SPINOHYPOTHALAMIC AND SPINOTELENCEPHALIC TRACTS

尽管下丘脑神经元可以被强大的 伤害性和其他形式的躯体感觉刺激， 脊椎对该区域的输入通常被认为是 多突触。然而，我们最近发现，一个很大的 脊髓神经元的数量直接投射到 大鼠下丘脑和端脑。注射任何一种 三种不同的逆行示踪剂被限制在 下丘脑标记脊髓内的许多神经元。已标记 神经元主要发现在边缘区，即 外侧网状区(V层)，周围的灰质 中央管和外侧脊髓核。基于 这种注射的结果我们已经确定有更多 超过5000个贯穿整个脊髓长度的神经元 投射到下丘脑。顺行示踪剂注射 Pal进入脊髓标记纤维和静脉曲张 下丘脑核团的数量，也在几个 端脑区，包括基底前脑、隔核 和伏隔核。注射逆行示踪剂 仅限于这些端脑区域中的每一个也被标记 脊髓神经元。我们对10个神经元进行了生理学检查 它们是以低强度电流逆序激活的 来自下丘脑。所有10人都对无伤大雅的 机械刺激，但对有害物质的反应更强烈 机械和热刺激。在建议的研究中，我们 将继续我们对脊髓神经元的生理学研究 从下丘脑逆行激活的，2) 生理检查脊髓神经元投射到 端脑核团，3)决定轴突在 当脊髓上升到下丘脑时， 端脑，4)使用逆行标记技术来确定 猫身上是否存在类似的投射，并确定是否类似 投射存在于使用逆行示踪剂的猴子身上。如果是这样的话 在猴子身上发现了投射，我们将确定 它们的终末在下丘脑和 端脑及其在脊髓内的走行。此外, 将确定其细胞或组织的响应属性 对各种无害和有害的皮肤刺激。这些 研究将提供有关脊髓神经元的重要数据 直接投射到涉及自主的区域， 神经内分泌和情感反应对伤害性和其他 体感刺激的形式。

Although hypothalamic neurons can be driven powerfully by nociceptive and other forms of somatosensory stimulation, the spinal input to this region has been generally believed to be multisynaptic. However, we have recently found that a large number of spinal cord neurons project directly to the hypothalamus and telencephalon in rats. Injections of any of three different retrograade tracers that were restricted to the hpothalamus labeled many neurons in the spinal cord. Labeled neurons were found primarily within the marginal zone, the lateral reticulated area (lamina V), the gray matter surrounding the central canal and the lateral spinal nucleus. Based on the results of such injections we have determined that there are more than 5000 neurons throughout the length of the spinal cord that project to the hypothalamus. Injections of the anterograde tracer PHAL into the spinal cord labeled fibers and varicosities in a number of hypothalamic nuclei and also within several telencephalic areas including the basal forebrain, septal nuclei and nucleus accumbens. Injections of retrograde tracers that were restricted to each of these telencephalic areas also labeled spinal cord neurons. We have physiologically examined 10 neurons thatat were antidromically activated wih low intesity current from the hypothalamus. All 10 responded to innocuous mechanical stimuli but responded more vigorously to noxious mechanical and thermal stimulation. In the proposed studies we will 1) continue our physiological studies of spinal cord nuerons that are antidromically activated from the hypothalamus, 2) physiologically examine spinal cord neurons that project to telencephalic nuclei, 3) determine the course of the axons within the spinal cord as they ascend to the hypothalamus and telencephalon, 4) use retrograde labeling techniques to determine if similar projections exist in cats and 5) determine if similar projections exist in monkeys using retrograde tracers. If such projections are found in monkeys, we will determine the distribution of their terminations within the hypothalamus and telencephalon and their course within the spinal cord. In addition, the response properties of their cells or orgin will be determined to a variety of innocuous and noxious cutaneous stimuli. These studies will provide important data on the spinal cord neurons that project directly to areas that are involved in autonomic, neuroendocrine and affective responses to nociceptive and other forms of somatosensory stimulation.