Fig. 2

Mecp2 haplodeficiency and maternal separation reduced anxiety-like behavior and neuronal activation in the paraventricular nuclei upon stress. WT and Mecp2.het females, both naive and MS animals, were re-exposed to the EPM now under bright light conditions, a more aversive version (WT-naive, n = 14; WT-MS, n = 13; Mecp2.het-naive, n = 12; Mecp2.het-MS, n = 18). A No differences were found among groups in the total distance travelled in the maze. B Mecp2.het females spent significantly longer time in the open arms of the maze, as compared to WT littermates, an effect further increased by MS. One hour after behavioral testing in the aversive EPM, a subset of the animals was sacrificed for c-FOS immunohistochemistry and quantification (WT-naïve, n = 4; WT-MS, n = 7; Mecp2.het-naïve, n = 5; Mecp2.het-MS, n = 6). C Representative photomicrographs of c-FOS staining in the paraventricular hypothalamic nucleus of WT-naive, C’ Mecp2.het-MS, C” WT-MS, and C”’ Mecp2.het-naive. Quantification of c-FOS-positive neurons in WT and Mecp2.het females, both naive and MS groups, in D Pa, E PV, F BSTLD, G LSV, and H DG. Pa, paraventricular hypothalamic nucleus; PV, paraventricular thalamic nucleus, BSTLD, bed nucleus of stria terminalis lateral division, dorsal part; LSV, lateral septum, ventral part; DG, dentate gyrus of the hippocampus; EPM, elevated plus maze; Mecp2.het, Mecp2 heterozygous females; MS, maternal separation; WT, wild type; vs, versus. *p < 0.05, **p < 0.01, ***p < 0.001