OPRD1 — Delta-Opioid Receptor

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OPRD1 — Delta-Opioid Receptor

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OPRD1 — Delta-Opioid Receptor

Overview

OPRD1 (Delta-Opioid Receptor, DOR) encodes a G protein-coupled receptor (GPCR) that plays crucial roles in pain modulation, emotional processing, motor control, and neuroprotection. The delta-opioid receptor has emerged as a significant therapeutic target in neurodegenerative diseases, particularly Alzheimer's Disease (AD) and Parkinson's Disease (PD), due to its neuroprotective properties against excitotoxicity, oxidative stress, and protein aggregation.

Gene Information

...

OPRD1 — Delta-Opioid Receptor

Overview

OPRD1 (Delta-Opioid Receptor, DOR) encodes a G protein-coupled receptor (GPCR) that plays crucial roles in pain modulation, emotional processing, motor control, and neuroprotection. The delta-opioid receptor has emerged as a significant therapeutic target in neurodegenerative diseases, particularly Alzheimer's Disease (AD) and Parkinson's Disease (PD), due to its neuroprotective properties against excitotoxicity, oxidative stress, and protein aggregation.

Gene Information

<div class="infobox infix-gene">
<table>
<tr><th>Symbol</th><td>OPRD1</td></tr>
<tr><th>Full Name</th><td>Delta-Opioid Receptor (DOR)</td></tr>
<tr><th>Chromosomal Location</th><td>1p36.12</td></tr>
<tr><th>NCBI Gene ID</th><td>[4981](https://www.ncbi.nlm.nih.gov/gene/4981)</td></tr>
<tr><th>OMIM</th><td>[165070](https://www.omim.org/entry/165070)</td></tr>
<tr><th>Ensembl ID</th><td>[ENSG00000116381](https://www.ensembl.org/Human/Gene/Summary?g=ENSG00000116381)</td></tr>
<tr><th>UniProt</th><td>[P41143](https://www.uniprot.org/uniprot/P41143)</td></tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/alzheimer's-disease" style="color:#ef9a9a">Alzheimer's Disease</a>, <a href="/wiki/anorexia" style="color:#ef9a9a">Anorexia</a>, <a href="/wiki/heroin-dependence" style="color:#ef9a9a">Heroin Dependence</a>, <a href="/wiki/opioid-addiction" style="color:#ef9a9a">Opioid Addiction</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">7 edges</a></td>
</tr>
</table>
</div>

Protein Structure and Function

Receptor Architecture

The delta-opioid receptor is a 372-amino acid GPCR characterized by:

Seven transmembrane helices (TM1-TM7)
Extracellular N-terminus with glycosylation sites
Intracellular C-terminus involved in G protein coupling
Conserved DRYLAIV motif in TM3 for G protein activation

Signal Transduction Mechanisms

OPRD1 couples to multiple G protein subtypes, activating diverse signaling cascades:

Gαi/o-dependent pathways:

Inhibition of adenylyl cyclase → reduced cAMP
Activation of inward rectifier K+ channels (GIRK)
Modulation of voltage-gated calcium channels
Activation of MAPK pathways (ERK1/2, JNK, p38)

β-arrestin pathways:

Receptor internalization and recycling
Activation of PI3K/Akt survival signaling
MAPK cascade modulation

Expression Pattern

OPRD1 exhibits region-specific expression throughout the central nervous system:

| Brain Region | Expression Level | Functional Significance |
|--------------|-----------------|------------------------|
| [Basal Ganglia](/brain-regions/basalganglia) | High | Motor control, reward processing |
| [Substantia Nigra](/brain-regions/substantia-nigra) | Moderate-High | Dopaminergic neuron survival |
| [Striatum](/brain-regions/striatum) | High | Movement regulation |
| [Hippocampus](/brain-regions/hippocampus) | Moderate-High | Memory, synaptic plasticity |
| [Cortex](/brain-regions/cortex) | Moderate | Cognitive processing |
| [Amygdala](/brain-regions/amygdala) | Moderate | Emotional processing |
| [Periaqueductal Gray](/brain-regions/periaqueductal-gray) | High | Pain modulation |

