Bittman E L, Bartness T J, Goldman B D, DeVries G J
Department of Zoology, University of Massachusetts, Amherst 01003.
Am J Physiol. 1991 Jan;260(1 Pt 2):R90-101. doi: 10.1152/ajpregu.1991.260.1.R90.
The effects of lesions of the suprachiasmatic (SCN) and paraventricular nuclei (PVN) of the hypothalamus on photoperiodic responses were examined in adult Siberian hamsters. SCN lesions reduced nocturnal water intake in long days, whereas PVN lesions increased body weight and food intake in both short and long days. SCN or PVN lesions blocked short-day-induced decreases in body, fat pad, and testes weights and in food intake. Serum prolactin (PRL), but not follicle-stimulating hormone, levels were increased. The distribution of immunostained neurons and fibers for gonadotropin-releasing hormone (GnRH), beta-endorphin, arginine vasopressin (AVP), and vasoactive intestinal polypeptide (VIP) resembled that of other rodent species. Short-day exposure reduced AVP staining in lateral septum, medial amygdala, and bed nucleus of the stria terminalis but not in the PVN of the thalamus or the SCN. Short-day-exposed hamsters had fewer beta-endorphin-positive arcuate nucleus cells and tended to have fewer GnRH-positive preoptic cells than long-day controls. VIP staining was unaffected by photoperiod. Most day length effects on immunostaining were eliminated by either lesion. These results establish the importance of the SCN and PVN in the photoperiodic control of several seasonal responses in Siberian hamsters.
在下丘脑视交叉上核（SCN）和室旁核（PVN）损伤对成年西伯利亚仓鼠光周期反应的影响。SCN损伤会减少长日照下的夜间饮水量，而PVN损伤会使短日照和长日照下的体重和食物摄入量增加。SCN或PVN损伤会阻断短日照诱导的体重、脂肪垫、睾丸重量和食物摄入量的减少。血清催乳素（PRL）水平升高，而促卵泡激素水平未升高。促性腺激素释放激素（GnRH）、β-内啡肽、精氨酸加压素（AVP）和血管活性肠肽（VIP）免疫染色神经元和纤维的分布与其他啮齿动物相似。短日照暴露会减少外侧隔、内侧杏仁核和终纹床核中的AVP染色，但不会减少丘脑PVN或SCN中的染色。与长日照对照组相比，短日照暴露的仓鼠弓状核中β-内啡肽阳性细胞较少，视前区GnRH阳性细胞也往往较少。VIP染色不受光周期影响。大多数日长对免疫染色的影响通过任何一种损伤都可消除。这些结果证实了SCN和PVN在西伯利亚仓鼠几种季节性反应的光周期控制中的重要性。
