Figure 4.

Functional validation of hM3 in each mouse line. A, CNO (0.3 mg/kg) strongly increases fos in hM3-mCherry-expressing neurons in all three lines of mice compared with saline (n = 3 mice of each line per condition). B, Sample traces of in vitro, whole-cell, current-clamp recordings of PPT neurons in vGluT2-Cre, ChAT-Cre, and vGAT-Cre mice expressing hM3-mCherry or hM4-Cherry (vGluT2-Cre only). Application of CNO (5 μm) for 1–5 min (black bars above traces) activates glutamatergic and cholinergic PPT neurons but has no effect on GABAergic neurons. Dashed horizontal line indicates 0 mV. **p < 0.01; ***p < 0.001: ****p < 0.0001 versus saline.