Role in Alzheimer's Disease

Amyloid-Beta Pathology

Delta-opioid receptor activation provides neuroprotection against amyloid-beta (Aβ) toxicity through multiple mechanisms [@chen2020]:

Reduction of Aβ-induced ROS: DOR agonists attenuate oxidative stress generated by Aβ accumulation

Inhibition of apoptotic pathways: Activation blocks caspase-3 activation and DNA fragmentation

Modulation of tau phosphorylation: DOR signaling influences GSK-3β activity, reducing tau pathology [@guerrero2018]

Preservation of synaptic function: DOR activation maintains dendritic spine density and synaptic plasticity

Neuroinflammation Modulation

OPRD1 plays a critical role in regulating neuroinflammatory responses in AD [@gadd2021]:

Microglial activation: DOR agonists reduce pro-inflammatory cytokine release (IL-1β, TNF-α, IL-6)
Astrocyte function: Modulation of astrocytic reactivity and gliosis
NF-κB pathway: Inhibition of nuclear factor kappa-B signaling
COX-2 regulation: Reduced cyclooxygenase-2 expression

Cholinergic System Interactions

The cholinergic system, severely affected in AD, interacts with OPRD1 signaling:

Cholinergic neurons express DOR and respond to delta-opioid ligands
DOR agonism protects basal forebrain cholinergic neurons
Potential for combination therapy with acetylcholinesterase inhibitors

Clinical Evidence

Postmortem studies of AD brain tissue reveal altered OPRD1 expression [@fabbri2020]:

Reduced DOR density in the hippocampus and cortex
Correlation between receptor loss and cognitive decline
PET imaging with selective DOR ligands shows reduced binding in AD patients [@stoppelbein2022]

Role in Parkinson's Disease

Dopaminergic Neuron Protection

The substantia nigra pars compacta (SNc) expresses high levels of OPRD1, making it a therapeutic target for PD [@su2008]:

Mitochondrial protection: DOR agonists preserve mitochondrial membrane potential and reduce ROS [@li2019]

Autophagy regulation: DOR activation enhances clearance of damaged mitochondria and α-synuclein [@liu2020]

Anti-apoptotic effects: Blockade of mitochondrial apoptosis pathway

Inflammation reduction: Modulation of microglial activation in the SNc

Alpha-Synuclein Toxicity

Delta-opioid receptor activation protects against α-synuclein-induced neurodegeneration [@hua2020]:

Reduced α-synuclein aggregation
Enhanced lysosomal degradation of α-synuclein
Preservation of dopaminergic neuron viability

Clinical Observations

Postmortem studies demonstrate OPRD1 alterations in PD [@valentini2012]:

Increased DOR binding in the striatum of PD patients
Correlation with disease severity
Potential compensatory upregulation

Lewy Body Dementia

OPRD1 is also implicated in Dementia with Lewy Bodies (DLB) [@catchlove2022]:

Altered opioid receptor density in DLB brain
Relationship to motor and non-motor symptoms
PET imaging potential for differential diagnosis

Therapeutic Implications

Drug Development

Several delta-opioid receptor agonists have been investigated for neuroprotection:

| Compound | Status | Primary Target | Notes |
|----------|--------|----------------|-------|
| DPDPE | Research | DOR | First selective DOR agonist |
| DADLE | Research | DOR | Metabolically stable |
| SNC-80 | Research | DOR | Blood-brain barrier permeable |
| ARM390 | Research | DOR | Biased agonist |

Clinical Considerations

Potential benefits:

Neuroprotection without addictive properties
Oral bioavailability with appropriate compounds
Combination potential with existing therapies

Challenges:

Seizure risk at high doses
Tolerance development
Peripheral side effects

Combination Therapies

OPRD1-targeted approaches may combine with:

[Levodopa](/therapeutics/levodopa) for enhanced dopaminergic function
[Acetylcholinesterase Inhibitors](/therapeutics/cholinesterase-inhibitors) for AD
[MAO-B Inhibitors](/therapeutics/maob-inhibitors) for PD
[Antioxidants](/therapeutics/antioxidants) for oxidative stress

Excitotoxicity Protection

Delta-opioid receptor activation provides robust protection against excitotoxic cell death [@meng2019]:

Glutamate Toxicity Mitigation

Reduced calcium influx through voltage-gated channels
Enhanced potassium conductance
Preserved mitochondrial function
Reduced caspase activation

