Treatment with magnesium improves reference memory but not working memory while reducing GFAP expression following traumatic brain injury.
OBJECTIVE
Previous studies have shown that administration of MgCl2 in animal models of brain injury significantly improves functional recovery: however, few studies have examined cognitive recovery. The present study evaluated the effect of MgCl2 pharmacotherapy on recovery of function following medial frontal cortex contusion injury.


METHODS
Groups of rats were assigned to either MgCl2 (1.0 mmol/kg) or saline treatment conditions and prepared with contusion injuries or shams. Drug treatment was administered 15 min and 24 hr following injury. Rats were examined on tests of sensorimotor performance (bilateral tactile adhesive removal) and cognitive ability (reference and working memory).


RESULTS
Administration of MgCl2 following injury significantly reduced the behavioral impairments observed on the bilateral tactile removal test. The acquisition of reference memory was also significantly improved compared to saline-treated rats; however, treatment did not improve working memory performance. Lesion analysis revealed that administration of MgCl2 did not significantly reduce lesion size compared to saline-treatment. Examination of glial fibrillary acidic protein (GFAP) expression showed that MgCl2 did significantly reduce the number of GFAP+ cells.


CONCLUSIONS
These results indicate that MgCl2 administration significantly improved behavioral outcome following injury in a task dependent manner and reduced GFAP expression.
Restorative Neuroscience Laboratory, Brain and Cognitive Science Program, Department of Psychology, Southern Illinois University, Carbondale, IL, USA. mhoane@siu.edu
Michael R
MR
Hoane
D000818:Animals; D001930:Brain Injuries / Q000188:drug therapy* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D005904:Glial Fibrillary Acidic Protein / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D015636:Magnesium Chloride / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D005904:Glial Fibrillary Acidic Protein; D015636:Magnesium Chloride