Fig. 4: Optical or chemogenetic silencing of CCK-positive neurons in the SFO induces water intake under the Na-depleted condition.

a Injection of AAV-DIO-eNpHR3.0-EYFP into the SFO of the CCK-Cre mouse. b Immunohistochemical staining of EYFP in the SFO. Scale bar, 50 µm. c Left: Experimental protocol to stimulate water intake under the Na-depleted condition with (opt+) or without (opt–) optical inactivation (wavelength, 577 nm). Center: Grayscale heat maps of water intake by individual mice with or without the optical stimulation. Right: Summary of water intake under the Na-depleted condition with or without the optical silencing of CCK-positive neurons in the SFO (n = 7 mice each; W = 0, P = 0.016). d Injection of AAV-DIO-hM4D(Gi)-mCherry into the SFO of the CCK-Cre mouse. e Immunohistochemical staining of mCherry in the SFO. Scale bar, 50 µm. f Left: Experimental protocol to stimulate water intake under the Na-depleted condition by a subcutaneous injection of the vehicle or CNO (2 mg/kg). Center: Grayscale heat maps of water intake by individual mice treated with the vehicle or CNO. Right: Summary of water intakes with the vehicle or CNO injection under the Na-depleted condition (n = 8 mice each; W = 0, P = 0.008). Immunohistochemical images in (b) and (e) were reproduced from more than three independent mice. bw, body weight. **P < 0.01; *P < 0.05; two-sided Wilcoxon’s signed-rank tests in (c) and (f). Data represent the mean ± s.e.m.