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Plasticity of neuro-endocrine cells induced by sex hormone.

性激素诱导的神经内分泌细胞的可塑性。

基本信息

批准号：
06670081
负责人：
NAKASHIMA Toshihiro
金额：
$ 1.54万
依托单位：
Kyoto Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06670081/
关键词：
Plasticity Neurosecretory Cell Estrogen Oxytocin Na^+ channel

项目摘要

It has been known that oxytocin (OXT) neurons in the hypothalamus were by OXT in male animals. Recently, we have demonstrated that inhibitory responses of OXT neurons to OXT in virgin and pregnant rats reverse to excitatory responses in delivering and lactating animals and return to inhibitory responses after delivery. It may be a new type of neural plasticity. The present work was carried out to investigate the key factor for reverse the response in OXT neurons to OXT and the difference of membrane mechanisms of responses to OXT between male and female rats.1.Supraoptic OXT neurons of ovariectomized virgin female rat were excited by OXT application. It means the inhibitory responses in virgin female rats may be derived from ovarian hormones.2.In Ovariectimized virgin female rat treated with estrogen, activity of OXT neurons was inhibited by OXT.It indicates estrogen, one of ovarian hormone, is a candidate of reversal factor.3.In virgin female rats pretreated with tamoxifen, anti-estrogen, OXT induced excitatory responses in OXT neurons. It is confirmed that estrogen is the key factor for reverse the response in the hypothalamic OXT neurons to OXT.4.Both excitatory responses in male and ovariectomized virgin female rats and inhibitory responses in normal and estrogen treated virgin female rats to OXT were effectively blocked by same OXT receptor antagonist. It is possible that both excitatory and inhibitory responses to OXT are mediated same type of OXT receptor.5.Excitatory response of OXT neurons in male rats results in opening of Na^+ channel but the channel did not participate in inhibitory response in virgin femaleThese results suggest that estrogen reversal of OXT response in OXT neurons is not due to modification at OXT receptor but due to redistribution of the functioning ionic channels.

雄性动物下丘脑中的催产素（oxytocin，OXT）神经元是由OXT引起的。最近，我们已经证明，在处女和妊娠大鼠的OXT神经元对OXT的抑制性反应逆转为兴奋性反应，在分娩和哺乳动物和返回到分娩后的抑制性反应。这可能是一种新型的神经可塑性。本研究旨在探讨OXT神经元对OXT反应性逆转的关键因素，以及OXT反应性膜机制在雌雄大鼠之间的差异。1. OXT对去势雌性大鼠视上神经元的兴奋作用。2.雌激素对去卵巢雌性大鼠OXT神经元的活性有抑制作用，提示雌激素是一种潜在的逆转因子; 3.雌激素拮抗剂三苯氧胺对去卵巢雌性大鼠OXT神经元有兴奋作用。雌激素是逆转下丘脑OXT神经元对OXT反应的关键因素。4.同一OXT受体拮抗剂能有效地阻断雄性和去势雌性大鼠对OXT的兴奋性反应以及正常和雌激素处理雌性大鼠对OXT的抑制性反应。5.雄性大鼠OXT神经元兴奋性反应导致Na^+通道开放，而雌性大鼠则不参与抑制性反应。这些结果表明，雌激素逆转OXT神经元的OXT反应不是由于OXT受体的修饰，而是由于功能离子通道的重新分布。