Neurobiology of tetrahydro-beta-carbolines

Tetrahydro-β-carbolines (THβC's) are tricyclic compounds structurally related to the indoleamines. Recent studies have reported the $\text{in}$$\text{vitro}$ and $\text{in}$$\text{vivo}$ formation of these compounds in brain and other tissues. This information and other data indicating that THβC's interact relatively specifically with various aspects of the serotonergic neurotransmitter system has suggested that THβC's may serve as endogenous neuromodulators of neurotransmitters. Evidence for the formation of these compounds as well as their neurochemical, neuroendocrinological, and behavioral effects is described in this review.