Neuroanatomy of aging brain : sensitivity to pharmacological treatment

Abstract

The influence of aging and of nucleus basalis magnocellularis (NBM) lesions on the morphology of the rat hippocampus were assessed using neurohistological techniques and the histochemical method for the detection of zinc tissue stores (sulfide-silver staining technique). Moreover, the effect of choline alfoscerate treatment on the changes induced by aging and by NBM lesioning was investigated. Aging was characterized by a loss of hippocampal neurons which occurs primarily between middle (12 months) and old (24 months) age, as well as by a reduction of the area occupied by mossy fibres and their density as revealed by sulfide-silver staining. NBM lesions induced primarily a decrease in the density of hippocampal mossy fibres as ear ly as 3 weeks after lesioning. In choline alfoscerate-treated old rats the number of hippocampal neurons, the area occupied by mossy fibres and their density of sulfidesilver staining are significantly higher than in age-matched controls. The same is true for the density of this staining in the mossy fibres of NBM-lesioned rats.