Functional mapping of neural sites mediating prolactin-induced hyperphagia in doves.
Functional mapping of neural sites mediating prolactin-induced hyperphagia in doves.
复制标题
介导催乳素诱导的鸽子食欲亢进的神经部位的功能图谱。
DOI：
10.1016/0006-8993(93)91436-v
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Buntin,JD
中科院分区：
文献类型：
--
作者：
Hnasko,RM;Buntin,JD
先前已经证明，将催乳素（PRL）微量注射到下丘脑腹内侧核（VMN）或视前区（POA）可以增加环鸽的摄食量和体重。在试图证实这些结果，并提供一个更完整的地图，PRL敏感的大脑网站介导的催乳素食欲的行动，显微注射程序中采用了本研究中提供的PRL或生理盐水的车辆在极小的体积（10 nl/注射），以各种间脑网站在鸽子的大脑，以前已被证明含有高浓度的PRL受体。从1例雌性受试者VMN单次注射10 nl [125 I]绵羊PRL获得的估计值支持了这样的注射体积导致扩散受限的声明，因为在注射后30 min，在注射部位周围280 mm区域内发现了80%的组织放射性。在6天基线期、初始4天给药期、6-12天给药后恢复期和第二个4天给药期内，每天监测映射研究中插管雄性鸽子的摄食量。在第一和第二处理期期间，约一半的鸡分别接受PRL注射（50 ng/10 nl，每日两次）和盐水溶媒注射（10 nl，每日两次），而其余鸡以相反顺序接受这些处理。在注射部位位于外侧POA、下丘脑室旁核（PVN）或结节下丘脑（TU）和VMN之间的内侧-基底下丘脑区域的禽类中，未观察到基线、溶媒、给药后或PRL给药期间摄食量的显著变化。与此相反，注射PRL到VMN区，内侧POA，或TU导致的平均每日食物摄入量值，显着超过在其他时期记录。在VMN组中观察到最强烈的进食反应，其中PRL注射导致食物摄入量比注射溶剂期间记录的增加58%。这种增加显著大于将PRL注射到mPOA（26%）或TU（32%）后观察到的增加。这些研究结果表明，VMN可能是一个主要的网站，催乳素的行动，在促进hyperphagia在这个物种，虽然催乳素的影响，在其他间脑位点，如mPOA和TU，也可能有助于食欲的行动，这种激素。
Microinjections of prolactin (PRL) into the ventromedial nucleus of the hypothalamus (VMN) or the preoptic area (POA) have been previously shown to increase food intake and body weight in ring doves. In an attempt to corroborate these results and to provide a more complete map of PRL-sensitive brain sites mediating the orexigenic action of PRL, a microinjection procedure was employed in the present study that delivered PRL or saline vehicle in extremely small volumes (10 nl/injection) to a variety of diencephalic sites in dove brain that had been previously demonstrated to contain high concentrations of PRL receptors. Estimates obtained from one female subject given a single 10 nl injection of [125I]ovine PRL into the VMN supported the claim that such injection volumes resulted in limited diffusion, as 80% of the tissue radioactivity was found within a 280 mm area surrounding the injection site at 30 min after injection. Food intake of cannulated male doves in the mapping study was monitored daily during a 6 day baseline period, an initial 4 day treatment period, a 6–12 day post-treatment recovery period, and a second 4 day treatment period. Approximately half of the birds received PRL injections (50 ng/10 nl twice daily) and saline vehicle injections (10 nl twice daily) during the first and second treatment periods, respectively, while remaining birds received these treatments in the reverse order. No significant changes in food intake across baseline, vehicle, post-treatment, or PRL treatment periods were observed in birds with injection sites in the lateral POA, paraventricular nucleus of the hypothalamus (PVN), or the medial-basal hypothalamic region between the tuberal hypothalamus (TU) and VMN. In contrast, injections of PRL into the VMN area, medial POA, or TU resulted in average daily food intake values that significantly exceeded those recorded during other periods. The most robust feeding response was seen in the VMN group, where PRL injections resulted in a 58% increase in food intake over that recorded during injection of vehicle. This increase was significantly greater than that observed following PRL injections into the mPOA (26%) or the TU (32%). These findings suggest that the VMN may be a primary site of PRL action in promoting hyperphagia in this species, although PRL effects at other diencephalic loci, such as the mPOA and TU, may also contribute to the orexigenic action of this hormone.