Changes in the structure of synaptic intercellular contacts in focal brain lesions

Abstract

Purpose: to evaluate changes in the structure of synaptic contacts in various types of focal brain pathology. Materials and methods. The results of treatment of 40 cases of supratentorial focal lesions of the brain (FLB) were retrospectively evaluated. The cases are divided into groups: 30 gliomas of various degrees of malignancy and 5 consequences of TBI, 5 epilepsy. All patients underwent surgical interventions. The synaptic plasticity of axo-dendritic and axo-spiny asymmetric synapses of neurons of the VI-VII layers of the frontotemporal cortex was studied by electron microscopy. Morphometric analysis was carried out on a computer image analyzer САИ-01АВН using the software "Kappa opto-electronics GmbH" using the STATISTICA 7 program package. The results. It was established that the density of synapses decreased in glioblastomas (GB) and craniocerebral injury (ССІ). Qualitative changes demonstrate the plasticity of architectonics of synapse, in particular due to the increase in the number of perforated synaptic contacts. Maximum thickening and diffuse stratification of the postsynaptic seal indicates a violation of the functional capacity of the postsynaptic component of the contacts. A decrease in the number of synaptic vesicles was revealed in ССІ and GB, with their rearrangement, which is probably a manifestation of synaptic dysfunction. The latter proves the irreversibility of destructive local changes and is unfavorable criterion. The risk of the formation of destructive-degenerative changes in the synaptic apparatus is 7.64 times higher in DA, 3.17 times higher in GB, and 17.31 times higher in ССІ compared to cases of epilepsy, with GB significantly increases by 13.5 times compared to DA. Therefore, the assessment of the structural features of neuroplasticity should take into account the morphogenesis of the BM in comparison with clinical data Conclusions. In the zones of invasive growth of gliomas of various degrees of malignancy and in ССІ and epilepsy, the indicators of synaptic plasticity differ statistically significantly. The density of placement of synapses is lower in GB and ССІ. The probability of non-reversibility of destructive-degenerative changes of synapses according to the number of SVs in FLB correlates with the degree of glioma differentiation with a sensitivity of 81.0% and a specificity of 76.0%. According to the structural changes of synaptic connections in tumors, probable differences between the variants have been proven: GB and DA, the sensitivity of the discriminant model is 85.0%, the specificity is 74.0%, which is an indirect evidence of the growth rate of the tumor mass and its destructive effect on the surrounding brain matter. The obtained results are important in assessing the prognosis of the further course of the disease.