RESUMO
Local cerebrovascular disorders were modeled by reversible photochemical clotting of hemispheric cortical vessels. Mild ischemia led to reversible edema in the surface layers of the cortex: cytotoxic edema of the neuropile, primarily of the distal dendrites. This status led to an increase in the lower delta rhythm frequency band power. After administration of systemic anesthetic, delta rhythm appeared sooner in the ischemic foci than in intact cortical areas. More severe ischemia led to the appearance of dark and pyknotic neurons and reduction of oscillation power in all EEG spectrum bands. Restructuring of primarily dendrites caused by local moderate ischemia of the surface cortical layers at the early stage of neurodegenerative processes stimulated the inhibitory recovery processes.
Assuntos
Anestésicos/farmacologia , Infarto Cerebral/fisiopatologia , Ritmo Delta/efeitos dos fármacos , Hipóxia-Isquemia Encefálica/fisiopatologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Córtex Cerebral/fisiopatologia , Infarto Cerebral/induzido quimicamente , Dendritos/efeitos dos fármacos , Dendritos/metabolismo , Eletroencefalografia , Hipóxia-Isquemia Encefálica/induzido quimicamente , Masculino , Neurópilo/patologia , Ratos , Ratos Wistar , Rosa Bengala/toxicidadeRESUMO
Structural changes in the sensorimotor cortex of the cerebral hemispheres were studied in rats with experimental hemorrhagic stroke in the internal capsule. Changes in the shape and decrease in the density distribution of spines on apical dendrites of layer V pyramidal neurons of the sensorimotor cortex were revealed. Some fractions isolated from the complex of neurotrophic factors of the cerebral cortex of animals with a favorable outcome of hemorrhagic stroke were shown to affect the distal and proximal dendritic loci. As differentiated from the "nonactive" fraction, the "active" fraction improved the behavior of rats surviving hemorrhagic stroke. The density distribution of spines (particularly in the distal region of apical dendrites of pyramidal neurons in layer V of the cerebral cortex) was stabilized after treatment with the "active" fraction. The "nonactive" fraction had a selective effect on the proximal loci.
