Figure 2.

Repeated cocaine exposure lowers t-LTP induction threshold. A, t-LTP induction by 50 EPSP–AP pairs in cocaine- but not saline-treated mice. B, t-LTP induction by 70 EPSP–AP pairs in both cocaine- and saline-treated mice. C, Summary of t-LTP induction by various numbers of EPSP–AP pairs. D, Cumulative distribution of t-LTP magnitude by 50 EPSP–AP pairs from A and C in individual cells in cocaine and saline mice. EPSP–AP pairs were delivered at Δt = +10 ms, 0.1 Hz. Scale bars, 2 mV, 20 ms. *p < 0.05 unpaired two-tailed t test with Welch's correction.