Neurons Exhibited Cell Shrinkage (IMAGE) Neural Regeneration Research Caption Following exposure to hypobaric hypoxia for six hours, a large number of neurons exhibited cell shrinkage, karyopyknosis as well as karyolysis (toluidine blue staining, × 400). Credit <i>Neural Regeneration Research</i> Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.