Hubscher Charles H
Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA.
Exp Neurol. 2006 Jul;200(1):227-39. doi: 10.1016/j.expneurol.2006.02.008. Epub 2006 Apr 19.
The lordosis posture and cervix stimulation during copulation are important reproductive events involving complex neural circuitries that are under hormonal influence. An important component of this circuitry, neurons within the medullary reticular formation (MRF), was examined in the present study using electrophysiological techniques. Single unit extracellular recordings were performed in the MRF of 27 urethane-anesthetized female rats. Using bilateral electrical stimulation of the dorsal nerve of the clitoris as the search stimulus, a detailed examination of the somatovisceral convergent responses of 585 individual MRF neurons was made. A total of 7 different groups of cycling and ovariectomized/hormone-supplemented rats were examined and their neuronal response properties to mechanical stimulation of various pelvic organs (cervix pressure, vaginal distension, colon distension) compared. The results indicate the existence of complex response properties as well as several variations in MRF response characteristics that are hormone-dependent. Specifically, estradiol is associated with hyposensitivity to cervix pressure and hypersensitivity to stroking the face. These opposing effects of estradiol in the same subset of neurons likely relate to lordosis behavior which can be either disrupted or elicited, depending on the area being stimulated (upper versus lower parts of the body, respectively).
交配过程中的脊柱前凸姿势和子宫颈刺激是重要的生殖事件，涉及受激素影响的复杂神经回路。本研究使用电生理技术检查了该回路的一个重要组成部分，即延髓网状结构（MRF）内的神经元。对27只经乌拉坦麻醉的雌性大鼠的MRF进行了单单位细胞外记录。以双侧电刺激阴蒂背神经作为搜索刺激，对585个单个MRF神经元的体-内脏会聚反应进行了详细检查。总共检查了7组不同的处于发情周期的大鼠以及卵巢切除/激素补充的大鼠，并比较了它们对各种盆腔器官机械刺激（子宫颈压力、阴道扩张、结肠扩张）的神经元反应特性。结果表明存在复杂的反应特性以及MRF反应特征的几种激素依赖性变化。具体而言，雌二醇与对子宫颈压力的低敏感性和对抚摸面部的高敏感性有关。雌二醇在同一神经元亚群中的这些相反作用可能与脊柱前凸行为有关，根据刺激的部位（分别为身体上部与下部），脊柱前凸行为可能会被破坏或引发。
