Basic NeuroscienceSo you think you can jump? A novel long jump assessment to detect deficits in stroked mice

- The 'long jump test' can assess potential psychosomatic deficits produced by stroke.
- Male and female mice differ in latency to jump, but not in jump success rate.
- Cerebral stroke does not affect jump success rate, but increases latency to jump.
- Higher jump latencies could not be explained by increased anxiety.
- Acute fluoxetine did not have any effect on jump latency or success rate.

BackgroundStroke survivors suffer from persistent disability, as well as severe sensorimotor and cognitive deficits. The preclinical assessment of such deficits is important for the development of novel interventions and therapeutics.New methodThe aim of this study was to develop a quantitative behavioral measure of hindlimb functionality in rodents, which could be used to assess deficits after a neural injury, such as stroke. Here we introduce a test to measure long jump behavior in mice.ResultsUsing this test we first showed that while male and female mice exhibited no differences in jump success rate, the female mice showed lower baseline jumping latencies. Next we demonstrated that the induction of a cerebral stroke via middle cerebral artery occlusion (MCAO) for 45 min did not affect the jump success rate in either group; however, it did significantly increase jump latencies in both male and female mice. Finally, we used therapeutic interventions to explore mechanisms that may be involved in producing this increase in jump latency by administering the anti-depressant fluoxetine prior to the long jump assay, and also tested for potential changes in anxiety levels after stroke.Comparison with existing methodsOther methods to assess hindlimb functionality are not specific, because they measure behaviors that rely not only on hindlimbs, but also on forelimbs and tail.ConclusionsThis study introduces a novel assay that can be used to measure a stroke induced behavioral deficit with great sensitivity, and raises interesting questions about potential mechanisms regulating this effect.