RESUMO
Structural changes in the rat hippocampus in response to chronic cerebrovascular disorders induced by gravity exposure in the caudocranial vector were studied. Qualitative and quantitative morphological analysis detected significant cytoarchitectonic changes in the pyramidal layer: spongiosis, manifest pericellular and perivascular edema, and a drastic increase in the counts of pyramidal neurons with signs of impairment in all hippocampal zones. The density of perikarya in the pyramidal layer decreased. Immunohistochemical study detected high expression of Beclin-1 in CA1 field. High expression of LAMP-2 was detected in CA4 field. Field CA2 was characterized by the maximum counts of damaged cells and high expression of Beclin-1 and LAMP-2.
Assuntos
Proteína Beclina-1/metabolismo , Hipocampo/metabolismo , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Animais , Autofagia/fisiologia , Região CA3 Hipocampal/metabolismo , Giro Denteado/metabolismo , Gravitação , RatosRESUMO
Animals were subjected to seven days combined stress in a special chamber (6 isolated compartments of equal area) with removable multi-modal stressors (noise, vibration, pulsating bright light) every 5 minutes on the stochastic scheme with restraint and temperature rise in the chamber during 30-minute stressing time sessions. After exposure to combined stress in the ventral hippocampus of old rats (24 months) compared with adult animals (12 months) following changes were revealed: marked dystrophic changes and increased inducible nitric oxide synthase expression in pyramidal neurons of CA3 field, signs of impaired hemodynamic disorders in the microvasculature, perivascular edema, decreased endothelial nitric oxide synthase expression in microvascular endothelial cells, as well as decreased expression of serine racemase in the neuropil of the radial layer of CA1 field.
Assuntos
Hipocampo , Envelhecimento , Animais , Óxido Nítrico Sintase , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Células Piramidais , RatosRESUMO
Adult rats were subjected to 7-day combined stress with stochastic changes of stressors of different modalities (noise, vibration, pulsating bright light) along with mobility restriction and elevated temperature in the chamber during stress exposures (daily 30-min sessions). Circulatory disorders, inhibition of endothelial NO-synthase expression in endothelial cells of the microcirculatory bed, perivascular edema, pronounced degenerative changes, and enhanced expression of inducible NO synthase in CA3 pyramidal neurons in the ventral hippocampus of stressed 12-month-old rats were observed. These findings can attest to the involvement NOdependent mechanisms and different contribution of NO synthase isoforms into the formation of hippocampal neuronal damage.