猫大脑皮质向后索核投射的实验形态学研究

AN EXPERIMENTAL STUDY OF THE CORTICAL FIBER PROJECTIONS TO THE DORSAL FUNICULAR NUCLEI IN THE CAT

用HRP逆行传递法和自行改进的Nauta法,研究了27只猫的大脑皮质向后索核的投射。投向后索核的纤维主要起源于对侧后乙状回第V层的锥体细胞。后乙状回向后索核的投射有明显的局部定位关系:起自后乙状回后肢区的纤维投向薄束核,前肢区的纤维投向楔束核。两核的中间腹侧部是皮质纤维的投射中心。至后索核的纤维在锥体束中下降。大部分经锥体交叉到对侧,少量纤维到同侧后索核。对大脑皮质与后索核联系的机能意义进行了讨论。

The cortical projections to the dorsal funucular nuclei were studied in 27 cats with the retrograde axonal transport of HRP and the modified Nauta method.The majority of cortical efferents which terminated to the dorsal funicular nuclei derived controlaterally from the pyramidal cells in layer V posterior sigmoid gyrus.A few fibers originated from the cortex ipsilaterally.The fiber projections from the cortex to the dorsal funicu-lar nuclei are somatotopically organized.The fibers from the forelimb area of the pos-terior sigmoid gyrus terminate in the cuneate nucleus and those from the hindlimb area in the gracile nucleus.The ventral parts of the median area in dorsal funicular nuclei are the central regions that receive cortical fibers.The fibers originated from the cortex to the dorsal funicular nuclei descend within the pyramidal tract,most of them reach to the controlateral nuclei by way of pyramidal decussation,and a few fibers to the ipsilateral ones.