81 — Rhythmical Photic Stimulation at Alpha Frequencies Produces Antidepressant-Like Effects in a Mouse Model of Depression

This paper discusses light therapy as a viable strategy for neuropsychiatric treatment. These sorts of papers and these sorts of topics usually make me feel a bit suspicious — neuropsychiatry is notoriously difficult to study because the features of these disorders are ① very complex and generally behavioral or otherwise high-level, and ② animal models for human psychiatry is difficult to support with fact.

With that in mind, I read these articles with a lot of grains of salt.

This paper in particular finds that 9 to 11 Hz flickering of LEDs — well within the $\alpha$ brainwave range — improves mouse performance on social and behavioral tests. Meanwhile, fluoxetine produced less robust effects in certain tasks, and approximately equal levels of improved performance in others.

This is a bit hard to swallow, but very interesting; my understanding is that CORT-induced depression models in mice are generally reasonable models of “naturally ocurring” human depression for certain flavors of behavioral studies.

Photic-CORT mice in this study appeared to perform better and have lower anxiety in maze or swimming tasks, though the fluoxetine-CORT populations were not dramatically behind in any behavioral tasks besides a measure of the amount of time spent in the center of an open-field box (an indication of lower levels of anxiety).

I think the takeaway message here is that photic stimulation produces some difference in behavior or (perhaps?) anxiety levels; but it’s very unclear to me if this is a result of the stimulation itself or perhaps a byproduct of the stimulating environment; I would love to see a control performed where another population was exposed to bright light of the same wavelength for the same amount of time, but without alpha-frequency fluctuations.