Activation of the 5-HT2A and 5-HT2C receptors in the neurons typically leads to the activation of Gq proteins. Gq proteins stimulate phospholipase C (PLC), leading to the production of inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 induces calcium release from intracellular stores, leading to increased intracellular calcium levels. Increased intracellular calcium and DAG activation of protein kinase C (PKC) can lead to the modulation of various signaling pathways. The net effect on neuronal excitability can vary involving both excitatory and inhibitory influences depending on the context and the specific neuron, brain region and down stream signaling pathways involved. 5-HT2A receptor activation via Gq protein signaling can have excitatory effects in some neurons, particularly in the cerebral cortex and certain excitatory circuits. In the cortex, activation of 5-HT2A receptors can enhance neuronal excitability, synaptic transmission, and plasticity.

Neuronal serotonin Gq protein cascade References