Assessment of cognitive function following magnesium therapy in the traumatically injured brain

Many studies have examined the preclinical efficacy of Mg²⁺ therapy in models of traumatic brain injury. However, more of these studies have examined sensorimotor and motor performance than cognitive performance following injury. The present paper reviews the use of Mg²⁺ therapy to facilitate cognitive recovery in several models of cortical injury in the rodent. The first study examined the ability of daily injections of MgCl ₂ (1 or 2 mmol) to impair acquisition of a reference memory task in the Morris Water Maze. Additional studies examined the ability of MgCl ₂ to improve cognitive function following bilateral anterior medial cortex ablations, bilateral frontal cortex contusions, and unilateral frontal contusions. The results from these studies indicate that MgCl₂ therapy is biologically active and readily crosses the blood-brain barrier because daily injections of MgCl₂ impaired learning of a reference memory task in intact rats. Mg²⁺ therapy for brain injury revealed that administration of post-injury MgCl₂ effectively improved recovery of cognitive deficits following injury. These results suggest that Mg²⁺ therapy is effective in facilitating cognitive recovery of function following brain injury; however, there are task and dose-dependent aspects to this recovery.