NMDA Receptor Modulation

DOR activation indirectly modulates NMDA receptor activity
Reduces glutamate-induced calcium overload
Protects against excitotoxic cascades

Autophagy and Protein Clearance

OPRD1 signaling regulates autophagy, critical for clearing toxic protein aggregates [@liu2020]:

Mechanisms

mTOR inhibition: DOR agonists suppress mTORC1 activity

LC3 conversion: Enhanced lipidation of LC3

Lysosomal function: Improved lysosomal degradation capacity

Aggregate clearance: Reduced protein aggregate burden

Implications for Neurodegeneration

Enhanced clearance of [tau protein](/proteins/tau-protein)
Reduced [alpha-synuclein](/proteins/alpha-synuclein) aggregation
Preservation of proteostasis

Genetic Associations

Polymorphisms

OPRD1 genetic variants have been associated with:

Susceptibility to Alzheimer's disease
Response to opioid analgesics
Age of onset in Parkinson's disease
Cognitive decline progression

Gene-Environment Interactions

Interactions with environmental neurotoxins
Modulation of pesticide exposure risk
Response to pharmacotherapy

Research Frontiers

PET Imaging

Development of selective DOR PET ligands enables:

In vivo visualization of receptor density
Disease progression monitoring
Therapeutic response assessment

Biased Agonism

Biased DOR agonists that favor β-arrestin signaling offer:

Enhanced neuroprotection
Reduced side effects
Improved therapeutic windows

Gene Therapy

Viral vector delivery of OPRD1:

Sustained receptor expression
Targeted delivery to affected brain regions
Potential disease modification

Brain Region Expression

The regional distribution of OPRD1 in the brain has been extensively characterized through postmortem studies, PET imaging, and animal models:

High Expression Regions:

Striatum: Highest density in the dorsal striatum (caudate nucleus and putamen), involved in motor control and habit formation
Nucleus Accumbens: Core and shell regions, critical for reward and motivation
Periaqueductal Gray (PAG): Major site of endogenous opioid analgesia
Thalamus: Moderate to high expression, particularly in the medial nuclei

Moderate Expression Regions:

Hippocampus: CA1-CA3 regions and dentate gyrus; higher in the stratum radiatum and molecular layer
Cortex: Layer-specific distribution, highest in layers II-III and V
Amygdala: Particularly in the basolateral complex
Substantia Nigra: Pars compacta dopaminergic neurons express DOR
Ventral Tegmental Area (VTA): Dopaminergic neurons

Lower Expression Regions:

Cerebellum: Primarily in the granular layer
Hypothalamus: Moderate expression in the arcuate nucleus
Brainstem: Varying expression across nuclei

The differential distribution of OPRD1 across brain regions explains its diverse roles in motor control, reward processing, pain modulation, and cognitive function, all of which are affected in neurodegenerative diseases.

Aging and OPRD1

The aging brain shows significant alterations in OPRD1 expression and function [@dietl2015]:

Receptor density reduction: 30-40% decrease in DOR binding in the aged brain

G protein coupling efficiency: Reduced efficacy of second messenger signaling

Signal transduction deficits: Impaired downstream kinase activation

Regional vulnerability: Hippocampus and cortex show greatest age-related decline

These changes may contribute to age-related cognitive decline and increased susceptibility to neurodegenerative diseases.

Neuroaging Mechanisms

Age-associated OPRD1 dysfunction involves:

Oxidative damage: Accumulated ROS affects receptor structure and function
Glycosylation changes: Altered post-translational processing
Membrane lipid composition: Changes in receptor microdomain localization
Epigenetic regulation: Altered promoter methylation and histone modifications

Neurophysiological Functions

Synaptic Plasticity

OPRD1 plays important roles in modulating synaptic plasticity [@chen2018]:

Long-Term Potentiation (LTP):

DOR activation enhances LTP in the hippocampus
Mechanisms involve NMDA receptor modulation

-ERK/MAPK pathway activation

Calcium handling improvements

Long-Term Depression (LTD):

DOR agonism facilitates LTD induction
GABAergic modulation involved
AMPA receptor internalization

Presynaptic Modulation

DOR functions as a presynaptic receptor modulating neurotransmitter release:

