Serotonin and alcohol-related brain damage.

Preliminary results from the immunohistochemical examination of the brainstems of chronic alcoholics, suggest that alcohol may have a role in damage to the principal serotonergic (5HT) nuclei. This view is reinforced by evidence from previous animal experiments which demonstrated a reduction in 5HT neurons in the brains of alcohol-preferring rats and selective neurotoxicity to 5HT neurons following 5,6-dihydroxytryptamine-induced increased ethanol intake. It is speculated that, like other neurotoxins, alcohol or its metabolites cause degeneration of 5HT axons and axon terminals. It is possible that if axonal damage is sufficiently severe and chronic, the eventual consequence is cell death. This could be due to insufficient opportunity for repair and regrowth under repeated and sustained insults of high alcohol consumption.