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The representation of the visual field in areas V3 and V4 of the macaque was mapped with multiunit electrodes. Twelve Macaca fascicularis were studied in repeated recording sessions while immobilized and anesthetized. V3 is a narrow strip (4-5 mm wide) of myeloarchitectonically distinct cortex located immediately anterior to V2. It contains a systematic(More)
We have examined the origin and topography of cortical projections to area PO, an extrastriate visual area located in the parieto-occipital sulcus of the macaque. Distinguishable retrograde fluorescent tracers were injected into area PO at separate retinotopic loci identified by single-neuron recording. The results indicate that area PO receives(More)
The representation of the visual field in the area adjacent to striate cortex was mapped with multiunit electrodes in the macaque. The animals were immobilized and anesthetized and in each animal 30 to 40 electrode penetrations were typically made over several recording sessions. This area, V2, contains a topographically organized representation of the(More)
SUMMARY AND CONCLUSIONS 1. The representation of the visual field in the striate projection zone in the posterior portion of the superior temporal sulcus of the macaque (MT) was mapped with mul-tiunit electrodes. The animals were immobilized and anesthetized and in each animal 25-35 electrode penetrations were typically made over several recording sessions.(More)
In addition to the major anatomical pathways from V1 into the temporal lobe, there are other smaller, "bypass" routes that are poorly understood. To investigate the direct projection from V1 to V4 (bypassing V2) and from V2 to TEO (bypassing V4), we injected the foveal and parafoveal representations of V4 and TEO with different retrograde tracers in five(More)
We investigated the patterns of projections from the pulvinar to visual areas V1, V2, V4, and MT, and their relationships to pulvinar subdivisions based on patterns of calbindin (CB) immunostaining and estimates of visual field maps (P(1), P(2) and P(3)). Multiple retrograde tracers were placed into V1, V2, V4, and/or MT in 11 adult macaque monkeys. The(More)
Visual receptive fields (RFs) were mapped inside and outside the cortical representation of the optic disk in the striate cortex (area V1) of anesthetized and paralyzed Cebus monkeys. Unexpectedly, most cells were found to be binocularly driven, and the RFs mapped with contralateral-eye stimulation progressed in a topographically appropriate fashion as the(More)
Based on cytoarchitectonic criteria, the primate pulvinar nucleus has been subdivided into medial (PM), lateral (PL), and inferior (PI) regions. However, these subdivisions show no correlation with those established by electrophysiological, immunocytochemical, or neuroanatomical tracer studies. In this work, we studied the connections of the pulvinar(More)
To determine the locus, full extent, and topographic organization of cortical connections of area V4 (visual area 4), we injected anterograde and retrograde tracers under electrophysiological guidance into 21 sites in 9 macaques. Injection sites included representations ranging from central to far peripheral eccentricities in the upper and lower fields. Our(More)
Previous studies of the primate cerebral cortex have shown that neurofilament protein is present in pyramidal neuron subpopulations displaying specific regional and laminar distribution patterns. In order to characterize further the neurochemical phenotype of the neurons furnishing feedforward and feedback pathways in the visual cortex of the macaque(More)