The projection from the dorsal lateral geniculate nucleus of the thalamus to extrastriate visual association cortex in the macaque monkey.

Both autoradiographic and horseradish peroxidase tracing techniques were used to characterize a projection from the dorsal lateral geniculate (DLG) nucleus of the thalamus to visual association cortex (extrastriate cortex) in the macaque monkey. The results show that medium to large caliber DLG axons end to discontinuous terminal "patches" in layers V and lower IV of extrastriate cortex. There is a topographical organization to these projections which are mainly to area 19 and anterior 18 located on the lateral and medial surfaces of the hemisphere. Apparently there are no DLG projections to any of the cortical subdivision located within the lunate and superior temporal sulci.