Plastic changes in GABAAR subunits and currents in rat hippocampal formation induced by CIE. A. EtOH-enhanced mIPSCs observed in hippocampal slices from CIE vs. CIV. Top left of A, recordings from CIV and CIE, including exposure to various concentrations of EtOH in the recording chamber. Top right of a, averaged mIPSC from each period response to EtOH applications during the recordings (left of a). Bottom of a, Summary of mIPSC area and tonic current for EtOH vs. pre-EtOH application. Redrawn from Liang et al., . b. Upper: Summary of Western blot analyses of hippocampal GABAAR subunit peptides after CIE compared with CIV. Data are presented as percent changes from control peptide levels mean ± SEM. (n = 10 ~ 12 rats). **
p < 0.01, t-test. b Lower: GABAAR subunit mRNA levels assayed by PCR, normalized to the unchanged reference gene GADPH. Data are expressed as percentage of CIV group (control) mean ± SEM, **
p < 0.01, t-test. c. Post-embedding immunogold labeling reveals a change in α4 but not in δ subunit location from perisynaptic to synaptic sites in the molecular layer of the DG after CIE. In CIV (top and middle of c), colloidal gold labeling of the α4 subunit (arrows) was present on or near the plasma membrane of dendrites that contacted axon terminals (T). Gold particles were found predominantly at the outer edges of symmetric synapses (arrows) but not at the center of these synapses (arrowheads). After CIE (bottom of c), labeling for α4 was found mainly in the center of symmetric synapses (arrows). d. Quantitative analysis showed that perisynaptic labeling was found at 93% of α4-labeled synapses (open bar) in CIV (n = 3). In CIE (n = 3), perisynaptic labeling was observed at 22% (open bar) of labeled synapses, but synaptic labeling was evident at 78% of labeled synapses (black bar). *
p < 0.001 vs. CIV. In contrast to the α4 labeling, δ subunit labeling (arrow) in CIE was present at perisynaptic locations but not within the synaptic contact (arrowhead). Figs. a, c, and d are reproduced from Liang et al.  with permission. Figs. b are redrawn from Cagetti et al.