Age-related changes of neuronal counts in the human pedunculopontine nucleus

Cholinergic neurons in the basal forebrain and the upper brainstem undergo changes during aging and in dementia of the Alzheimer type, Parkinson's dis ease and progressive supranuclear palsy. Little is known about the effect o f age on neurons in the tegmental pedunculopontine nucleus. Cholinergic neu rons revealed by choline acetyltransferase immunohistochemistry were quanti fied in the brains of 20 subjects who died without neurological disorder be tween 28 and 101 years of age. A U-shaped relationship between cell counts and age was found, namely, a decrease in counts between 28 and 70, a minimu m between 80 and 91 years of age, and, in four subjects aged 98-101 years c ounts comparable to those of subjects having died between 28 and 65 years. The findings suggest that the loss of cholinergic pedunculopontine nucleus neurons is not linear. In centenarians age-related neuronal decrease in ped unculopontine nucleus neurons may be slower or the stock of pedunculopontin e nucleus neurons greater than in subjects dying earlier. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.