It sounds like their control rats were kept literally in the dark... so unless I'm reading it wrong, this is an interesting result, with a terribly bad control

It sounds like their control rats were kept literally in the dark... so unless I'm reading it wrong, this is an interesting result, with a terribly bad control that renders (IMNSHO) their conclusions invalid based on poor controlling of the variables. This sort of thing should have had 2 control groups. One kept in the dark, the other exposed to the light protocol they used for artificial lighting, using natural sunlight as the light source.