Physiol. Res. 55: 339-348, 2006

Temporal Profile of Ultrastructural Changes in Cortical Neurons after a Compression Lesion


1Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden, 2Institute of Experimental Medicine AS CR, Prague and 3Department of Neuroscience, Second Medical Faculty, Charles University, Prague, Czech Republic

Received October 25, 2004
Accepted July 18, 2005
On-line available August 5, 2005

We studied the occurrence of apoptosis and secondary delayed cell death at various time points in the penumbra zone, which is the target for therapeutic intervention after stroke. A compression lesion was induced in the right sensory motor cortex of rat brains. At 0.5, 1, 3, 6, 12, 24, 48 and 72 h after lesioning, motor functions were evaluated by behavioral tests, and cortical layers IV and V were examined by electron microscopy. Behavioral recovery was observed at 48 h after lesioning. At 0.5-1 h in the lesioned area, the neuropil was expanded and contained affected cells. Apoptotic cells were found between 0.5-72 h, and at 12 h, 47.3 % of the total cell number was apoptotic cells. On the contralateral side, cells showed an enlarged endoplasmic reticulum at 3 h, indicating secondary delayed cell death. Our results show that a compression lesion is a useful model for studying ultrastructural changes in injured cells. The lesion results in the penumbra zone with apoptotic cell death between 0.5-72 h. As secondary delayed cell death occurred on the contralateral side at three hours after lesioning might be the time period during which injured, but still viable, neurons can be targets for acute treatment.

Key words
Stroke • Ischemia • Sensory motor cortex • Cell death • Ultrastructure

© 2006 by the Institute of Physiology, Czech Academy of Sciences