Comparison of a short irradiation (50 sec) by different wavelengths on audiogenic seizures in magnesium-deficient mice: evidence for a preventive neuroprotective effect of yellow.

Audiogenic seizures triggered by an acoustic stimulus of determined frequency and amplitude have been described in many laboratory animals in many circumstances including magnesium deficiency. This model, recently validated, was used, in DBA/2 mice, to study the preventive neuroprotective effect of 6 wavelengths of the visible spectrum used in Chromatotherapia* (lambda(max) 440, 484, 528, 572, 616 and 660 nm) at low irradiance. Each short illumination lasted 50 seconds and was followed by 20 minutes of darkness. It appeared that yellow fully protected 16 out of 17 mice from seizure occurrence. Green allowed the survival of 69% of mice but did not protect them from seizure occurrence. On the contrary, the other four colors (orange, red, purple and blue) failed to protect the mice and showed a tendency to accelerate their death. White color was not protective but allowed the difficult survival of 30% of mice. Darkness had no protective effect. These results even though surprising open a great field of investigation.