Fig. 2

Modulation of cone I _Ca by a high-pH solution applied to the cone terminal layer. A Alkalinized Ringer’s solution (pH 9.0) was focally ejected to cone synaptic terminal layer in newt retinal slice. The cone was voltage-clamped at various voltages in the range of −50 to +6 mV in 8-mV steps. The representative four traces, voltage clamped at −42, −26, −18 and +6 mV, are shown. The current was sampled at the points marked by a symbol to construct the I–V curves shown in B. Small spot illumination (30 μm in diameter) was maintained throughout. B Top leak-subtracted I–V curve of cone I _Ca in normal Ringer’s solution (pH 7.4, filled squares) and in response to a high-pH solution (pH 9.0, open circles). Bottom activation curves derived from the I–V curves fitted to the Boltzmann function (from Hirasawa and Kaneko [28])