Purpose: Previous studies have shown that administration of
MgCl
$_{2}$
in animal models of brain injury significantly
improves functional recovery: however, few studies have examined cognitive
recovery. The present study evaluated the effect of MgCl
$_{2}$
pharmacotherapy on recovery of function following medial frontal cortex
contusion injury.
Methods: Groups of rats were assigned to either
MgCl
$_{2}$
(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 MgCl
$_{2}$
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 MgCl
$_{2}$
did not significantly reduce
lesion size compared to saline-treatment. Examination of glial fibrillary
acidic protein (GFAP) expression showed that MgCl
$_{2}$
did
significantly reduce the number of GFAP
$^+$
cells.
Conclusion: These results indicate that MgCl
$_{2}$
administration significantly improved behavioral outcome following injury in a
task dependent manner and reduced GFAP expression.
