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Journal of the American Academy of... Feb 2006
Topics: Auditory Diseases, Central; Auditory Pathways; Cochlear Nerve; Diagnosis, Differential; Evoked Potentials, Auditory, Brain Stem; Humans; Otoacoustic Emissions, Spontaneous; Terminology as Topic; Vestibulocochlear Nerve Diseases
PubMed: 16640067
DOI: 10.3766/jaaa.17.2.7 -
Clinical Neurosurgery 1959
Topics: Cochlear Nerve; Follow-Up Studies; Neoplasms; Neurilemmoma; Neuroma, Acoustic
PubMed: 13704656
DOI: 10.1093/neurosurgery/7.cn_suppl_1.21 -
Journal of Neurophysiology Mar 2019Sensory systems exploit parallel processing of stimulus features to enable rapid, simultaneous extraction of information. Mechanisms that facilitate this differential...
Sensory systems exploit parallel processing of stimulus features to enable rapid, simultaneous extraction of information. Mechanisms that facilitate this differential extraction of stimulus features can be intrinsic or synaptic in origin. A subdivision of the avian cochlear nucleus, nucleus angularis (NA), extracts sound intensity information from the auditory nerve and contains neurons that exhibit diverse responses to sound and current injection. NA neurons project to multiple regions ascending the auditory brain stem including the superior olivary nucleus, lateral lemniscus, and avian inferior colliculus, with functional implications for inhibitory gain control and sound localization. Here we investigated whether the diversity of auditory response patterns in NA can be accounted for by variation in intrinsic physiological features. Modeled sound-evoked auditory nerve input was applied to NA neurons with dynamic clamp during in vitro whole cell recording at room temperature. Temporal responses to auditory nerve input depended on variation in intrinsic properties, and the low-threshold K current was implicated as a major contributor to temporal response diversity and neuronal input-output functions. An auditory nerve model of acoustic amplitude modulation produced synchrony coding of modulation frequency that depended on the intrinsic physiology of the individual neuron. In Primary-Like neurons, varying low-threshold K conductance with dynamic clamp altered temporal modulation tuning bidirectionally. Taken together, these data suggest that intrinsic physiological properties play a key role in shaping auditory response diversity to both simple and more naturalistic auditory stimuli in the avian cochlear nucleus. NEW & NOTEWORTHY This article addresses the question of how the nervous system extracts different information in sounds. Neurons in the cochlear nucleus show diverse responses to acoustic stimuli that may allow for parallel processing of acoustic features. The present studies suggest that diversity in intrinsic physiological features of individual neurons, including levels of a low voltage-activated K current, play a major role in regulating the diversity of auditory responses.
Topics: Action Potentials; Animals; Chickens; Cochlear Nerve; Cochlear Nucleus; Evoked Potentials, Auditory, Brain Stem; Neurons; Potassium; Potassium Channels
PubMed: 30649984
DOI: 10.1152/jn.00459.2018 -
Neurological Research Sep 1999The short- and long-term effects of static compression of the cochlear nerve were studied in dogs. The nerve was exposed in the cerebellopontine angle and a modified...
The short- and long-term effects of static compression of the cochlear nerve were studied in dogs. The nerve was exposed in the cerebellopontine angle and a modified aneurysm clip was applied to reduce the diameter of the nerve trunk to 50%, 40%, 30% or 20% of normal (designated respectively as 50%, 60%, 70%, and 80% compression). Brainstem auditory evoked potentials (BAEPs) were monitored intraoperatively and post-operatively. The animals were sacrificed between 5 and 119 days after nerve compression and temporal bones were examined histologically. In the 50% compression group, all peaks except peak I disappeared immediately after nerve compression. After release of the clip, however, peak II and subsequent components recovered and prolonged interpeak latency (IPL) between peaks I and IV normalized within 7 days. In the 60% compression group, recovery was incomplete for as long as 49 days after compression. Significant histological changes were not always reflected in the electrophysiological recordings, as shown by the finding of multiple cavitations at the compressed portion of the cochlear nerve in cases in which conduction block of cochlear nerve impulses was reversible. In the 70% compression group, peak IV did not reappear for more than 1 week, and histological examination revealed severe damage to all cochlear nerve fibers except those from the apical turn, which lie in the center of the cochlear nerve trunk. Severe injury occurred to the cochlear nerve fibers that are situated more superficially in the nerve, which are tonotopically responsible for the perception of high-frequency sound and the generation of BAEPs. This means that the BAEP changes due to cochlear nerve compression would be detectable by BAEP monitoring, although changes in the apical region of the cochlea are not fully detectable by BAEP monitoring. In the 80% compression group, all peaks except peak I were lost permanently and the amplitude of peak I, which had been preserved in the acute phase, gradually decreased. Reversibility of impaired cochlear nerve impulse conduction was related to the severity of compression, and at some level of compression between 70% and 80% the nerve fibers generating BAEPs permanently lost the ability to conduct electrical impulses proximal to the site of compression. In the 70% and 80% compression groups, the amplitude of peak I gradually decreased over the first 30 days after compression and did not change significantly thereafter. Histologically, the branches of the internal auditory artery were resilient to compression, although they are easily avulsed due to stretch force. Furthermore, retrograde degeneration of cochlear neurons triggered by compression at the cisternal portion of the cochlear nerve was apparent. Such slowly progressive degeneration of nerve fibers may play a part in development of the delayed postoperative hearing disturbance.
