Figure 12.

Regulation of the DA amacrine cell–M1 ipRGC microcircuit by SRIF amacrine cells. The principle contacts at which SRIF amacrine cells mediate parallel inhibition (red arrows) of DA amacrine cells and M1 ipRGCs (whose reciprocal interactions are denoted with black arrows) occur within stratum 1 (S1) of the IPL. Few contacts occur in strata 3 (S3) and 5 (S5). SRIF amacrine cells target M1 ipRGCs for inhibition in a manner that can compensate for the loss of DA-mediated inhibition of M1 ipRGCs, which occurs when SRIF inhibits the DA amacrine cell.