Congenital and acquired mechanisms implicated in the etiology of central precocious puberty. ARC, arcuate nucleus; AVPV, anteroventral periventricular nucleus; GABA, gamma-aminobutyric acid; ME, median eminence; MnPO, median preoptic nucleus; PMV, ventral premammillary nucleus; POA, preoptic area; OPG: optic pathways glioma.