Figure 4.

Relationship of atypical labeling in the parietal cortex with anatomical and physiological boundaries. Example of alignment of myelin-stained section with a somatosensory map. A, Myelin-stained section in experimental case 21B. The hand/face septum is indicated by a thick black line. The boundary between area 3b and area 1/2 is demarcated by a sharp transition from dense to light myelin staining (thin black line). Caudal border of the ischemic lesion in M1 is indicated by a white triangle. As in Figure 1, asterisks represent fiducial markers indicating the locations of selected large blood vessels observable in the same location throughout the depths of the cortical gray matter. CS, Central sulcus. Scale bar, 1 mm. B, Photograph of cortical surface vasculature in the same case (21B). Somatosensory mapping data are superimposed on the vascular pattern. In the collection of physiological data, microelectrode penetration sites (red, white, and yellow dots) are located with reference to the surface vasculature. Asterisks indicate the location of surface blood vessels at which they penetrate radially into the cortex. Locations correspond to those of large blood vessels identified in the myelin-stained sections. C, Alignment of blood vessel pattern in both anatomical and physiological datasets allowed confirmation of the border between areas 3b and 1/2. These data were then superimposed on the reconstructions of BDA labeling using the same approach. Gray rectangle indicates the location of higher-power photomicrographs shown in D. D, Left, Photomicrograph from area 1/2 in same experimental case (21B). Numerous BDA-labeled terminal arbors and fibers can be observed. Asterisk corresponds to largest asterisk in A. Gray box shows location of higher-magnification photomicrograph on the right. Scale bar, 100 μm. Right, Small fiber with varicosities (arrowheads). Scale bar, 1 μm. E, Photomicrograph of area 1/2 in a control case with a large injection (1934). Area 1/2 is virtually devoid of BDA labeling. Scale bar, 100 μm. F, Photomicrograph of the area 1/2 of an experimental case with a large injection (9406). Here, in addition to the numerous terminal arbors and fibers, a labeled somata can be seen. Scale bar, 10 μm.