Transcranial photobiomodulation reduces predator‐induced anxiety‐like behavior (risk assessment) in male Rattus norvegicus threatened by Bothrops jararaca pit vipers

Photobiomodulation, also known as low-level laser therapy, uses specific wavelengths of light to stimulate biological tissues. Evidence from the literature indicates that transcranial photobiomodulation can alter neurophysiological activity; however, studies investigating its effects on the neurobiology of emotions remain scarce. Therefore, the objective of the present study was to investigate the effects of acute transcranial photobiomodulation administered at five irradiation sites using an 808 nm (± 10 nm) wavelength on anxiety-like behavior in rodents (Rattus norvegicus) exposed to either a potential wild predator (Bothrops jararaca) or predator-related cues (snake odor). Both the presence of the snake and exposure to its odor elicited anxiety-like risk-assessment behavior in the rodents. In turn, photobiomodulation treatment significantly reduced both the frequency and duration of this behavior, suggesting a potential anxiolytic-like effect.