Light-induced modulation of coupling between AII amacrine cells in the rabbit retina

摘要: The rod-driven, AII amacrine cells in the mammalian retina maintain homologous gap junctions with one another as well heterologous on-cone bipolar cells. We used background illumination to study whether changes adaptational state of affected permeabilities these two sets junctions. To access permeability, we injected single biotinylated tracer, Neurobiotin, and measured extent tracer coupling neighboring cone also center-receptive field size assess concomitant electrical coupling. Our results indicate that dark-adapted retinas, form relatively small networks averaging 20 covering about 75 microns. matched closely cell on-center receptive fields. However, over most their operating range, formed dramatically larger networks, 326 cells, which corresponded an increased receptive-field size. As was light adapted beyond range they uncoupled comparable those seem retinas. results, then, has a profound effect on between Although observed light-induced number tracer-coupled appeared be epiphenomenon Therefore, contrast robust AII-AII produced by illumination, our data provided no evidence modulation