DURING REPETITIVE FOREBRAIN ISCHEMIA, POSTISCHEMIC HYPOTHERMIA PROTECTS NEURONS FROM DAMAGE

In rodents damage from repetitive transient cerebral ischemia is more severe than that seen with a single ischemic insult of similar duration. Mild hypothermia has been shown to be very effective in protecting the brain during single ischemic insults. We tested the protective effects of hypothermia in repetitive ischemic insults. We used the gerbil model of repetitive ischemia (three minutes ischemia repeated at one hourly intervals three times) and histological evaluation was done using the silver staining technique. Our study reveals that a decrease in body and scalp temperature by 1-2 degrees Celsius can significantly reduce neuronal damage in the cerebral cortex, CA1 region of the hippocampus and substantia nigra reticulata during repetitive ischemia. As the hypothermia was induced after the initial insult, we believe this offers an opportunity for intervention in the clinical settings.