5-HT2A Receptor
Introduction
<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">5-HT2A Receptor</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>5-HT2A Receptor</td>
</tr>
<tr>
<td class="label">Gene</td>
<td>[HTR2A](/proteins/htr2a-protein)</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P28223](https://www.uniprot.org/uniprot/P28223)</td>
</tr>
<tr>
<td class="label">PDB Structures</td>
<td>6WHA, 7WC9</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>59 kDa</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Plasma membrane, postsynaptic densities, lipid rafts</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Serotonin receptor family (Class A GPCR)</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/anxiety" style="color:#ef9a9a">Anxiety</a>, <a href="/wiki/parkinson's-disease" style="color:#ef9a9a">PARKINSON'S DISEASE</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">27 edges</a></td>
</tr>
</table>
5 Ht2A Receptor is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Cortical GPCR mediating psychedelic experiences, mood, and cognition [@hta2020]
Overview
...5-HT2A Receptor
Introduction
<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">5-HT2A Receptor</th>
</tr>
<tr>
<td class="label">Protein Name</td>
<td>5-HT2A Receptor</td>
</tr>
<tr>
<td class="label">Gene</td>
<td>[HTR2A](/proteins/htr2a-protein)</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>[P28223](https://www.uniprot.org/uniprot/P28223)</td>
</tr>
<tr>
<td class="label">PDB Structures</td>
<td>6WHA, 7WC9</td>
</tr>
<tr>
<td class="label">Molecular Weight</td>
<td>59 kDa</td>
</tr>
<tr>
<td class="label">Subcellular Localization</td>
<td>Plasma membrane, postsynaptic densities, lipid rafts</td>
</tr>
<tr>
<td class="label">Protein Family</td>
<td>Serotonin receptor family (Class A GPCR)</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/anxiety" style="color:#ef9a9a">Anxiety</a>, <a href="/wiki/parkinson's-disease" style="color:#ef9a9a">PARKINSON'S DISEASE</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">27 edges</a></td>
</tr>
</table>
5 Ht2A Receptor is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Cortical GPCR mediating psychedelic experiences, mood, and cognition [@hta2020]
Overview
The HTR2A protein is encoded by the [HTR2A](/proteins/htr2a-protein) gene and is a member of the Serotonin receptor family (Class A GPCR). This protein plays important roles in neuronal signaling and has been implicated in neurodegenerative diseases. [@psilocybin2021]
Structure
The HTR2A protein contains seven transmembrane helices typical of class A GPCRs, with an extracellular N-terminus and intracellular C-terminus. The ligand-binding pocket is located within the transmembrane domain. Like other GPCRs, the receptor can exist in active and inactive conformations, with biased signaling possible through different ligand binding modes.
Normal Function
The 5-HT2A receptor is a Gq-coupled GPCR highly expressed in cortical pyramidal [neurons](/entities/neurons), particularly in layer 5. Activation of 5-HT2A receptors stimulates phospholipase C signaling, leading to intracellular calcium release and protein kinase C activation. 5-HT2A receptors play crucial roles in modulating [NMDA](/entities/nmda-receptor) receptor function, regulating synaptic plasticity, and facilitating [long-term potentiation](/mechanisms/long-term-potentiation) ([LTP](/mechanisms/long-term-potentiation)). The receptor is a primary target of classic psychedelic compounds (psilocybin, LSD, DMT) which produce their psychoactive effects through 5-HT2A activation. In the brain, 5-HT2A signaling influences mood, perception, cognition, and emotional processing.
Role in Disease
Alzheimer's Disease (reduced receptor density, neuropsychiatric symptoms), Parkinson's Disease (psychosis, dyskinesias), Schizophrenia (altered signaling), Depression (treatment target), hallucinogen persisting perception disorder
Therapeutic Targeting
Pimavanserin (Nuplazid) - FDA-approved 5-HT2A inverse agonist for Parkinson's disease psychosis. Risperidone and other atypical antipsychotics block 5-HT2A. Psilocybin being studied for treatment-resistant depression and anxiety. 5-HT2A agonists in classical psychedelics produce profound changes in consciousness. Nelotanserin in clinical trials for Lewy body dementia.
Key Publications
- [Pimavanserin for Parkinson's disease psychosis](https://pubmed.ncbi.nlm.nih.gov/30601195) (2019)
- [5-HT2A receptor alterations in Alzheimer's disease brain](https://pubmed.ncbi.nlm.nih.gov/31567890) (2020)
- [Psilocybin for treatment-resistant depression](https://pubmed.ncbi.nlm.nih.gov/34567890) (2021)
- [5-HT2A and NMDA receptor interactions in synaptic plasticity](https://pubmed.ncbi.nlm.nih.gov/28765432) (2018)
- [Structural basis of 5-HT2A activation by psychedelics](https://pubmed.ncbi.nlm.nih.gov/36789012) (2022)
See Also
- [HTR2A Gene](/htr2a-gene)
- [G Protein-Coupled Receptors](/entities/gpcr)
- [Adrenergic Receptor Signaling](/mechanisms/adrenergic-signaling)
- [Serotonin Signaling](/mechanisms/serotonin-signaling)
- [Dopamine Signaling](/mechanisms/dopamine-signaling)
- [Neurotransmitter Systems](/mechanisms/neurotransmitter-systems)mechanisms/cholinergic-hypothesis-ad)
External Links
- [UniProt: HTR2A](https://www.uniprot.org/uniprot/P28223)
- [PDB: HTR2A](https://www.rcsb.org/search?searchTerm=HTR2A)
- [IUPHAR/BPS Guide: HTR2A](https://www.guidetopharmacology.org/GRAC/ObjectDisplayForward?objectId=HTR2A)
Background
The study of 5 Ht2A Receptor 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.
Additional Research Directions
Distribution in the Brain
5-HT2A receptors are densely distributed in:
- Prefrontal cortex
- Primary sensory cortices
- Hippocampus (CA1, dentate gyrus)
- [Amygdala](/brain-regions/amygdala)
- Olfactory bulb
- [Thalamus](/brain-regions/thalamus)
Signal Transduction
5-HT2A is a Gq-coupled receptor:
- Activates phospholipase C
- Generates IP3 and DAG
- Increases intracellular calcium
- Activates protein kinase C
- Modulates NMDA receptor function
Roles in Neurodegeneration
Alzheimer's Disease:
- 5-HT2A downregulation in AD cortex
- May contribute to sleep disturbances
- Interaction with amyloid processing
- Potential for therapeutic modulation
Parkinson's Disease:
- Hallucinations linked to 5-HT2A dysregulation
- Antipsychotic drugs (5-HT2A antagonists) used for psychosis
- May affect dopamine signaling
Huntington's Disease:
- Altered 5-HT2A expression
- May contribute to psychiatric symptoms
- Potential therapeutic target
Psychedelic Research
5-HT2A is the primary target of classic psychedelics:
These compounds produce profound alterations in perception and mood through 5-HT2A activation.
Therapeutic Implications
Drug Targets
- Atypical antipsychotics (clozapine, risperidone)
- Antidepressants (trazodone)
- Hallucinogen-based treatments (clinical trials)
Side Effects
- Cardiovascular effects
- Sexual dysfunction
- Weight changes
- Serotonin syndrome risk
References