Gravitt KC, Cai RS, Marson L (2004) Effect of removal of neurons expressing serotonin reuptake transporter on male sexual reflexes. Neuroscience 2004 Abstracts 998.2. Society for Neuroscience, San Diego, CA.
Summary: Ejaculatory reflexes are regulated by spinal circuits that are tonically inhibited or facilitated by specific regions of the brain. Serotonin can facilitate or inhibit sexual responses depending on the site of action and the predominate receptor subtype involved. Sexual function, in particular ejaculation, can be reduced by administration of serotonin reuptake inhibitors (SSRI’s). The urethrogenital (UG) reflex comprises erections, rhythmic contractions of perineal muscles and ejaculation in male rats. We previously demonstrated that a direct pathway from the nucleus paragigantocellularis to the lumbosacral cord is involved in regulating the tonic inhibition of UG reflexes. Neurons in the ventral medulla contain serotonin and removal of serotonin inputs in the spinal cord allow the UG reflex to be exposed. The present study examined the effect of specific lesions of ventral medullary neurons containing the serotonin reuptake transporter (SERT) on sexual reflexes. Anti-SERT-saporin (50-100nl, 1uM) was injected bilaterally into the nPGi of male rats. Ten-fourteen days following surgery, animals were deeply anesthetized and the presence of the UG reflex examined. Urethral stimulation was performed before and after cutting the spinal cord (SCT) and recordings made from the bulbospongiosus muscle. Following the experiment immunocytochemical localization of serotonin was examined. In control rats the UG reflex was not present before SCT. In 50% of males that received anti-SERT-saporin the UG reflex was exposed before SCT. Responses after spinal cord transection were similar in all groups. Rats treated with ant-SERT-saporin showed a significant reduction in the number of serotonin containing neurons and a decrease in the intensity staining in the nPGi, parapyramidal region and medullary raphe. These studies suggest that neurons containing serotonin reuptake transporter systems are involved inhibiting male sexual reflexes.
Related Products: Anti-SERT-SAP (Cat. #IT-23)