Transcortical Alterations inNa+-K+ATPase and Microtubule-Associated Proteins Immunoreactivity in the Rat Cortical Atrophy Model Induced by Hypoxic Ischemia

[摘要] To identify the chronological transcorticalchange in the contralateral hemispherefollowing ischemic insults, we investigated thechanges in microtubule associated protein(MAP) andNa+-K+ATPase expressions in theperi-infarct zone and contralateral hemisphere,including the hippocampus. Two days afterhypoxic ischemia,Na+-K+ATPase immunoreactivitywas significantly enhanced in thecontralateral cortex and was maintained up to 7days after ischemia, whereasNa+-K+ATPase immunoreactivity in the peri- and infarct zoneswas unaffected by hypoxic ischemia. In contrast,2 to 7 days after ischemia, MAP1A and MAP2immunoreactivity in the ipsi- and contralateralcortex significantly decreased, whereas in layerV, MAP1 immunoreactivity obviously accumulatedin the neurons and their processes. In thehippocampus, 2 days after insults both MAP1Aand MAP2 immunoreactivity was significantlyreduced within the ipsi- and contralateralhippocampus. In the contralateral hippocampus,however, the distribution of MAP2 immunoreactivityrecovered to the sham level 7 daysafter ischemia, whereas MAP1A immunoreactiveaxons remained 2 months afterischemia. The results suggest that the unilateralelevation ofNa+-K+ATPase immunoreactivityreflects elevated neuronal activity. In addition,this asymmetric hyperexcitability might play animportant role in the recovery or thereorganization of the brain, accompanied bytranscortical changes in MAPs expression.

[学科分类] 精神健康和精神病学