Brain intracellular free magnesium declines after impact-acceleration induced brain injury in rats

Abstract

Significant declines in brain intracellular free magnesium concentration (Mgf) have been reported following focal traumatic brain injury but not following diffuse axonal brain injury. Since diffuse axonal brain injury is a common feature of clinical trauma, we have used 31P magnetic resonance spectroscopy to determine whether Mgf decline is also a feature of a nonfocal traumatic brain injury model that primarily induces widespread axonal injury. Impact acceleration-induced injury resulted in a highly significant decline in Mgf with an associated decline in cytosolic phosphorylation ratio. There were no significant changes in either ATP concentration or brain pH. We propose that decline in brain Mgf may be a common feature of both focal and diffuse forms of traumatic brain injury and therefore a possible target for therapeutic intervention.