Serotonergic Modulation of Sex and Aggression

Abstract

The serotonergic system in the central nervous system (CNS) has complexinteractions with many, if not all other neurotransmitter systems in thebrain. Its localization, distribution and amazing receptor diversitymakes it an appealing system for modulatory aspects in many basicbehaviors, including sexual and aggressive behaviors. Notwithstandingdecades of research into the putative role of the serotonin (5-HT)system in aggression and sex, no clear picture has emerged. Inaggression, depending on state or trait, 5-HT is involved in either theperformance or its termination. Application of drugs, and particularselective ligands for certain receptors, suggests a specific role forthe (postsynaptic) 5-HT(1B) and to a lesser extent, the 5-HT(1A)receptor in the modulation of (offensive) aggression. In sexualbehavior, the role of 5-HT is less well studied. Here, 5-HT(1A) receptoractivation and blockade of 5-HT(2C) receptors are prosexual, whereas5-HT(1B) receptor activation is inhibitory. Selective serotonergicuptake inhibitors have no acute effects on sexual behavior but areinhibitory after chronic administration. The role of serotonin inaggression and sexual behavior most likely involves different, partlyoverlapping, neurochemical systems, suggesting that independent networksin both behavioral systems are differentially influenced by serotonergictone influencing various 5-HT receptors.