Fig. 7.

Reducing GABA release reduced the duration of train-induced STD. A: 300 μM GABA significantly reduced STD induced by the 10-pulse, 100-Hz conditioning train (cf., Fig 6A) [one-way repeated-measures ANOVA (P = 0.035)]. Exponential fits are shown from 100 to 1,400 ms after the conditioning train for ACSF (dashed gray line) and 300 μM GABA (black line). B: exponentials were fit to the recovery from STD of each slice before and after GABA application. 300 μM GABA caused a significant decrease in the time constant of recovery. C: 3 mM isoniazid reduced GABA synthesis and significantly reduced the train-induced STD at the 100- and 200-ms time points. *P < 0.05. Exponential fits are as in A. D: the time constant of recovery from STD reached significance (P = 0.021) at 3 mM isoniazid.