Figure 1.

Components of 5-HT neurotransmission. Shown are the major components involved in the synthesis, vesicular packaging, reuptake, and degradation of serotonin in the brain, and the major receptors that mediate pre- and post-synaptic regulation of 5-HT neurotransmission. TRP, tryptophan; 5-HTP, 5-hydroxy-TRP; 5-HIAA, 5-hydroxy indole acetic acid; TPH2, tryptophan hydroxylase-2; AADC, aromatic amino-acid decarboxylase; VMAT2, vesicular monoamine transporter-2; MAO-B, monoamine oxidase B; 5-HTT, 5-HT transporter.