Cortical connections of area V4 in the macaque

CORTICAL CONNECTIONS OF AREA V4 IN THE MACAQUE^*

LESLIE G. UNGERLEIDER¹, RENATA A. P. MONTEIRO³, RICARDO GATTASS³AND ROBERT DESIMONE²

¹

²Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Bethesda, Maryland 20892 USA.

³Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21941-900 Rio de Janeiro, RJ, , Brazil.

To determine the locus, extent, and topographic organization of cortical projections of area V4, we injected tritiated amino acids, WGA-HRP, and retrograde fluorescent tracers under electrophysiological guidance into 21 sites in V4 in 9 macaques. The injection sites included the representation of the fovea and representations ranging from central to far peripheral eccentricities in both the upper (4) and lower visual field (18). The results indicated that all V4 sites receive and project topographically back to V2 and V3 and forward to V3A, V4t, MT, TEO, LIPv, LIPd, TEp and TEm. In addition to these projections to occipital visual areas, V4 sites representing eccentricities of about 30º and greater project to visual areas in parietal cortex, namely, areas DP, 7, PO, and ventral intraparietal (VIP) areas. This peripheral field representation of V4 also projects to area TF on the posterior parahippocampal gyrus. Projections from the peripheral field representation of V4 to parietal areas could provide a direct route for rapid activation of circuits serving spatial vision and spatial attention. The convergence of projections from central and peripheral field representation of V4 to temporal areas could provide the necessary means for the translation of oculocentric coordinates to object centered coordinates. — ( June 27, 2000 ).

THEMES ON NEUROSCIENCE (a session in honor of CARLOS CHAGAS FILHO)

Organizers:

LENY A. CAVALCANTE AND ROBERTO LENT

Publication Dates

• Publication in this collection
  05 Oct 2000
• Date of issue
  Sept 2000