Biomaterial Database

Representation of tones in noise in the responses of auditory nerve fibers in cats. I. Comparison with detection thresholds. 1985

J A Costalupes

Rate and temporal responses evoked by 1-kHz or 8-kHz tones in continuous broadband noise are described for large populations of auditory nerve fibers in anesthetized cats. The signal-to-noise ratios (S/Ns) of the tone and noise stimuli were above behavioral detection thresholds. Stimulus combinations were presented (1) over a range of moderate to high noise intensities at a constant S/N and (2) using high intensity noise and varying S/N. Responses of low (less than 1 spike/sec) and medium (1 to 19 spikes/sec) spontaneous rate (SR) fibers were compared with those of high SR (greater than 19 spikes/sec) fibers. Low and medium SR fibers with best frequencies in the region of the test tone frequency exhibited tone-evoked rate changes at all sound levels tested. High SR fibers, in contrast, exhibited much weaker tone-evoked rate changes at the lowest noise level tested. In the presence of high intensity noise, high SR fibers did not exhibit tone-evoked rate changes due to saturation by the noise. Fibers with best frequencies in the region of 1 kHz also exhibited strong phase-locking to the 1 kHz tone which increased as the tone level increased but which did not differ for the various SR groups. Results suggest that information in the rate responses of low and medium SR fibers can account for the encoding of information about tones in noise by the nervous system.

UI	MeSH Term	Description	Entries
D009412	Nerve Fibers	Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.	Cerebellar Mossy Fibers,Mossy Fibers, Cerebellar,Cerebellar Mossy Fiber,Mossy Fiber, Cerebellar,Nerve Fiber
D009622	Noise	Any sound which is unwanted or interferes with HEARING other sounds.	Noise Pollution,Noises,Pollution, Noise
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D004056	Differential Threshold	The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold.	Difference Limen,Just-Noticeable Difference,Weber-Fechner Law,Difference Limens,Difference, Just-Noticeable,Differences, Just-Noticeable,Differential Thresholds,Just Noticeable Difference,Just-Noticeable Differences,Law, Weber-Fechner,Limen, Difference,Limens, Difference,Threshold, Differential,Thresholds, Differential,Weber Fechner Law
D000159	Vestibulocochlear Nerve	The 8th cranial nerve. The vestibulocochlear nerve has a cochlear part (COCHLEAR NERVE) which is concerned with hearing and a vestibular part (VESTIBULAR NERVE) which mediates the sense of balance and head position. The fibers of the cochlear nerve originate from neurons of the SPIRAL GANGLION and project to the cochlear nuclei (COCHLEAR NUCLEUS). The fibers of the vestibular nerve arise from neurons of Scarpa's ganglion and project to the VESTIBULAR NUCLEI.	Cranial Nerve VIII,Eighth Cranial Nerve,Cochleovestibular Nerve,Statoacoustic Nerve,Cochleovestibular Nerves,Cranial Nerve VIIIs,Cranial Nerve, Eighth,Cranial Nerves, Eighth,Eighth Cranial Nerves,Nerve VIIIs, Cranial,Nerve, Cochleovestibular,Nerve, Eighth Cranial,Nerve, Statoacoustic,Nerve, Vestibulocochlear,Nerves, Cochleovestibular,Nerves, Eighth Cranial,Nerves, Statoacoustic,Nerves, Vestibulocochlear,Statoacoustic Nerves,VIIIs, Cranial Nerve,Vestibulocochlear Nerves
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001307	Auditory Perception	The process whereby auditory stimuli are selected, organized, and interpreted by the organism.	Auditory Processing,Perception, Auditory,Processing, Auditory
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor