Induction of Fos immunoreactivity in oxytocin neurons in the paraventricular nucleus after female odor exposure in male rats: effects of sexual experience.
1. We examined whether oxytocin (OT) neurons in the paraventricular nucleus of the hypothalamus (PVN) were activated by estrus female odor and sexual contact in sexually naïve and experienced Long-Evans rats. 2. Male rats were not presented to anesthetized estrus females (control) or presented to the females without (exposure to the female odor without sexual contact) or with direct contact (exposure to the female odor with sexual contact). 3. Exposure to the female odor with sexual contact significantly increased OT neurons with Fos-ir in both males. Exposure to the female odor without contact increased OT neurons with Fos-immunoreactive cells (Fos-ir) in sexually experienced males but not in naïve males, suggesting that the female odor without sexual contact activated the oxytocinergic neuronal system in the PVN in the experienced males. 4. Therefore, exposure to the estrus female odor itself may exert different effects on sexually naïve and experienced males.
Nishitani
Shota
S
Division of Neurobiology and Behavior, Department of Translational Medical Sciences, Course of Medical and Dental Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Moriya
Takahiro
T
Kondo
Yasuhiko
Y
Sakuma
Yasuo
Y
Shinohara
Kazuyuki
K
D000818:Animals; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D007150:Immunohistochemistry; D007858:Learning / Q000502:physiology; D008297:Male; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009812:Odorants; D010121:Oxytocin / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012903:Smell / Q000502:physiology*
D016760:Proto-Oncogene Proteins c-fos; D010121:Oxytocin