Transcranial photobiomodulation (tPBM), also known as transcranial low-level laser therapy (LLLT), is a non-invasive treatment that uses red or near-infrared (NIR) light to stimulate the brain. Over the past few years, researchers have found promising evidence that this method may help improve brain function, particularly in cases of aging, memory loss, oxidative stress, and neurodegeneration.
How tPBM Works: A Mitochondrial Boost
One key mechanism behind tPBM is its effect on mitochondria—the powerhouse of cells. When light penetrates brain tissue, it activates a molecule called cytochrome c oxidase. This enzyme plays a vital role in energy production within mitochondria. By stimulating this enzyme, tPBM boosts cellular energy (ATP) and enhances brain function.
In a 2017 study, Salehpour and colleagues tested this approach in aging mice that were injected with D-galactose, a substance that mimics aging effects. They found that tPBM improved mitochondrial function and reduced cognitive impairment in these mice. The researchers suggested that tPBM might reduce oxidative stress and increase ATP levels in brain cells, helping to reverse age-related declines (Salehpour et al., 2017).
Fighting Memory Loss in Sleep-Deprived Mice
In another study, the same research team explored how tPBM affects sleep-deprived mice—a condition known to impair memory. They found that using NIR light therapy could significantly reduce memory loss. Additionally, the therapy decreased oxidative stress in the hippocampus, a part of the brain critical for learning and memory. This suggests that tPBM could help manage the negative effects of sleep loss on the brain (Salehpour et al., 2018).
Benefits Across Different Ages
The impact of tPBM is not limited to old or impaired brains. Cardoso and colleagues conducted a 2022 study where they applied tPBM over a long period to both young and aged rats. They found that chronic treatment enhanced the activity of cytochrome c oxidase in both age groups. This means tPBM can improve brain energy metabolism even in healthy individuals, possibly supporting better cognitive performance regardless of age (Cardoso et al., 2022).
Potential for Treating Cognitive Impairment
Other researchers have proposed that tPBM could be a new way to treat cognitive issues. Dr. de la Torre emphasized that this therapy might support patients with conditions such as Alzheimer’s disease by improving blood flow and boosting brain metabolism. His review highlighted that light stimulation may have neuroprotective effects, making it a valuable addition to current treatment options (de la Torre, 2017).
What Animal and Human Studies Say
A 2024 review by Lin et al. looked at both animal and human studies on tPBM. The review pointed out that tPBM has shown consistent benefits in improving memory, reducing inflammation, and promoting brain recovery in different models of brain diseases. One exciting trend is the growing use of wearable tPBM devices, which may make home-based treatments more accessible in the future (Lin et al., 2024).
Final Thoughts
Transcranial photobiomodulation is a promising therapy that may improve brain health by enhancing mitochondrial function, reducing oxidative stress, and supporting memory and learning. Although more human trials are needed to confirm its benefits, the current research provides a strong foundation. Whether used to treat aging, sleep deprivation, or general brain health, tPBM could play a key role in the future of non-invasive brain therapy.
References：
Salehpour, F., Ahmadian, N., Rasta, S. H., Farhoudi, M., Karimi, P., & Sadigh-Eteghad, S. (2017). Transcranial low-level laser therapy improves brain mitochondrial function and cognitive impairment in D-galactose-induced aging mice. Neurobiology of Aging, 58, 140–150. https://doi.org/10.1016/j.neurobiolaging.2017.06.025
Salehpour, F., Farajdokht, F., Erfani, M., Sadigh-Eteghad, S., Shotorbani, S. S., Hamblin, M. R., Karimi, P., Rasta, S. H., & Mahmoudi, J. (2018). Transcranial near-infrared photobiomodulation attenuates memory impairment and hippocampal oxidative stress in sleep-deprived mice. Brain Research, 1682, 36–43. https://doi.org/10.1016/j.brainres.2017.12.040
de la Torre, J. C. (2017). Treating cognitive impairment with transcranial low level laser therapy. Journal of Photochemistry and Photobiology B: Biology, 168, 149–155. https://doi.org/10.1016/j.jphotobiol.2017.02.008
Cardoso, F. D. S., Barrett, D. W., Wade, Z., Gomes da Silva, S., & Gonzalez-Lima, F. (2022). Photobiomodulation of Cytochrome c Oxidase by Chronic Transcranial Laser in Young and Aged Brains. Frontiers in Neuroscience, 16, 818005. https://doi.org/10.3389/fnins.2022.818005
Lin, H., Li, D., Zhu, J., Liu, S., Li, J., Yu, T., Tuchin, V. V., Semyachkina-Glushkovskaya, O., & Zhu, D. (2024). Transcranial photobiomodulation for brain diseases: review of animal and human studies including mechanisms and emerging trends. Neurophotonics, 11(1), 010601. https://doi.org/10.1117/1.NPh.11.1.010601
