Figure 2. A single in vivo administration of cocaine reduces LTP_GABA 24 hours after exposure, but not at 2 hours.

A, Single experiment illustrating LTP_GABA in a brain slice prepared 24 hours after saline-treatment. Insets, Representative IPSCs evoked before (Control) and 15 min after (SNAP) drug application. In this and all subsequent figures, ten IPSCs were averaged for illustration. B, Single experiment illustrating impaired ability of SNAP to induce LTP_GABA in a slice from an animal injected with cocaine 24 hours earlier. C, At 24 hours after exposure, averaged experiments show SNAP potentiation of IPSCs in slices from cocaine-treated animals (n = 10) is reduced compared to those from saline-treated animals (n = 10). Two-way ANOVA analysis revealed significant effects of drug treatment (F_1,39 = 99.2, p < 0.001), time (F_1,39 = 10.2, p < 0.001) and an interaction between these two factors (F_1,39 = 1.85, p < 0.001). D, Single experiment illustrating LTP_GABA in a brain slice prepared 2 hours after saline-treatment. E, Single experiment illustrating LTP_GABA in a slice from an animal injected with cocaine 2 hours earlier. F, At 2 hours after exposure, averaged experiments show no significant difference in SNAP-induced potentiation of IPSCs in slices from cocaine-treated animals (n = 9) compared to saline-treated animals (n = 7). There were significant effects of drug treatment (F_1,39 = 24.8, p < 0.001) and time (F_1,39 = 3.70, p < 0.001), but not a significant interaction between these two factors (F_1,39 = 0.50, p > 0.05). Scale bars: 10 ms, 50 pA.