Cortical connections of striate cortex in the owl monkey.

Injections of tritiated proline and horseradish peroxidase were used to study cortical connections of striate cortex in owl monkeys. All cases resulted in label in area 18 (V-II) and the middle temporal visual area (MT). In most, but not all cases, label was also present in the dorsomedial visual area (DM). The connections between striate cortex and each of these three visual areas were retinotopic and reciprocal. Projections to V-II, MT, and DM were concentrated in layers IV and III, while pyramidal cells in layers III, V, and VI of these areas projected back to striate cortex.