TITLE:
Alpha Rhythms Response to 10 Hz Flicker Is Wavelength Dependent
AUTHORS:
Francesco Ferro Milone, Antonio Tullio Minelli, Roberto Cian
KEYWORDS:
Alpha Rhythms; Light Stimulation; Wavelength
JOURNAL NAME:
Neuroscience and Medicine,
Vol.4 No.2,
June
18,
2013
ABSTRACT: Since
Adrian and Metthew [1], light may be considered the dominant stimulus for the
brain. This statement is confirmed after
the discovery of the suprachiasmatic nucleus (SCN) that regulates the master biological clock [2]. In 1998 the discovery
of photopigment melanopsin in the ganglion cells of the retina, give new
insight in the importance of the light in the pathophysiology of the brain [3]. We have studied the effect of flashing at 10 Hz with LED
light of different wavelength on the response of the alpha system. We have
shown that this response, consistent with the drive of the frequency and the augmentation of the voltage of the alpha
rhythms, is far more significant with the RED-LED than GREEN-LED or BLUE-LED or
WHITE-LED (three-chrome) light flashing.
We stem the hypothesis that the amplitude increase and phase reset of the alpha
waves produced by RED-LED flashing at 10 Hz may be due either to photobiomodulation on the cytochromo c oxidase [4,5] and/or of the photopigment melanopsin, at the level of
the retinal ganglion cells, that
reinforce the incoming cone-LHC signal and therefore the projection to the SCN
[6] or to reinforcement of postsynaptic short term responsiveness, in retinal
cone-LHC synapse, due to repetitive stimulation [7,8] or both. We may speculate
that the increase of amplitude and phase reset of alpha rhythms, due to
flashing at 10 Hz, is primarily modulated in the retina.