Chronic alcohol consumption induces plastic changes in granule cell synaptic boutons of the rat cerebellar cortex.

The reduction of cerebellar cortex molecular layer afferents, as a consequence of an alcohol-induced granule cell degeneration, is followed by a remodeling activity which leads to marked structural changes. Using Golgi, ultrastructural and combined Golgi-ultrastructural methods, it was evaluated the role played by granule cell synaptic boutons in this plastic process and, furthermore, determined whether there were differences between the boutons located in the ascending portions of the axons and those belonging to parallel fibers. No significant differences were found in the number of boutons per unit length of axon when the alcohol-fed animals were compared to the controls, despite a significant increase in the volumetric density of nerve terminal profiles after 12 months of alcohol intake. This increase is likely to depend on variations in the size of the nerve terminals rather than on their number.