Figure 6.

Increasing 20 Hz trains to 100 stimuli suggests multiple components of EPSC depression and a greater estimate of RRP size. A, Peak EPSC amplitude values, measured in the presence of 200 μm kynurenate, during 100 stimuli, 20 Hz trains, normalized to the initial peak amplitude to illustrate the amplitude depression (n = 8). The normalized amplitudes were fit with a double-exponential decay; τ₁ = 122 ms; τ₂ = 773 ms. B, Representative cumulative EPSC area (Cumul. Area) values from a 100 stimuli, 20 Hz train. The dashed line represents a linear regression fit to time 0 from data points between 1.5 and 2 s, and the dotted line represents a linear regression fit to time 0 from data points between 4.5 and 5 s. C, Summary of the total RRP charge, as determined with 20 Hz trains of 40 or 100 stimuli (stim.), expressed as a percentage of the sucrose estimates of RRP size performed in the same neurons; ^*p < 0.001 compared with estimates derived from 40 stimuli (n = 8). Error bars represent SEM.