Brain Edema XIII pp 239-243

Restitution of ischemic injuries in penumbra of cerebral cortex after temporary ischemia

  • U. Ito
  • E. Kawakami
  • J. Nagasao
  • T. Kuroiwa
  • I. Nakano
  • K. Oyanagi
Conference paper

DOI: 10.1007/3-211-30714-1_51

Part of the Acta Neurochirurgica Supplementum book series (NEUROCHIRURGICA, volume 96)
Cite this paper as:
Ito U., Kawakami E., Nagasao J., Kuroiwa T., Nakano I., Oyanagi K. (2006) Restitution of ischemic injuries in penumbra of cerebral cortex after temporary ischemia. In: Hoff J.T., Keep R.F., Xi G., Hua Y. (eds) Brain Edema XIII. Acta Neurochirurgica Supplementum, vol 96. Springer, Vienna

Summary

We investigated, at both light and ultrastructural levels, the fate of swollen astrocytes and remodeling of neurites connected to disseminated, dying neurons in the ischemic neocortical penumbra. Specimens from left cerebral cortex were cut coronally at the infundibulum and observed by light and electron microscopy. We measured synapses and spines, and the thickness of neuritic trunks in the neuropil on electron microscopy photos. We also determined percent volume of axon terminals and spines by Weibel’s point-counting method. Astrocytic swelling gradually subsided from day 4 after the ischemic insult, with increases in cytoplasmic glial fibrils and GFAP-positive astrocytes. Disseminated dying electron-dense neurons were fragmented by invading astrocytic cell processes and accumulated as granular pieces. The number of synapses and spines and total percent volume of axon terminals and spines decreased with an increasing sparsity of synaptic vesicles until day 4. One to 12 weeks after the ischemic insult, these values increased to or exceeded control values, and sprouting and increased synaptic vesicles were seen. Axons that had been attached to the dying neurons appeared to have shifted their connections to the spines and the neurites of the surviving neurons, increasing their thickness. Astrocytic restitution and neuronal remodeling processes started at 4 days continuing until 12 weeks after ischemic insult.

Keywords

Maturation phenomenon cerebral ischemia neuronal remodeling 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • U. Ito
    • 2
    • 4
    • 1
  • E. Kawakami
    • 2
  • J. Nagasao
    • 2
  • T. Kuroiwa
    • 3
  • I. Nakano
    • 4
  • K. Oyanagi
    • 2
  1. 1.TokyoJapan
  2. 2.Department of NeuropathologyTokyo Metropolitan Institute for NeuroscienceTokyoJapan
  3. 3.Department of Neuropathology, Medical Research InstituteTokyo Medical and Dental UniversityTokyoJapan
  4. 4.Department of NeurologyJichi Medical SchoolTochigiJapan

Personalised recommendations