GAL and brain disorder: One of the mechanisms of galanin-induced impairment in cognition is its down regulation of cholinergic transmission, supported by the finding that beneficial effects of acetylcholine administration to rodents with cholinergic lesions in selected brain regions were blocked by administration of galanin [19]; thus, galanin appeared to exacerbate cognitive impairment and limit long term potentiation [20] arising from cholinergic deficit in brain disorders.