CHANGES OF THE ULTRASTRUCTURE OF SYNAPSES IN THE ANTERIOR CORTICAL NUCLEUS OF THE AMYGDALA OF THE BRAIN OF FEMALE RATS DEPENDING ON THE LEVELS OF SEX HORMONES

The analysis of the ultrastructural characteristics of synapses was performed in the anterior cortical nucleus of the amygdala of the brain in female WAG/Rij rats (n=9) at different levels of female sex hormones. The results of the study demonstrated that ovariectomy lead to structural changes of synapses and decline in their total population compared with that in the control group, while hormone replacement therapy was able to restore the structure of the synapses and their number. It was shown that according to the degree of expression of dense projections both in the control group and after ovariectomy asymmetrical synapses predominated (52%), according to the type of curvature of the plane of the synaptic contact, the synapses with positively curved contact prevailed. After replacement therapy, there was a slight decline in the number of asymmetric synapses (47%), most of them had negatively curved contact. Elaborate synaptic complexes of divergent and convergent types were determined, suggesting the active functional state of the contacts. The number of perforated synapses significantly increased from 14.3 to 50%, which may indicate the estrogenic activation of synapses.

amygdala, anterior cortical nucleus, synapses, sex hormones, WAG/Rij rats