The effects of early exercise on brain damage and recovery  after focal cerebral infarction in rats.
OBJECTIVE
Exercise can be used to enhance neuroplasticity and facilitate motor recovery after a stroke in rats. We investigated whether treadmill running could reduce brain damage and enhance the expression of midkine (MK) and nerve growth factor (NGF), increase angiogenesis and decrease the expression of caspase-3.


METHODS
Seventy-seven Wistar rats were split into three experimental groups (ischaemia-control: 36, ischaemia-exercise: 36, sham-exercise: 5). Stroke was induced by 90-min left middle cerebral artery occlusion using an intraluminal filament. Beginning on the following day, the rats were made to run on a treadmill for 20 min once a day for a maximum of 28 consecutive days. Functional recovery after ischaemia was assessed using the beamwalking test and a neurological evaluation scale in all rats. Infarct volume, and the expression of MK, NGF, anti-platelet-endothelial cell adhesion molecule (PECAM-1), and caspase-3 were evaluated at 1, 3, 5, 7, 14 and 28 days after the induction of ischaemia.


RESULTS
Over time motor coordination and neurological deficits improved more in the exercised group than in the non-exercised group. The infarct volume in the exercised group (12.4 ± 0.8%) subjected to treadmill running for 28 days was significantly decreased compared with that in the control group (19.8 ± 4.2%, P < 0.01). The cellular expression levels of MK, NGF and PECAM-1 were significantly increased while that of caspase-3 was decreased in the peri-infarct area of the exercised rats.


CONCLUSIONS
Our findings show that treadmill exercise improves motor behaviour and reduces neurological deficits and infarct volume, suggesting that it may aid recovery from central nervous system injury.
Matsuda
F
F
School of Health Sciences, Faculty of Medicine, Kagoshima University, Kagoshima, Japan. fumiyo@health.nop.kagoshima-u.ac.jp
Sakakima
H
H
Yoshida
Y
Y
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D005081:Exercise Therapy; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology / Q000628:therapy*; D008297:Male; D000078792:Midkine; D009043:Motor Activity; D018919:Neovascularization, Physiologic; D020932:Nerve Growth Factor / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000473:pathology / Q000628:therapy*
D016207:Cytokines; D000078792:Midkine; D020932:Nerve Growth Factor; C505410:Casp3 protein, rat; D053148:Caspase 3