Cholinergic Deficiencies in Senile Dementia of the Alzheimer Type

Abstract

I shall focus on the cholinergic system that may be affected in Alzheimer’s dementia and senile dementia of the Alzheimer type. One of the interesting questions that arises with regard to subcortical neuronal systems and their role in these disorders concerns the surprising evidence of recent neuropathological studies that suggest a rather modest loss of neurons in the cerebral cortex. It is clear that the cortex, hippocampus, and related limbic structures are the sites heavily affected by such pathological stigmata as plaques, tangles, and granular vacuolar degeneration. In studies in which objective cell-counting techniques have been used, Terry and his colleagues found that thinning of the cerebral cortex is minimal and loss of cells is difficult to document. The largest cells are, however, selectively affected, and recent findings by the Cambridge group from substantial numbers of age-matched controls and pathologically diagnosed demented patients again support documentable, but not overwhelmingly large, cell loss in various areas of the cortex.