A joint team from KAIST and the Korea Brain Research Institute (KBRI) developed a three-color organic light-emitting diode (OLED) photostimulation technology that can emit various colors of light—including blue, green, and red—uniformly. Using this technology on an animal model induced with Alzheimer's, the team exposed the subjects to different colors of light and found that red 40 Hz light most effectively improved Alzheimer's pathology and memory, they said on the 24th.
Comparing white, red, green, and blue light under identical conditions (40 Hz, the same brightness and exposure time) using the OLED device, the researchers found that in an early Alzheimer's model (3 months old), just two days of light stimulation noticeably improved pathology and memory function. When white or red light was applied, long-term memory recovered, and amyloid-beta plaques—the representative causative substance that accumulates in the brain in Alzheimer's—decreased. ADAM17, an enzyme that helps remove plaques, was produced in greater amounts.
The researchers said this means that even very short periods of light stimulation can reduce harmful proteins in the brain and improve memory.
In a mid-stage Alzheimer's model (6 months old), where the disease had progressed further, the differences were clearer. After two weeks of stimulation, a significant reduction in amyloid plaques appeared only with red light. Both white and red light improved memory, but pathology improved only with red.
The core of this study is that brain function can be modulated with light alone, without drugs. In addition, thanks to the developed OLED technology, the color, brightness, flicker speed (frequency), and exposure time of light can be precisely controlled. These features are useful for designing personalized photostimulation therapies.
Choi Gyeong-cheol, a KAIST professor, predicted that a wearable OLED-based electroceutical that can be easily used in daily life will open a new paradigm for Alzheimer's treatment.
The results were published online Oct. 25 (local time) in ACS Biomaterials Science & Engineering, an international journal in the fields of biomedicine and materials.
References
ACS Biomaterials Science & Engineering (2025), DOI: https://doi.org/10.1021/acsbiomaterials.5c01162