Neurokinin A (NK2) Receptor Neurons

Neurokinin A (NK2) Receptor Neurons

Introduction

<table class="infobox infobox-cell">
<tr>
<th class="infobox-header" colspan="2">Neurokinin A (NK2) Receptor Neurons</th>
</tr>
<tr>
<td class="label">Taxonomy</td>
<td>ID</td>
</tr>
<tr>
<td class="label">Cell Ontology (CL)</td>
<td>[CL:0000197](https://www.ebi.ac.uk/ols4/ontologies/cl/classes/http%253A%252F%252Fpurl.obolibrary.org%252Fobo%252FCL_0000197)</td>
</tr>
<tr>
<td class="label">Receptor Type</td>
<td>NK2 (TACR2)</td>
</tr>
<tr>
<td class="label">Family</td>
<td>Tachykinin (Neurokinin)</td>
</tr>
<tr>
<td class="label">Signaling Mechanism</td>
<td>Gq protein-coupled, activates phospholipase C</td>
</tr>
<tr>
<td class="label">Primary Location</td>
<td>Hippocampus, cortex, peripheral nervous system</td>
</tr>
<tr>
<td class="label">Agonists</td>
<td>Neurokinin A (NKA), Substance P (lower affinity)</td>
</tr>
<tr>
<td class="label">Antagonists</td>
<td>GR-159897, SR-48968 (NK2 selective)</td>
</tr>
<tr>
<td class="label">Region</td>
<td>NK2 Expression</td>
</tr>
<tr>
<td class="label">Hippocampus</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Cerebral cortex</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Enteric nervous system</td>
<td>High</td>
</tr>
<tr>
<td class="label">Bladder</td>
<td>High</td>
</tr>
<tr>
<td class="label">Bronchi</td>
<td>High</td>
</tr>
<tr>
<td class="label">Compound</td>
<td>Status</td>
</t

Neurokinin A (NK2) Receptor Neurons

Introduction

<table class="infobox infobox-cell">
<tr>
<th class="infobox-header" colspan="2">Neurokinin A (NK2) Receptor Neurons</th>
</tr>
<tr>
<td class="label">Taxonomy</td>
<td>ID</td>
</tr>
<tr>
<td class="label">Cell Ontology (CL)</td>
<td>[CL:0000197](https://www.ebi.ac.uk/ols4/ontologies/cl/classes/http%253A%252F%252Fpurl.obolibrary.org%252Fobo%252FCL_0000197)</td>
</tr>
<tr>
<td class="label">Receptor Type</td>
<td>NK2 (TACR2)</td>
</tr>
<tr>
<td class="label">Family</td>
<td>Tachykinin (Neurokinin)</td>
</tr>
<tr>
<td class="label">Signaling Mechanism</td>
<td>Gq protein-coupled, activates phospholipase C</td>
</tr>
<tr>
<td class="label">Primary Location</td>
<td>Hippocampus, cortex, peripheral nervous system</td>
</tr>
<tr>
<td class="label">Agonists</td>
<td>Neurokinin A (NKA), Substance P (lower affinity)</td>
</tr>
<tr>
<td class="label">Antagonists</td>
<td>GR-159897, SR-48968 (NK2 selective)</td>
</tr>
<tr>
<td class="label">Region</td>
<td>NK2 Expression</td>
</tr>
<tr>
<td class="label">Hippocampus</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Cerebral cortex</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">Enteric nervous system</td>
<td>High</td>
</tr>
<tr>
<td class="label">Bladder</td>
<td>High</td>
</tr>
<tr>
<td class="label">Bronchi</td>
<td>High</td>
</tr>
<tr>
<td class="label">Compound</td>
<td>Status</td>
</tr>
<tr>
<td class="label">GR-159897</td>
<td>Research</td>
</tr>
<tr>
<td class="label">SR-48968</td>
<td>Clinical trials</td>
</tr>
<tr>
<td class="label">nepicastat</td>
<td>Preclinical</td>
</tr>
</table>

Neurokinin A (Nk2) Receptor Neurons is an important cell type in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Overview

Neurokinin A (NK2) Receptor Neurons are neurons expressing the NK2 receptor, a member of the Tachykinin receptor family. These receptor neurons play crucial roles in smooth muscle contraction, gut motility and are implicated in various neurological and neurodegenerative conditions. [@tachykinin]

<!-- multi-taxonomy-enrichment -->

Multi-Taxonomy Classification

Taxonomy Database Cross-References

External Database Links

• [Cell Ontology (CL:0000197)](https://www.ebi.ac.uk/ols4/ontologies/cl/classes/http%253A%252F%252Fpurl.obolibrary.org%252Fobo%252FCL_0000197)
• [OBO Foundry (CL:0000197)](http://purl.obolibrary.org/obo/CL_0000197)
• [Allen Brain Cell Atlas](https://portal.brain-map.org/atlases-and-data/bkp/abc-atlas)
• [CellxGene Census](https://cellxgene.cziscience.com/)
• [Human Cell Atlas](https://www.humancellatlas.org/)

