CONVERGENCE AND DIVERGENCE OF SOMATOSENSORY PATHWAYS

这项补助金资助的研究的长期目标是提供 功能相关的，解剖学描述的模式， 涉及中枢神经系统通路的发散和会聚 在躯体感觉上。 由于相互关系的复杂性 在这些途径中的元素之间，这些描述是必要的 在了解各个方面的神经机制之前， 身体感觉，如触摸，疼痛和动觉。 下一个赠款期的拟议工作重点是两个 区域-腹柱核（DCN）和齿状回（ZI）。 的 迄今为止对DCN的研究结果初步表明， 至少有两个独立的系统。 一是此前 众所周知的背柱-DCN-腹基底复合体（VB）-躯体感觉 皮质中继通路及其相关的"丘系"特征。 的 另一种以前未被识别的系统由一组单独的DCN组成 神经元（未知特性）以及这些神经元之间的相互连接 除了VB，还有其他靶点。 下一个资助期的研究 将继续进行实验，其中多种标记策略， 用于获得尽可能完整的空间描述， DCN多发性的形态及侧支特点 传出系统 如果时间允许，额外的电生理检查 将开始调查的躯体反应特性的一些 DCN中的差异投射神经元。 DCN的一个主要 除VB外的间脑靶点是不确定性。 此外， 接受来自网状结构和小脑的密集输入。 虽然 这些和其它结果表明ZI是间脑区， 与VB和板内复合体一样， 在这方面，ZI相对被忽视了。 因此，委员会认为， 下一个资助期提出的其他研究将使用多重标签 策略和电生理技术来检查连接 ZI的解剖及其躯体反应特性 神经元 这些研究的目的是提供解剖学和生理学上的 这些数据不仅会增加我们对DCN和ZI的理解， 特定的躯体感觉功能，以及它们的功能如何与 那些躯体通路的其他部分。

The long-range goal of the studies funded by this grant is to provide functionally-relevant, anatomical descriptions of the patterns of divergence and convergence of the central nervous system pathways involved in somatic sensation. Because of the complexity of the interrelationships between the elements in these pathways, these descriptions are necessary before an understanding of the neural mechanisms underlying various aspects of somatic sensation, such as touch, pain and kinesthesia can be achieved. The work proposed for the next grant period is focused upon two regions---the odrsal column nuclei (DCN) and the zona incerta (ZI). The results obtained so far on DCN tentatively indicate that the DCN are involved in at least two independent systems. One is the previously well-known dorsal column-DCN-ventrobasal complex (VB)-somatic sensory cortex relay pathway with its associated "lemniscal" characteristics. The other, previously unrecognized system consists of a separate set of DCN neurons (of unknown characteristics) and the interconnections of these neurons with other targets besides VB. Studies in the next grant period will continue ongong experiments in which multiple labeling strategies are being used to obtain as complete a description as possible of the spatial, morphological and collateralization characteristics of DCN's multiple efferent systems. If time permits, additional electrophysiological studies will be initiated to investigate the somatic response properties of some of the differentially-projecting neurons in DCN. One of DCN's major diencephalic targets besides VB is the zona incerta. The ZI in addition receives dense input from the reticular formation and cerebellum. Although these and other results indicate that ZI is a diencephalic region that, like VB and the intralaminar complex, has some function in somatic sensation, ZI has been relatively ignored in this regard. Accordingly, other studies proposed for the next grant period will use multiple labeling strategies and electrophysiological techniques to examine the connective anatomy of ZI together with the somatic response properties of its neurons. The aim of the studies is to provide anatomical and physiological data that will increase our understanding not only of DCN's and ZI's specific somatic sensory functions, but also how their functions relate to those of other parts of the somatic pathways.