Time course of neuronal death following endothelin-1 induced focal ischemia in rats

Background: Endothelin-1 (ET-1) induced focal ischemia is increasingly being used as a preclinical model of stroke. Here, we described for the first time, the time course of neuronal death and infarct evolution during the first 7 days following ischemia. New method: We used hematoxylin and eosin (H&E) staining to evaluate infarct progression and Fluoro-Jade C (FJC) to quantify neuronal degeneration at 24, 48, 72 h and 7 days after ET-1 injection to the forelimb motor cortex in Sprague-Dawley rats. Results: We found that infarct volume and neuronal degeneration are maximal at 24h post-stroke. Neuronal degeneration is also significantly reduced within 7 days of stroke induction. Comparison with existing method: This study is the first to provide a direct evaluation of both infarct volume evolution and neuronal death time course following ET-1 induced focal ischemia in the forelimb motor cortex. Conclusion: This study describes the short-term time course of neuronal death and brain injury in the ET-1 stroke model, which provides a significant reference when determining the appropriate time to commence neuroprotective or recovery promoting strategies. (C) 2015 Elsevier B.V. All rights reserved.