Balance beam walking test

The neuro-behavioral outcome was evaluated using the balance beam walking test at 8 and 21 days after surgery. The beam dimensions were 2.5 cm width and 150 cm length, at a height of 70 cm above a sawdust cushion. A box was placed at the end of the beam for rats to rest on between tests. Before the first test, rats were trained to walk on the beam from one end to the other and then stayed in the box after walking. A 5-point scale was adopted as follows (Zausinger et al., 2000): 0, the rat was able to balance and walk on the beam using its forelimbs symmetrically; 1, the rat was able to balance and walk on the beam using its unaffected limb preferentially; 2, the rat was able to balance and walk on the beam mostly relying on the unaffected limb; 3, once it started to move, the rat was not able to balance on the beam; 4, the rat fell off the beam immediately. The test was conducted three times for each rat by a blinded rater to the group division. The average scores were calculated for statistical analysis. The balance beam walking test was performed before surgery and at 8 and 21 days after surgery.