Fig. 1: CCK-positive neurons in the SFO are AT1a-negative excitatory neurons.

a CCK levels in plasma (left) and the SFO (right) of mice under control, Na-depleted, and water-depleted conditions (n = 5 samples each; left graph, U_(Na) = 12, P = 0.917; U_(Water) = 22, P = 0.047; right graph, U_(Na) = 25, P = 0.009; U_(Water) = 15, P = 0.676; U_{(Na vs. Water)} = 25, P = 0.012). The right figure was reproduced from ref. ²⁵. b Injection of AAV-DIO-mCherry into the SFO of the CCK-Cre or CCK-Cre; AT1a^lacZ/+ mouse. c–e Immunohistochemical detection of mCherry and nNOS (c), GFAP (d), and β-gal (e) in the SFO. The squared area in the merged panel was shown as the magnified view. Arrowheads indicate double-positive cells. These images were reproduced from more than three independent mice. f mRNA expression of CCK in the SFO under the control and Na-depleted conditions (n = 5 samples each; U = 0, P = 0.008). Scale bars, 50 µm. **P < 0.01; *P < 0.05; ns, not significant; two-sided Mann–Whitney U tests in (a) and (f). Data represent the mean ± s.e.m.