Gatter K C, Sloper J J, Powell T P
Brain. 1978 Sep;101(3):513-41. doi: 10.1093/brain/101.3.513.
The intrinsic connections of area 4 of the monkey have been investigated with axonal degeneration methods after the placement of microelectrode lesions within the cortex. The fibre degeneration is restricted to within a few millimetres of the damage and is asymmetrically distributed in the form of an ellipse with its long axis anteroposteriorly. The same pattern is found in all topographic subdivisions of the motor cortex. There are two distinct zones of degeneration, dense fine terminal degeneration for 200 to 300 micrometer all around the lesion, and a moderate degree of fibre terminal degeneration for a further 2 to 3 mm. The intrinsic connections are disposed predominantly in a horizontal or oblique direction and within the laminae of origin, but there are fibres passing between adjoining laminae and between layers III and V and VI. Two horizontal plexuses of degenerating fibres are present, at the boundary layers II and III and at the level of the Betz cells, and these fibres arise within the cortex. The afferent and efferent fibres of the cortex are arranged strictly perpendicular to the surface. The extent and pattern of the intrinsic connections of area 4 are very similar to those of area 17 of the visual cortex.
在猴脑皮层内放置微电极损伤后，运用轴突退变方法对4区的内在联系进行了研究。纤维退变局限于损伤部位周围几毫米范围内，呈椭圆形不对称分布，其长轴为前后方向。在运动皮层的所有地形分区中均发现了相同的模式。有两个明显的退变区域，损伤周围200至300微米范围内为密集的细终末退变，再向外2至3毫米为中等程度的纤维终末退变。内在联系主要沿水平或斜向分布于起始层内，但也有纤维在相邻层之间以及III层与V层和VI层之间穿行。存在两个水平的退变纤维丛，分别位于II层和III层的边界以及贝茨细胞水平，这些纤维起源于皮层内。皮层的传入和传出纤维严格垂直于表面排列。4区内在联系的范围和模式与视觉皮层17区非常相似。
