Enhancement of forward suppression begins in the ventral cochlear nucleus
| Autor: | Ingham, Neil J., Itatani, Naoya, Bleeck, Stefan, Winter, Ian M. |
|---|---|
| Přispěvatelé: | Winter, Ian [0000-0002-1801-5281], Apollo - University of Cambridge Repository |
| Rok vydání: | 2014 |
| Předmět: |
Research Report
CN cochlear nucleus Auditory Pathways Acoustics and Ultrasonics AN auditory nerve Action Potentials Choice Behavior 0302 clinical medicine PEST parameter estimation by sequential testing PL primary-like 10. No inequality Auditory Neurons 0303 health sciences Signal Processing Computer-Assisted ON onset VCN ventral cochlear nucleus Ch chopper DCN dorsal cochlear nucleus IC inferior colliculus ICc central nucleus of the inferior colliculus Brainstem CS chopper-sustained Algorithms Cochlear Nucleus PN primary-like with notch OL onset-L Neuroscience(all) Guinea Pigs OC onset-chopper Clinical Neurology OS onset- sustained 03 medical and health sciences S sustained AC auditory cortex PSTH peri-stimulus time histogram Arts and Humanities (miscellaneous) OI onset-I Animals Cochlear Nerve Molecular Biology 030304 developmental biology GoS growth of suppression CF characteristic frequency Context CV coefficient of variation Auditory Threshold P pauser Guinea pig ISI inter-spike interval Inferior Colliculi BF best frequency CT chopper-transient Masking Acoustic Stimulation Microelectrodes 030217 neurology & neurosurgery Developmental Biology |
| Zdroj: | Brain Research |
| ISSN: | 0001-4966 |
| DOI: | 10.1121/1.4877713 |
| Popis: | A neuron׳s response to a sound can be suppressed by the presentation of a preceding sound. It has been suggested that this suppression is a direct correlate of the psychophysical phenomenon of forward masking, however, forward suppression, as measured in the responses of the auditory nerve, was insufficient to account for behavioural performance. In contrast the neural suppression seen in the inferior colliculus and auditory cortex was much closer to psychophysical performance. In anaesthetised guinea-pigs, using a physiological two-interval forced-choice threshold tracking algorithm to estimate suppressed (masked) thresholds, we examine whether the enhancement of suppression can occur at an earlier stage of the auditory pathway, the ventral cochlear nucleus (VCN). We also compare these responses with the responses from the central nucleus of the inferior colliculus (ICc) using the same preparation. In both nuclei, onset-type neurons showed the greatest amounts of suppression (16.9–33.5 dB) and, in the VCN, these recovered with the fastest time constants (14.1–19.9 ms). Neurons with sustained discharge demonstrated reduced masking (8.9–12.1 dB) and recovery time constants of 27.2–55.6 ms. In the VCN the decrease in growth of suppression with increasing suppressor level was largest for chopper units and smallest for onset-type units. The threshold elevations recorded for most unit types are insufficient to account for the magnitude of forward masking as measured behaviourally, however, onset responders, in both the cochlear nucleus and inferior colliculus demonstrate a wide dynamic range of suppression, similar to that observed in human psychophysics. Highlights • A two-interval forced choice procedure was used to measure suppressed thresholds. • The time course of recovery from suppression was fastest for onset units. • Growth of suppression with increased suppressor level was greatest for onset units. • Suppression in onset units was greater than that seen in auditory nerve fibres. |
| Databáze: | OpenAIRE |
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