Abstract
Ovariectomized (OVX) rats respond to estrogen administration by exhibiting daily afternoon surges of luteinizing hormone (LH). Interruption of neural pathways reaching the hypothalamus from the limbic system resulted in the inhibition of the estrogen-induced LH release in OVX rats. Bilateral lesion of the amygdaloid complex (AMYG) was also effective in inhibiting this LH surge. These data suggest that the mechanism by which estrogen induces an LH surge in OVX rats involves the participation of the limbic system, in particular the AMYG.