Lordosis inhibiting systems in the septum and dorsal raphe nucle-us

隔膜和中缝背核的脊柱前凸抑制系统

基本信息

批准号：
09680802
负责人：
YAMANOUCHI Korehito
金额：
$ 0.7万
依托单位：
Waseda University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680802/
关键词：
Lordosis Inhibition Septum Dorsal Raphe Nucleus Sexual Differentiation Estrogen Serotonergic Neuron Neural Transection Rats ロードーシス抑制力

项目摘要

The lateral septum (LS) exerts an inhibitory influence in regulation of female characteristic sexual behavior, such as lordosis and soliciting behavior in both female and male rats. The inhibitory mechanism also exist in the serotonergic neurons in the dorsal raphe nucleus (DRN). In male rats, these female sexual behavioral patterns are very rare, even when treated with large doses of estrogen. The low incidence of female sexual behavior in males is thought to be cased by strong inhibitory influences in the LS and DRN.In this experiment, these inhibitory mechanisms have been analyzed by neuroendocrinological methods and following results were obtained. 1 : Since the ventral cut of the anterior part of the DRN enhanced lordotic behavior in both male and female rats, anteroventral projections of this nucleus are involved in lordosis inhibitory mechanisms. 2 : Female levels of lordotic activity was induced by transection of the medial forebrain bundle in male rats. This suggests an importance of the bundle as a pathway for lordosis inhibiting influence. 3 : To clarify the role of estrogen in the inhibitory systems of the LS and DRN, estradiol was implanted directly in these areas and lordosis was observed in subthreshold doses of estradiol benzoate-injected castrated female and male rats. As a result, estrogen implanted in the LS butnot in the DRN facilitated lordosis in female rats. This result indicates that the inhibition for lordosis in the LS is released directly by estrogen but not in the DRN.Furthermore, implantation of estrogen into the LS in males had no effect on lordosis. Thus, the reason of low incidence of female sexual behavior in male rats is the development of strong inhibition in the LS which can not be released directly by estrogen.

外侧隔膜（LS）在调节雌性特征性行为中发挥抑制作用，例如雌性和雄性大鼠的脊柱前凸和引诱行为。抑制机制也存在于中缝背核（DRN）的血清素能神经元中。在雄性大鼠中，这些雌性性行为模式非常罕见，即使用大剂量雌激素治疗也是如此。男性性行为中女性性行为发生率低的原因被认为是由于LS和DRN的强烈抑制影响所致。在本实验中，通过神经内分泌学方法对这些抑制机制进行了分析，并获得了以下结果。图1：由于DRN前部的腹侧切口增强了雄性和雌性大鼠的前凸行为，因此该核的前腹侧投射参与前凸抑制机制。图2：通过横断雄性大鼠的内侧前脑束来诱导雌性前凸活动水平。这表明束作为抑制脊柱前凸的影响途径的重要性。图3：为了阐明雌激素在LS和DRN抑制系统中的作用，将雌二醇直接植入这些区域，并在注射雌二醇苯甲酸酯的去势雌性和雄性大鼠的阈下剂量中观察到脊柱前凸。结果，在 LS 中植入雌激素，但在 DRN 中则没有，促进了雌性大鼠的脊柱前凸。这一结果表明，对LS中脊柱前凸的抑制作用是由雌激素直接释放的，但在DRN中则不然。此外，将雌激素植入男性的LS中对脊柱前凸没有影响。因此，雄性大鼠雌性性行为发生率低的原因是LS中产生了强烈的抑制作用，而雌激素不能直接释放该抑制作用。