Morphometric study of the magnocellular basal forebrain system in patients with Alzheimer's disease

Morphometric study of neurons within the magnocellular basal forebrain system (MBFS) in the three normal controls and three cases with Alzheimer's disease (AD) was studied. Immunocytochemical staining using anti-acetylcholinesterase was performed to identify the measuring areas of the MBFS, and cross sectional areas of all neurons within the MBFS in one preparation was measured making use of cresyl violet staining. About 50% of the entire neuronal cells within the MBFS were decreased and case 2 had neurofibrillary tangles in the substantia innominata. In the septal nucleus neuronal cell depopulation was observed through the all range of the neuronal cell size, and in the diagonal band of Broca neuronal cells of which cross sectional areas were more than 200 microns2 were preferentially decreased and case 3 had inverse increase of the neurons of which cross sectional areas were less than 200 microns2. In the basal nucleus of Meynert in the substantia innominata neurons of which cross sectional areas were more than 250 microns2 were markedly decreased and neurons of which cross sectional areas less than 250 microns2 were well preserved. The large neurons within the basal nucleus and diagonal band of Broca were more affected in AD. In the septal nucleus and diagonal band it was suspected that non-cholinergic neurons were also decreased and these findings suggested that other series of monoamines also bore a relationship to the dementia and neuropsychological symptoms in AD.