Comparative morphometric analysis of age-related changes in the pyramidal neurons of the human prefrontal and posterior associative cortex from birth to 7 years

Abstract

Aim: This article is devoted to the study of age-related changes in the body volume of pyramidal neurons (VP) of the human prefrontal (PFC) and posterior associative cortex (PAC) in children from birth to 7 years of age. Methods: The material consisted of left cerebral hemispheres obtained from 60 male individuals. We studied the areas 8, 45 and 10 in the PFC and area 37 in subareas 37ac, 37a, 37d in the PAC. For morphometry of pyramidal neurons in cortical sublayer III3, we used virtual images of serial frontal paraffin sections of cortex 10 thick stained by Nissl. We determined the mean value of VP (mean VP), the standard error of the mean, and the confidence interval for each age group. Results: The most significant changes in the mean VP in all studied cortical areas occurred during the first 6 months of life. The greatest increase in the VP was detected in the PFC from 3.5 to 7 years, and in the PAC from 1.5 to 3 years of age. There are close positive correlations between agerelated changes in the size of neurons in the PFC and in the PAC. Conclusion: In children, the development of pyramidal neurons of the external pyramidal plate in the PAC occurs earlier and at a more intensive pace compared to the PFC. We suggest that VP is an important quantitative indicator that allows us to assess the timing and rate of age-related structural changes in the cerebral cortex.