Comparison of Cochlear Microphonic Potentials from Albino and Pigmented Guinea Pigs

Recent behavioral tests would seem to indicate that auditory thresholds of albino guinea pigs are significantly lower than the thresholds of pigmented guinea pigs. In the present study, cochlear microphonic 10μV isopotential (CM sensitivity) functions were recorded from the round windows of these two groups of anesthetized guinea pigs (Cavia procellus) as one measure of the inner ear performance. For 15 of 20 tested frequencies (between 70 and 7000 Hz), the mean CM sensitivities of 6 albino animals were not significantly different from the mean CM sensitivities of 6 pigmented animals. The maximum cochlear potential magnitudes obtainable at three frequencies (100, 1000 and 4000 Hz) from each animal group also were found statistically alike. It is concluded that there is no difference between the tested guinea pig strains with regard to the measured parameters of the cochlear microphonic potential.