Brain function in antarctic fish: frequency response analysis of central vestibular units

Summary Extracellular single-unit recordings were made from central vestibular units responding to horizontal head rotation in antarctic fish (Pagothenia borchgrevinki) at temperatures below 0 °C. The frequency of head rotation was varied between 0.05–16 Hz and the results were analysed in terms of the phase and gain of the response with respect to the stimulus. The model of the peripheral vestibular system derived by Hartmann and Klinke (1980) was fitted to the data from antarctic fish in order to obtain a quantitative comparison of vestibular function at two different temperatures. Despite the 20 °C temperature difference, and the different recording sites (primary afferents in the goldfish, and central vestibular units in the antarctic fish) vestibular function in antarctic fish is comparable to that previously reported in goldfish.