Red neurons - Acute neuronal injury
There is not some simple dichotomy of "neurons shrink and other cells swell" in response to hypoxia/ischemia.

Neuronal death can be necrotic or apoptotic or both, and at different stages different morphology is observed: generally swelling earlier, shrinkage later, though both are observed together early as well. Eosinophilia/"red neurons" tends to occur later as mentioned in this passage (after 6 hours, consistent with 12-24 hours) so that's probably why the author is referring mostly to shrinkage. Cells can also have swelling of some organelles, like mitochondria, despite shrinking overall.

Without further context of the passage you provided it's hard to say much more.



Garcia, J. H., Yoshida, Y., Chen, H., Li, Y., Zhang, Z. G., Lian, J. I. N. Y. I. N. G., ... &amp; Chopp, M. (1993). Progression from ischemic injury to infarct following middle cerebral artery occlusion in the rat. The American journal of pathology, 142(2), 623.

Jenkins, L. W., Povlishock, J. T., Lewelt, W., Miller, J. D., &amp; Becker, D. P. (1981). The role of postischemic recirculation in the development of ischemic neuronal injury following complete cerebral ischemia. Acta neuropathologica, 55(3), 205-220.

Portera‐Cailliau, C., Price, D. L., &amp; Martin, L. J. (1997). Excitotoxic neuronal death in the immature brain is an apoptosis‐necrosis morphological continuum. Journal of Comparative Neurology, 378(1), 10-87.