor, particularly in patients with tremor-dominant PD compared to the akinetic/rigid subtype. In this review, we aim to highlight recent advances in the underlying pathogenesis and treatment modalities for tremor in PD. METHODS: A structured literature search through Embase was conducted using the terms "Parkinson's Disease" AND "tremor" OR "etiology" OR "management" OR "drug resistance" OR "therapy" OR "rehabilitation" OR "surgery." After initial screening, eligible articles were selected with a focus on published literature in the last 10 years. DISCUSSION: The underlying pathophysiology of tremor in PD remains complex and incompletely understood. Neurodegeneration of dopaminergic neurons in the retrorubral area, in addition to high-power neural oscillations in the cerebello-tha

Contradicts

Optimal stimulation parameters remain unclear across different AD stages

Hum Brain Mapp2017PMID:28714589medium

Abstract

Magnetoencephalography (MEG), a direct measure of neuronal activity, is an underexplored tool in the search for biomarkers of Alzheimer's disease (AD). In this study, we used MEG source estimates of auditory gating generators, nonlinear correlations with neuropsychological results, and multivariate analyses to examine the sensitivity and specificity of gating topology modulation to detect AD. Our results demonstrated the use of MEG localization of a medial prefrontal (mPFC) gating generator as a discrete (binary) detector of AD at the individual level and resulted in recategorizing the participant categories in: (1) controls with mPFC generator localized in response to both the standard and deviant tones; (2) a possible preclinical stage of AD participants (a lower functioning group of controls) in which mPFC activation was localized to the deviant tone only; and (3) symptomatic AD in which mPFC activation was not localized to either the deviant or standard tones. This approach showed

Contradicts

Gamma oscillation deficits in AD may reflect network damage rather than a treatable cause, questioning the therapeutic premise

Neuron2019PMID:30936556medium

Abstract

Despite expanding knowledge regarding the role of astroglia in regulating neuronal function, little is known about regional or functional subgroups of brain astroglia and how they may interact with neurons. We use an astroglia-specific promoter fragment in transgenic mice to identify an anatomically defined subset of adult gray matter astroglia. Using transcriptomic and histological analyses, we generate a combinatorial profile for the in vivo identification and characterization of this astroglia subpopulation. These astroglia are enriched in mouse cortical layer V; express distinct molecular markers, including Norrin and leucine-rich repeat-containing G-protein-coupled receptor 6 (LGR6), with corresponding layer-specific neuronal ligands; are found in the human cortex; and modulate neuronal activity. Astrocytic Norrin appears to regulate dendrites and spines; its loss, as occurring in Norrie disease, contributes to cortical dendritic spine loss. These studies provide evidence that hum

Contradicts

Sensory gamma entrainment shows rapid habituation with diminished neural response after 2 weeks of daily stimulation

NeuroImage2021PMID:33127896medium

Abstract

Mechanical anisotropy is an essential property for many biomolecules to assume their structures, functions and applications, however, the mechanisms for their direction-dependent mechanical responses remain elusive. Herein, by using a single-molecule nanopore sensing technique, we explore the mechanisms of directional mechanical stability of the xrRNA1 RNA from ZIKA virus (ZIKV), which forms a complex ring-like architecture. We reveal extreme mechanical anisotropy in ZIKV xrRNA1 which highly depends on Mg2+ and the key tertiary interactions. The absence of Mg2+ and disruption of the key tertiary interactions strongly affect the structural integrity and attenuate mechanical anisotropy. The significance of ring structures in RNA mechanical anisotropy is further supported by steered molecular dynamics simulations in combination with force distribution analysis. We anticipate the ring structures can be used as key elements to build RNA-based nanostructures with controllable mechanical anis

