Fig. 2.

A small number of silent synapses are present during ON/OFF sublamination, but their proportion is constant before and after sublamination. A, Failure rates at −60 and +40 mV for individual cells. The outside markers are the means for the two conditions. B, Failure rates by age at −60 and +40 mV. The slight decrease in failure rates at +40 mV is equivalent at P14–P17 (at the onset of sublamination; filled bars) and P28–P31 (after its completion; open bars). C, Spontaneous EPSCs recorded at −60 (bottom) and +40 (top) mV. Note the absence of a dramatic increase in the number of sEPSCs at +40 mV. Same cell as in Figure 1. D, The frequency of sEPSCs was not significantly decreased at +40 mV, suggesting that the results fromB are attributable to a small rather than large number of silent synapses. Data are mean ± SEM. Denotes *p < 0.05.