Serotonin System Gene Knockouts

To better understand the roles of individual serotonin receptor subtypes in modulating the neural circuitry of complex behavior, a number of groups have generated “knockout” mice lacking individual serotonin receptor subtypes over the last decade. Overall, 10 (at least 14) serotonin receptor subtypes have been knocked out in mice, as well as several genes that regulate the development and activity of serotonin neurons (e.g., Pet-1, the serotonin transporter, and tryptophan hydroxylase). We review these studies, discuss their relevance to the pathophysiology of neuropsychiatric disorders, and close with a perspective on where the field may head in the future.