Exploring the effect of photobiomodulation and gamma visual stimulation induced by 808 nm and visible LED in Alzheimer's disease mouse model

Photobiomodulation in the aging brain: a systematic review from animal models to humans

“…Of those, 30% employed healthy aged rats between with 16 [25,26] and 20 months old [9,[27][28][29][30], 17% used healthy aged mice with 12 months [31], 18 months [32] or with an aging-induced protocol [33,34], 39% employed an AD mice model [35][36][37][38][39][40][41][42][43], 9% a PD rat model [44,45], and 4% used a postoperative neurocognitive disorder (PND) mice model with 18-20 months [46]. Considering sex, most of the studies (74%) were performed only in males [9, 25-31, 33-37, 39, 45, 46], 13% in females [38,42,44], 4% included both sexes [41], and 9% did not report the sex of animals [40,43]. Most of the studies were methodologically cross-sectional, while 17% performed longitudinal analysis at ages 3, 7, and 12 months [38]; 3 until 9 months [37]; 4 until 6 months [39]; 1 until 6 months [41].…”

“…Regarding the PBM wavelength, 70% of the studies used NIR light, at 808 nm [37,43,44], 810 nm [9, 27-29, 33, 41, 46], 830 nm [25,26,45], 1070 nm [42], 1072 nm [38], and at 1267 nm [39]. Other studies (26%) employed wavelengths in the red spectrum with 610 nm [36], 630 nm [35], 635 nm [40], 660 nm [30,32], and 670 nm [31].…”

“…Only one (4%) compared both an NIR light at 810 nm and a red light at 660 nm [34]. Considering wavelength type, 44% used a continuous wave [9, 25-30, 32, 45, 46], 17% pulsed at 10 Hz [33,34], 100 Hz [41], and 600 Hz [38], while others 9% compared both continuous wave with pulsed at 40 or 100 Hz [37,43], and 4% between 10 and 40 Hz [42]. Notably, 26% of the studies did not report whether the wave was continuous or pulsed [31,35,36,39,40,44].…”

“…The 13% used a total intensity of 71.96 J [25,26,45], 22% 15 J -3 J per point [9,[27][28][29][30], 4% used 16 J/ cm 2 [32], 4% used 2.0 J/cm 2 [36], 4% 4.5 J/cm 2 [42], 4% 6 J/cm 2 [40], 17% compared different intensities, such as 4 and 8 J/ cm 2 [34], 16 and 32 J/ cm 2 [39], 16 and 36 J/cm 2 [33], and 80 and 160 J/ cm 2 [46]. The 30% did not include data about intensity [31,35,37,38,41,43,44]. Regarding irradiance, 35% reported a value of 100 mW [25][26][27][28][29][30]45], 4% reported 5 mW [38], 9% 200 mW [32,34], 4% 8.75 mW [40], 4% 1 W [35], 4% 80 mW/cm 2 [46], 4% 50 mW/cm 2 [43], 4% 25 mW/cm 2 [42], 4% 4.75 mW/cm 2 [33] and 4% 1.7 mW/cm 2 [36], 13% compared different irradiances, one with 40, 200 and 400 mW [37], another with 5 and 470 mW [41] and the last one with 2.5, 5 10, 25 and 30 mW/cm 2 [44].…”

“…The 30% did not include data about intensity [31,35,37,38,41,43,44]. Regarding irradiance, 35% reported a value of 100 mW [25][26][27][28][29][30]45], 4% reported 5 mW [38], 9% 200 mW [32,34], 4% 8.75 mW [40], 4% 1 W [35], 4% 80 mW/cm 2 [46], 4% 50 mW/cm 2 [43], 4% 25 mW/cm 2 [42], 4% 4.75 mW/cm 2 [33] and 4% 1.7 mW/cm 2 [36], 13% compared different irradiances, one with 40, 200 and 400 mW [37], another with 5 and 470 mW [41] and the last one with 2.5, 5 10, 25 and 30 mW/cm 2 [44]. Finally, 9% did not report the irradiance employed [31,39].…”