Figure 5. Proposed circuitry generating antagonistic eye‐specific responses.

Our data suggest that, for cells with contra‐ON/ipsi‐OFF antagonistic responses, contralateral ON responses are driven by retinal input while ipsilateral OFF responses are driven by inhibitory input from monocular (contralateral ON) cells in the opposite LGN. For ipsi‐ON/contra‐OFF cells, both response components involve commissural signalling. These cells receive excitatory commissural input (presumably via monocular cells that receive crossed retinal inputs) that drives ipsilateral ON responses. By contrast, their contralateral OFF responses are predicted to derive from commissurally projecting neurons that receive binocular retinal input biased towards uncrossed projections. In addition to a weak contralateral ON input from the retina, this arrangement is predicted to generate well balanced antagonistic inputs.