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

•We analyzed the time course of neuronal death in a rat model of ET-1 induced stroke targeting the forelimb motor cortex.•Maximal infarct volume is achieved within 24 h of ischemia in this model.•The process of neuronal degeneration is maximal within 24 h of ischemia.

BackgroundEndothelin-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 methodWe 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.ResultsWe found that infarct volume and neuronal degeneration are maximal at 24 h post-stroke. Neuronal degeneration is also significantly reduced within 7 days of stroke induction.Comparison with existing methodThis 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.ConclusionThis 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.