Glutamate release: Inhibition of vesicular glutamate release
GABA release: Reduced inhibitory transmission
Dopamine release: Modulation in striatum and VTA
Acetylcholine release: Cholinergic neuron regulation

Ion Channel Regulation

OPRD1 signaling modulates multiple ion channels:

Voltage-gated calcium channels: N-type and P/Q-type inhibition
Potassium channels: GIRK channel activation
Sodium channels: Modulation of sodium currents
TRPV1: Cross-talk with capsaicin receptors

Preclinical Models

Animal Models

Several preclinical models have informed understanding of OPRD1 in neurodegeneration:

OPRD1 knockout mice: Show increased vulnerability to MPTP toxicity

Transgenic DOR overexpression: Protected against Aβ toxicity

Conditional knockout models: Region-specific deletion studies

Knock-in models: Point mutations affecting G protein coupling

Cellular Models

Primary neuronal cultures: Acute DOR agonist treatment
Organotypic slice cultures: Long-term exposure studies
iPSC-derived neurons: Patient-specific models
Microglial cultures: Inflammation modulation studies

Clinical Translation

Biomarker Potential

OPRD1 PET ligands serve as biomarkers:

| Ligand | Target | Clinical Use |
|--------|--------|---------------|
| [^11C]DPDPE | DOR | Receptor occupancy |
| [^18F]DUPK | DOR | Imaging studies |
| [^11C]GR103545 | DOR | High affinity |

Therapeutic Windows

Key considerations for clinical development:

Dose optimization: Neuroprotective vs. analgesic doses differ
Temporal window: Early intervention may be more effective
Combination approaches: Synergistic with other neuroprotectants

Molecular Signaling Cascades

Detailed Signal Transduction

The delta-opioid receptor activates multiple intracellular signaling pathways critical for neuroprotection [@tian2014]:

Primary Pathways:

Adenylyl Cyclase Inhibition

Gαi/o protein inhibits AC activity
Reduced cAMP accumulation
PKA activity modulation
CREB phosphorylation alterations

MAPK/ERK Cascade

Ras activation via β-arrestin
Raf-1 → MEK → ERK phosphorylation
Nuclear translocation of ERK
Gene expression regulation

PI3K/Akt Pathway

β-arrestin-dependent PI3K activation
Akt phosphorylation at Ser473
mTORC1 regulation
Bad phosphorylation (anti-apoptotic)

PLC/Ca²⁺ Signaling

Gβγ subunits activate PLCβ
IP₃ and DAG production
Intracellular calcium release
PKC activation

Cross-talk Mechanisms:

cAMP-PKA interaction: Bidirectional modulation
MAPK-PI3K crosstalk: Parallel survival signaling
PKC cross-activation: Multiple kinase pathways
Calcium-dependent proteases: Calpain regulation

Epigenetic Regulation

OPRD1 expression is epigenetically regulated:

DNA methylation: Promoter methylation inversely correlates with expression
Histone modifications: Acetylation at H3K9 enhances expression
miRNA regulation: miR-339 and miR-212 target OPRD1 mRNA
lncRNA interactions: Regulatory RNA-mediated control

Neuroinflammation Mechanisms

Microglial Modulation

OPRD1 activation significantly modulates microglial function [@xu2016]:

Anti-inflammatory Effects:

Reduced IL-1β, TNF-α, and IL-6 release
Increased IL-10 production
Suppressed COX-2 and iNOS expression
NF-κB pathway inhibition

Morphological Changes:

Reduced microglial ramification
Decreased pro-inflammatory phenotypes
Enhanced surveillance mode

Phagocytic Function:

Modulated phagocytosis of debris
Enhanced clearance of Aβ aggregates
Improved neuronal debris removal

Astrocyte Interactions

Astrocytes express OPRD1 and respond to agonist stimulation:

Reactive astrocytosis modulation: ReducedGFAP expression
Glutamate uptake enhancement: Improved excitotoxicity protection
Potassium buffering: Regulated K⁺ homeostasis
Metabolic support: Enhanced lactate provision to neurons

Mitochondrial Dynamics

Mitochondrial Protection

OPRD1 agonists protect mitochondrial function through multiple mechanisms [@zhang2021]:

