Behavioral Characterization of the Motor Disorder of Granule Cell Yellow Cameleon Transgenic Mice

John Tieben, Robb Dunbar, Rodd Feddersen, Tim Ebner.

The granule cell yellow cameleon transgenic mice were originally developed to image the cerebellum. This was done by implantation of the genetic sequence of a fluorescent protein into the genome of the mice using the promoter GABA A6. Implantation of the protein into the cerebellum caused some of the mice to experience extreme motor disorder and hyperactivity, however, some mice experienced greater motor disorder than others. The goal of this study was to determine the behavioral phenotype, and compare the phenotype to the genotype of the mice. In order to characterize the phenotype of the mice two behavior tests were done; beam balance and wire hang. The genotype of the mice was then tested using PCR and compared to the phenotypic behavior. As expected the homozygous mice performed poorly on both the wire hang and beam balance while the wild type mice performed better on average. The heterozygous mice’s performance was variable, but on average they performed better than the homozygous and worse than the wild type. The results show if the granule cells are genetically altered or disturbed the phenotype of the mice will be affected differently depending on genotype. The development of these mice may be a useful model of granule cell dysfunction in humans. Further studies can be done to determine what produces the abnormality in mice and determine a therapy or cure for the disorder.