Effects of estrogen on stress-induced activation of peptide neurons in PVN of ovariectomized rats.
Estrogen has been implicated in brain function related to stress responses. We investigated whether estrogen affects psychological stress-induced activation of peptide-containing or nitric oxide-producing neurons in the paraventricular hypothalamic nucleus (PVN) in ovariectomized (OVX) rats, both placebo-treated (OVX + Pla) and estrogen-treated (OVX + E2) by comparison of c-Fos expression using immunohistochemistry. Cage-switch stress increased activation in oxytocinergic neurons in the parvocellular PVN (pPVN) in OVX + Pla, but not in that of OVX + E2, rats. Moreover, the stress-induced activation in NADPH-diaphorase-positive neurons in the pPVN was larger in the OVX + E2 than in the OVX + Pla group. These findings suggest that estrogen attenuates the activation of oxytocinergic neurons in the pPVN, at least in part via nitric oxide.
Hara
Yasuko
Y
Department of Environmental Health, Faculty of Life Science and Human Technology, Nara Women's University, Nara, Japan.
Kohno
Tomomi
T
Takamata
Akira
A
Ueyama
Takashi
T
Morimoto
Keiko
K
D000818:Animals; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010052:Ovariectomy; D010121:Oxytocin / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology* / Q000378:metabolism; D010919:Placebos; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological
D004967:Estrogens; D010919:Placebos; D016760:Proto-Oncogene Proteins c-fos; D010121:Oxytocin; D009252:NADPH Dehydrogenase