Effects of Chronic Photobiomodulation with Transcranial Near-Infrared Laser on Seizure Frequency and Brain Metabolomics of Rats with Pilocarpine-Induced Seizures.

Epilepsy is a chronic brain disorder characterized by abnormal and highly synchronous activity of neuronal cells. This condition is often associated with neuronal hyperexcitability and metabolic imbalances in regions such as the neocortex and archicortex (hippocampus). Pharmacological treatment with antiepileptic drugs has been essential in most cases. However, some patients continue to experience seizures despite medication. Consequently, the search for alternative treatments and new therapeutic interventions has garnered significant interest within the medical community. Among these, photobiomodulation (PBM) shows great promise, particularly due to its cerebral and neuroprotective effects. We evaluated and compared the seizure frequency and the neocortical and hippocampal metabolomic profiles of pilocarpine-induced epileptic rats exposed to chronic transcranial photobiomodulation treatment (30 days of treatment) with an 810-nm, 100-mW laser. Our data show that PBM treatment significantly reduced the seizure frequency in rats with pilocarpine-induced seizures. Additionally, significant changes were observed in the metabolomic profiles of the neocortex and hippocampus. In the neocortex, the treatment reduced metabolic pathways associated with excitotoxicity and oxidative stress. In the hippocampus, an increase in phenylalanine concentration was detected. In addition, the reduction in the number of seizures in laser-treated rats with pilocarpine-induced seizures was correlated with lower neocortical lysine concentration. Taken together, our findings indicate that transcranial PBM prevents the increase in seizure frequency in rats with epilepsy and modulates the brain metabolic pathways of epileptic rats.