Individual variability in the structural asymmetry of the dorsomedial nucleus of the thalamus in men and women.

Quantitative neurohistochemical parameters were used to study the structure of the dorsomedial nucleus of the thalamus. The study set consisted of 10 specimens from the collection of the Institute of the Brain, Russian Academy of Medical Sciences and included seven men and three women aged 19-59 years, all right-handed, who died suddenly and had no neurological or mental diseases during life. The following parameters were measured: neuron density, total and satellite glia densities, the density of satellite-surrounded neurons, and the ratios of satellite glia to all glia and neurons surrounded by satellite glia to all neurons. On a background of individual variability in these measures, a number of gender-related and interhemisphere differences were found. Thus, neuron density in both men and women showed no asymmetry and individual variability was less marked in women. Glial cell density in men was greater on the right, while in women it was greater on the left; satellite glial cell density, conversely, was greater on the left in men and more variable in women. Significant asymmetry with greater values on the left in men was seen for the density of neurons surrounded by satellite glia, while this was more variable in women, though the ratio of neurons with satellite glia to all neurons was greater on the left in men and women, as was the ratio of satellite glia to all glial cells. Overall, there was a tendency to rather greater asymmetry in this structure in men and a tendency to greater individual variability in women.