Terminal nerve damage impairs the mating behavior of the male hamster

We examined the effects of bilateral terminal nerve (TN) transections (TNx) on the sexual behavior of male hamsters. These lesions produced a decrease in mating frequency and/or an increase in the number of intromissions required to reach ejaculation. Damage to the olfactory bulbs or rostral forebrain did not account for these effects. No amelioration of the behavioral impairments occurred over the mating sessions. Basal testosterone levels in the blood of male hamsters were not altered by TN damage. Hamsters with TNx retained their ability to detect odors, but demonstrated reduced attraction to vaginal odors as compared with unoperated animals. The reduced attraction to vaginal odors was most pronounced in sporadically mating TNx animals. These data suggest that the TN may facilitate odor-induced sexual excitation in the male hamster.