Responses of the salamander inner ear to vibrations of the middle ear

1982 ◽  
Vol 60 (2) ◽  
pp. 220-226 ◽  
Author(s):  
R. J. Ross ◽  
J. J. B. Smith
Keyword(s):  
Inner Ear ◽  
Middle Ear ◽  
Action Potentials ◽  
Sense Organs ◽  
Recording Site ◽  
Eighth Cranial Nerve ◽  
Sensitivity Functions ◽  
Irregular Action ◽  
The Central Nervous System ◽  
Peak Sensitivity

Microphonic and action potentials were recorded from the inner ear and eighth cranial nerve respectively of Notophthalmus viridescens, supine in air, while the exposed operculum of the middle ear was vibrated. Microphonic potentials were double the frequency of the vibrating source and were produced for a range of vibrations from 30 to at least 700 Hz. Sensitivity functions were irregular. Action potentials were obtained for a range of vibrations from between 30 and 60 Hz up to 550 Hz depending on the recording site. Populations of neurons were found that were narrowly tuned to a range of frequencies and that had peak sensitivities representing almost the entire range of frequencies to which responses were obtained (50–400 Hz). The most sensitive preparation required only 0.003 μm (peak to peak) with a peak sensitivity at 400 Hz to obtain a response. Vibration energy applied to a part of the middle ear can activate inner ear sense organs and at least part of this information can reach the central nervous system.

scholarly journals Noninvasive recording of the Mauthner neurone action potential in larval zebrafish

1982 ◽  
Vol 101 (1) ◽  
pp. 83-92 ◽  
Author(s):  
J. I. Prugh ◽  
C. B. Kimmel ◽  
W. K. Metcalfe
Keyword(s):  
Neural Activity ◽  
Action Potentials ◽  
Cell Function ◽  
Recording Site ◽  
M Cell ◽  
Larval Zebrafish ◽  
System 2 ◽  
The Central Nervous System ◽  
Freely Behaving ◽  
M Spike

We describe the identification of Mauthner (M-) cell action potentials in an intact zebrafish larva, utilizing recording electrodes located outside the fish: 1. The externally recorded spike occurs at approximately the same time, and its waveform changes with recording site in the same way, as the extracellular M-spike recorded within the central nervous system. 2. The externally recorded M-spike may be readily distinguished from other forms of neural activity. 3. The M-spike can be identified in recordings from unrestrained larvae. This finding permits the direct study of M-cell function in the freely behaving animal.

scholarly journals A Mechanism by Which the Hair Cells of the Inner Ear Transduce Mechanical Energy into a Modulated Train of Action Potentials

1974 ◽  
Vol 63 (6) ◽  
pp. 757-772 ◽  
Author(s):  
Richard Malcolm
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Hair Cells ◽  
Action Potentials ◽  
Mechanical Energy ◽  
Electrical Current ◽  
Physical Models ◽  
Resting Potential ◽  
Systematic Fashion ◽  
The Central Nervous System

Physical models of the hair cells of the inner ear were built and analyzed. These models suggest that a straightforward physical process is capable of modulating the electrical resistance of the hair cell. Strong evidence in the literature indicates that such a change in resistance would modulate an otherwise steady electrical current which flows across the hair cell. This would cause the resting potential of the hair cell to change in a systematic fashion, eventually giving rise to the modulated train of action potentials in the neurons leading from the hair cell to the central nervous system.

