Ultrastructural Changes in the Edematous Central Nervous System

CEREBRAL EDEMA produced by localized cortical freezing has become an experimental modus operandi since the introduction of an easily reproducible technique by Hass and Taylor in 1948.1This technique was refined subsequently.2-4A review of the literature shows that, regardless of freezing agents and sites of application, the results obtained from different animal species are essentially the same, namely, a focal hemorrhagic lesion in the cerebral cortex accompanied by wide-spread edema in the white matter of the damaged hemisphere. The details of pathological changes studied by histological, chemical, and tracer methods were previously reported by one of us.5 In contrast to the extensive light microscopic investigation of cold-induced edema, the ultrastructural changes have been studied only by Torack et al.6These authors limited their electron microscopic examination to the cerebral cortex adjacent to the lesion. For this reason their observations cannot be extended to