ISSN:
1432-0533
Schlagwort(e):
Complete cerebral ischemia
;
Postischemic recirculation
;
Electron microscopy
;
Nuclear perturbations
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary Neuronal, astrocytic, and oligodendrocytic elements in several brain loci of the cat were examined at the light and electron microscopic level immediately after periods of complete cerebral ischemia (CCI) uncomplicated by post-ischemic recirculation. Such CCI episodes ranged from 1.5–25 min duration and were methodically produced in a cat model employing rigorous physiological controls. Subsequent to these CCI insults, morphological alterations occurred in a homogeneous manner within each cell type of all loci examined; however, variation in the temporal onset and magnitude of alterations among the various cell types was observed. With brief ischemic insults all cell nuclei demonstrated pronounced nuclear alterations, while their cytoplasmic organelles displayed minimal change. Chromatin clumping and nucleolar condensation were observed in both neurons and glia subsequent to 1.5–5 min of CCI, respectively. With increasing durations of CCI such changes were more dramatic and conspicuous alterations of the cytoplasmic organelles were observed. On the basis of extensive morphological analyses the present study illustrates that nuclear alterations are the first to occur subsequent to CCI. The homogeneity of neuronal involvement seen subsequent to CCI uncomplicated by post-ischemic recirculation is inconsistent with the “selective vulnerability” purported to occur by others. The significance of this inconsistency remains to be assessed; yet, the suggestion is advanced that post-ischemic recirculation may be a factor in the genesis of such vulnerability.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00691152
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