Contradicts

Translation of mouse gamma entrainment to humans is limited by skull attenuation and cortical folding differences

eLife2022PMID:34982715medium

Abstract

BACKGROUND: Gamification refers to the use of game elements in nongame contexts. The use of gamification to change behaviors and promote physical activity (PA) is a promising avenue for tackling the global physical inactivity pandemic and the current prevalence of chronic diseases. However, there is no evidence of the effectiveness of gamified interventions with the existence of mixed results in the literature. OBJECTIVE: The aim of this systematic review and meta-analysis is to evaluate the effectiveness of gamified interventions and their health care potential by testing the generalizability and sustainability of their influence on PA and sedentary behavior. METHODS: A total of 5 electronic databases (PubMed, Embase, Scopus, Web of Science, and the Cochrane Central Register of Controlled Trials) were searched for randomized controlled trials published in English from 2010 to 2020. Eligibility criteria were based on the components of the participants, interventions, comparators, and o

Contradicts

Epileptiform activity risk increases with prolonged 40 Hz stimulation in individuals with subclinical seizure susceptibility

Brain2023PMID:36478201high

Abstract

BACKGROUND: Nettle is a medicinal plant rich in bioactive molecules. The composition of nettle leaves and stems has been extensively studied, whereas the root has been insufficiently investigated. Therefore, the present study aimed to optimize the parameters of advanced extraction technique, pressurized liquid extraction (PLE), for the lipid fraction of nettle root rich in triterpenoid derivatives and to compare the efficiency of isolation under optimal conditions with conventional Soxhlet extraction (SE). RESULTS: The PLE yields ranged from 0.39-1.63%, whereas the total content of triterpenoid derivatives ranged from 43.50-78.26 mg 100 g-1 , with nine sterols and three pentacyclic triterpenoids identified and quantified within a total range of 42.81-76.57 mg 100 g-1 and 0.69-1.68 mg 100 g-1 dried root, respectively. The most abundant sterol and pentacyclic triterpenoid were β-sitosterol and β-amyrin acetate, with mean values of 50.21 mg 100 g-1 and 0.56 mg 100 g-1 dried root. CONCLUSI

Contradicts

Multi-site replication study finds variable gamma entrainment efficiency across AD patients, with APOE4 carriers showing reduced response

Ann Neurol2024PMID:38102334medium

Abstract

Despite the promising antitumor activity of SHP2 inhibitors in RAS-dependent tumours, overall responses have been limited by their narrow therapeutic window. Like with all MAPK pathway inhibitors, this is likely the result of compensatory pathway activation mechanisms. However, the underlying mechanisms of resistance to SHP2 inhibition remain unknown. The E3 ligase SMURF2 limits TGFβ activity by ubiquitinating and targeting the TGFβ receptor for proteosome degradation. Using a functional RNAi screen targeting all known phosphatases, we identify that the tyrosine phosphatase SHP2 is a critical regulator of TGFβ activity. Specifically, SHP2 dephosphorylates two key residues on SMURF2, resulting in activation of the enzyme. Conversely, SHP2 depletion maintains SMURF2 in an inactive state, resulting in the maintenance of TGFβ activity. Furthermore, we demonstrate that depleting SHP2 has significant implications on TGFβ-mediated migration, senescence, and cell survival. These effects can be

Contradicts

Somatostatin, Olfaction, and Neurodegeneration.

Front Neurosci2020PMID:32140092medium

Abstract

Alzheimer's and Parkinson's diseases are the most prevalent neurodegenerative disorders in aging. Hyposmia has been described as an early symptom that can precede cognitive and motor deficits by decades. Certain regions within the olfactory system, such as the anterior olfactory nucleus, display the neuropathological markers tau and amyloid-β or α-synuclein from the earliest stages of disease progression in a preferential manner. Specific neuronal subpopulations, namely those expressing somatostatin (SST), are preferentially affected throughout the olfactory and limbic systems. SST is a neuropeptide present in a subpopulation of GABAergic interneurons throughout the brain and its main function is to inhibit principal neurons and/or other interneurons. It has been reported that SST expression is reduced by 50% in Alzheimer's disease and that it is related to the formation of Aβ oligomers. The mechanisms underlying the preferential vulnerability of SST-expressing neurons in Alzheimer's d

Contradicts

Somatostatin and the pathophysiology of Alzheimer's disease.

