Figure 6.

MOC–OHC synapses from L9′T mice strongly facilitate upon stimulating the MOC fibers with 20 Hz trains. A, The average response (S), the probability of release (P), and the eIPSCs average amplitude (A) were computed for every pulse during 10 shock trains at frequencies of 10 (left) and 20 Hz (right). The normalized mean values for these parameters at the two stimulation frequencies are plotted versus the pulse number. Interestingly, the 20 Hz stimulation train caused a significant increase in the total average response (S) only in the L9′T mice. Note there is a significant increase in the probability of release (P) during the train, whereas the eIPSCs amplitude remains stable. B, Bar graphs showing the ratio between the tenth and the first pulse for the total average response (S₁₀/S₁), the release probability (P₁₀/P₁) and the amplitude of the successfully evoked postsynaptic responses (A₁₀/A₁). 10 Hz: wt, n = 5 cells from five different mice, L9′T, n = 7 cells from seven different mice; 20 Hz: wt, n = 4 cells from four different mice, L9′T n = 6 cells from five different mice; **p < 0.01, Kolmogorov–Smirnov test.