The effect of cholecystokinin (CCK) on c-Fos expression in the brain of 3×TgAD and Non-Tg control mice.
(A) Representative photomicrographs illustrating c-Fos expression in the brain of Non-Tg control (a, b, e, f, i, j) or 3×TgAD (c, d, g, h, k, l) mice after i.p. injection of either vehicle (5 ml/kg saline, n = 6) or CCK (15 µg/kg, n = 6). Significant increases in c-Fos expression were observed after CCK injection in the supraoptic nucleus of the hypothalamus (SON; a–d), paraventricular nucleus of the hypothalamus (PVN; e–h), nucleus tractus solitarius (NTS; i–l) and area postrema (AP; i–l) of Non-Tg control and 3×TgAD mice, although the number of c-Fos-positive cells in response to CCK was lower in PVN of 3×TgAD compared to Non-Tg control mice. Scale bar, 50 µm for a–d and 100 µm for e–l. 3V, third ventricle; cc, central canal. (B) quantification of the number of c-Fos positive nuclei per section. Data are mean ± SEM, *P<0.05, ***P<0.001 versus respective vehicle-treated mice, # P<0.05 versus CCK-treated Non-Tg mice, Two-way ANOVA.