A sensitive and reliable locomotor rating scale for open field testing in rats

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Spinal Cord Injury Research

Background:

• Traditional behavioral assessments for spinal cord contusion rely on modified open field locomotion scales.
• Existing modifications lack standardization, hindering inter-laboratory comparisons of locomotor outcomes.
• A need exists for an efficient, unambiguous scale to standardize outcome measures.

Purpose of the Study:

• To develop an efficient, expanded, and unambiguous locomotor rating scale.
• To standardize locomotor outcome measures across different laboratories.
• To provide a more discriminating measure for evaluating treatments after spinal cord injury.

Main Methods:

• Adult rats (n=85) underwent T7-9 spinal cord contusion using electromagnetic or weight drop devices.
• Locomotor behavior was assessed pre-injury, post-operatively, and for up to 10 weeks.
• Scoring categories and attributes were defined and ranked based on observed recovery patterns, forming the Basso, Beattie, Bresnahan (BBB) Locomotor Rating Scale.

Main Results:

• The BBB scale demonstrated validity and predictive power for locomotor recovery.
• The scale effectively distinguished behavioral outcomes related to different injury types.
• Inter-rater reliability tests confirmed consistent application and scoring across examiners with varying experience.

Conclusions:

• The BBB Locomotor Rating Scale provides a standardized and discriminating measure for behavioral outcomes after spinal cord injury.
• This scale facilitates reliable inter-laboratory comparison of locomotor recovery.
• The BBB scale can predict anatomical alterations at the lesion center and aid in treatment evaluation.