Memantine, but not dizocilpine, ameliorates cognitive deficits in adult rats withdrawn from chronic ingestion of alcohol

Adult rats were given a 20% ethanol solution as their only source of fluid for 6 months and then withdrawn from alcohol. During the first 4 weeks of the withdrawal period, animals were intraperitoneally injected with either memantine (20 mg/kg bolus followed by 1 mg/kg every 12 h) or dizocilpine (MK-801; 0.1 mg/kg every 12 h), both of which are antagonists of N-methyl-D-aspartate receptors. Ten weeks after initiation of the withdrawal procedure, cognitive status of animals was assessed using the Morris water maze. Withdrawal from alcohol produced robust deficits in the performance of rats on the acquisition task and on the probe trial. Treatment with memantine resulted in a complete reversal of these behavioral impairments. In contrast, treatment with MK-801 was found to be ineffective in preventing cognitive alterations associated with chronic alcohol consumption and withdrawal. (C) 2001 Published by Elsevier Science Ireland Ltd.