Morphometric Characteristics of Cell Structures in the Substantia Nigra in Humans

Neurons and glial cells were studied by computerized morphometry in segments of the ventral and dorsal areas of the compact zone of the substantia nigra (CZSN) of the brain in autopsy material obtained from six men and three women aged 52–87 years. Neuron body and nuclear sizes were found to be greater in segments of the ventral area of the CZSN than in segments of the dorsal area. Neuron and glial cell densities in the ventrolateral segment were higher than in segments of the dorsal area. The glial index in the ventromedial segment was lower than in segments of the dorsal area. These morphometric differences between CZSN segments need to be considered for assessment of morphological changes in the substantia nigra associated with both age-related involution and pathological processes.