Fig 1: Mecp2 haplodeficiency and maternal separation reduced the density c-FOS/CRH neuronal population in the paraventricular hypothalamic nucleus. Representative photomicrographs of A c-FOS/CRH and B c-FOS/AVP double immunofluorescence in the paraventricular hypothalamic nucleus (WT-naïve, n = 4; WT-MS, n = 7; Mecp2.het-naïve, n = 5; Mecp2.het-MS, n = 6). The number of c-FOS-positive cells that colocalize with CRH neurons was significantly reduced in Mecp2.het females and upon maternal separation. Quantification of the number of c-FOS neurons that colocalize with C CRH or D AVP. AVP, arginine vasopressin; c-FOS, FOS proto-oncogene; CRH, corticotropin-releasing hormone; Mecp2.het, Mecp2 heterozygous females; MS, maternal separation; WT, wild type; vs, versus. *p < 0.05; **p < 0.01