Fig. 11.

A sustained center and transient surround GABAergic inputs to ganglion cells. Bright annular stimuli clearly show 2 GABAergic components. One is from center and another is from surround. Strychnine and APB are always in perfusion to isolate the off GABAergic currents and eliminate the glycinergic currents and on GABAergic currents. Annulus outer diameter is 1,000 μm and inside diameter is either 400 or 200 μm as indicated. The diameters of the dendrites of on beta, on parasol, off beta, and off parasol cells are 190, 370, 230, and 320 μm. Stimulus trace, indicates the on (1.5 s) and off of bright annuli. Open arrows, sustained center currents; filled arrows, transient surround currents.