The authors attempted to repeat a portion of the study by Oscar and Hawkins in which pulsed and continuous wave microwave radiation increased permeation of labeled tracers through the blood-brain barrier. At the SAR used (0.1 W/kg) the calculated average brain temperature rise is less than 0.1C. The authors found no changes in permeation, however, there were differences in experimental conditions, including type of tracers, frequency and microwave field configuration. It is possible but unlikely that one of these differences is responsible for the apparent discrepancy in results.