QUANTITATION AND 3-DIMENSIONAL RECONSTRUCTION OF CH4 NUCLEUS IN THE HUMAN BASAL FOREBRAIN

The basal nucleus of Meynert, incorporating the Ch4 group of cholinerg ic neurons, was examined in six patients with no signs of neurological abnormalities. The ages of the patients ranged from 20 to 80 years. D espite a number of descriptions of these neurons, few age-related stud ies have been dedicated to the analysis of the entire anteroposterior extent of the nucleus. Staining with cresyl violet and acetylcholinest erase histochemistry, alone or in combination, was used to identify th e cytoarchitectural organization of the Ch4. Computer-assisted morphom etry was used for three-dimensional visualization and quantitation. Th e three-dimensional computer reconstructions revealed a continuous rib bon of neurons with a highly variable density. Four distinct subregion s could be clearly identified in all cases by their cytoarchitecture a nd cellular morphology, although these subgroups were different to tho se previously described. There were no quantitative differences betwee n the hemispheres in volume, density or cell number of the Ch4, althou gh equivalent levels varied in area and density. The measures were sim ilar in all cases with the exception of the case aged 80 years old. Th e data demonstrate individual variability in three dimensions and conf irm previous studies that found only a mild decline of the Ch4 in old age. (C) 1993 Wiley-Liss, Inc.