OLED Gamma 40Hz visual stimuli affect Amyloid Beta accumulation and cognitive impairment with the potential of color-dependent effects.

초록

Gamma oscillations (about 20-50 Hz) are altered in many neurodegenerative diseases and psychiatric disorders. Gamma entrainment using 40 Hz visual stimulation induces 40 Hz oscillations and several outputs, such as attenuated amyloid beta load with the increased phagocytic activity of microglia in Alzheimer’s disease and mood improvement in major depressive disorder. Therefore, these days, gamma entrainment using 40 Hz visual stimulation suggested as therapeutic treatment for psychiatric and neurological conditions. However, the underlying mechanisms of optical stimulation on molecular and circuit level remain unclear. We evaluated whether the OLED (Organic Light-Emitting Devices) 40 Hz visual stimulation affects cognitive impairments in 5XFAD mice and depressive-like symptoms in chronic social defeat stress (CSDS) animal model. In addition, we divided mice group according to the wavelength within visible light. White and red gamma stimulation significantly reduced Amyloid Beta accumulation in ventral hippocampus of 5XFAD mice and enhanced cognitive function in novel object recognition test which indicates long-term memory. In CSDS mouse model, we investigated the recovery of depressive-like symptoms after the visual stimulation. The group of susceptible mice with gamma stimulation displayed improved social interaction ratio in social interaction test and reduced immobile time in forced swimming test. These results implicate that certain wavelength of OLED 40 Hz flickering light stimulus induces molecular changes and memory improvement in Alzheimer’s disease model. Also, it influences antidepressant-like behaviors in depression model.