Concordantly, PACAP rescues hippocampal synaptic plasticity through stimulation of adenylate cyclase, and corrects abnormal metabotropic glutamate receptor-mediated long-term depression in the hippocampal neurons of Fragile X Mental Retardation 1 (Fmr1) knockout mice, a Fragile X Syndrome model [59]. The gene discussed is FMR1; the disease is fragile X syndrome.