Pre-ischemic treadmill training affects glutamate and gamma aminobutyric acid levels in the striatal dialysate of a rat model of cerebral ischemia.

Abstract

AIMS: Treadmill training has been shown to improve function in animal models and patients with cerebral ischemia. However, the neurochemical effects of this intervention on the ischemic brain have not been well studied. This study was designed to evaluate the effects of pre-ischemic treadmill training on the release of glutamate and gamma-aminobutyric acid (GABA) from the striatum in a rat middle cerebral artery occlusion (MCAO) model. MAIN METHODS: Rats were divided into five groups: sham control without MCAO, and 0, 1, 2 and 4 weeks pre-ischemic treadmill training. After training, cerebral ischemia was induced by MCAO for 120 min, followed by reperfusion. Microdialysis was used to collect dialysates from the striatum immediately before ischemia, and at 40, 80 and 120 min after ischemia, as well as at 40, 80, 120, 160, 200 and 240 min after reperfusion. KEY FINDINGS: Pre-ischemic treadmill training decreased glutamate release and increased GABA release during the acute phase of cerebral ischemia/reperfusion. Treadmill training for at least 2 weeks produced statistically significant changes in GABA/glutamate release. SIGNIFICANCE: The present study suggests that treadmill training inhibits the excessive release of glutamate, by stimulating GABA release during the acute phase of cerebral ischemia. This may be one of the important mechanisms to protect the striatal neurons from ischemic damage.