To study whether a systemically-injected derivate of the muscarinic antagonist scopolamine hydrobromide (scopolamine methylbromide) altered maze performance of rats after a 45 min exposure to 2.45 GHz electromagnetic field.
First, it was verified that the maze test enabled demonstration of memory deficits in rats treated with the muscarinic antagonist scopolamine hydrobromide (0.5 mg/kg), which poorly crosses the blood-brain barrier and which is known to induce memory impairments. The drug was injected before and after irradiation.
Scopolamin methylbromide is another muscarinic antagonist that does not cross the blood-brain barrier easily; if observed such an alteration would reflect changes in blood-brain barrier permeability.
Finally, animals were subjected to injections of Evans blue, a dye binding serum albumin, before or after electromagnetic field exposure.
|Exposure duration||continuous for 45 min|
|Pulse width||2 µs|
|Repetition frequency||500 Hz|
|Setup||Rats (n=12) were placed individually in a transparent plastic chamber (20 cm long x 17.5 cm in diameter, 13.5 cm high) located in the middle of the waveguide where they were able to move freely. Two waveguides were simultaneously excited hence exposing two rats at a time.|
|Additional info||Naive rats (n=12) were brought into the testing room in their home cages and were left in there for 45 min to serve as cage control.|
Whether scopolamine methylbromide was injected before or after exposure, the exposed animals did not perform differently from the naive (no experience of the exposure device) or sham-exposed rats. Thus, electromagnetic fields most probably failed to disrupt the blood-brain barrier. This conclusion was further supported by the absence of Evans blue extravasation into the brain parenchyma of the exposed animals.