Source of geniculate input to the rostral contralateral eye zone. A, After optical imaging of the visual cortex to reveal ocular dominance domains, a contralateral eye site rostral to the large ipsilateral eye domains was selected for injection of WGA-HRP. The stippled circular region inA marks the location andsize of the cortical injection. B, C, In the LGN, retrogradely labeled neurons were primarily confined to the medial portion of lamina C; each symbol inB marks a labeled neuron. An occasional labeled cell was found in neighboring regions of lamina A1, presumably as a result of the encroachment of the injection site into the ipsilateral eye domain.C, A photomicrograph shows the boxedportion of B viewed under dark-field illumination. Scale bars: A, 1 mm; arrowlength in B, 500 μm; C, 250 μm.