Effects on the Blood Brain Barrier (BBB). The following studies demonstrate effects on the blood brain barrier (BBB). Microwave alteration of the blood-brain barrier system of rats. Radiofrequency and extremely low-frequency electromagnetic field effects on the blood-brain barrier. Reversible microwave effects on the blood-brain barrier Effects of radiofrequency radiation exposure on blood-brain barrier permeability in male and female rats Blood-brain barrier permeability and nerve cell damage in rat brain 14 and 28 days after exposure to microwaves from GSM mobile phones Microwave irradiation of rats at 2.45 GHz activates pinocytotic-like uptake of tracer by capillary endothelial cells of cerebral cortex.