Discharge characteristics of neurons in anteroventral and dorsal cochlear nuclei of cat.

Abstract

Abstract A comparison was made of the discharge characteristics in two regions of the cochlear nuclear complex, the dorsal nucleus (DCN) and the spherical cell region (SCR) of the anteroventral nucleus. SCR neurons have narrow excitatory tuning curves and usually do not have inhibitory sidebands. The response to tone-burst stimulation is primary-like. Rate-intensity functions are almost always monotonic. The spacing of action potentials is irregular. Discharge may be phase-locked for frequencies exceeding 3 kHz. DCN neurons have more complicated discharge characteristics. Excitatory tuning curves may be broad or narrow and, in some cases, are multipeaked. Inhibitory sidebands are common and are especially prominent in units with narrow tuning curves. The response to tone bursts may be simple or complex. Complex response patterns involve silent pauses in discharge or the gradual buildup of activity. On occasion afterdischarges are seen. Many neurons, particularly those with complex response patterns, exhibit non-monotonic rate-intensity functions. Steady-state discharge patterns are regular. Phase-locking is usually limited to frequencies below 1.5 kHz. Results are discussed in terms of the morphology of the DCN and SCR.