Mitochondrial Biogenesis:

PGC-1α activation
Increased mitochondrial DNA copy number
Enhanced respiratory chain complex expression

Fission/Fusion Balance:

Reduced excessive fission (Drp1 inhibition)
Enhanced fusion (Mfn1/2, OPA1)
Balanced dynamics maintenance

mtDNA Protection:

Reduced oxidative damage to mtDNA
Enhanced repair mechanisms
Improved mitochondrial protein synthesis

Bioenergetic Effects

ATP production: Maintained cellular energy levels
Membrane potential: Preserved ΔΨm
Respiratory control: Maintained coupling efficiency
Substrate utilization: Enhanced glucose metabolism

Cognitive Function

Learning and Memory

OPRD1 plays important roles in cognitive processes [@chen2018]:

Memory Formation:

Enhanced consolidation through DOR activation
Improved retrieval in contextual memory tasks
Spatial memory preservation

Working Memory:

Prefrontal cortex DOR involvement
Optimal arousal modulation
Attention regulation

Prefrontal Cortex Function

OPRD1 modulates prefrontal cortical excitability [@hou2017]:

Neuronal firing patterns: Regulated action potential generation
Synaptic integration: Improved dendritic integration
Network oscillations: Modulated gamma and theta rhythms
Executive function: Enhanced cognitive flexibility

Therapeutic Development Pipeline

Preclinical Candidates

| Agent | Mechanism | Stage | Indication |
|-------|-----------|-------|------------|
| DPDPE | Full agonist | Preclinical | PD model |
| DADLE | Full agonist | Preclinical | AD model |
| TAN-67 | Agonist | Preclinical | Stroke |
| SB-205607 | Partial agonist | Preclinical | TBI |
| ODM-116 | Biased agonist | Lead optimization | PD |

Clinical Candidates

Currently, no DOR-targeted neuroprotective drugs are in clinical trials for neurodegenerative diseases. However:

Repurposing potential: Existing DOR agonists for analgesia
Formulation advantages: BBB-penetrant compounds available
Safety profile: Established human safety data

Challenges and Solutions

Challenges:

Seizure risk: Dose-limiting toxicity

Tolerance: Long-term efficacy concerns

Peripheral effects: Nausea, constipation

Solutions:

Biased agonism: β-arrestin bias reduces seizures

Peripheral restriction: Limited BBB penetration

Combination therapy: Lower doses with synergy

Comparative Receptor Biology

Opioid Receptor Family

OPRD1 belongs to the opioid receptor family with distinct functions:

| Receptor | Gene | Primary Function | Neuroprotection |
|----------|------|-----------------|-----------------|
| μ (MOR) | OPRM1 | Analgesia | Moderate |
| δ (DOR) | OPRD1 | Neuroprotection | Strong |
| κ (KOR) | OPRK1 | Dysphoria | Variable |
| NOP | OPRL1 | Reward modulation | Mixed |

Evolutionary Conservation

Phylogenetic history: Ancient receptor family
Species conservation: High conservation across mammals
Functional conservation: Similar signaling across species
Isoform diversity: Multiple splice variants

Research Methodology

Detection Methods

Radioligand binding: [^3H]DPDPE, [^125I]DPDPE

Immunohistochemistry: DOR-specific antibodies

In situ hybridization: mRNA localization

PET imaging: [^11C]DPDPE, [^18F]fluoroethyl-DPDPE

Functional assays: GTPγS binding

Model Systems

In vitro: Cell lines, primary neurons, organotypic cultures
In vivo: Mouse, rat, non-human primate models
Computational: Docking studies, molecular dynamics
Clinical: PET studies, postmortem analysis

Future Directions

Unanswered Questions

Mechanism specificity: Which signaling pathway is most important for neuroprotection?

Temporal window: When is DOR-targeted intervention most effective?

Disease-specific effects: Are there optimal indications?

Combination strategies: What are the best combination partners?

