[Neurono-glial ratios in the frontal cortex of the human cerebrum in normal and pathologic aging (Alzheimer's disease)].

Structural organization of the frontal area cortex (fields 8 and 47) in the left and right cerebral hemispheres has been studied cytoarchitectonically in mentally sound and sick persons of various age groups (34-40, 50-60 and 80-90 years). In sections 20 mcm thick, stained with cresyl-violet, in 0.001 mm3 of the cerebral substance (layers III and V) arrangement density is estimated for all pyramidal neurons, for all gliocytes, neurons surrounded with satellite glia and separately for perineuronal gliocytes, as well as per cent ratio of all the parameters obtained. In the process of normal and pathological ageing certain changes, both common for these two processes and specific for each of them, take place in the structural organization of the fields 8 and 47. Under normal ageing the changes are more distinct in the field 8, in the layer III, and at Alzheimer's disease there is a slight prevalence of them in the associative field 47, in the layer V.