HO inhibition increases GABA-mediated IPSCs in PVN VP neurons in HF rats. A, Summary of the incidence of PVN VP neurons showing changes in GABA-mediated IPSCs in response to the HO inhibitor SnPP (20μM) in sham (n = 13) and HF (n = 14) rats (A). Representative examples showing the most predominant effect of SnPP on the IPSC frequency (average in 1-s bins) of PVN VP neurons in sham (B1) and HF (B2) rats. Samples of expanded GABA currents are shown before and during SnPP bath application. Graphs summarizing the mean effect of HO inhibition on the IPSCs frequency and amplitude of VP neurons in sham (C1, D1) and HF (C3, D3) rats. Cumulative distribution histograms of IPSC frequency (C2, D2) and amplitude (C4, D4) before and during SnPP application. Data are reported as the mean ± SEM. Student's paired t test. *, P < .05 vs aCSF group.