PELVIC INFORMATION AND SPINOHYPOTHALAMIC TRACT NEURONS

刺激盆腔脏器可明显改变 下丘脑神经元的活动 这些变化可能是 重要的是参与控制几个自主和 神经内分泌功能，包括分娩的调节， 分娩 目前尚不清楚来自盆腔内脏的信息 结构到达下丘脑。 然而，使用几种解剖学 和生理技术，我们发现，大量（多达 9000）脊髓神经元直接投射到下丘脑。 几 数百个投射到下丘脑的神经元位于 腰骶部灰质方式处理内脏信息 发生。 拟议研究的工作假设是，至少 一些盆腔内脏信息直接传递到 下丘脑通过脊髓下丘脑束（SHT）。 这一假设将 使用多种技术进行测试。逆行和顺行束 追踪研究被提议来确定下丘脑哪些区域 接收来自脊髓区域的直接投射（即， 腰骶段），参与处理大部分的 源自盆腔内脏器官的信息。 双标记 提出实验以确定脊髓的轴突是否 神经元直接投射到催产素免疫反应神经元。 室旁核（PVN）和视上核（SON）。 我们将 还确定催产素能神经元是否从SHT接收输入 远端树突上的轴突静脉曲张。 在这些实验中， PVN和SON中的神经元将充满荧光黄In厚， 固定部分。 SHT神经元的轴突曲张和催产素- 将对含有神经元的细胞进行免疫细胞化学鉴定。 Appositions 将对SHT静脉曲张和填充神经元之间的差异进行计数， 重建。 在另外的解剖实验中，我们将确定 SHT神经元的纤维是否与催产素免疫反应阳性 PVN和SON中的神经内分泌神经元。 电生理研究 被提出来确定神经元的响应特性， 从腰骶脊髓投射到下丘脑。 在这些 研究中，我们将使用定量刺激盆腔内脏器官， （包括结肠/直肠、膀胱和女性生殖器官）和 腰骶部皮肤感受野

Stimulation of pelvic visceral organs can markedly alter the activity of neurons In the hypothalamus. These changes in firing may be importantly involved In the control of several autonomic and neuroendocrine functions including the regulation of labor and parturition. It is unclear how information from pelvic visceral structures reaches the hypothalamus. However, using several anatomical and physiological techniques, we found that a large number (as many as 9000) spinal cord neurons project directly to the hypothalamus. Several hundred neurons that project to the hypothalamus are In areas of the lumbosacral gray manner in which processing of visceral information occurs. The working hypothesis of the proposed studies is that at least some pelvic visceral information is transmitted directly to the hypothalamus via the spinohypothalamic tract (SHT). This hypothesis will be tested using several techniques. Retrograde and anterograde tract tracing studies are proposed to determine which hypothalamic regions receive a direct projection from regions of the spinal cord (i.e. lumbosacral segments) that are involved in processing much of the information that originates In pelvic visceral organs. Double labeling experiments are proposed to determine whether the axons of spinal cord neurons project directly to (appose) oxytocin-immunoreactive neurons In the paraventricular nucleus (PVN) and supraoptic nucleus (SON). We will also determine whether oxytocinergic neurons receive an Input from SHT axonal varicosities on their distal dendrites. In these experiments, neurons In the PVN and SON will be filled with Lucifer Yellow In thick, fixed sections. The axonal varicosities of SHT neurons and oxytocin- containing neurons will be immunocytochemically Identified. Appositions between SHT varicosities and filled neurons will be counted and reconstructed. In additional anatomical experiments, we will determine whether fibers of SHT neurons appose oxytocin-immunoreactive neuroendocrine neurons In the PVN and SON. Electrophysiological studies are proposed to determine the response characteristics of neurons that project to the hypothalamus from the lumbosacral spinal cord. In these studies, we will use quantified stimulation of pelvic visceral organs (including the colon/rectum, bladder and female reproductive organs) and lumbosacral cutaneous receptive fields.