BRAIN-STEM SEROTONERGIC NEURONS IN CHRONIC-ALCOHOLICS WITH AND WITHOUT THE MEMORY IMPAIRMENT OF KORSAKOFFS PSYCHOSIS

There are several lines of evidence to suggest that serotonergic neuro ns in the brain are detrimentally affected by chronic alcohol consumpt ion. The present study aims to quantify pathological changes in brains tem regions containing serotonergic neurons in chronic alcoholics comp ared to age-matched non-alcoholic controls. An antibody specific for t ryptophan hydroxylase was used to immunohistochemically demonstrate se rotonergic neurons in serial sections of postmortem brainstem. The cas es analyzed were divided into four groups on the basis of their clinic al and pathological presentation; chronic alcoholics with Wernicke's e ncephalopathy, chronic alcoholics with additional Korsakoff's psychosi s, non-alcoholic controls, and a single chronic alcoholic without neur ological complications. There was an overall reduction in the number o f serotonergic neurons in all alcoholic cases when compared with contr ols. All brainstem regions were affected, but the largest neuronal los s was found in areas of the medullary and caudal pontine reticular for mation (reduced by 80-90%). Alcoholics with Korsakoffs psychosis did n ot differ in the amount or extent of pathology from the other alcoholi c cases analyzed. The data indicate that significant numbers of seroto nergic neurons degenerate in chronic alcoholics. Such a loss is likely to have significant clinical consequences.