Patterns of motor and seminal vesicle activities during copulation in the male rat

The interaction between behavioral and visceral events during copulation was studied in nine intact adult male Wistar rats. The motor copulatory pattern was analyzed by an accelerometric technique and the seminal vesicle pressure (SVP) was recorded through a catheter chronically inserted into the right seminal vesicle. Mounting was associated with a small broad rise in SVP that often preceded the initiation of pelvic thrusting. Penile insertion resulted in a second sharp rise in SVP superimposed on the primary wave related to mounting. A steep rise in SVP occurred during the performance of the motor ejaculatory pattern after a variable period of intravaginal thrusting. This final rise was associated with ejaculation. Analysis of the temporal relationships ships between the SVP changes and copulatory behavior revealed that each of the three rises of SVP was related to distinct patterns of stimulation, suggesting that they were mediated by separate reflex arcs.