Figure 4.

Increased GABA release after ethanol exposure requires HSF1 transcriptional activity. (A) HSF1 transcriptional activity increases the probability of GABA release. Hsf1-act transfection increased mIPSC frequency, similar to the level seen with 60 mM ethanol exposure for 4–8 h (E). Control cultures were sham transfected with an empty pcDNA3.1+ construct [C; n_C = 15, n_E = 17, n_Hsf1act = 19; F_{(2, 48)} = 3.46; p < 0.05]. (B) HSF1 activity does not alter the mean mIPSC amplitude in neurons transfected with an Hsf1-act construct, exposed to ethanol (E) or control sham transfected [C; n_C = 15, n_E = 17, n_Hsf1act = 19; F_{(2, 48)} = 0.32; p = 0.73]. (C) Ethanol stimulation of mIPSC frequency is mediated by activated HSF1. Hsf1-inact transfection reduced the effects of ethanol (E) on mIPSC frequency. Hsf1-inact transfection alone had no effect on mIPSC frequency compared to control cultures sham transfected with empty pcDNA3.1+ construct [C; n_C = 16, n_E = 10, n_Hsf1inact = 12, n_Hsf1inact+E = 14; F_{(3, 48)} = 2.56; p = 0.07]. (D) HSF1 activity does not alter the mean amplitude of mIPSCs in neurons transfected with an Hsf1-inact construct, exposed to ethanol (E) or vehicle control [C; n_C = 16, n_E = 10, n_Hsf1inact = 12, n_Hsf1inact_+E = 14; F_{(3, 48)} = 0.0639; p = 0.60; ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, or n.s. denotes no significance].