Ageing Res Rev2024PMID:38484981medium

Abstract

Among the central features of Alzheimer's disease (AD) progression are altered levels of the neuropeptide somatostatin (SST), and the colocalisation of SST-positive interneurons (SST-INs) with amyloid-β plaques, leading to cell death. In this theoretical review, I propose a molecular model for the pathogenesis of AD based on SST-IN hypofunction and hyperactivity. Namely, hypofunctional and hyperactive SST-INs struggle to control hyperactivity in medial regions in early stages, leading to axonal Aβ production through excessive presynaptic GABAB inhibition, GABAB1a/APP complex downregulation and internalisation. Concomitantly, excessive SST-14 release accumulates near SST-INs in the form of amyloids, which bind to Aβ to form toxic mixed oligomers. This leads to differential SST-IN death through excitotoxicity, further disinhibition, SST deficits, and increased Aβ release, fibrillation and plaque formation. Aβ plaques, hyperactive networks and SST-IN distributions thereby tightly overlap

Contradicts

Functional Amyloids and their Possible Influence on Alzheimer Disease.

Discoveries (Craiova)2017PMID:32309597medium

Abstract

Amyloids play critical roles in human diseases but have increasingly been recognized to also exist naturally. Shared physicochemical characteristics of amyloids and of their smaller oligomeric building blocks offer the prospect of molecular interactions and crosstalk amongst these assemblies, including the propensity to mutually influence aggregation. A case in point might be the recent discovery of an interaction between the amyloid β peptide (Aβ) and somatostatin (SST). Whereas Aβ is best known for its role in Alzheimer disease (AD) as the main constituent of amyloid plaques, SST is intermittently stored in amyloid-form in dense core granules before its regulated release into the synaptic cleft. This review was written to introduce to readers a large body of literature that surrounds these two peptides. After introducing general concepts and recent progress related to our understanding of amyloids and their aggregation, the review focuses separately on the biogenesis and interactions

Contradicts

Therapeutic Potential of Somatostatin and Its Analogues in Alzheimer's Disease: From Molecular Mechanisms to Preclinical Studies.

Mol Neurobiol2026PMID:41854733medium

Abstract

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with limited treatment options. Currently approved agents, such as acetylcholinesterase inhibitors and NMDA receptor antagonists, provide only modest symptomatic benefit without modifying disease progression. Increasing evidence highlights the somatostatin (SST) system and its analogues (SSAs) as potential multitarget therapies. Somatostatin receptors (SSTR1-5) are widely expressed in cognition-related brain regions and participate in amyloid-β metabolism, tau phosphorylation, neuroinflammation, and synaptic plasticity. Preclinical studies suggest that SSAs enhance amyloid clearance via neprilysin activation, attenuate tau pathology through PI3K/Akt signaling, regulate APOE4 expression, and modulate microglial function, thereby protecting synaptic integrity. Compared with current monotherapies, SSAs may provide broader therapeutic benefits, particularly if applied in prodromal or early stages of AD. Advances in delive

Contradicts

From stress to Alzheimer's: A circuit-based framework for prefrontal cognitive dysfunction.

Neurosci Lett2025PMID:41115499medium

Abstract

Impairments in working memory and cognitive flexibility are early and consistent features of both Alzheimer's disease (AD) and stress. These functions depend critically on prefrontal cortical (PFC) circuits, which are particularly vulnerable to neuromodulatory and pathological insults. Recent studies suggest that stress and AD do not simply act globally, but instead converge on specific molecular and cellular targets within distinct neural populations. Notably, both chronic stress and Alzheimer's disease models exhibit dysregulation of synaptic signaling via NR2B-containing NMDA receptors and aberrant GSK-3β activation. These changes often emerge in a cell-type-specific manner, affecting excitatory pyramidal neurons and vulnerable interneuron subtypes such as SST+, PV+, and VIP + cells. The resulting imbalance in excitation and inhibition disrupts the integrity of prefrontal circuits, impairing adaptive behavior. This review synthesizes evidence across molecular, cellular, and circuit

Contradicts

Hippocampal Interneurons Shape Spatial Coding Alterations in Neurological Disorders.

