Stria terminalis lesions alter the temporal pattern of copulatory behavior in the male golden hamster.

The mating behavior of a group of male golden hamsters was observed before and after bilateral electrolytic lesions or knife cuts interrupting the stria terminalis (ST). Whereas males with bilateral lesions of the medial nucleus of the amygdala had previously been observed to stop mating, a majority of hamsters with bilateral ST destruction, whether by electrolytic lesions or knife cuts, continued to display mounts, intromissions, and ejaculations during tests over a two month postoperative period. ST-lesioned males did, however, display a distinctly altered pattern of copulation over the course of postoperative testing, consisting of an increase in mount latency during the first week, an increase in the inter-intromission interval during the second week, and an increase in the number of intromissions preceding ejaculation during the third and subsequent weekly tests. Males with bilateral lesions of the caudal amygdala, which damaged the amygdaloid exit of the ST, displayed alterations in copulatory behavior similar to those seen after bilateral ST destruction at a more rostral level.