DIFFERENT CELL POPULATIONS IN AREA V4 PROJECT TO POSTERIOR AND ANTERIOR INFEROTEMPORAL CORTEX IN THE MACAQUE: A DOUBLE LABEL TRACER STUDY.
Abstract for Japanese Neuroscience Meeting, 1991
The inferotemporal cortex of the macaque is divided into areas TEO and TE. Both TEO and the posterior part of TE(TEp) receive afferent inputs from area V4. In this study we made simultaneous injections of 2 different retrograde fluorescent tracers (fast blue and diamidino yellow) into TEO and TEp in 4 monkeys (Macaca fuscata) and compared the distribution of TEO- and TEp- projecting cells in V4. TEO injections led to an extensive and continuous labeling in the part of V4 that corresponds to central representation in the ventral part of the prelunate gyrus and to a sparse labeling in the part of V4 representing peripheral visual fields in the dorsal prelunate gyrus. Labeling in V4 also extended ventrally across both banks of the inferior occipital sulcus. TEp injections labeled cells in a similar part of central V4, as TEO injections did. TEp injections, however, resulted in a patchy distribution, in contrast to the continuous labeling after TEO injections. Cells labeled with different dyes were intermingled with each other in the patches, and only a small number of cells (0.5%) were double labeled. We conclude that different cell populations in V4 project to TEO and TEp, although two populations are intermingled in the same area.