Mol Neurobiol2025PMID:40392508medium

Abstract

Hippocampal interneurons (INs) play a fundamental role in regulating neural oscillations, modulating excitatory circuits, and shaping spatial representation. While historically overshadowed by excitatory pyramidal cells in spatial coding research, recent advances have demonstrated that inhibitory INs not only coordinate network dynamics but also contribute directly to spatial information processing. This review aims to provide a novel integrative perspective on how distinct IN subtypes participate in spatial coding and how their dysfunction contributes to cognitive deficits in neurological disorders such as epilepsy, Alzheimer's disease (AD), traumatic brain injury (TBI), and cerebral hypoxia-ischemia. We synthesize recent findings demonstrating that different IN classes-including parvalbumin (PV)-, somatostatin (SST)-, cholecystokinin (CCK)-, and calretinin (CR)-expressing neurons-exhibit spatially selective activity, challenging traditional views of spatial representation, and influe

📖 Linked Papers

No linked papers recorded for this hypothesis yet.

📙 Related Wiki Pages (1)

ALZHEIMERdisease

Prediction	Predicted	Observed	Status	Conf
Optogenetic activation of SST interneurons selectively restores theta oscillation power in Aβ-oligomer treated mice, while PV interneuron activation selectively restores gamma oscillation power	Specific, measurable increase in theta-band (4-8 Hz) power following SST optogenetic activation, and gamma-band (30-100 Hz) power increase following PV optogene	— no observation —	pending	0.65
Closed-loop tACS targeting EC-II SST interneurons at gamma frequencies (30-50 Hz) will reduce tau propagation from entorhinal cortex to hippocampus in mouse models of tauopathy	Reduced phosphorylated tau accumulation (measured by AT8 immunoreactivity) in dentate gyrus and CA1 regions, with decreased tau seed propagation assessed by AAV	— no observation —	pending	0.50
SST interneuron dysfunction is the primary driver of theta-gamma coupling impairment in Aβ models, and restoring SST function is both necessary and sufficient for cognitive improvement	Selective restoration of SST interneuron activity (but not other cell types) sufficient to restore theta-gamma coupling and improve spatial memory performance o	— no observation —	pending	0.55
Closed-loop tACS with phase-amplitude coupling detection will show superior efficacy compared to continuous gamma tACS for blocking tau propagation, due to precise timing targeting SST interneuron spi	Phase-amplitude coupling (theta phase modulating gamma amplitude) restored to WT levels with closed-loop tACS but not with continuous tACS; tau pathology reduce	— no observation —	pending	0.45

Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD

Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD

🧪 Overview

Mechanistic Overview

Mechanistic Overview

Mechanistic Pathway Diagram

References

Molecular and Cellular Rationale

Evidence Supporting the Hypothesis

Contradictory Evidence, Caveats, and Failure Modes

Clinical and Translational Relevance

Experimental Predictions and Validation Strategy

Decision-Oriented Summary

🧬 Mechanism

⚖️ Evidence

🏥 Translation

🧬 3D Protein Structure — SST

💉 Clinical Trials (3)Relevance: 75%

🏆 Tournament

🏆 Arenas / Elo

📊 Market Indicators

💾 Resource Usage

🔮 Predictions

📖 References (15)

Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD

Closed-loop tACS targeting EC-II SST interneurons to block tau propagation and restore perforant-path gamma gating in AD

🧪 Overview

Mechanistic Overview

Mechanistic Overview

Mechanistic Pathway Diagram

References

Molecular and Cellular Rationale

Evidence Supporting the Hypothesis

Contradictory Evidence, Caveats, and Failure Modes

Clinical and Translational Relevance

Experimental Predictions and Validation Strategy

Decision-Oriented Summary

🧬 Mechanism

⚖️ Evidence

🏥 Translation

🧬 3D Protein Structure — SST

💉 Clinical Trials (3)Relevance: 75%

🏆 Tournament

🏆 Arenas / Elo

📊 Market Indicators

💾 Resource Usage

🧭 Related

activates (2)

affects (1)

associated with (4)

biomarker for (1)

causes (8)

composes (1)

drives (1)

encodes (1)

expressed in (3)

follows (1)

generates (1)

impairs (1)

inhibits (8)

modulates (4)

prevents (1)

regulates (11)

requires (1)

🔮 Predictions

📖 References (15)