SPINOHYPOTHALAMIC AND SPINOTELENCEPHALIC TRACTS

尽管下丘脑神经元可以被 伤害性和其他形式的躯体感觉刺激， 一般认为，对该区域的脊髓输入是 多突触的 然而，我们最近发现， 许多脊髓神经元直接投射到 大鼠下丘脑和端脑。 注射任何 三种不同的逆行追踪器， 下丘脑标记了脊髓中的许多神经元。 标记 神经元主要位于边缘区， 外侧网状区（V层），灰质周围 中央管和外侧脊核。 基于 这种注射的结果，我们已经确定，有更多的 超过5000个神经元遍布整个脊髓， 投射到下丘脑。 顺行示踪剂注射 PHAL进入脊髓标记的纤维和静脉曲张， 下丘脑核团的数量，也在几个 端脑区包括基底前脑、隔核 和神经核。 逆行示踪剂的注射 仅限于这些端脑区域， 脊髓神经元 我们对10个神经元进行了生理学检查 用低强度电流逆向激活 从下丘脑。 所有10人都对无害的 机械刺激，但反应更积极， 机械和热刺激。 在拟议的研究中， 将继续我们对脊髓神经元的生理学研究 从下丘脑逆向激活，2） 从生理学上检查脊髓神经元， 端脑核，3）决定轴突内的路线 当它们上升到下丘脑时， 端脑，4）使用逆行标记技术，以确定 如果在猫中存在类似的投射，以及5）确定是否类似 在猴子中存在使用逆行示踪剂的投射。 如果这样 在猴子身上发现了投射，我们将确定 它们的末端在下丘脑内的分布， 端脑及其在脊髓内的行程。 此外，本发明还提供了一种方法， 将确定它们的细胞或来源的响应特性 各种无害和有害的皮肤刺激。 这些 研究将提供关于脊髓神经元的重要数据， 直接投射到涉及自主的领域， 神经内分泌和情感反应的伤害性和其他 躯体感觉刺激的形式。

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.