adapted to the test apparatus and, for each test, the animals were filmed from the side during 3 trials. The HLRWT apparatus was 100 cm long and 5 cm wide with horizontal parallel metal rungs (3 mm in diameter) that could be inserted to create a horizontal ladder with a minimum distance of 1 cm between rungs that was elevated 30 cm above the floor. A small dark box was located at the end of the apparatus. In this test, the animals were required to walk along the horizontal ladder, which had an irregular pattern (the distance between the rungs varied from 1 to 5 cm) that was changed between the adaptation phase and the testing phase to prevent the animals from learning the pattern. In the NBT, the rats were required to walk along a 100cm-long, 3-cm-wide flat surface beam (in the adaptation phase) and a 100-cm-long, 2.6-cm-wide surface beam (in the test phase) that was elevated 30 cm above the floor to reach a small dark box at the end. In both tests, the number of hindlimb step slips in each trial was counted by 2 blinded observers, and these counts were used for analysis.