Figure 1.

The membrane potential and spike frequency in arcuate NPY neurons from Tg2576 mice are sensitive to the L-type Ca²⁺ channel blocker nimodipine (NMD). A, Brain slices containing the hypothalamic arcuate nucleus from young (3- to 4-month-old) NPY-GFP mice with APP_swe transgene (Tg2576) were used for whole-cell patch-clamp recordings. Representative traces are shown before and after nimodipine (2 μm). B, Application of the L-type voltage-gated Ca²⁺ channel antagonist nimodipine (2 μm) hyperpolarized the membrane potential of arcuate NPY neurons in Tg2576 brain slices. n = 8 cells from 6 mice per group. Statistical analysis: two-tailed paired Student's t test (t = 4.508, df = 7, p = 0.0028). C, Application of the L-type voltage-gated Ca²⁺ channel antagonist nimodipine (2 μm) reduced the spike frequency of arcuate NPY neurons in Tg2576 brain slices. n = 8 cells from 6 mice per group. Statistical analysis: two-tailed paired Student's t test (t = 4.548, df = 7, p = 0.0026). D, Application of the N-type (ω-Cgtx-GVIA,1 μm) or the P/Q-type Ca²⁺ channel (ω-AgaIVA, 1 μm) antagonists had no effect on membrane potential of arcuate NPY neurons in Tg2576 brain slices. n = 4 cells from 3 mice per group. Statistical analysis: repeated-measures one-way ANOVA (F_{(1.030, 3.089)} = 0.968, p = 0.3993). E, Application of the N-type (ω-Cgtx-GVIA,1 μm) or the P/Q-type Ca²⁺ channel (ω-AgaIVA, 1 μm) antagonists had no effect on the spike frequency of arcuate NPY neurons in Tg2576 brain slices. n = 4 cells from 3 mice per group. Statistical analysis: repeated-measures one-way ANOVA (F_{(1.947, 5.841)} = 1.168, p = 0.3727). Data are mean ± SEM. **p < 0.01.