A behavioral method for identifying recovery and compensation: Hand use in a preclinical stroke model using the single pellet reaching task

• Hand use is often affected by stroke in humans and can be improved with therapy.
• Functional improvement after stroke could be due to compensation or recovery.
• Rodents trained for skilled hand movements can be used to evaluate behavioral therapy.
• Multiple behavioral measures distinguish improvement due to compensation or recovery.
• Behavioral therapies can independently target compensation vs recovery.

One objective of preclinical animal models of stroke is to distinguish behavioral compensation from behavioral recovery. In compensation, a new behavior is substituted for a lost behavior, whereas in recovery, the original behavior is restored. Distinguishing between these processes is important because: (1) compensation can be mistaken for recovery, (2) compensatory strategies can disrupt performance, (3) the behavioral methods, therapy, and neural changes associated with enhancing compensation can be different from those associated with recovery, (4) under different conditions both compensation and recovery can be desirable outcomes. The review describes a behavioral method for assessing hand use in reaching (skilled reaching or reach-to-eat) by the rat, a behavior analogous to single handed prehension in humans. The method consists of seven separate assessments obtained with end point, movement notation, and biometric measures. The method highlights the importance of using multiple measures to identify behavioral change during acute, early, and chronic poststroke periods. Distinguishing between compensation and recovery refines the interpretation of preclinical behavioral findings and expands opportunities for developing therapies for stroke.