Biomaterial Database

Temporal response patterns of auditory nerve fibers to electrical stimulation in deafened squirrel monkeys. 1989

C W Parkins

Division of Otolaryngology, University of Rochester School of Medicine and Dentistry, New York.

Electroneural response patterns of single auditory-nerve neurons were studied in aminoglycoside-deafened squirrel monkeys. The electrical stimuli were delivered through bipolar electrodes implanted in the scala tympani. The effects of pulse width, shape, frequency, and intensity on neural adaptation, phase locking, and spectral content were evaluated. Our results did not demonstrate the characteristic adaptation seen in auditory-nerve neurons in response to acoustic stimulation. Phase locking to a broad stimulus pulse (3200 microseconds/phase) was found to a very restricted phase angle of the electrical stimulus which was broader for square wave than for sine wave stimulation. The latency of the phase locked response varied inversely with stimulus intensity with greater variation for square wave stimulation than for sine wave stimulation. Auditory neurons were capable of a very high degree of phase locking to a 200-microseconds/phase pulse presented at 156 pulses per second (PPS) and to the first pulse of a 2500-Hz pulse burst. Phase locking was much poorer for the subsequent 200-microseconds/phase pulses comprising the 2500-Hz pulse burst where the neuron's response was determined by its relative recovery status. These findings can be explained by an interaction between the neuron's relative refractory status and its integration of charge over the stimulatory half cycle of the electrical stimulus. These two factors also appear to determine the interspike interval of the neural response. This interval decreased monotonically with increasing stimulus intensity. The neural spike rate (150-500 Hz) producing this interval increased with intensity and may be a source of periodicity information which the central auditory nervous system could interpret as pitch. This may account for the proportional relationship between pitch and stimulus intensity seen in some cochlear implant patients. Our study demonstrates that auditory-nerve neurons comply with basic neurophysiological principles in their responses to electrical stimulation. These principles should be incorporated into the cochlear prosthesis stimulator if more normal neural response patterns are desired in the cochlear prosthesis patient.

UI	MeSH Term	Description	Entries
D003054	Cochlear Implants	Electronic hearing devices typically used for patients with normal outer and middle ear function, but defective inner ear function. In the COCHLEA, the hair cells (HAIR CELLS, VESTIBULAR) may be absent or damaged but there are residual nerve fibers. The device electrically stimulates the COCHLEAR NERVE to create sound sensation.	Auditory Prosthesis,Cochlear Prosthesis,Implants, Cochlear,Auditory Prostheses,Cochlear Implant,Cochlear Prostheses,Implant, Cochlear,Prostheses, Auditory,Prostheses, Cochlear,Prosthesis, Auditory,Prosthesis, Cochlear
D003638	Deafness	A general term for the complete loss of the ability to hear from both ears.	Deafness Permanent,Hearing Loss Permanent,Prelingual Deafness,Deaf Mutism,Deaf-Mutism,Deafness, Acquired,Hearing Loss, Complete,Hearing Loss, Extreme,Acquired Deafness,Complete Hearing Loss,Deafness, Prelingual,Extreme Hearing Loss,Permanent, Deafness,Permanent, Hearing Loss,Permanents, Deafness
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D005072	Evoked Potentials, Auditory	The electric response evoked in the CEREBRAL CORTEX by ACOUSTIC STIMULATION or stimulation of the AUDITORY PATHWAYS.	Auditory Evoked Potentials,Auditory Evoked Response,Auditory Evoked Potential,Auditory Evoked Responses,Evoked Potential, Auditory,Evoked Response, Auditory,Evoked Responses, Auditory,Potentials, Auditory Evoked
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
D000161	Acoustic Stimulation	Use of sound to elicit a response in the nervous system.	Auditory Stimulation,Stimulation, Acoustic,Stimulation, Auditory
D000222	Adaptation, Physiological	The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.	Adaptation, Physiologic,Adaptations, Physiologic,Adaptations, Physiological,Adaptive Plasticity,Phenotypic Plasticity,Physiological Adaptation,Physiologic Adaptation,Physiologic Adaptations,Physiological Adaptations,Plasticity, Adaptive,Plasticity, Phenotypic
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
D012453	Saimiri	A genus of the family CEBIDAE consisting of four species: S. boliviensis, S. orstedii (red-backed squirrel monkey), S. sciureus (common squirrel monkey), and S. ustus. They inhabit tropical rain forests in Central and South America. S. sciureus is used extensively in research studies.	Monkey, Squirrel,Squirrel Monkey,Monkeys, Squirrel,Saimirus,Squirrel Monkeys
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor