Differences between cats in response properties of horizontal semicircular canal primary afferents

The response properties of cat horizontal canal afferents (N = 81) were characterized by three parameters: their long time constants (τ), low frequency gain constants (G₁), and middle frequency gain constants (G_m). An average value of each of these parameters was calculated for each of eight animals and comparisons were made across animals. There were significant differences between individual animals in their average values of τ and G_m. There was also a significant negative correlation between τ's and G_m's. An animal with a larger average τ tended to have a smaller average G_m. We also used anatomic data on membranous canal duct diameter from the literature to independently estimate the potential effect of interanimal anatomic variability on the predicted range of τ and G_m values in a population. We then compared the data from our 81 afferents with the predictions from the anatomic data.