Differential activation of c-fos immunoreactivity after hypophysectomy in developing and adult rats.
The aim of the present study is to compare c-fos expression in identified hypothalamic vasopressin (AVP) and oxytocin (OT) neurons in developing (PN7 and PN14) and adult rats following hypophysectomy using dual-labeled immunostaining. Our results showed that hypophysectomy induced c-fos expression in supraoptic (SON) and paraventricular (PVN) nuclei in both the developing and adult rats. Few or no positive cells were observed in the same nuclei in sham-operated animals. Quantitative analysis for c-fos and either of the above named neuropeptides revealed that almost all AVP and OT neurons in the adult and PN14 groups expressed c-fos in response to hypophysectomy. In PN7, hypophysectomy also induced all AVP neurons to express c-fos in SON and PVN. However, few OT neurons in the SON and PVN produced c-fos after hypophysectomy. In addition, the time course of c-fos expression was different in the developing and adult rats after hypophysectomy. The c-fos expression in the developing rats exhibited a more prolonged induction in which staining for c-fos persisted for at least 3 days after hypophysectomy compared with that in the adult in which c-fos immunoreactivity disappeared within 24 hr post-lesion. This study demonstrates that c-fos expression after hypophysectomy is regulated differently during development.
Yuan
Qiuju
Q
Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
Scott
David E
DE
So
Kwok-Fai
KF
Wu
Wutian
W
D000375:Aging / Q000378:metabolism*; D000818:Animals; D007016:Hypophysectomy; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D009474:Neurons / Q000378:metabolism*; D010121:Oxytocin / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013495:Supraoptic Nucleus / Q000166:cytology / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation; D014667:Vasopressins / Q000378:metabolism*
D016760:Proto-Oncogene Proteins c-fos; D014667:Vasopressins; D010121:Oxytocin