Serotonin receptors, also known as 5-hydroxytryptamine receptor or 5-HT receptor, are a group of G protein-coupled receptors and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand . The serotonin receptors modulate the release of many neurotransmitters and influence various biological and neurological processes such as aggression, anxiety, appetite, cognition, learning, memory, mood, nausea, sleep, and thermoregulation. And great differences exist in 5-HT receptor subtypes; some of them play inhibitory roles, while others play exciting roles. In our study, the 5-HT receptor 1 was significantly downregulated in SP AG, implying that we found that the 5-HT receptor 1 gene negatively regulates the development of AG.