Proceedings of The Physiological Society

Physiology 2014 (London, UK) (2014) Proc Physiol Soc 31, PCB060

Poster Communications

The effect of TMS and static magnetic field exposure in the behavioral recovery of rats with Traumatic Brain Injury TBI

D. E. Viñas1, A. García Espinoza2, T. Calvario1, F. Estrada Rojo2, L. Verdugo Díaz2, L. Navarro2

1. BIOELECTRONICA, CINVESTAV-IPN, Distrito Federal, Distrito Federal, Mexico. 2. FISIOLOGIA, FACULTAD DE MEDICINA, UNAM, DISTRITO FEDERAL, Mexico.


Traumatic Brain Injury TBI is currently one of the main health issues in the world. When TBI occurs, besides primary damages at the moment of impact, diverse mechanisms that increase the cellular damage are also triggered and result in the secondary damage. For example, the liberation of free radicals enhances the destruction of membranes because of the lipid peroxidation and also alters the function of diverse enzymes; the damage generated by the free radicals is established in the first 24 hours after the trauma, which means that in this period it is crucial to develop therapies that reduce the impairment. Diverse reports in the literature, our group included, have observed that the exposure to electromagnetic fields, static and variable induce changes in the activity of some Antioxidant Enzymes which can help to reduce the injury by free radicals after a TBI. This represents a potential therapeutic use of electromagnetic fields. In this research we analyzed the effect to static magnetic field exposure and Transcraneal Magnetic Stimulation (TMS) in the behavioral recovery of rats with TBI.53 male Wistar rats were employed on this research (250 - 300 g), they were kept at constant temperature, with a light-darkness cycle of 12:12 h (lights on at 8:00 h). The rats were divided in 8 groups (size of sample between 5 and 9); G1 and G2 received anesthesia (250 mg/kg Chloral Hydrate, ip). G3 and G4 were submitted to the procedure but were not induced with TBI. To the remaining groups G5, G6, G8 and G8, a TBI was induced using the standard "close head injury". G1, G3 and G5 were placed in boxes of movement restriction and exposed to low frequency static magnetic fields (0.8 mili-Tesla) for 2 hours. G2, G4 and G6 were kept in the boxes of movement restriction for 2 hours. G7 was submitted to Transcranial Magnetic Stimulation for 15 minutes. G8 was kept in the same conditions as G7, but the magnetic stimulation was not applied. Movement restriction and/or the magnetic field exposure was repeated each 24h for 8 days; furthermore, the body weight, water and food ingestion, and the execution of a neurobehavioral test (Hunter, 2000) were applied to the groups. At day 8, rats were sacrificed, and blood and brain samples were taken to determine some antioxidant enzymes. Our research shows that TBI produce a diminution in the ingestion of water and food that is associated with a decrease of weight in the first post-TBI days. The TBI causes decay in the execution of neurobehavioral tests. The application of magnetic fields reduces the damage caused by TBI and it is associated with an increase in the Superoxide Dismutase activity and of Catalase in the brain.

Where applicable, experiments conform with Society ethical requirements