Morphologic Changes in the Inner Ear of Chinchilla Laniger after Middle Ear Administration of Gentamicin in a Sustained-Release Vehicle

1999 ◽  
Vol 120 (5) ◽  
pp. 643-648 ◽  
Author(s):  
Michael E. Hoffer ◽  
Ben J. Balough ◽  
Richard D. Kopke ◽  
Jenifer Henderson ◽  
Michael Decicco ◽  
...  
Keyword(s):  
Sustained Release ◽  
Inner Ear ◽  
Middle Ear ◽  
Morphologic Changes

Synaptic transmission in the chronically decentralized middle cervical and stellate ganglia of the dog

1983 ◽  
Vol 61 (10) ◽  
pp. 1149-1155 ◽  
Author(s):  
J. A. Armour
Keyword(s):  
Central Nervous System ◽  
Action Potentials ◽  
Autonomic Nerves ◽  
Autonomic Ganglia ◽  
Afferent Nerves ◽  
Stellate Ganglia ◽  
Compound Action Potentials ◽  
The Central Nervous System ◽  
Compound Action ◽  
Stimulation Of

Afferent stimulation of one thoracic cardiopulmonary nerve generated compound action potentials in the efferent axons of other ipsilateral cardiopulmonary nerves in dogs, 14 days after their thoracic autonomic ganglia had been decentralized. The compound action potentials were influenced by the frequency of activation and (in 5 of 12 dogs) by pharmacological autonomic blocking agents (hexamethonium, atropine, phentolamine, and propranolol). Moreover, they were abolished transiently when chymotrypsin was injected locally into the ganglia, and extendedly when manganese was injected. Thus, synapses that can be activated by stimulation of afferent nerves exist in chronically decentralized thoracic autonomic nerves and ganglia. It is proposed that regulation of the heart and lungs occurs in part via thoracic autonomic neural elements independent of the central nervous system.

Effects of Platelet Activating Factor on the Tubotympanic Mucosa and Inner Ear in the Guinea Pig

1998 ◽  
Vol 107 (10) ◽  
pp. 876-884 ◽  
Author(s):  
Yoshiharu Ohno ◽  
Yoshihiro Ohashi ◽  
Hideki Okamoto ◽  
Yoshikazu Sugiura ◽  
Yoshiaki Nakai
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Inner Ear ◽  
Otitis Media ◽  
Middle Ear ◽  
Otitis Media With Effusion ◽  
Platelet Activating Factor ◽  
Sensorineural Hearing ◽  
Ciliary Activity ◽  
Middle Ear Mucosa

The effect of platelet activating factor (PAF) was studied to elucidate its role in the pathogenesis of otitis media and sensorineural hearing loss. The PAF alone did not induce a reduction of ciliary activity of the cultured middle ear mucosa. However, a dose-dependent decrease in ciliary activity was observed in the presence of the medium containing both PAF and macrophages. Intravenous injection of PAF did not induce dysfunction of the mucociliary system or morphologic changes of epithelium in the tubotympanum, but cytoplasmic vacuolization and ballooning were observed in the inner ear within 1 hour after injection of PAF. In contrast, intratympanic injection of PAF induced mucociliary dysfunction and some pathologic changes in the tubotympanum. Intratympanic inoculation of PAF induced no pathologic findings in the inner ear. These results suggest that PAF is at least partially involved in the pathogenesis of certain middle ear diseases such as otitis media with effusion. Additionally, PAF might be involved in the pathogenesis of some types of unexplained sensorineural hearing loss.

Classes of Light-Evoked Response in the Retina of Strombus

1979 ◽  
Vol 80 (1) ◽  
pp. 287-297
Author(s):  
FREDERICK N. QUANDT ◽  
HOWARD L. GILLARY
Keyword(s):  
Optic Nerve ◽  
Action Potentials ◽  
Input Resistance ◽  
Resting Potential ◽  
Recording Site ◽  
Charging Time ◽  
Rate Of Decay ◽  
Hyperpolarizing Response ◽  
Strombus Luhuanus ◽  
A Site

Two general classes of light-evoked responses were recorded intracellularly from the retina of Strombus luhuanus. In one class, retinal illumination caused depolarization, the amplitude of which was graded with light intensity. In the other, it produced hyperpolarization and concomitant inhibition of repetitive action potentials. There were two types of depolarizing waveform. Each was associated with a different type of intraccllular recording site, characterized on the basis of electrical properties in the dark. In general, the type of response with a more rapid rate of decay was recorded from a site which exhibited a lower resting potential, higher input resistance, and longer ‘membrane charging time.’ The two depolarizing responses and the hyperpolarizing response apparently each arose from a different type of neurone. The depolarizing types, at least one of which is a photoreceptor, apparently give rise to the cornea-negativity of the electroretinogram and ‘on’ activity in the optic nerve fibres. The hyperpolarizing type apparently mediates ‘off’ activity in the optic nerve.

