Fig. 6.

Activation of p38 MAPK results in the development of resistance to the inhibition of the NMDAR response to short-term ethanol application. Brain slices were incubated with anisomycin (Anis; 20 μM), anisomycin (20 μM) + SB202190 (0.5 μM; SB + Anis), cycloheximide (Cyhx; 60 μM), SB202190 alone (SB), or SB202190 + E45 (SB+E45). The effects of an 80 mM ethanol challenge on NMDA EPSCs were measured. Representative traces show NMDA EPSC responses during baseline (BSL), 80 mM ethanol challenge (EtOH), or during washout (Wash) from anisomycin-treated brain slices (A), from anisomycin + SB-treated brain slices (B), from SB-treated brain slices (C), and from a 45 mM ethanol + SB-treated neuron (D). Dotted lines indicate the baseline and the extent of 80 mM ethanol inhibition. E, the average values show the effects of an 80 mM ethanol challenge on NMDA EPSCs in cells from the control (Con, −34.3 ± 4.1%, n = 9), anisomycin-treated (Anis, 14.3 ± 4.8%, n = 5), anisomycin + SB-treated (SB + Anis, −36.4 ± 5.0%, n = 6) brain slices, and from a subgroup of slices treated with cycloheximide (Cyhx, −23.4 ± 1.7%, n = 5). There are significant statistical differences among groups [F(3,21) = 28.087, p < 0.001, one-way ANOVA]. Post hoc Holm-Sidak analysis shows that the cycloheximide treatment does not differ significantly from control slices. F, time course of the NMDAR current responses during baseline, 80 mM ethanol application, and washout periods from brain slices treated with 45 mM ethanol (E45), PP2 (2 μM), or PP2 plus 45 mM ethanol (E45 + PP2) for 3 h. G, mean values for the effects of acute ethanol (80 mM) on NMDA currents recorded from control neurons (Con, −34.8 ± 2.9%, n = 8), E45-treated neurons (E45, 5.0 ± 3.4%, n = 18), SB202190-treated neurons (SB, −30.0 ± 3.2%, n = 12), neurons treated with SB and 45 mM ethanol (SB + E45, −27.8 ± 3.4%, n = 8), PP2-treated neurons (−28.8 ± 5.1%, n = 7), and PP2 + E45 treated neurons (−0.7 ± 5.5%, n = 6). Scale bar, 100 pA and 150 ms. ***, p < 0.001.