OBJECTIVETo determine whether the skilled reaching test is an objective method for evaluating long-term neurological deficits after focal cerebral ischemia in mice.

METHODSIn a reaching box, mice were trained to reach food pellets with their left forelimb through a 0.5 cm slit for 3 weeks. Then focal cerebral ischemia was induced by occluding the right middle cerebral artery, and the percentage of success in obtaining food was observed for 4 weeks. In comparison, the neurological deficit score, the holding angle in an inclined board test, and right turns in a corner test were simultaneously performed. At the end of the experiments, brain infarcts and neuron densities were determined.

RESULTAfter focal cerebral ischemia, the percentage of success in the reaching test was reduced, the right turns in the corner test were increased, the neurological deficit score was increased, and the holding angle in the inclined board test was reduced as well. The holding angle recovered 5 d after ischemia, whereas other 3 indicators remained abnormal until 4 weeks. At the end of the experiments, the brain infarct volumes were increased, and the neuron densities in the cortex, hippocampal CA1 region and striatum were reduced in ischemic mice.

CONCLUSIONThe skill reaching test is an objective and stable method for evaluating long-term neurological deficits after focal cerebral ischemia in mice.