دانلود مقاله : Inversion of lefteright asymmetry alters performance of Xenopus tadpoles in nonlater

چکیده : 

Lefteright behavioural biases are well documented across the animal kingdom, and handedness has long

been associated with cognitive performance. However, the relationship between body laterality and

cognitive ability is poorly understood. The embryonic pathways dictating normal lefteright patterning have

been molecularly dissected in model vertebrates, and numerous genetic and pharmacological treatments

nowfacilitate experimental randomization or reversal of the lefteright axis in these animals. Several recent

studies showed a link between brain asymmetry and strongly lateralized behaviours such as eye use preference.

However, links between laterality of the body and performance on cognitive tasks utilizing nonlateralized

cues remain unknown. Xenopus tadpoles are an establishedmodel for the study of early lefteright

patterning, and protocols were recently developed to quantitatively evaluate learning and memory in these

animals. Using an automated testing and training platform,we tested wild-type, lefteright-randomized and

lefteright-reversed tadpoles for their ability to learn colour cues in an automated assay. Our results indicate

that animals with either randomization or reversal of somatic lefteright patterning learned more slowly

than wild-type siblings, although all groups were able to reach the same performance optimum given

enough training sessions. These results are the first analysis of the link between body laterality and learning

of nonlateralized cues, and they position the Xenopus tadpole as an attractive and tractable model for future

studies of the links between asymmetry of the body, lateralization of the brain and behaviour.