The role of AMPA-receptors in mechanisms of neuroprotective effect of cerebral ischemic postconditioning

Abstract

Objective. The purpose of the study is to explore the role of AMPA receptors in the neuroprotective effect of ischemic postconditioning (IРost) in the model of reversible global forebrain ischemia in Mongolian gerbils. Design and methods. Reversible global cerebral ischemia was induced by bilateral occlusion of common carotid arteries in Mongolian gerbils for 7 minutes. IРost was induced by three 15-s episodes of reperfusion/reocclusion. Antagonist of AMPA receptors NBQX was administered intraperitoneally at 2 nd minute of ischemia at a dose of 30 mg/kg. In the early and delayed reperfusion period, the number of viable neurons in the CA1, CA2, CA, and CA4 fields of the hippocampus was estimated. Results. Reversible 7 minutes ischemia followed by 48 hours of reperfusion resulted in a significant reduction in the number of viable neurons in the fields CA1 and СА3 of the hippocampus, while in the late reperfusion period a significant reduction in the number of viable neurons was observed in fields CA1, СА3 and CA4. Application of IРost has led to an increase in the number of viable neurons in fields CA1 and CA3 in the early reperfusion period and in fields CA1, CA3 and CA4 — in delayed period. AMPA receptor antagonist NBQX attenuated neuroprotective effect of IPost to a level comparable with the effect of a separate application of NBQX for neurons in the CA1 and CA3 fields of the hippocampus. Conclusions . Along with other mechanisms, the activation of AMPA receptors might be implicated in the mechanisms of cerebral IPost.