Fig. 5. Histograms showing a progressive loss of hair cells from most of the vestibular sensory epithelia and of vestibular ganglion neurons in the Hmx2^lacZ null inner ears. (A-E) Cell counts of the cristae of all three semicircular canals, maculae of the utricle and saccule, as well as ganglion neurons in the vestibular and spiral ganglia, were performed on the Hmx2^lacZ+/– and Hmx2^lacZ–/– inner ears. Black bars represent the number of hair cells and ganglion neurons of the Hmx2^lacZ+/– inner ear; gray, those of the Hmx2^lacZ–/– inner ear. Statistical analysis was performed using an unpaired Student’s t-test. Error bars indicate standard deviations.