Topics: Animals; Cochlear Nerve; Dogs; Evoked Potentials, Auditory, Brain Stem; Nerve Compression Syndromes; Nerve Fibers; Neuroma, Acoustic; Spiral Ganglion; Surgical Instruments; Time Factors
PubMed: 10491823
DOI: 10.1080/01616412.1999.11740983 -
Archives of Otolaryngology (Chicago,... Oct 1964
Topics: Classification; Cochlea; Cochlear Nerve; Deafness; Ear, Inner; Geriatrics; Humans; Pathology; Presbycusis; Temporal Bone
PubMed: 14198699
DOI: 10.1001/archotol.1964.00750040381003 -
Science (New York, N.Y.) Aug 1975Short-latency evoked potentials recorded from the vertex of adult cats in response to click stimulation (the far-field acoustic response) were analyzed in a series of...
Short-latency evoked potentials recorded from the vertex of adult cats in response to click stimulation (the far-field acoustic response) were analyzed in a series of lesion experiments to determine the origins of each component. The resultant data indicate that the primary generator of potential is the acoustic nerve; of potential 2, the cochlear nucleus; of potential 3, neurons of the superior olivary complex activated by projections crossing the midline; of potential 4, neurons of the ventral nucleus of the lateral lemniscus and preolivary region activated equally by crossed and uncrossed projections; and of potential 5, neurons of the inferior colliculus activated primarily by crossed projections.
Topics: Acoustic Stimulation; Animals; Auditory Pathways; Auditory Perception; Brain Mapping; Brain Stem; Cats; Cochlear Nerve; Evoked Potentials; Inferior Colliculi; Membrane Potentials; Olivary Nucleus; Vestibulocochlear Nerve
PubMed: 1145206
DOI: 10.1126/science.1145206 -
Journal of Neurosurgery Jan 1948
Topics: Brain; Brain Diseases; Brain Neoplasms; Brain Stem; Cerebellum; Cochlear Nerve; Hernia; Humans
PubMed: 18917351
DOI: 10.3171/jns.1948.5.1.0051 -
Internal Medicine (Tokyo, Japan) 2012We herein report a 26-year-old man with Guillain-Barré Syndrome (GBS) coexisting facial nerve palsy (FP) and deafness. He developed deafness, facial weakness, and limb...
We herein report a 26-year-old man with Guillain-Barré Syndrome (GBS) coexisting facial nerve palsy (FP) and deafness. He developed deafness, facial weakness, and limb weakness and numbness. Neurological examination showed facial diplegia, bilateral hypoacusia, areflexia and sensorimotor deficits in the distal limbs. The nerve conduction study findings supported the diagnosis of the demyelinating polyneuropathy. An audiogram revealed sensorineural hearing loss of 40-50 dB. Auditory brainstem responses disclosed no elicitation of waves I to IV on both sides. Magnetic resonance imaging depicted abnormal enhancement in bilateral facial and acoustic nerves. Physicians should pay more attention to auditory dysfunction in GBS patients with FP.
Topics: Adult; Cochlear Nerve; Comorbidity; Facial Nerve; Facial Paralysis; Guillain-Barre Syndrome; Hearing Loss, Sudden; Humans; Magnetic Resonance Imaging; Male; Neural Conduction; Radiographic Image Enhancement
PubMed: 22975563
DOI: 10.2169/internalmedicine.51.7737 -
Journal of Veterinary Diagnostic... Jan 2009A malignant schwannoma of the right acoustic nerve of a dog is described. The neoplasm was found during necropsy of a 12-year-old, spayed, female Labrador Retriever that...
A malignant schwannoma of the right acoustic nerve of a dog is described. The neoplasm was found during necropsy of a 12-year-old, spayed, female Labrador Retriever that experienced a sudden onset of severe pain in the neck and upon opening the mouth. Concurrent mild hind limb ataxia also was present. The tumor had infiltrative growth, and the spindle-shaped neoplastic cells were arranged in sheets and concentric whorls. Immunohistochemical staining of the neoplastic spindle cells was positive for S-100 antigen, neuron-specific enolase, and glial fibrillary acidic protein.
Topics: Animals; Cochlear Nerve; Dog Diseases; Dogs; Female; Neuroma, Acoustic
PubMed: 19139514
DOI: 10.1177/104063870902100121 -
Manitoba Medical Review Oct 1947
Topics: Cochlear Nerve; Humans; Neuroma; Neuroma, Acoustic; Vestibulocochlear Nerve
PubMed: 20265204
DOI: No ID Found