The Impact of Previous Physical Training on Redox Signaling after Traumatic Brain Injury in Rats: A Behavioral and Neurochemical Approach

Abstract

Throughout the world, traumatic brain injury (TBI) is one of the major causes of disability, which can include deficits in motor function and memory, as well as acquired epilepsy. Although some studies have shown the beneficial effects of physical exercise after TBI, the prophylactic effects are poorly understood. In the current study, we demonstrated that TBI induced by fluid percussion injury (FPI) in adult male Wistar rats caused early motor impairment (24 h), learning deficit (15 days), spontaneous epileptiform events (SEE), and hilar cell loss in the hippocampus (35 days) after TBI. The hippocampal alterations in the redox status, which were characterized by dichlorofluorescein diacetate oxidation and superoxide dismutase (SOD) activity inhibition, led to the impairment of protein function (Na(+), K(+)-adenosine triphosphatase [ATPase] activity inhibition) and glutamate uptake inhibition 24 h after neuronal injury. The molecular adaptations elicited by previous swim training protected against the glutamate uptake inhibition, oxidative stress, and inhibition of selected targets for free radicals (e.g., Na(+), K(+)-ATPase) 24 h after neuronal injury. Our data indicate that this protocol of exercise protected against FPI-induced motor impairment, learning deficits, and SEE. In addition, the enhancement of the hippocampal phosphorylated nuclear factor erythroid 2-related factor (P-Nrf2)/Nrf2, heat shock protein 70, and brain-derived neurotrophic factor immune content in the trained injured rats suggests that protein expression modulation associated with an antioxidant defense elicited by previous physical exercise can prevent toxicity induced by TBI, which is characterized by cell loss in the dentate gyrus hilus at 35 days after TBI. Therefore, this report suggests that previous physical exercise can decrease lesion progression in this model of brain damage.

Previous physical exercise alters the hepatic profile of oxidative‐inflammatory status and limits the secondary brain damage induced by severe traumatic brain injury in rats

“…In the present study, we have demonstrated that high levels of circulating cytokines elicited by FPI affect the brain response to injury and contribute to BBB opening, neurtrophil infiltration and Na + ,K + -ATPase activity inhibition. These results are in line with previous findings from our group suggesting that a single episode of FPI affects the inflammatory status of the brain (Mota et al 2012), impairs performance in spatial learning and induces cell loss in the dentate gyrus hilus (Lima et al 2008;da Silva Fiorin et al 2016). However, the understanding of secondary damage post-injury is essential for establishing scientific-based rehabilitation following TBI.…”

“…Motor impairment is a common TBI disability (Mota et al 2012;da Silva Fiorin et al 2016). Using the composite neuroscore, we demonstrated that FPI-induced motor impairment (F 1,20 = 10.58; P < 0.05) ( Fig.…”

“…; da Silva Fiorin et al . ). Using the composite neuroscore, we demonstrated that FPI‐induced motor impairment ( F 1,20 = 10.58; P < 0.05) (Fig.…”

“…; da Silva Fiorin et al . ). However, the understanding of secondary damage post‐injury is essential for establishing scientific‐based rehabilitation following TBI.…”

Effects of previous physical exercise to chronic stress on long‐term aversive memory and oxidative stress in amygdala and hippocampus of rats

“…Gene expression of catalytic subunits of Na + , K + ‐ATPase was not altered in amygdala. Moreover, as demonstrated by da Silva Fiorin et al (2016), previous exercise may have a preventive therapeutic potential on the redox signaling and activity of Na + , K + ‐ATPase in model of traumatic brain injury, as well as in experimental depression as seen in our study.…”