Evidence for a ventral non-strial pathway from the amygdala to the bed nucleus of the stria terminalis in the male golden hamster.

Male hamsters in which the stria terminalis (ST) had been interrupted either by electrolytic lesions or knife cuts, or normal control males, received iontophoretic injections of horseradish peroxidase in either the bed nucleus of the stria terminalis (BNST) or the medial preoptic-anterior hypothalamic area (MPOAH). Comparison of intact and ST-lesioned brains revealed the existence of a ventral non-strial pathway, from cells in the medial amygdaloid nucleus (M) to the preoptic portion of the BNST but not to the MPOAH. Since bilateral lesions of M completely eliminate male hamster mating behavior, but ST lesions do not, we suggest that the ventral pathway to the BNST may be an important route by which M influences male copulatory behavior.