The nature and timing of @entity528 in the cerebral cortex, hippocampus and thalamus due to XXXX -induced @entity159 .

@entity1400 @entity1399 @entity63 @entity4 @entity4053 @entity15945 @entity302 @entity159 @entity528
@entity15945 -induced @entity159 was studied by light and electron microscopy (LM, EM) to determine the time course and structural features of @entity528 in the vulnerable brain regions in @entity302 . The cerebral cortex, hippocampus and thalamus were examined after closely spaced recovery periods of up to 1 week. The results showed that acidophilic neurons appeared simultaneously in neurons of the neocortex, hippocampus and thalamus, and that this occurred within 1 h following the end of the @entity302 . The corresponding features of acidophilic neurons by EM were mitochondrial flocculent densities and large discontinuities in cell and nuclear membranes. Dark neurons were ubiquitous during the @entity302 , but recovered almost universally. A few dark neuronal forms persisted and underwent cytorrhexis after 12-h recovery or longer. Axon-sparing dendritic lesions characteristic of excitotoxic @entity528 were found in the neuropil of the neocortex, and in both vulnerable @entity1399 and resistant @entity1400 neurons of the hippocampus. Other than acute @entity4 , glial changes were absent. The findings support an excitotoxic mechanism in @entity302 -induced selective @entity528 also in brain regions outside the hippocampus, and contrast with previous reports in @entity63 and @entity4053 in that @entity528 occurs virtually immediately after an @entity302 insult. No "maturation" of cell damage, as described in @entity63 , was seen. Furthermore, even exceedingly dark neuronal forms and massive @entity4 must be considered sub-lethal or prelethal cellular changes. Lethal cellular changes include acidophilia by LM, cell membrane breaks, and mitochondrial flocculent densities by EM.
