Effects of voluntary exercise on spatial memory and BDNF-related miRNAs expression after traumatic brain injury

Abstract

Traumatic brain injury (TBI) is a common cause of neurological damage and disability among pediatric and adult population. The deleterious effects of TBI on memory processes are well documented. Physical exercise is known to improve many aspects of brain function and to ameliorate neurologic impairment induced by various brain insults, including TBI. MicroRNAs (miRNAs) are small, non-coding RNAs of approximately 23 nucleotides that act as potent silencers of gene expression by inducing translational repression or degradation of target mRNA. These molecules have emerged as potential regulators of cell differentiation, proliferation, apoptosis, neuronal development, neuroprotection, synaptic plasticity and memory formation. Recently, it has been showed that miRNAs can modulate some pathways required for learning and memory through intricate epigenetic mechanisms that regulate cognition in the normal and diseased brain. Considering that BDNF is implicated in the pro-cognitive effects of physical exercise and the existence of a growing body of evidence showing the close relationship between BDNF, miRNA-132 (miR-132) and miR-134 on regulation of neuronal plasticity and memory formation, the present project aims to verify the effects of exercise-induced BDNF activity on spatial memory and miRNA expression after TBI. (AU)