부산대학교 도서관

We have identified deafness of circling mice because of its inner ear abnormalities; degenerated cochlea and reduced cellularity in the spiral limbus. Circling mice become hyperactive at approximately 7 days of age and then begin to exhibit circling behavior. The circling behavior of circling mice might be highly correlated with the vestibular system. The inspection of the epithelia and ganglion neurons in vestibule revealed mild abnormalities: some hair cells in the ampulla tended to have longer stereocilia and the numbers of ganglion cells were remarkably reduced compared to heterozygous mice. The reduced cell density in the vestibular neurons is thought to be the main reason for the phenotypic abnormalities. The circling mutant cerebellum is grossly normal, with characteristic lobulation and lamination in cresylvioletstained sections. The thickness of the granular layer, distributions of stellate cells and basket cells, and morphology of Purkinje cells of the circling homozygous mutant were normal. This suggests that the abnormal behavior of the circling (cir/cir) mouse is not the results of the morphological defects in the cerebellum.