The complexity of the afterpotential of rabbit A-type horizontal cells

Afterpotentials of A-type horizontal cells (HCs) are believed to be rod-induced. They are, however, complex potentials and evidently of multiple causation. That part of the HC potential immediately after light-off is not entirely rod-determined because it has the same spectral sensitivity as the response to light-on, which is cone-induced with only some rod influence. It persists during a strong blue adapting light, which suppresses rod activity. The afterpotential may also be influenced by feedback from HCs to photoreceptors. The later part of the afterpotentials of A-type HCs is, however, rod dominated, as are the afterpotentials of axon terminals of B-type HCs.