Receptor Properties

Function

Neurokinin A (NK2) Receptor Neurons are neurons expressing the [NK2 receptor](/entities/tacr2), a member of the [Tachykinin receptor family](/mechanisms/tachykinin-signaling). These receptor neurons play crucial roles in [smooth muscle contraction](/mechanisms/autonomic-dysfunction), [gut motility](/mechanisms/gut-brain-axis-ad), [neuroinflammation](/mechanisms/neuroinflammation), and are implicated in [Alzheimer's disease](/diseases/alzheimers-disease), [Parkinson's disease](/diseases/parkinsons-disease), and [irritable bowel syndrome](/diseases/ibs-neurodegeneration).

The NK2 receptor signals through [Gq protein-coupled](/mechanisms/gpcr-signaling) mechanisms, activating phospholipase C:

• [Intracellular calcium release](/mechanisms/calcium-dysregulation-alzheimers) via IP3
• [Protein kinase C activation](/mechanisms/protein-kinase-c-signaling)
• [MAPK/ERK signaling](/mechanisms/erk-mapk-signaling-neurodegeneration)
• [Gene transcription via CREB](/mechanisms/camp-pka-signaling)

Distribution in Brain and Periphery

Disease Implications

NK2 receptor neurons are implicated in several conditions:

Alzheimer's Disease

• [Neuroinflammation](/mechanisms/neuroinflammation): NKA promotes microglial activation
• [Hippocampal dysfunction](/mechanisms/amyloid-cascade-pathway): NK2 modulates memory circuits
• [Calcium dysregulation](/mechanisms/calcium-dysregulation-alzheimers): Gq signaling contributes to overload

Parkinson's Disease

• [Gut-brain axis](/mechanisms/gut-brain-axis-ad): NK2 in enteric nervous system affects PD
• [Neuroinflammation](/mechanisms/neuroinflammation): Tachykinin-mediated glial activation
• [Autonomic dysfunction](/mechanisms/autonomic-dysfunction): GI tract involvement

Irritable Bowel Syndrome (IBS)

• [Enteric nervous system](/mechanisms/gut-brain-axis-ad): Altered NK2 signaling in gut
• [Pain hypersensitivity](/mechanisms/visceral-pain): NKA-mediated nociception
• [Microbiome interactions](/mechanisms/microbiome-gut-brain): Bidirectional signaling

Bladder Dysfunction

• [Detrusor overactivity](/mechanisms/autonomic-dysfunction): NK2 in micturition reflex
• [Parkinson's disease bladder](/diseases/parkinsons-disease): Common autonomic symptom

Tachykinin System Overview

The tachykinin family includes:

• Substance P (SP): NK1 > NK2 > NK3
• Neurokinin A (NKA): NK2 > NK1 > NK3
• Neurokinin B (NKB): NK3 > NK2 > NK1

Therapeutic Targets

NK2 Receptor Antagonists

Drug Development Strategies

• Peripheral targeting: GI and bladder applications
• CNS penetration: For brain diseases
• Dual NK1/NK2 antagonists: Broader tachykinin blockade

Combination Approaches

• [Gut-brain axis modulation](/mechanisms/gut-brain-axis-ad): NK2 + gut microbiome
• [Anti-inflammatory strategies](/mechanisms/neuroinflammation): NK2 + cytokine inhibition

See Also

• [Hippocampus](/brain-regions/hippocampus)
• [Cerebral Cortex](/brain-regions/cerebral-cortex)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Irritable Bowel Syndrome](/diseases/ibs-neurodegeneration)
• [NK3 Receptor Neurons](/cell-types/nk3-receptor-neurons)
• [Neuroinflammation](/mechanisms/neuroinflammation)
• [Tachykinin Signaling](/mechanisms/tachykinin-signaling)
• [GPCR Signaling](/mechanisms/gpcr-signaling)
• [Gut-Brain Axis](/mechanisms/gut-brain-axis-ad)
• [Autonomic Dysfunction](/mechanisms/autonomic-dysfunction)
• [Calcium Dysregulation](/mechanisms/calcium-dysregulation-alzheimers)

Background

The study of Neurokinin A (Nk2) Receptor Neurons has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
• [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
• [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data

Pathway Diagram

The following diagram shows the key molecular relationships involving Neurokinin A (NK2) Receptor Neurons discovered through SciDEX knowledge graph analysis: