Summary of catecholaminergic & serotonergic neurochemical measurements in the Mecp2-/ybrain. In mouse, Mecp2 dysfunction leads to the gradual postnatal reduction of dopamine (DA), norepinephrine (NE), serotonin (5-HT) and their principal degradation product dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindolacetic acid (5-HIAA) in several neuronal populations. These monoaminergic nuclei-related perturbation result in characterized phenotypes that constitute some of the key features of RTT pathology in humans. Sagittal mouse brain drawing adapted from The Mouse Brain in Stereotaxic Coordinates atlas . Area fill in green depict the cortical mantle. In gray the substantia nigra pars compacta (SNpc) irradiating the caudate-putamen (CPu) through the medial forebrain bundle (mfb). Hypothalamic (Hyp) region is symbolized in purple and the pons + brainstem in pink. OB (olfactory bulb), c.c (corpus callosum), CB (cerebellum), LV (lateral ventricle), IV (4th ventricle). Scale bar, 1 mm.