Enigmatic ear stones: what we know about the functional role and evolution of fish otoliths.

Enigmatic ear stones: what we know about the functional role and evolution of fish otoliths.

Biol Rev Camb Philos Soc. 2018 Sep 21;:

Authors: Schulz-Mirbach T, Ladich F, Plath M, Heß M

Abstract
Otoliths in bony fishes play an important role in the senses of balance and hearing. Otolith mass and shape are, among others, likely to be decisive factors influencing otolith motion and thus ear functioning. Yet our knowledge of how exactly these factors influence otolith motion is incomplete. In addition, experimental studies directly investigating the function of otoliths in the inner ear are scarce and yield partly conflicting results. Herein, we discuss questions and hypotheses on how otolith mass and shape, and the relationship between the sensory epithelium and overlying otolith, influence otolith motion. We discuss (i) the state-of-the-art knowledge regarding otolith function, (ii) gaps in knowledge that remain to be filled, and (iii) future approaches that may improve our understanding of the role of otoliths in ear functioning. We further link these functional questions to the evolution of solid teleost otoliths instead of numerous tiny otoconia as found in most other vertebrates. Until now, the selective forces and/or constraints driving the evolution of solid calcareous otoliths and their diversity in shape in teleosts are largely unknown. Based on a data set on the structure of otoliths and otoconia in more than 160 species covering the main vertebrate groups, we present a hypothetical framework for teleost otolith evolution. We suggest that the advent of solid otoliths may have initially been a selectively neutral 'by-product' of other key innovations during teleost evolution. The teleost-specific genome duplication event may have paved the way for diversification in otolith shape. Otolith shapes may have evolved along with the considerable diversity of, and improvements in, auditory abilities in teleost fishes. However, phenotypic plasticity may also play an important role in the creation of different otolith types, and different portions of the otolith may show different degrees of phenotypic plasticity. Future studies should thus adopt a phylogenetic perspective and apply comparative and methodologically integrative approaches, including fossil otoliths, when investigating otoconia/otolith evolution and their function in the inner ear.

PMID: 30239135 [PubMed - as supplied by publisher]

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A closer look at subjective caloric sensations: Is there more to vertigo than spinning?

Related Articles

A closer look at subjective caloric sensations: Is there more to vertigo than spinning?

J Vestib Res. 2018;27(5-6):271-277

Authors: Mijovic T, Remillard A, Zaia EH, Reid YM, Harrington JK, Westerberg BD, Lea J

Abstract
BACKGROUND: There is a prevailing opinion that spinning sensations signify a peripheral vestibular pathology while non-spinning sensations are not of vestibular origin.
OBJECTIVES: 1) Characterize the subjective sensations reported by patients during caloric testing. 2) Assess if the sensation was correlated with the peak slow phase velocity (SPV).
METHODS: Retrospective chart review at a Canadian adult tertiary-quaternary care balance centre for patients undergoing diagnostic caloric testing between December 2014 and September 2015.
RESULTS: Of 163 patients included, 122 had normal calorics and 41 demonstrated unilateral weakness. Spinning/rotatory movements were the most commonly reported sensations (55-70%). No sensation was reported among 10-20% of patients. Other non-rotatory sensations were reported 20-25% of the time. Both lack of sensation and other sensations were more likely to be correlated with SPVs that were significantly lower than those associated with spinning/rotating sensations. However, 18% of patients with normal calorics and robust SPVs with warm irrigation still reported non-spinning sensations.
CONCLUSIONS: During caloric irrigation, subjective sensations other than spinning and rotating are reported 20-25% of the time and these tend to be associated with lower peak SPV. Non-spinning vertigo is not uncommon as a subjective description of vestibular sensation even in normal patients with strong SPVs.

PMID: 29154301 [PubMed - indexed for MEDLINE]

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Enigmatic ear stones: what we know about the functional role and evolution of fish otoliths.

Enigmatic ear stones: what we know about the functional role and evolution of fish otoliths.

Biol Rev Camb Philos Soc. 2018 Sep 21;:

Authors: Schulz-Mirbach T, Ladich F, Plath M, Heß M

Abstract
Otoliths in bony fishes play an important role in the senses of balance and hearing. Otolith mass and shape are, among others, likely to be decisive factors influencing otolith motion and thus ear functioning. Yet our knowledge of how exactly these factors influence otolith motion is incomplete. In addition, experimental studies directly investigating the function of otoliths in the inner ear are scarce and yield partly conflicting results. Herein, we discuss questions and hypotheses on how otolith mass and shape, and the relationship between the sensory epithelium and overlying otolith, influence otolith motion. We discuss (i) the state-of-the-art knowledge regarding otolith function, (ii) gaps in knowledge that remain to be filled, and (iii) future approaches that may improve our understanding of the role of otoliths in ear functioning. We further link these functional questions to the evolution of solid teleost otoliths instead of numerous tiny otoconia as found in most other vertebrates. Until now, the selective forces and/or constraints driving the evolution of solid calcareous otoliths and their diversity in shape in teleosts are largely unknown. Based on a data set on the structure of otoliths and otoconia in more than 160 species covering the main vertebrate groups, we present a hypothetical framework for teleost otolith evolution. We suggest that the advent of solid otoliths may have initially been a selectively neutral 'by-product' of other key innovations during teleost evolution. The teleost-specific genome duplication event may have paved the way for diversification in otolith shape. Otolith shapes may have evolved along with the considerable diversity of, and improvements in, auditory abilities in teleost fishes. However, phenotypic plasticity may also play an important role in the creation of different otolith types, and different portions of the otolith may show different degrees of phenotypic plasticity. Future studies should thus adopt a phylogenetic perspective and apply comparative and methodologically integrative approaches, including fossil otoliths, when investigating otoconia/otolith evolution and their function in the inner ear.

