Synaptic neurochemistry of the basal forebrain cholinergic projection

Excitotoxin lesions of the rat basal forebrain magnocellular complex, a dispersed equivalent of the nbM, results in selective decrements in the presynaptic markers for cortical cholinergic neurons, which are quantitatively and qualitatively similar to those reported in AD. Combined lesions and retrograde tracing studies have demonstrated the topographic organization of these projections that provide the bulk of the cholinergic innervation to the cerebral cortex and hippocampal formation, although a subpopulation of cholinergic neurons appear to be intrinsic to the cerebral cortex. Lesions of the basal forebrain cholinergic complex have provided a useful animal model for AD and may help clarify the anatomy, physiology, and pharmacology of this system.