Common drugs used in ENT

2009 ◽  
pp. 347-350
Author(s):  
Rogan Corbridge ◽  
Nicholas Steventon
Keyword(s):  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Otitis Externa ◽  
Round Window ◽  
Acid Reflux ◽  
Tympanic Membrane Perforation ◽  
Active Infection ◽  
Middle Ear Mucosa ◽  
Membrane Perforation

Drugs used in the ear 348 Drugs used in the nose 349 Drugs used in the treatment of acid reflux 350 This group of drugs is widely used for the treatment of otitis externa. Otitis externa 2 drops tds for 10 days Presence of grommet or tympanic membrane perforation due to aminoglycoside ototoxicity in the inner ear. Risk thought to be low in the presence of active infection where the middle-ear mucosa is swollen and the antibiotic is unlikely to reach the inner ear via the round window...

Hearing loss

2018 ◽  
Author(s):  
James Ramsden
Keyword(s):  
Hearing Loss ◽  
Facial Nerve ◽  
Middle Ear ◽  
Cranial Nerve ◽  
Nerve Palsy ◽  
Facial Nerve Palsy ◽  
Conductive Hearing Loss ◽  
Ear Canal ◽  
Eighth Cranial Nerve ◽  
Conductive Hearing

Hearing loss must be divided into conductive hearing loss (CHL) and sensorineural hearing loss (SNHL). CHL is caused by sound not reaching the cochlear (abnormality of the ear canal, tympanic membrane, middle ear, or ossicles), whereas SNHL is a condition affecting the cochlear or auditory (eighth cranial) nerve. Hearing loss may be accompanied by other cardinal signs of ear disease, such as pain or discharge from the ear, vertigo, facial nerve palsy, and tinnitus, which guide the diagnosis. This chapter describes the approach to the patient with hearing loss.

scholarly journals Study on the Prosthesis Structural Design and Vibration Characteristics Based on the Conduction Effect of Human Middle Ear

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Wu Ren ◽  
Huijuan Yan ◽  
Yi Yu ◽  
Jinghong Ren ◽  
Jinlong Chang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Transmission Function ◽  
Ossicular Chain ◽  
Sound Signal ◽  
Sound Perception ◽  
Response Characteristics ◽  
Middle Ear Prosthesis

As a bridge from the sound signal in the air to the sound perception of the inner ear auditory receptor, the tympanic membrane and ossicular chain of the middle ear transform the sound signal in the outer ear through two gas-solid and solid-liquid conversions. In addition, through the lever principle formed by three auditory ossicle structure, the sound was concentrated and amplified to the inner ear. However, the sound transmission function of the middle ear will be decreased by disease, genetic, or trauma. Hence, using middle ear prosthesis to replace the damaged ossicles can restore the conduction function. The function realization of middle ear prosthesis depends on the vibration response of the prosthesis from the tympanic membrane to the stapes plate on the human auditory perception frequency, which is affected by the way the prosthesis combined with the tympanic membrane, the material, and the geometric shape. In this study, reasonable prosthetic structures had been designed for different types of ossicular chain injuries, and the frequency response characteristics were analyzed by the finite element method then. Moreover, in order to achieve better vibration frequency response, a ball structure was designed in the prosthesis to simulate its amplification function. The results showed that the middle ear prostheses constructed by different injury types can effectively transfer vibration energy. In particular, the first- and second-order resonant frequencies and response amplitudes are close to each other when ball structure models of different materials are added. Instead, the resonance frequency of the third stage formed by aluminum alloy ball materials is larger than that of the other two, which showed good response features.

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