Structural changes in human brain tissue during prenatal alcoholization at different stages of intrauterine development

Abstract

To assess the degree of influence of intrauterine alcoholization on the formation of various structural components of the brain of human embryos. Twenty-six samples of embryonic material from 8 to 11 weeks of intrauterine development were studied. The material was divided into four subgroups in accordance with the gestational age (Control 1 - 8-9 weeks of gestation and Control 2 - 10-11 weeks of gestation) and the history of the mother (presence or absence of the diagnosis «Alcoholism stage I-II» in the anamnesis). Morphometry was subjected to semi-thin sections stained by Nissl. The diameter and area of each individual tissue element (neuroblasts, glioblasts, vessels of the microvasculature, as well as the determination of the specific area (the ratio of the total area of the studied structure to the area of the entire section) and the calculation of the average number of these structures per unit area of the section, were determined. The AxioVision 4.8 program (Carl Zeiss, Germany) was used for analysis, and the Mann-Whitney test was used for statistical analysis of differences between the samples (significant differences, p<0.05). An insufficient increase in the area of vessels of the microvasculature was revealed in combination with a compensatory increase in their number per unit area of the section in the Alcohol groups compared with intact groups (48.5 μm2 vs 83.3 μm2, p<0.05). When comparing the sizes of glioblasts in the Control and Alcohol subgroups at different stages of development, a lag in the sizes of cellular structures in the Alcohol groups at the initial stages was revealed (average area 21.3 μm2 vs 32.1 μm2; 12.9 μm2 vs 13.3 μm2). When comparing data on later periods, no significant differences were found, only an increase in the specific number of cells in subgroup Alcohol 2 was noted (p<0.05). In neuroblasts, there was also a decrease in cell size with an increase in gestational age both among the Control and among the Alcohol subgroups. However, the cell sizes in Alcohol 2 exceeded those in Control 2 and their number was smaller (p<0.05). Alcohol leads to changes in the size and number of neuroblasts, glioblasts and vessels of the microvasculature and, as a result, to a disproportionate development of the entire brain tissue. The changes progress with an increase in the development period.