Cognitive and neural effects of physical exercise in traumatic brain injury in young and middle-aged rats

Traumatic brain injury (TBI) usually leads to chronic or even life-long disturbances in multiple domains, including memory deficits. The prevalence of TBI is highest in young people, but over the last years has significantly increased in middle-aged and aged people. While there are several strategies to reduce the cognitive deficits associated to a TBI, their efficacy is still limited. Given the chronic nature of the deficits, it would be helpful to design effective strategies that could be easily incorporated into daily life. Physical exercise could be one of these strategies. In this sense, our research group has repeatedly found that physical exercise is capable of reducing some of the memory deficits associated to TBI in young rats. These benefits depend on amount and intensity of exercise, on the time of initiation after injury and on whether exercise is discontinued or is maintained on the long-term. However, up to now the benefits of exercise on TBI-related deficits using animal models have been mainly studied in male animals injured during adolescence or young adulthood, while research on the effects at older ages is lacking. Another research gap is the study of sex-related differences in the behavioral and pathophysiological effects of TBI and of exercise benefits. Based on this, the main aim of our research is to determine the role of physical exercise in the treatment of hippocampal-dependent memory impairment associated to TBI in late middle-aged rats, and whether the effects of exercise are sex-, time- and amount-dependent. In addition, we will study the neuroprotective and neuroreparative mechanisms involved in the effects of exercise, and the role of the crosstalk between the muscles and the brain (through chemicals released by muscle cells during exercise, the myokines). 

Cognitive and neural effects of physical exercise in traumatic brain injury in young and late middle-aged rats. 

• To examine the pathophysiological events associated to memory deficits in late middle-aged rats after a TBI 
• To examine the relationship between amount of exercise and effects on memory, neuroinflammation, neurogenesis and neuroprotection after TBI in middle-aged rats. 
• To determine the relationship between myokines released by muscle cells during exercise and the cognitive and neural effects of exercise after a TBI 
• To explain sex differences in the cognitive and neural effects of TBI and voluntary physical exercise in late middle-aged rats