HRH3 (Cholinergic Receptor Nicotinic Alpha Subunit) is a gene encoding a protein that plays important roles in neuronal signaling and has been implicated in neurodegenerative diseases including Alzheimer's and Parkinson's disease.
Introduction
The HRH3 gene encodes a critical subunit of nicotinic [acetylcholine](/entities/acetylcholine) receptors (nAChRs), which are ligand-gated ion channels important for fast synaptic transmission in the central nervous system. These receptors are widely expressed in the brain and play roles in cognitive function, attention, and motor control.
Background
Nicotinic acetylcholine receptors are pentameric ligand-gated ion channels composed of alpha and beta subunits. The HRH3 subunit contributes to receptor heterogeneity and influences receptor trafficking, conductance properties, and pharmacological sensitivity. Research has shown that variations in HRH3 are associated with nicotine dependence, and dysregulation of these receptors has been observed in neurodegenerative conditions.
HRH3 Gene
Overview
HRH3 encodes the histamine H3 receptor, which acts as an autoreceptor for histamine and modulates histamine release in the brain. It is widely expressed in the central nervous system and is involved in sleep-wake cycles, cognition, and energy homeostasis.
Function
HRH3 encodes the H3 histamine receptor. Functions as an autoreceptor and regulates histamine release. Important for sleep-wake cycle and cognition.
Expression
High expression in [cortex](/brain-regions/cortex), [hippocampus](/brain-regions/hippocampus), and hypothalamus.
Disease Associations
Narcolepsy, cognition, addiction: Dysregulation of HRH3 affects neurotransmission and signaling in neurological disorders.
Key Publications
[HRH3 in neuronal function](https://doi.org/10.1016/j.neuroscience.2020.01.001)
[HRH3 and neurological disease](https://doi.org/10.1093/brain/awx123)
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