Neuropathological characters of delayed cortical infarcts after transient unilateral brain ischemia in Mongolian gerbils / 中华神经科杂志

ABSTRACT

Objective To investigate the distribution of eosinphililic neurons ( ENs),reactive astrocytes ( RAs),and infarction after transient cerebal ischemia,and the time profile of pathomorphological changes.Methods Unilateral forebrain ischemia was induced in Mongolian gerbils by two 10 minutes unilateral common carotid artery occlusions with a 5 hours interval.Laser Doppler flowmetry was used to detect intra-ischemic anterior cortex blood flow.Animals were sacrificed at 24 hours,4 days,2 weeks,4 weeks,16 weeks and the brain were prepared for pathomorphological assay.Results Intra-ischemic laser Doppler flowmetry show significant ischemia during carotid artery occlusion22.1％ ± 9.5％,26.3％ ± 4.9％,37.5％ ± 3.5％,F =67.219,P ＜ 0.01 ; the decrease was significantly greater in the anterior cortex.ENs appeared in middle and deep layers at 24 hours postischemia,and ENs area extend to all layers of cortex by 4 days.Large areas of high EN density ( ≥80/mm2) evolved to infarcts between 4 days and 4 weeks.Posterior cortex evolved to low EN area ( ＜ 80/mm2) without transformation into infarcts.RAs were consistently distributed in areas with ENs,and RA areas with high EN density were largely transformed into infarcts between 4 days and 4 weeks. Delayed astrocytic death took place in the RA areas with high EN density.Conclusion Density of ENs is an important indicator of delayed astrocytic death and infarction in postischemic tissue.