Figure 4.

Retrogradely labeled neurons in V1 after injections of rabies virus in cortical area V3. A, A montage of digitally photographed images of a single parasagittally cut cortical section stained for myelin showing the location of the rabies-injected region (red arrow) in the uniformly dense myelination of area V3 (green arrows) along the annectent gyrus (AnG), buried in the lunate sulcus (LuS) ∼12 mm anterior to the V1/V2 border (blue line). B, A montage of digitally photographed images of an adjacent parasagittal cortical section to that in A stained for the nucleocapsid protein of the rabies virus (black) and for CO (brown). D, Dorsal; V, ventral; P, posterior; A, anterior. Scale bars: A, B, 2 mm. C, Parasagittally cut cortical section of V1 from case JNM4 stained for the nucleocapsid protein of the rabies virus (black) and for CO (brown). The bottom of the image is cropped at the layer 6/white matter border. Cortical layers are indicated. D, Higher magnification image of the location indicated by the blue rectangle in C showing the presence of rabies-labeled cells in layers 4B and 4Cα of V1, but not 4Cβ. Scale bars: C, D, 100 μm. E, Computer-assisted reconstruction of rabies-labeled cells (blue dots) in a single parasagittally cut cortical section through a dense region of label in the calcarine sulcus (CalS) of V1. Scale bar, 1 mm. F, The percentages of rabies-labeled cells in each layer of V1 for JNM3 (black squares) and JNM4 (red squares). The averaged values across both cases (gray bars) were derived from a total of 8515 labeled cells.