A New Model for Long-Term Investigations of Cerebral Oxygen Supply in Rats

Abstract

Micro-electrode as well as micro-application studies of the brain cortex require in most cases the exposure of the cerebral surface. Since trepanation of the skull and opening of the dura cause a drastic reduction of intracranial pressure, especially in small animals, brain swelling and local ischemia are often to be observed (Maekawa et al., 1979; Morii et al., 1986). In order to prevent brain herniation with subsequent insufficient tissue oxygen supply in the course of the experiments, the conventional open cranial window technique was modified by covering the exposed cortical area with an oil layer, by means of which the level of hydrostatic pressure was maintained close to that of the intracranial pressure (Morii et al., 1986). The efficiency of the modified model was evaluated by long-term investigations of the tissue oxygen supply in the brain cortex measuring the tissue oxygen tension distribution over a period of up to 6 hours.