Type: Indolamine
Receptors: 5-HT1–5-HT7 (diverse functions)
Region-specific functions:

• Raphe nuclei (origin): Diffuse projections

• Prefrontal cortex: Mood regulation, decision-making

• Amygdala: Emotion processing and fear inhibition

• Hippocampus: Memory formation and anxiety modulation

• Hypothalamus: Appetite, sleep, sexual behavior

• Basal ganglia: Movement modulation

• Imbalance → depression, OCD, anxiety