Fig. 6

Center and surround responses of an OFF-type bipolar cell (BC) recorded in a solution enriched with HEPES. Light responses of an OFF-type BC in newt retinal slice were recorded under the voltage-clamp conditions (holding voltage, −40 mV). A In control Ringer’s solution, spot illumination (50 μm in diameter) evoked an outward current as a center response and surround illumination (diffuse light superimposed on the spot light: 4,000 μm in diameter) evoked an inward current as a surround response. B Changing the superfusate to the HEPES-enriched solution (10 mM) abolished the surround response. The transient inward current at the time of switch-off of spot illumination was prominently increased in HEPES buffer (from Hirasawa and Kaneko [28])