Vomeronasal organ-mediated induction of fos in the central accessory olfactory pathways in repetitively mated female rats.
Removal of the VNO significantly reduced the enhancement of lordosis and the induction of fos immunoreactivity in luteinizing hormone-releasing hormone (LHRH) neurons in ovariectomized estrogen-primed rats. There was a significant positive correlation between the two variables. In the accessory olfactory bulb (AOB) of the repetitively mated rats, the number of fos-positive cells in the granule (G) cell layer was significantly lower in the VNO-removed rats, whereas that in the mitral (M) cell layer was not significantly different between VNO-removed and VNO-sham females. The G/M ratio (calculated by dividing the mean number of fos-positive cells in the G cell layer by that in the M cell layer), taken as an estimate of the output of the AOB, was relatively larger in the VN-sham as compared with the VNO-removed rats. There were significant positive correlations between G/M ratio and the increase in LQ and between the G/M ratio and the percentage of fos-positive LHRH cells. The positive correlation between the number of fos-positive cells in the posterodorsal medial amygdala (PDMA) and the increase in LQ and that between the number of fos-positive cells in the PDMA and the percentage of fos-positive LHRH cells were significant, supporting the role of the medial nucleus of amygdala in lordosis. However, the correlation between G/M ratio and the number of fos-positive cells in the PDMA was not significant, indicating that fos immunoreactivity in the PDMA is not directly related to that in the AOB.(ABSTRACT TRUNCATED AT 250 WORDS)
Rajendren
G V
GV
Department of Physiology, University of Texas Southwestern Medical Center at Dallas, TX 75235-9040.
Moss
R L
RL
D000679:Amygdala / Q000166:cytology / Q000378:metabolism; D000818:Animals; D003307:Copulation; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D009296:Nasal Cavity / Q000502:physiology*; D009300:Nasal Septum / Q000502:physiology*; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D009830:Olfactory Bulb / Q000166:cytology / Q000378:metabolism; D009833:Olfactory Pathways / Q000378:metabolism*; D010052:Ovariectomy; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012726:Sexual Behavior, Animal / Q000502:physiology
D004967:Estrogens; D016760:Proto-Oncogene Proteins c-fos; D007987:Gonadotropin-Releasing Hormone