A. Mean (+SEM) LH levels in wildtype-littermates (n=7) and ERβ mutant mice (n=7), ovariectomized, treated with estrogen and killed at 19:00h. B. The percentage of GnRH neurons (+SEM) found to express c-Fos in wildtype-littermates (n=7) and ERα mutant mice (n=8), ovariectomized, treated with estrogen and killed at 19:00h. C. The number of c-Fos-expressing neurons detected within the AVPV of wildtype-littermates (n=7) and ERα mutant mice (n=8), ovariectomized, treated with estrogen and killed at 19:00h.