C-FOS PROTOONCOGENE ACTIVITY-INDUCED BY MATING IN THE PREOPTIC AREA, HYPOTHALAMUS AND AMYGDALA IN THE FEMALE RAT - ROLE OF AFFERENT INPUT VIA THE PELVIC NERVE

In order to identify brain areas which receive afferent genitosensory input important for mating-induced prolactin release, we compared numb ers of Fos-immunoreactive (Fos-IR) cells in brains of intact estrous f emales 1 h after differential mating stimulation. Numbers of Fos-IR ce lls were approximately 3-fold higher in the preoptic area (POA), media l amygdala (mAMYG) and bed nucleus of the stria terminalis (BNST) when females received intromissions (I) from males than when they received mounts-without-intromission (M) or were taken directly from their hom e cage. In the ventrolateral portion of the ventromedial nucleus (VL-V MN), the paraventricular nucleus (PVN) of the hypothalamus and the mid brain central tegmental field (CTF) numbers of Fos-IR cells were signi ficantly higher than home cage levels in groups of females exposed to males regardless of type of mating stimulation received. Bilateral tra nsection of the pelvic nerve eliminated the increases in Fos-IR in POA and mAMYG which occurred in sham-transected females in these areas af ter intromissions from males. These data demonstrate that afferent inp ut via the pelvic nerve activates cell groups within the POA, mAMYG an d BNST and suggests that these areas may be involved in initiation of mating-induced prolactin surges.