Short communicationRight-but not left-paw use in female rats provides advantage in forced swim tests

- Behavioral laterality including paw preference in rats reveals hemispheric asymmetry.
- Left-pawed female rats are more susceptible to induction of depression by means of forced swim tests than right-pawed rats.
- Paw preference in female rats does not affect spatial learning in the Morris water maze.
- Paw preference is stable and may provide a model of lateralization in depression.

Left- and right-pawed adult female Wistar rats were subjected to forced swimming on two consecutive days. Compared to the right-pawed group, left- pawed rats displayed significantly increased immobility from the first to the second swim test and remained significantly more immobile in the second swim test. Both groups performed similarly in spatial learning in the Morris water maze suggesting that left- pawed rats are differentially and specifically susceptible to depressogenic treatment.