Effects of contralateral sound on auditory-nerve responses. II. Dependence on stimulus variables

The suppression by moderate-level contralateral sound of auditory-nerve-fiber responses to ipsilateral stimuli at the characteristic frequency (CF) was studied in barbiturate-anesthetized cats. The dependence of suppression strength on ipsilateral and contralateral stimulus variables, including level, frequency, bandwidth, and timing relationships, was investigated. The principal findings were: (1) Contralateral-sound suppression is greatest when the ipsilateral stimulus level is within the dynamic range of the unit. (2) When the contralateral stimuli are tones, suppression is greatest when the contralateral tone frequency is at or near CF. (3) Units with CFs above 3-4 kHz are only weakly suppressed by contralateral CF tones but more strongly suppressed by contralateral broad-band noise. (4) Continuous contralateral stimuli are significantly more effective suppressors than are gated stimuli. The characteristics of contralateral-sound suppression are compared with the physiology and anatomy of the uncrossed medial olivocochlear efferents, the subset of efferents which are the primary mediators of the effect.

[1]  M. Liberman,et al.  Response properties of cochlear efferent neurons: monaural vs. binaural stimulation and the effects of noise. , 1988, Journal of neurophysiology.

[2]  Responses of Single Auditory‐Nerve Fibers in Cochleas Damaged by Ototoxic Drugs , 1969 .

[3]  Tuning curves and masking functions of auditory-nerve fibers in cat. , 1978 .

[4]  John J Guinan,et al.  Effects of electrical stimulation of efferent olivocochlear neurons on cat auditory-nerve fibers. III. Tuning curves and thresholds at CF , 1988, Hearing Research.

[5]  W. Buño,et al.  Auditory nerve fiber activity influenced by contralateral ear sound stimulation , 1978, Experimental Neurology.

[6]  M. Charles Liberman,et al.  Effects of contralateral sound on auditory-nerve responses. I. Contributions of cochlear efferents , 1989, Hearing Research.

[7]  J. Guinan,et al.  Topographic organization of the olivocochlear projections from the lateral and medial zones of the superior olivary complex , 1984, The Journal of comparative neurology.

[8]  E. Javel,et al.  High‐intensity “notches” in responses of auditory nerve fibers , 1981 .

[9]  M. Sachs,et al.  Rate versus level functions for auditory-nerve fibers in cats: tone-burst stimuli. , 1974, The Journal of the Acoustical Society of America.

[10]  M. Liberman,et al.  Single-neuron labeling and chronic cochlear pathology. IV. Stereocilia damage and alterations in rate- and phase-level functions , 1984, Hearing Research.

[11]  Alexander Joseph.  Book reviewDischarge patterns of single fibers in the cat's auditory nerve: Nelson Yuan-Sheng Kiang, with the assistance of Takeshi Watanabe, Eleanor C. Thomas and Louise F. Clark: Research Monograph no. 35. Cambridge, Mass., The M.I.T. Press, 1965 , 1967 .

[12]  P. Dallos,et al.  Forward masking of auditory nerve fiber responses. , 1979, Journal of neurophysiology.

[13]  Perman Es.  Studies on the antabuse--alcohol reaction in rabbits. , 1962 .

[14]  M. Liberman.  Physiology of cochlear efferent and afferent neurons: Direct comparisons in the same animal , 1988, Hearing Research.

[15]  J. Guinan,et al.  Effects of crossed-olivocochlear-bundle stimulation on cat auditory nerve fiber responses to tones. , 1983, The Journal of the Acoustical Society of America.

[16]  Pierre Bonfils,et al.  Efferent tracts and cochlear frequency selectivity , 1986, Hearing Research.

[17]  J. Guinan,et al.  Effects of electrical stimulation of medial olivocochlear neurons on ipsilateral and contralateral cochlear responses , 1987, Hearing Research.

[18]  M. Wiederhold.  Variations in the effects of electric stimulation of the crossed olivocochlear bundle on cat single auditory-nerve-fiber responses to tone bursts. , 1970, The Journal of the Acoustical Society of America.

[19]  M. Sachs,et al.  Effect of electrical stimulation of the crossed olivocochlear bundle on auditory nerve response to tones in noise. , 1987, Journal of neurophysiology.

[20]  J. Horikawa,et al.  Mechanical and neural interactions between binaurally applied sounds in cat cochlear nerve fibers , 1980, Neuroscience Letters.

[21]  N. Y. S. Kiang,et al.  Discharge Rates of Single Auditory‐Nerve Fibers as Functions of Tone Level , 1969 .

[22]  D. H. Johnson,et al.  The relationship between spike rate and synchrony in responses of auditory-nerve fibers to single tones. , 1980, The Journal of the Acoustical Society of America.

[23]  M. C. Brown,et al.  Physiology and anatomy of single olivocochlear neurons in the cat , 1986, Hearing Research.

[24]  P. Bonfils,et al.  Functional properties of the crossed part of the medial olivo-cochlear bundle , 1987, Hearing Research.

[25]  John J. Guinan,et al.  Effects of electrical stimulation of efferent olivocochlear neurons on cat auditory-nerve fibers. I. Rate-level functions , 1988, Hearing Research.

[26]  John J. Guinan,et al.  Effects of electrical stimulation of efferent olivocochlear neurons on cat auditory-nerve fibers. II. Spontaneous rate , 1988, Hearing Research.

[27]  N. Kiang,et al.  Effects of electric stimulation of the crossed olivocochlear bundle on single auditory-nerve fibers in the cat. , 1970, The Journal of the Acoustical Society of America.