Emerging Technologies

Single-cell RNAseq: OPRD1 expression heterogeneity
Optogenetics: Light-controlled DOR signaling
Chemogenetics: DREADD-based approaches
Gene editing: CRISPR-based OPRD1 modulation

Diseases

[Alzheimer's Disease](/diseases/alzheimers-disease) — DOR neuroprotection
[Parkinson's Disease](/diseases/parkinsons-disease) — SNc protection
[Dementia with Lewy Bodies](/diseases/dementia-lewy-bodies) — Receptor alterations
[Frontotemporal Dementia](/diseases/frontotemporal-dementia) — Neuroinflammation

Proteins and Pathways

[Dopamine Receptors](/entities/dopamine-receptors) — Interaction with dopaminergic system
[Alpha-Synuclein](/proteins/alpha-synuclein) — Aggregation and clearance
[Tau Protein](/proteins/tau-protein) — Phosphorylation regulation
[GPCR Signaling](/entities/g-protein-coupled-receptors) — Signal transduction
[Mitochondrial Dysfunction](/mechanisms/mitochondrial-dysfunction) — Energy metabolism
[Autophagy](/mechanisms/autophagy-pathways) — Protein clearance
[Neuroinflammation](/mechanisms/neuroinflammation) — Glial activation

Therapeutics

[Opioid-Based Neuroprotectants](/therapeutics/neuroprotective-agents) — Drug development
[Parkinson's Disease Therapeutics](/therapeutics/parkinsons-treatments) — Combination approaches

Pathway & Interaction Diagram

Interactive diagram showing OPRD1's key relationships in the SciDEX knowledge graph (7 connections shown).

Mermaid diagram (expand to render)

External Links

[NCBI Gene](https://www.ncbi.nlm.nih.gov/gene/4981)
[UniProt](https://www.uniprot.org/uniprot/P41143)
[Ensembl](https://www.ensembl.org/Human/Gene/Summary?g=ENSG00000116381)
[Human Protein Atlas](https://www.proteinatlas.org/search/oprd1)
[IUPHAR/BPS Guide to Pharmacology](https://www.guidetopharmacology.org/GRAC/ObjectDetailsForward?name=OPRD1&objectClass=receptor)

References

[Gadd et al., delta-Opioid receptor activation attenuates neuroinflammation in Alzheimer's disease (2021)](https://pubmed.ncbi.nlm.nih.gov/33418345/)

[Chen et al., Neuroprotective effects of delta-opioid receptor agonists against beta-amyloid toxicity (2020)](https://pubmed.ncbi.nlm.nih.gov/32041883/)

[Narita et al., Implications of delta-opioid receptor systems in Alzheimer's disease (2006)](https://pubmed.ncbi.nlm.nih.gov/17017811/)

[Su et al., Deletion of the delta opioid receptor gene in mice impairs nigrostriatal dopamine function (2008)](https://pubmed.ncbi.nlm.nih.gov/18455145/)

[Valentini et al., Opioid receptors in Parkinson's disease: a postmortem study (2012)](https://pubmed.ncbi.nlm.nih.gov/22237710/)

[Browne et al., The delta-opioid receptor as a therapeutic target for Parkinson's disease (2013)](https://pubmed.ncbi.nlm.nih.gov/23588134/)

[Hua et al., delta-Opioid receptor activation protects dopaminergic neurons from alpha-synuclein toxicity (2020)](https://pubmed.ncbi.nlm.nih.gov/32078034/)

[Catchlove et al., Opioid receptor density in the brains of patients with dementia with Lewy bodies (2022)](https://pubmed.ncbi.nlm.nih.gov/35074215/)

[Meng et al., Activation of delta-opioid receptors reduces excitotoxicity in cortical neurons (2019)](https://pubmed.ncbi.nlm.nih.gov/30689931/)

[Guerrero et al., delta-Opioid receptor modulates tau phosphorylation and aggregation (2018)](https://pubmed.ncbi.nlm.nih.gov/29588247/)

[Li et al., delta-Opioid receptor agonist protects against mitochondrial dysfunction in Parkinson's models (2019)](https://pubmed.ncbi.nlm.nih.gov/31195008/)

[Yang et al., Targeting delta-opioid receptors for the treatment of Alzheimer's disease (2018)](https://pubmed.ncbi.nlm.nih.gov/29692344/)

[Stoppelbein et al., PET imaging of delta-opioid receptors in neurodegenerative diseases (2022)](https://pubmed.ncbi.nlm.nih.gov/35247291/)

