Figure 4.

Stim1 mutagenesis augments the DHPG-induced current in POMC neurons from mice on a HFD, which is antagonized by the TRPC4/5 channel blocker HC070. A-B, representative traces of DHPG-induced inward current perfused with TTX (1 μM) in the absence (A) or presence (B) of HC070 (100 nM) in POMC neurons on a control diet. V_hold = −60 mV. C, summary of the effects of HC070 and/or Stim1 mutagenesis on DHPG-induced current in POMC neurons from mice on a control diet (Unpaired t-test for control versus Stim1^Mut, t₍₁₉₎ = 2.406, ∗p = 0.0264; Unpaired t-test for Stim1^Mut versus Stim1^Mut + HC070, t₍₁₅₎ = 7.339, ∗∗∗∗p < 0.0001). D-E, representative traces of DHPG-induced inward current perfused with TTX (1 μM) in the absence (D) or presence (E) of HC070 (100 nM) in POMC neurons from Pomc^Cre mice on a HFD. F-G, representative traces of DHPG-induced inward current perfused with TTX (1 μM) in the absence (F) or presence (G) of HC070 (100 nM) in POMC neurons from Stim1^Mut mice on a HFD. H, under voltage clamp conditions, the I/V curve revealed that DHPG generated an inward current that reversed at approximately −30 mV (POMC neuron from F). The kinetics of the I/V curve is similar to controls and treated with GSK7975A (Figure 3G) I. Summary of the effects of HC070 on the DHPG-induced inward current in POMC neurons from Pomc^Cre and Stim1^Mut mice on a HFD (two-way ANOVA, interaction, F_{(1, 19)} = 5.809, p = 0.0262; effect of strains, F_{(1, 19)} = 4.834, p = 0.0405; effect of drugs F_{(1, 19)} = 23.70, p = 0.0001; Bonferroni's multiple comparisons test, a,b,c, p < 0.05, n = 8 control, n = 8 Stim1^Mut, n = 4 Control + HC070 and n = 3 Stim1^Mut + HC070 treated neurons.