Human 5-Hydroxytryptamine Receptor 2A / 5-HT2A (HTR2A) Protein

Background

HTR2A is a G protein-coupled receptor (GPCR) that mediates the actions of serotonin (5-HT), a neurotransmitter crucial for mood regulation, perception, and cognition. It is widely expressed in the central nervous system (CNS), particularly in the prefrontal cortex, hippocampus, and amygdala, regions involved in executive function, emotion, and learning. HTR2A is highly implicated in neuropsychiatric conditions, including schizophrenia, depression, anxiety, and mood disorders. Its activation influences intracellular calcium signaling and downstream pathways such as the phospholipase C cascade. HTR2A also interacts with various neurotransmitter systems, including dopamine, glutamate, and norepinephrine, which are critical for regulating mood and behavior. Importantly, many antipsychotic drugs, such as risperidone and clozapine, function as antagonists of HTR2A, improving symptoms of psychosis and mood stabilization. It is also the principal target for psychedelic compounds, like LSD and psilocybin, which bind to HTR2A and induce altered perceptions and consciousness. Genetic polymorphisms in the HTR2A gene have been associated with an increased risk of major depressive disorder and resistance to antidepressant therapy. Understanding HTR2A's role in serotonin signaling, mood regulation, and cognitive processes makes it a crucial target for pharmacological intervention in a range of psychiatric and neurodevelopmental disorders.