Serotonin impairs copulation and attenuates ejaculation-induced glutamate activity in the medial preoptic area.
The medial preoptic area (MPOA) is critical for male sexual behavior. Glutamate is released in the MPOA of male rats during copulation, and increasing glutamate levels by reverse dialysis of glutamate uptake inhibitors facilitates mating. Conversely, increased release of serotonin (5-HT) inhibits sexual behavior. In both rats and men, selective serotonin reuptake inhibitors (SSRIs) impair erection, ejaculation, and libido. Here we reverse-dialyzed 5-HT through concentric microdialysis probes in the MPOA of male rats; concurrently we collected 2-min samples for analysis of glutamate and measured sexual behavior. Sexual activity, and especially ejaculation, increased levels of glutamate in the MPOA. However, reverse dialysis of 5-HT into the MPOA impaired ejaculatory ability and attenuated glutamate release. Implications of these results for impairment of sexual behavior that results from administration of SSRIs are discussed.
Dominguez
Juan M
JM
Department of Psychology and Institute for Neuroscience, The University of Texas at Austin, 78712, USA. dominguez@psy.utexas.edu
Hull
Elaine M
EM
D000818:Animals; D003307:Copulation / Q000187:drug effects*; D004195:Disease Models, Animal; D004542:Ejaculation / Q000187:drug effects* / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D017551:Microdialysis / Q000379:methods; D011301:Preoptic Area / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000187:drug effects; D012701:Serotonin / Q000009:adverse effects*; D012735:Sexual Dysfunction, Physiological / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology
D012701:Serotonin; D018698:Glutamic Acid