DIFFERENTIAL EXPRESSION OF NEUROFILAMENT PROTEIN IN THE VISUAL-SYSTEMOF THE VERVET MONKEY

It has been previously reported that the monoclonal antibody SMI-32 re veals a characteristic pattern of immunostaining which may be used to delineate various cortical modules in the monkey visual system. We wis hed to examine staining patterns with this antibody at both the latera l geniculate nucleus (LGN) and cortical levels with regard to magno- a nd parvocellular processing schemes in the vervet monkey. Using standa rd immunohistochemical procedures, we have found that the M-layers of the LGN were intensely stained in comparison to P-layers and that ther e were regional variations in staining within the visual cortex that r eflected this input. The transition between areas V1 and V2 was especi ally prominent due to differences in the laminar staining profiles. An other striking result was found within the superior temporal sulcus wh ere heavy SMI-32 immunostaining confined to the floor of the sulcus co incided with a similar zone of intense myelin staining. We have also f ound a number of other areas within the intraparietal and lateral sulc i that show foci of heavy SMI-32 staining. As with Cat-301 immunostain ing, the regional variabilities that are observed with SMI-32 in the v isual cortex reflect molecular distinctions that may provide further c riteria for functional segmentation.