[Synaptic plasticity of neocortex of albino rats in diffuse-focal injuries of the brain].

In an experiment conducted using mature albino rats, the regularities of reorganization of synaptic architectonics of cortical layer I of the brain were studied in the areas of diffuse-focal injuries. The models of acute break of systemic circulation (clinical death) as a result of 6-minute-long mechanical asphyxia, compression of common carotid arteries for 20 min (ischemia) and rotatory sublethal injury according to Noble-Collip method (cranial trauma), were used. Using the methods of electron microscopy and morphometric analysis, it was shown that a reduction in a general numerical density of synapses was accompanied by the changes in relative and absolute numbers of major variants of synaptic organization. The content of large simple and perforated contacts was increased, as well as of synapses with invaginated synaptic membranes, containing mitochonria and spine apparatus. The changes detected are considered as a structural basis for realization of the mechanisms of synaptic plasticity in diffuse-focal injuries of the brain.

[Ultrastructural changes in organelles of the dog cerebral cortex astrocytes in post-ischemic period (morphometric analysis)]. / Ul'trastrukturnye izmeneniia organell astrotsitov kory bol'shogo mozga sobaki v postishemicheskom periode (morfometricheskii analiz).

Morphometric analysis of volume density of mitochondria, rough endoplasmic reticulum (RER), Golgi complex, vacuoles, lysosomes, fibrils, superficial density of mitochondria and RER, postischemic mitochondria/RER superficial and volume ratio and astrocyte ultrastructure was carried out experimentally in dogs. The findings obtained indicate that in early postischemic period (5-10 min-3-7 d) changes in astrocyte were reactive, although since the second wk of postischemic period metabolic processes in astrocytes were disturbed, which were manifested through structural changes maximally pronounced on d 14-21 of reparative period. At late reparative period (first-third month) astrocyte structure was normalised to significant extent.