PIRACETAM PROMOTES MOSSY FIBER SYNAPTIC REORGANIZATION IN RATS WITHDRAWN FROM ALCOHOL

Prolonged alcohol intake affects the morphology of the hippocampal for mation of the rat and the resulting alterations do not reverse after w ithdrawal. Actually, an increase of the degenerative activity might oc cur in this condition. This unexpected observation prompted us to test the efficacy of neuronoprotective drugs during withdrawal. Because in a previous study we found that piracetam, a cyclic derivative of GABA , once added during withdrawal impedes hippocampal cell loss, we decid ed to evaluate the effect of this compound at the synaptic level. Usin g unbiased stereological techniques, we estimated the total number of contacts between messy fibers and CA3 pyramids, as well as the volume and the surface area of the respective pre- and postsynaptic compartme nts. We found that in piracetam-treated withdrawn rats the number of s ynapses was higher than that observed in nonpiracetam-treated and alco hol-fed animals. The mechanisms leading to the synaptic reorganization took place at the messy fiber level. The postsynaptic compartment doe s not seem to participate in the reorganization. It is suggested that the role of piracetam in this process might depend on the protective e ffect that this compound has upon glutamatergic receptors.