Mechanistic aspects of photobiomodulation therapy in the nervous system.

Photobiomodulation therapy (PBMT) previously known as low-level laser therapy (LLLT) has been used for over 30 years, to treat neurological diseases. Low-powered lasers are commonly used for clinical applications, although recently LEDs have become popular. Due to the growing application of this type of laser in brain and neural-related diseases, this review focuses on the mechanisms of laser action. The most important points to consider include the photon absorption by intracellular structures; the effect on the oxidative state of cells; and the effect on the expression of proteins involved in oxidative stress, inflammation, pain, and neuronal growth.