Transition of areas of eosinophilic neurons and reactive astrocytes to delayed cortical infarcts after transient unilateral forebrain ischemia in Mongolian gerbils

Abstract

The fate of postischemic tissues containing eosinophilic neurons (ENs), whether they remain viable or evolve into infarction, is largely unknown. We analyzed the time profile and distribution of ENs, reactive astrocytes (RAs), and infarction after transient cerebral ischemia. Unilateral forebrain ischemia was induced in Mongolian gerbils by two 10-min unilateral common carotid artery occlusions with a 5-h interval, and the brains at 24 h, 4 days, and 2, 4, and 16 weeks were prepared for morphometric analysis. Intra-ischemic laser Doppler flowmetry revealed significant ischemia, deeper in the anterior cortex, during carotid occlusion. Here, ENs appeared in the middle and deep layers at 24 h postischemia, and EN areas had extended to all cortical layers by 4 days. Large areas of high EN density turned into infarcts between 4 days and 4 weeks. In the posterior cortex, middle and deep cortical layers evolved low EN density areas without subsequent transformation into infarcts. RAs were consistently observed in areas with ENs, and RA areas with high EN density were largely transformed into infarcts between 4 days and 4 weeks postischemia. Areas of high, but not low, EN density were slowly transformed into infarcts after transient cerebral ischemia. Delayed astrocytic death took place in the RA areas with high EN density. In conclusion, density of ENs is an important indicator of delayed astrocytic death and infarction in postischemic tissue.

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

“…While the infarct volume per se did not change at 7-days poststroke, the FJC-positive cell population significantly decreased compared to the pattern observed at 24 or 48 h. After stroke, in brain tissue stained with H & E, degenerating cells becomes eosinophilic and areas of high eosinophilic positive cells evolve into infarcts (Sun et al, 2006). The goal of this staining is to allow a macroscopic differentiation between damaged and undamaged tissue (Garcia et al, 1993).…”

Effects of ebselen on ischemia/reperfusion injury in rat brain

“…Eosinophilic neurons (EN) are the hallmarks of ischemic encephalopathy [16]. Sun et al [12] reported that intense EN areas transform into infarct areas when compared to areas of low-density EN. In our study, IR group revealed a large number of EN compared to Ebselen and control group.…”

“…Total (Cu/Zn and Mn) SOD (EC 1.15.1.1) activity was determined based on the method of Sun et al [12]. The principle of the method is based on the inhibition of Nitro Blue Tetrazolium (NBT) reduction by the xanthine-xanthine oxidase system as a superoxide generator.…”

Protective Effects of Minocycline against Short-Term Ischemia-Reperfusion Injury in Rat Brain

“…Eosinophilic neurons (EN) are the hallmarks of ischemic encephalopathy. Sun et al [30,31] reported that intense EN areas transform into infarct areas when compared to areas of low-density EN. They added that low-density EN areas remained as areas of selective neuronal death.…”