IMMEDIATE SHIFT OF AFFERENT DRIVE OF DORSAL COLUMN NUCLEUS CELLS FOLLOWING DEAFFERENTATION - COMPARISON OF ACUTE AND CHRONIC DEAFFERENTATION IN GRACILE NUCLEUS AND SPINAL-CORD
IMMEDIATE SHIFT OF AFFERENT DRIVE OF DORSAL COLUMN NUCLEUS CELLS FOLLOWING DEAFFERENTATION - COMPARISON OF ACUTE AND CHRONIC DEAFFERENTATION IN GRACILE NUCLEUS AND SPINAL-CORD
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DOI：
10.1016/0014-4886(76)90219-3
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发表时间：
1976-01-01
影响因子：
5.3
通讯作者：
WALL, PD
中科院分区：
文献类型：
--
作者：
DOSTROVSKY, JO;MILLAR, J;WALL, PD
用钨电极在麻醉的成年猫上测定了薄束核的躯体定位图。通过切断L3尾侧的所有背根来切断后腿的传入神经后，重新映射核。图中记录腹部反应的点的总数在传入神经阻滞后立即加倍。刷腹反应细胞的反应潜伏期在切断传入神经后无明显变化。一些开始对腹部刺激作出反应的细胞具有以下一个或多个特征：需要快速甩动头发来激发细胞;习惯化;以及广泛的抑制场。为了确认单个细胞已经转换了兴奋它们的传入，在对来自后腿的所有传入进行可逆冷阻断之前、期间和之后检查单个细胞的反应。在40个接受检查的单细胞中，有11个在腿上有感受野的细胞在腿传入阻滞完成后立即将其感受野切换到腹部。8个月时薄束核定位。在传入神经阻滞后，仍然显示出腹部代表性的增加。在L 6 -7节段的这些慢性deafferented猫的背角检查表明，腹部传入兴奋的细胞在一个地区通常响应腿传入。去传入可能会导致正常无效连接的暴露。解蔽可能是一种机制，解释了许多观察到的变化，中枢神经系统神经元的反应后病变。
The somatotopic map of the gracile nucleus was determined using tungsten electrodes in anesthetized adult cats. Following deafferentation of the hind leg by cutting all dorsal roots caudal to L3, the nucleus was remapped. The total number of points in the map where abdomen responses were recorded doubled immediately following deafferentation. The latency of responses of cells responding to brush of the abdomen was not different after deafferentation. Some of the cells which began responding to abdominal stimulation had one or more of the following characteristcs: a rapid flick of the hair was required to fire the cell; habituation; and widespread inhibitory fields. To confirm that individual cells had switched the afferents which excite them, the response of single cells was examined before, during, and after a reversible cold block of all the afferents from the hind leg. Of 40 single cells examined, 11 which had receptive fields on the leg switched their receptive fields to the abdomen as soon as the block of leg afferents was complete. Mapping the gracile nucleus 8 mo. following deafferentation still showed an increase in abdominal representation. Examination of the dorsal horn in the L6-7 segment of these chronically deafferented cats showed that abdominal afferents excited cells in a region normally responding to leg afferents. Deafferentation may result in the unmasking of normally ineffective connections. Unmasking could be a mechanism which explains many of the observed changes in the responses of CNS neurons following lesions.