Remodeling of the cerebellar glomeruli after long-term alcohol consumption in the adult rat

Abstract

The morphological effects of the prolonged alcohol consumption on the cerebellar glomeruli of adult rats were studied in groups of controls and animals fed alcohol for 1, 3, 6, 12 and 18 months, by applying qualitative and quantitative ultrastructural methods. Following 6 months of alcohol consumption degenerated granule cell dendritic profiles were randomly dispersed over the granular layer surrounding mossy fiber terminals. In 12- and 18-month alcohol-fed groups, some glomeruli appeared with an atrophic design owing to the lack of their post-synaptic targets while others presented a remodeled organization, with Golgi cell dendrites replacing the missing granule cell digits. An extensive glial reaction was seen investing both types of glomeruli. The total number of synapses per glomerulus remained unchanged in all groups. this is due to an increase of the mossy fiber terminal—Golgi cell dendrite synapses, which compensate the decrease of the mossy fiber terminal — granule cell dendrite synapses. It is suggested that the morphological remodeling of the cerebellar glomeruli after long-term alcohol consumption can lead to changes in the balance of the excitatory-inhibitory activities of the cerebellar circuitry. This could be related to the important functional changes observed in the cerebellum under these circumstances.