A Straight Alley Version of the BBB Locomotor Scale

This study introduces a modified version of the BBB locomotor scale, a standard method for assessing hindlimb motor function in rats after spinal cord injury. Instead of the traditional open field test, rats are evaluated in a reward-baited straight alley. The rats were trained to walk in the straight alley for a food reward, which encouraged them to take continuous steps. This allowed for a more standardized assessment of their locomotion compared to the open field where they might be less motivated to move. The results showed a high correlation between the scores obtained in the straight alley and the open field, indicating that the straight alley is a valid alternative. The straight alley also provided more reliable scores across different testing days.

• 1
  BBB scores in the open field and straight alley were highly correlated (r=0.90), validating the straight alley for locomotor assessment.
• 2
  Rats exhibited a larger number of bouts of continuous steps (passes) in the straight alley versus the open field, providing more opportunities to score hindlimb use and coordination.
• 3
  The straight alley yielded more reliable scores, as indicated by higher day-to-day correlations (r2=0.90) compared to the open field (r2=0.74).