Amnesic Pathologies in Regulation of Dopamine as Supplement to Wernicke-Korsakoff Syndrome: A Limbic-Reticular Coupling View

Background: It was suggested by the limbic-reticular coupling theory that the hippocampus and amygdala regulate such descending limbic structures as the mammillary bodies, septum, hypothalamus and habenula, and in turn regulate the ascending noradrenergic, serotonergic, dopaminergic and cholinergic systems to consolidate and recall declarative memory, while the anterior and mediodorsal thalamic nuclei of Wernicke-Korsakoff syndrome beyond limbic-reticular coupling be related else to familiarity. Aim: It was aimed to highlight a portion of limbic-reticular coupling structures in alcoholic Korsakoff’s syndrome, including the dopaminergic system, habenula, mammillary bodies, etc. Methods: It was searched the papers from Pubmed and Baidu. Results and Discussions: It is highlighted that, (a) the mesolimbic dopamine, liable to be affected by alcohol, induces the hippocampal theta rhythm via septum, helping encode and consolidate new memories, such as dopaminergic enhancement of motivational declarative memory in young human adults; (b) dopamine can activate cortical gamma wave and help recall; (c) joint damage of habenula and mammillary bodies, both sending efferents to ventral tegmental area(VTA) rich in dopaminergic neurons, is sufficient to cause Korsakoff’s amnesia; (d) the loop of hippocampal CA3 to lateral septum(LS) to VTA(CA3-LS-VTA) activates dopamine for contextual memory in animals, consistent with dopaminergic antagonist impairing declarative memory recall in humans; (e) whereas thiamine deficiency, the major nutritional deficit causing Wernicke-Korsakoff syndrome, impairs noradrenergic but spares dopaminergic system. Conclusion: It is supplemented the integrative dysfunctions in regulation of such neglected dopaminergic system, including the habenula, mammillary bodies and VTA dopamine, as partial contribution to memory impairments in Korsakoff’s syndrome.