Light therapy, known as brain photobiomodulation (PBM) therapy, is used to help with neurological and psychological conditions. This therapy uses red to near-infrared (NIR) light to stimulate brain cells and improve their function. PBM therapy can increase energy production in brain cells, reduce inflammation and cell death, and promote the growth of new brain cells and connections. This treatment method shows promising results in treating conditions such as dementia, Parkinson's disease, stroke, head injury and depression.
What is PBM therapy?
Over the last twenty years, a treatment method called "brain photobiomodulation (PBM) therapy" has been developed to improve brain function. This therapy uses low-intensity red to near-infrared light to stimulate brain cells. There are different methods of delivering the light to the brain, and research has investigated the safety and optimal settings for PBM therapy, such as wavelength, light intensity, treatment duration and delivery method. Studies in animals have shown that PBM therapy has the potential to prevent or repair brain damage after stroke. The therapy has also shown protective effects in conditions such as traumatic head injury, ischemic stroke, Alzheimer's disease, Parkinson's disease, depression, anxiety and age-related cognitive decline.
Photobiomodulation (PBM) therapy has positive effects on brain function. It works by stimulating mitochondria, which are the energy-producing units of cells. By using red to near-infrared light, PBM therapy can can improve energy metabolism in the brain, increase blood flow, strengthen the immune system and affect the balance between neuron survival, cell death and inflammation. PBM therapy has also shown benefits at the behavioral level, such as improved cognition, antidepressant effects and better sleep.
Mitochondrial dysfunction is linked to neurological and psychological disorders, and PBM therapy can help improve mitochondrial function in neurons. The therapy activates an enzyme called cytochrome c oxidase, which is important for energy production in brain cells. By using specific wavelengths of light, PBM therapy can increase the activity of cytochrome c oxidase and levels of ATP, a key energy source in the brain.
PBM therapy can also improve blood flow in the brain by increasing the production of nitric oxide, which dilates blood vessels. By using specific wavelengths of light, PBM therapy can improve the synthesis of nitric oxide and increase blood flow in the brain. This can help improve the oxygen and nutrient supply to brain cells.
Studies have shown that PBM therapy has positive effects on energy production in the brain, oxygen consumption and oxygenation of brain cells. This suggests that PBM therapy may be a useful approach to improve brain function and treat neurological conditions.
What are the benefits of PBM therapy?
Oxidative stress: Oxidative stress is harmful substances in the body that can damage neurons. Mitochondria play an important role in this stress. Brain disorders such as Alzheimer's disease, traumatic brain injury, stroke and severe depression are linked to increased vulnerability to oxidative stress. Photobiomodulation (PBM) can have both positive and negative effects on oxidative stress. Low doses of PBM can regulate cellular signaling pathways, while high doses can lead to excessive production of harmful substances and cell death. Studies have shown that laser and LED treatment can protect against oxidative stress and affect the activity of enzymes and antioxidants that protect against it.
Neural inflammation: Neural inflammation plays an important role in brain disorders and is driven by microglial cells. When neurons are damaged, microglia produce pro-inflammatory substances. PBM can reduce pro-inflammatory substances and dampen inflammatory reactions by affecting signaling pathways in the cells. Studies have shown that PBM can reduce levels of pro-inflammatory substances in laboratory models of brain injury and improve outcomes in stroke and head injury. PBMs can also affect the activity of specific pro-inflammatory substances.
Neural apoptosis: Apoptosis, or programmed cell death, plays an important role in normal aging of the brain and neurodegenerative diseases such as Alzheimer's and Parkinson's. Light therapy can protect cells from apoptosis and improve mitochondrial function. This may explain the protective effect of phototherapy on the brain.
Neurotrophic factors and neurogenesis: Light therapy stimulates the production of neurotrophic factors that contribute to the growth of new neurons and the formation of synapses. Increased production of these factors can prevent the degradation of brain cells in Alzheimer's disease. Light therapy activates signaling pathways in the cells and increases the production of neurotrophic factors. Studies have shown that phototherapy increases the production of certain factors in the brain and improves behavior. The effect of light therapy on neurogenesis has only been proven in animal models of stroke and traumatic brain injury, and more research is needed to understand the effects in depression and Alzheimer's disease.
Alzheimer's and Parkinson's: Studies have shown that phototherapy (PBM therapy) can have positive effects on people with Alzheimer's disease (AD) and dementia. The use of near-infrared (NIR) light therapy has shown improvements in sleep quality, mood, brain activity and cognitive functions in people with AD. NIR light therapy directly to the brain through a catheter in the vein has also shown reductions in dementia symptoms. In the case of Parkinson's disease (PD), studies have focused less on light therapy through the cranium due to limitations in light penetration. Nevertheless, one study without a control group has shown improved motor and cognitive functions in PD patients after cranial phototherapy.
Traumatic head injury: Studies have shown that light therapy can have positive effects on patients with traumatic head injury (TBI). LED light therapy through the cranium has shown improvements in self-awareness, social function and sleep quality in TBI patients. Higher doses of near-infrared (NIR) laser have shown greater efficacy in reducing headaches, improving sleep quality and increasing cognitive and mood states in TBI patients. Light treatment with 785 nm wavelength has also improved attention and awareness in TBI patients with severe loss of consciousness.
Depression: Studies have shown that light therapy can have positive effects on patients with major depression. The use of light therapy has reduced symptoms of depression and anxiety in patients with major depression. Light therapy through the cranium has also shown a reduction in post-traumatic stress disorder (PTSD) and depression in patients with traumatic brain injury and concurrent depression.
Healthy people: In reality, mental activities involve complex cognitive processes such as short-term and long-term memory, decision-making, attention, problem solving, planning and executive functions. For older adults, who often experience some decline in cognitive functions with age and are at risk of dementia, maintaining or improving cognitive function is of great interest. Light therapy has shown improvement in advanced cortical functions such as rule-based learning in the prefrontal cortex, attention, short-term memory and executive functions in healthy young participants. Another study from the same research group provided evidence that light therapy in the prefrontal area could improve oxygen delivery to the brain and enhance the hemodynamic processes important for higher cognitive function.
The conclusion is that the use of red and near-infrared light (600-850 nm) for therapy in the brain, known as PBM therapy, is very promising due to the amount of mitochondrial cytochrome c oxidase in the brain. In the past, it has been difficult to deliver sufficient light to the brain to achieve desired effects. However, experiments with wavelengths between 980 nm and 1100 nm have shown promising results in recent years. These wavelengths can potentially be combined with red and near-infrared light. PBM therapy in the brain has been shown to have various effects, including improved metabolism, stimulation of new formation of nerve cells and synapses, regulation of neurotransmitters, as well as protection of the brain through anti-inflammatory and antioxidant signals.
