A search for brain damage in a rat model of alcoholic sleep apnea

To determine whether or not brain damage is likely to occur in the repeated apneic episodes experienced by some alcoholics during intoxicated sleep, rats were anesthetized with alcohol and subjected to repeated episodes to asphyxia. Each episode lasted 90 s, arterial PO2 was less than 50 mm Hg for 60 s, and 30 episodes of asphyxia occupied 45 min in the first h of anesthesia. In other rats asphyxic episodes occupied more than half of the first 2 or 3 h of anesthesia, or 1 h of asphyxic episodes was repeated on 5 successive days. In none of these rats was there evidence of neuronal damage by electron microscopy, or axonal degeneration by Fink-Heimer staining, or Purkinje cell loss by counting. It was found that even in normal nervous tissue about 3% of mitochondria were in condensed forms suggestive of a degenerative phase in their life cycle.