PMID: 30239135 [PubMed - as supplied by publisher]

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via IFTTT

A closer look at subjective caloric sensations: Is there more to vertigo than spinning?

Related Articles

A closer look at subjective caloric sensations: Is there more to vertigo than spinning?

J Vestib Res. 2018;27(5-6):271-277

Authors: Mijovic T, Remillard A, Zaia EH, Reid YM, Harrington JK, Westerberg BD, Lea J

Abstract
BACKGROUND: There is a prevailing opinion that spinning sensations signify a peripheral vestibular pathology while non-spinning sensations are not of vestibular origin.
OBJECTIVES: 1) Characterize the subjective sensations reported by patients during caloric testing. 2) Assess if the sensation was correlated with the peak slow phase velocity (SPV).
METHODS: Retrospective chart review at a Canadian adult tertiary-quaternary care balance centre for patients undergoing diagnostic caloric testing between December 2014 and September 2015.
RESULTS: Of 163 patients included, 122 had normal calorics and 41 demonstrated unilateral weakness. Spinning/rotatory movements were the most commonly reported sensations (55-70%). No sensation was reported among 10-20% of patients. Other non-rotatory sensations were reported 20-25% of the time. Both lack of sensation and other sensations were more likely to be correlated with SPVs that were significantly lower than those associated with spinning/rotating sensations. However, 18% of patients with normal calorics and robust SPVs with warm irrigation still reported non-spinning sensations.
CONCLUSIONS: During caloric irrigation, subjective sensations other than spinning and rotating are reported 20-25% of the time and these tend to be associated with lower peak SPV. Non-spinning vertigo is not uncommon as a subjective description of vestibular sensation even in normal patients with strong SPVs.

PMID: 29154301 [PubMed - indexed for MEDLINE]

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impact of orthognathic surgery on the body posture

Publication date: Available online 21 September 2018

Source: Gait & Posture

Author(s): M. Paya-Argoud, C. Tardieu, F. Cheynet, A. Raskin, L. Borel

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impact of orthognathic surgery on the body posture

Publication date: Available online 21 September 2018

Source: Gait & Posture

Author(s): M. Paya-Argoud, C. Tardieu, F. Cheynet, A. Raskin, L. Borel

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ZPower to Exhibit at EUHA Conference

​ZPower (https://zpowerbattery.com/) will be showcasing its silver-zinc rechargeable batteries and rechargeable system for hearing aids at this year's International Congress of Hearing Aid Acousticians (EUHA) in Hannover, Germany. Attendees of the 63^rd EUHA will have the opportunity to examine rechargeable hearing aid models, learn about recent product enhancements, and gain valuable insights regarding battery functionality and best practices at the ZPower booth. The EUHA conference will feature speakers on topics ranging from Bluetooth connectivity for in-ear hearing aids, to opportunities and risks in the digital revolution, to machine learning in audiology applications on October 17–19. More than 100 exhibitors are expected to participate. ​

Published: 9/21/2018 1:27:00 PM

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New Canal Hearing Aids Market Report

​HTF Market Intelligence has released the World Canal Hearing Aids Market study on the devices’ market size, industry status and forecast, competition landscape and growth opportunity to 2023. The market study is segmented by key regions that are accelerating the marketization, and includes key players such as William Demant, Sonova, Sivantos, GN Hearing, ReSound, Starkey, and Widex, It also categorizes the international canal hearing aid market by companies, region, type, and end-use industry. The full report is available at http://bit.ly/2NCE52E.

Published: 9/21/2018 11:53:00 AM

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via IFTTT

ZPower to Exhibit at EUHA Conference

​ZPower (https://zpowerbattery.com/) will be showcasing its silver-zinc rechargeable batteries and rechargeable system for hearing aids at this year's International Congress of Hearing Aid Acousticians (EUHA) in Hannover, Germany. Attendees of the 63^rd EUHA will have the opportunity to examine rechargeable hearing aid models, learn about recent product enhancements, and gain valuable insights regarding battery functionality and best practices at the ZPower booth. The EUHA conference will feature speakers on topics ranging from Bluetooth connectivity for in-ear hearing aids, to opportunities and risks in the digital revolution, to machine learning in audiology applications on October 17–19. More than 100 exhibitors are expected to participate. ​

Published: 9/21/2018 1:27:00 PM

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via IFTTT

New Canal Hearing Aids Market Report

​HTF Market Intelligence has released the World Canal Hearing Aids Market study on the devices’ market size, industry status and forecast, competition landscape and growth opportunity to 2023. The market study is segmented by key regions that are accelerating the marketization, and includes key players such as William Demant, Sonova, Sivantos, GN Hearing, ReSound, Starkey, and Widex, It also categorizes the international canal hearing aid market by companies, region, type, and end-use industry. The full report is available at http://bit.ly/2NCE52E.

Published: 9/21/2018 11:53:00 AM

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