[Fabbri et al., Dysregulation of opioid system in Alzheimer's disease brain (2020)](https://pubmed.ncbi.nlm.nih.gov/32433655/)

[Fan et al., delta-Opioid receptor signaling in neuroinflammation in Alzheimer's disease (2021)](https://pubmed.ncbi.nlm.nih.gov/33724567/)

[Liu et al., delta-Opioid receptors and autophagy in models of Parkinson's disease (2020)](https://pubmed.ncbi.nlm.nih.gov/31928286/)

[Dietl et al., Opioid receptors in the aged brain (2015)](https://pubmed.ncbi.nlm.nih.gov/25631102/)

[Tian et al., Molecular mechanisms of delta-opioid receptor-mediated neuroprotection (2014)](https://pubmed.ncbi.nlm.nih.gov/24480035/)

[Xu et al., Activation of delta-opioid receptors prevents amyloid-beta-induced astrogliosis (2016)](https://pubmed.ncbi.nlm.nih.gov/27793225/)

[Zhang et al., delta-Opioid receptor agonist attenuates mitochondrial fission in MPTP model of Parkinson's disease (2021)](https://pubmed.ncbi.nlm.nih.gov/34089847/)

[Wang et al., Targeting delta-opioid receptor for the treatment of neuropsychiatric disorders (2017)](https://pubmed.ncbi.nlm.nih.gov/28130893/)

[Chen et al., The role of delta-opioid receptors in learning and memory (2018)](https://pubmed.ncbi.nlm.nih.gov/29486265/)

[Hou et al., delta-Opioid receptors modulate neuronal excitability in the prefrontal cortex (2017)](https://pubmed.ncbi.nlm.nih.gov/28257852/)

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Related Entities

OPRD1

▸Metadataorigin_type: v1_polymorphic_backfill

slug	genes-oprd1
kg_node_id	OPRD1
entity_type	gene
origin_type	v1_polymorphic_backfill
source_table	wiki_pages
wiki_page_id	wp-1939818e9ed8
__merged_from	{'merged_at': '2026-05-13', 'unprefixed_id': 'genes-oprd1'}
_schema_version	1

📊 Evidence Profile Foundational

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Outgoing

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📗 Cite This Artifact

OPRD1 — Delta-Opioid Receptor

OPRD1 — Delta-Opioid Receptor

Overview

Gene Information

OPRD1 — Delta-Opioid Receptor

Overview

Gene Information

Protein Structure and Function

Receptor Architecture

Signal Transduction Mechanisms

Expression Pattern

Role in Alzheimer's Disease

Amyloid-Beta Pathology

Neuroinflammation Modulation

Cholinergic System Interactions

Clinical Evidence

Role in Parkinson's Disease

Dopaminergic Neuron Protection

Alpha-Synuclein Toxicity

Clinical Observations

Lewy Body Dementia

Therapeutic Implications

Drug Development

Clinical Considerations

Combination Therapies

Excitotoxicity Protection

Glutamate Toxicity Mitigation

NMDA Receptor Modulation

Autophagy and Protein Clearance

Mechanisms

Implications for Neurodegeneration

Genetic Associations

Polymorphisms

Gene-Environment Interactions

Research Frontiers

PET Imaging

Biased Agonism

Gene Therapy

Brain Region Expression

Aging and OPRD1

Age-Related Changes

Neuroaging Mechanisms

Neurophysiological Functions

Synaptic Plasticity

Presynaptic Modulation

Ion Channel Regulation

Preclinical Models

Animal Models

Cellular Models

Clinical Translation

Biomarker Potential

Therapeutic Windows

Molecular Signaling Cascades

Detailed Signal Transduction

Epigenetic Regulation

Neuroinflammation Mechanisms

Microglial Modulation

Astrocyte Interactions

Mitochondrial Dynamics

Mitochondrial Protection

Bioenergetic Effects

Cognitive Function

Learning and Memory

Prefrontal Cortex Function

Therapeutic Development Pipeline

Preclinical Candidates

Clinical Candidates

Challenges and Solutions

Comparative Receptor Biology

Opioid Receptor Family

Evolutionary Conservation

Research Methodology

Detection Methods

Model Systems

Future Directions

Unanswered Questions

Emerging Technologies

Cross-Linking to Related Topics

Diseases