 After nearly 50 years of research on brain-stimulation reward, experts have certified that dozens of sites in the brain will maintain intracranial self-stimulation.Regions include the lateral hypothalamus and medial forebrain bundles, which are especially effective.Stimulation there activates fibers that form the ascending pathways; the ascending pathways include the mesolimbic dopamine pathway, which projects from the ventral tegmental area to the nucleus accumbens.