MORPHOMERTIC ANALYSIS OF AGE-RELATED CHANGES IN THE PYRAMIDAL NEURONS OF THE HUMAN PREFRONTAL CORTEX FROM 8 TO 21 YEARS

- The article is devoted to the study of age-related changes in the size of pyramidal neurons of the human prefrontal cortex in postnatal ontogenesis. Histological material was obtained from 42 left cerebral hemispheres of males aged 8 to 21 years who died as a result of injuries without brain damage. The material was divided into three age groups: 1 - children aged 8 to 12 years (the age period of the second childhood, 15 observations), 2 - adolescents aged 13 to 16 years (12 observations), young men aged 17 to 21 years (15 observations). Morphometric analysis of pyramidal neuron sizes was performed in the 1113 sublayer of the prefrontal cortex in the frontal eye field 8, the speech field 45 (Broca zone) and in the field 10 on the lateral surface of the frontal pole. For this purpose, we used virtual images of frontal paraffin sections of the prefrontal cortex 10 microns thick, stained with cresyl violet on Nissl. In each field of each of the three age groups we measured the height and width of the basal part of bodies at least 3000 neurons. The body volume of each neuron was calculated using a formula to calculate the cone volume. In each field of the prefrontal cortex we also analyzed age-related changes in the percentage of small, medium and large neurons. For indicators of different age groups and different individuals we calculated the average, the error of the average and the confidence interval with the level of significance P=95% (p<0.05). It was found that the largest individual differences in the size of pyramid neurons were characteristic of children whose individual indicators differed from the average indicators of the whole age group by 18-26%. We found a significant increase in the average volume of pyramid neurons in the field of 10 in adolescents compared to children. We also showed that in young men the change in the number of neurons in the classes oflarge cells led to the appearance of single neurons of the largest size in the range from 6101 to 8100 mu m(3), which accounted for 5-7% of the total number of neurons studied. The obtained results demonstrate significant age-related changes in the size of pyramid neurons of the external pyramidal layer in the fields of 8, 45 and 10 prefrontal cortex in men aged from 8 to 21 years.