Fig. 4.

EPSC amplitude histograms show multiple peaks consistent with the presence of multiple ribbon contacts between individual cones and horizontal cells. A: the amplitude distribution of EPSCs fit using a multiple Gaussian function (—, R² = 0.93, n = 217) with individual Gaussian components averaging 46.3 ± 17.8 (SD) pA. B: the histogram of charge transfer measurements of the initial fast component of the EPSC was also fit with a multiple Gaussian function (—, R² = 0.90, n = 217). The amplitude of the fast component was determined from the fit to charge transfer using a double exponential function as described in Fig. 3. After scaling charge transfer measurements by 16 pC/vesicle, individual Gaussian components averaged 15.2 ± 5.7 (SD) vesicle.