Pathology of the Inner Ear in Ames Waltzer Mice

Abstract

Neither behavioral nor electrical responses could be elicited to auditory stimuli at any stage after birth in Ames waltzer mice.
Light and electron microscopic studies revealed no significant difference between normal and these deaf mice from 81/2 days in embryo to 10 days after birth. At about 10 days after birth, these deaf mice always failed to develop the space of Nuel and were late or deficient in forming the tunnel of Corti. The hair cells and nerve endings were normal by electron microscopy through 14 days. Later the hair cells and the spiral ganglion cells degenerate and disappear. These deaf mice exhibit no other morphological defects. The saccule and other vestibular apparatus and endolymph volume are normal. Circulation and innervation are anatomically normal during maturation. These deaf mice showed no significant permeability abnormalities in the cochlea with the aid of Karnovsky peroxidase technique.