Figure 1.

A delayed component of the EPSC recorded in AII amacrine cells. A1, Prolonged depolarization of the presynaptic RB elicits a partially inactivating Ca current (top) and an EPSC (bottom) with a pronounced delayed component (arrow). The EPSC is blocked by the AMPAR antagonist GYKI 52466 (25 μm; magenta; n = 5 pairs). A2, The delayed EPSC (arrow) on an expanded timescale. The lines show zero current (solid) and the delayed component (dashed). B, Ca current and EPSC are blocked by Cd²⁺ (200 μm; magenta; n = 4 pairs). C1, Electrical coupling between AIIs is blocked by the gap junction antagonist MFA (100 μm). Top, Electrical coupling under control conditions is stable for 1 h. Bottom, Bath-applied MFA blocks coupling in under 20 min. C2, The delayed EPSC persists after prolonged incubation in MFA (200 μm) to block gap junctions (n = 5 recorded pairs).