Local blood flow in the thalamus and frontal cortex in alert and narcotized dogs

The magnitude of the local blood flow in the thalamus and cerebral cortex is studied on 22 sexually mature nonpedigree dogs. Mean values of local blood flow are obtained in alert animals, and the effect of narcosis (nitrous oxide) on the local cerebral blood flow is studied. The mean local blood flow in alert dogs is found to be 84.8 +/- 2.9 ml/100 g/min in the cerebral cortex and 68.7 +/- 1.6 ml/100 g/min in the thalamus. Insignificant fluctuations are found during a dynamic recording of the local blood flow during 7 days. Under narcosis (70% nitrous oxide) the local blood flow decreases 3-12%. According to the findings, nitrous oxide narcosis does not significantly affect the brain circulation, so that it is suitable for an experimental study of the latter.