SPATIOTEMPORAL TUNING OF LOW-FREQUENCY CELLS IN THE ANTEROVENTRAL COCHLEAR NUCLEUS

Low-frequency cells in the anteroventral cochlear nucleus (AVCN) can b e sensitive to changes in the spatiotemporal pattern of discharges acr oss their auditory nerve (AN) inputs (Carney, 1990). This sensitivity suggests that these cells may be tuned to particular spatiotemporal pa tterns, or features, in the discharge patterns of populations of AN fi bers. To evaluate and characterize this sensitivity, we developed a te chnique whereby the physiological responses of AVCN cells to wide-band noise were analyzed using the simulated response of a population of A N fibers to the same noise stimulus. By averaging the simulated two-di mensional spatiotemporal pattern of AN activity that preceded each AVC N discharge, it was possible to derive a two-dimensional reverse-corre lation function that characterized the spatiotemporal tuning of each A VCN cell. The derived spatiotemporal tuning pattern represented a feat ure in the AM population response that was most likely to precede disc harges of the AVCN cell. To test the spatiotemporal tuning characteriz ations, we used these patterns to predict the responses of cells to no ise stimuli statistically independent from the stimuli used to charact erize the cells. This technique provides a general tool for the study of any neural system that involves the analysis of spatiotemporal inpu t patterns.