INFLUENCE OF MAP SCALE ON PRIMARY AFFERENT TERMINAL FIELD GEOMETRY IN CAT DORSAL HORN
INFLUENCE OF MAP SCALE ON PRIMARY AFFERENT TERMINAL FIELD GEOMETRY IN CAT DORSAL HORN
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DOI：
10.1152/jn.1991.66.3.696
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发表时间：
1991-09-01
影响因子：
2.5
通讯作者：
BROWN, PB
中科院分区：
文献类型：
--
作者：
MILLECCHIA, RJ;PUBOLS, LM;BROWN, PB
1.用辣根过氧化物酶（HRP）对31条生理学鉴定的初级传入纤维进行细胞内标记.计算机分析用于确定皮肤机械感受性传入末梢的分布是否随背角躯体定位图内位置的变化而变化。对这些传入神经投射的几何形状的分析表明：1）末端乔木在足表征区域内的中间外侧宽度大于其外侧宽度; 2）末端乔木在足表征区域外的长宽比大于足表征区域内的长宽比; 3）末端乔木在足表征区域边界附近的取向反映了边界的角度。先前将内侧外侧宽度变化归因于初级传入类型可能是错误的，尽管存在作为初级传入类型的函数的纵向范围的真正变化。不均匀的终端分布代表了第一个三个组件的过程下组装的单突触部分的细胞感受野（RF）和somatotopic地图。其他两个组成部分包括细胞树突树的阐述和选择性连接的建立。初级传入终末分布随地图位置的变化并不是地图开发的绝对要求;例如，突触后细胞的RF可以通过使用所有传入的均匀终末分布来组装，在地图中的任何地方，只要细胞树突穿透突触前神经元的适当部分并仅从贡献其RF的传入轴突接收连接。初级传入神经终末分布与局部地图比例尺的相关性表明它们之间存在因果关系。
1. Thirty-one physiologically identified primary afferent fibers were labeled intracellularly with horseradish peroxidase (HRP).2. A computer analysis was used to determine whether the distribution of cutaneous mechanoreceptive afferent terminals varies as a function of location within the dorsal horn somatotopic map.3. An analysis of the geometry of the projections of these afferents has shown that 1) terminal arbors have a greater mediolateral width within the region of the foot representation than lateral to it, 2) terminal arbors have larger length-to-width ratios outside the foot representation than within it, and 3) the orientation of terminal arbors near the boundary of the foot representation reflects the angle of the boundary. Previous attribution of mediolateral width variations to primary afferent type are probably in error, although there appear to be genuine variations of longitudinal extent as a function of primary afferent type.4. Nonuniform terminal distributions represent the first of a three-component process underlying assembly of the monosynaptic portions of cell receptive fields (RFs) and the somatotopic map. The other two components consist of the elaboration of cell dendritic trees and the establishment of selective connections.5. The variation of primary afferent terminal distributions with map location is not an absolute requirement for development of the map; for example, the RFs of postsynaptic cells could be assembled with the use of a uniform terminal distribution for all afferents, everywhere in the map, as long as cell dendrites penetrate the appropriate portions of the presynaptic neuropil and receive connections only from afferent axons contributing to their RFs.6. The correlation of primary afferent bouton distribution and local map scale suggests a causal relation between them.