Morphofunctional changes and expression of LAMP2 in the rat hippocampus in chronic cerebral ischemia

Abstract

AbstractBackgroundThe hippocampus, part of the limbic system, is involved in the formation of the cognitive sphere and is one of the most vulnerable structures in chronic cerebral ischemia.MethodChronic cerebrovascular disorders modeled in rats by limiting blood flow with applying ligatures to the carotid arteries. Behavioral status, cognitive and mnemonic functions, the degree of neuronal damage, and the level of LAMP2 expression in the pyramidal layer of the hippocampus were investigated.ResultAfter a 20‐day subtotal cerebral ischemia, we revealed a change in the functional state of the nervous system, expressed in a decrease of the main reflexes, tentative‐research activity, as well as a decrease in memory. Dystrophic changes in pyramidal neurons were of different severity, determined by a significant increase in the number of hyperchromic neurons, and in most of them total nuclear and cytoplasmic hyperchromia was observed, combined with a picture of spongiosis due to pericellular edema. A significant increase in LAMP2 expression compared to the control in both the relative area by 0.8% (p <0.05) and the intensity of the expression was detected in the CA1 zone.ConclusionThe amplification of LAMP‐2 expression is a marker for the inclusion of autophagy mechanisms aimed at implementing compensatory processes in many disorders of the central nervous system, including chronic cerebral ischemia. The observed increase in the specific number of pyramidal neurons with signs of damage, sharp pericellular and perivascular edema in combination with increased expression of LAMP‐2 in the CA1 zone of the hippocampus indicates the important role of autophagy for the survival of neurons in chronic cerebral ischemia.