Intracerebral grafts promote recovery of the cholinergic innervation of the hippocampal formation in rats withdrawn from chronic alcohol intake. An immunocytochemical study.

We have previously found that alcohol withdrawal aggravates the neuronal cell loss induced by chronic alcohol consumption in the rat hippocampal formation. We have also shown that intracerebral grafts of immature hippocampal tissue could reverse the progressive degeneration that occurs during this withdrawal. Furthermore, we have shown that chronic alcohol consumption reduces the areal density of choline acetyltransferase-immunoreactive neurons and the density of choline acetyltransferase-immunoreactive fibres in the hippocampal formation. Thus, we thought it would be of interest to investigate the effects of alcohol withdrawal in the hippocampal cholinergic innervation and to determine whether the intracerebral grafting of immature hippocampal tissue would have beneficial effects upon the cholinergic system in this condition. Choline acetyltransferase-immunoreactive fibres and perikarya were analysed in 14-month-old control, alcohol-fed, withdrawal and withdrawal-grafted groups of rats. The areal density of choline acetyltransferase-immunoreactive neurons was reduced in all experimental groups when compared to controls. The density of choline acetyltransferase-immunoreactive fibres was lower in the alcohol-fed and withdrawal groups than in the control and withdrawal-grafted groups. We conclude that the grafted tissue probably produced neurotrophic factors which allowed a recovery of the hippocampal cholinergic fibre network. This recovery might be of importance to reverse the cognitive dysfunction described after chronic alcohol consumption and withdrawal.