What can stimulus polarity and interphase gap tell us about auditory nerve function in cochlear-implant recipients?

Michelle L Hughes, Sangsook Choi, Erin Glickman

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Modeling studies suggest that differences in neural responses between polarities might reflect underlying neural health. Specifically, large differences in electrically evoked compound action potential (eCAP) amplitudes and amplitude-growth-function (AGF) slopes between polarities might reflect poorer peripheral neural health, whereas more similar eCAP responses between polarities might reflect better neural health. The interphase gap (IPG) has also been shown to relate to neural survival in animal studies. Specifically, healthy neurons exhibit larger eCAP amplitudes, lower thresholds, and steeper AGF slopes for increasing IPGs. In ears with poorer neural survival, these changes in neural responses are generally less apparent with increasing IPG. The primary goal of this study was to examine the combined effects of stimulus polarity and IPG within and across subjects to determine whether both measures represent similar underlying mechanisms related to neural health. With the exception of one measure in one group of subjects, results showed that polarity and IPG effects were generally not correlated in a systematic or predictable way. This suggests that these two effects might represent somewhat different aspects of neural health, such as differences in site of excitation versus integrative membrane characteristics, for example. Overall, the results from this study suggest that the underlying mechanisms that contribute to polarity and IPG effects in human CI recipients might be difficult to determine from animal models that do not exhibit the same anatomy, variance in etiology, electrode placement, and duration of deafness as humans.

Original languageEnglish (US)
Pages (from-to)50-63
Number of pages14
JournalHearing Research
Volume359
DOIs
StatePublished - Mar 1 2018

Fingerprint

Cochlear Nerve
Cochlear Implants
Interphase
Health
Action Potentials
Survival
Deafness
Growth
Ear
Anatomy
Electrodes
Animal Models
Neurons
Membranes

Keywords

  • Cochlear implant
  • Electrically evoked compound action potential
  • Interphase gap
  • Polarity

ASJC Scopus subject areas

  • Sensory Systems

Cite this

What can stimulus polarity and interphase gap tell us about auditory nerve function in cochlear-implant recipients? / Hughes, Michelle L; Choi, Sangsook; Glickman, Erin.

In: Hearing Research, Vol. 359, 01.03.2018, p. 50-63.

Research output: Contribution to journalArticle

Hughes, Michelle L ; Choi, Sangsook ; Glickman, Erin. / What can stimulus polarity and interphase gap tell us about auditory nerve function in cochlear-implant recipients?. In: Hearing Research. 2018 ; Vol. 359. pp. 50-63.
@article{0ce2f8d05acf4ca1a5af9ffa7bd42d09,
title = "What can stimulus polarity and interphase gap tell us about auditory nerve function in cochlear-implant recipients?",
abstract = "Modeling studies suggest that differences in neural responses between polarities might reflect underlying neural health. Specifically, large differences in electrically evoked compound action potential (eCAP) amplitudes and amplitude-growth-function (AGF) slopes between polarities might reflect poorer peripheral neural health, whereas more similar eCAP responses between polarities might reflect better neural health. The interphase gap (IPG) has also been shown to relate to neural survival in animal studies. Specifically, healthy neurons exhibit larger eCAP amplitudes, lower thresholds, and steeper AGF slopes for increasing IPGs. In ears with poorer neural survival, these changes in neural responses are generally less apparent with increasing IPG. The primary goal of this study was to examine the combined effects of stimulus polarity and IPG within and across subjects to determine whether both measures represent similar underlying mechanisms related to neural health. With the exception of one measure in one group of subjects, results showed that polarity and IPG effects were generally not correlated in a systematic or predictable way. This suggests that these two effects might represent somewhat different aspects of neural health, such as differences in site of excitation versus integrative membrane characteristics, for example. Overall, the results from this study suggest that the underlying mechanisms that contribute to polarity and IPG effects in human CI recipients might be difficult to determine from animal models that do not exhibit the same anatomy, variance in etiology, electrode placement, and duration of deafness as humans.",
keywords = "Cochlear implant, Electrically evoked compound action potential, Interphase gap, Polarity",
author = "Hughes, {Michelle L} and Sangsook Choi and Erin Glickman",
year = "2018",
month = "3",
day = "1",
doi = "10.1016/j.heares.2017.12.015",
language = "English (US)",
volume = "359",
pages = "50--63",
journal = "Hearing Research",
issn = "0378-5955",
publisher = "Elsevier",

}

TY - JOUR

T1 - What can stimulus polarity and interphase gap tell us about auditory nerve function in cochlear-implant recipients?

AU - Hughes, Michelle L

AU - Choi, Sangsook

AU - Glickman, Erin

PY - 2018/3/1

Y1 - 2018/3/1

N2 - Modeling studies suggest that differences in neural responses between polarities might reflect underlying neural health. Specifically, large differences in electrically evoked compound action potential (eCAP) amplitudes and amplitude-growth-function (AGF) slopes between polarities might reflect poorer peripheral neural health, whereas more similar eCAP responses between polarities might reflect better neural health. The interphase gap (IPG) has also been shown to relate to neural survival in animal studies. Specifically, healthy neurons exhibit larger eCAP amplitudes, lower thresholds, and steeper AGF slopes for increasing IPGs. In ears with poorer neural survival, these changes in neural responses are generally less apparent with increasing IPG. The primary goal of this study was to examine the combined effects of stimulus polarity and IPG within and across subjects to determine whether both measures represent similar underlying mechanisms related to neural health. With the exception of one measure in one group of subjects, results showed that polarity and IPG effects were generally not correlated in a systematic or predictable way. This suggests that these two effects might represent somewhat different aspects of neural health, such as differences in site of excitation versus integrative membrane characteristics, for example. Overall, the results from this study suggest that the underlying mechanisms that contribute to polarity and IPG effects in human CI recipients might be difficult to determine from animal models that do not exhibit the same anatomy, variance in etiology, electrode placement, and duration of deafness as humans.

AB - Modeling studies suggest that differences in neural responses between polarities might reflect underlying neural health. Specifically, large differences in electrically evoked compound action potential (eCAP) amplitudes and amplitude-growth-function (AGF) slopes between polarities might reflect poorer peripheral neural health, whereas more similar eCAP responses between polarities might reflect better neural health. The interphase gap (IPG) has also been shown to relate to neural survival in animal studies. Specifically, healthy neurons exhibit larger eCAP amplitudes, lower thresholds, and steeper AGF slopes for increasing IPGs. In ears with poorer neural survival, these changes in neural responses are generally less apparent with increasing IPG. The primary goal of this study was to examine the combined effects of stimulus polarity and IPG within and across subjects to determine whether both measures represent similar underlying mechanisms related to neural health. With the exception of one measure in one group of subjects, results showed that polarity and IPG effects were generally not correlated in a systematic or predictable way. This suggests that these two effects might represent somewhat different aspects of neural health, such as differences in site of excitation versus integrative membrane characteristics, for example. Overall, the results from this study suggest that the underlying mechanisms that contribute to polarity and IPG effects in human CI recipients might be difficult to determine from animal models that do not exhibit the same anatomy, variance in etiology, electrode placement, and duration of deafness as humans.

KW - Cochlear implant

KW - Electrically evoked compound action potential

KW - Interphase gap

KW - Polarity

UR - http://www.scopus.com/inward/record.url?scp=85039900184&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85039900184&partnerID=8YFLogxK

U2 - 10.1016/j.heares.2017.12.015

DO - 10.1016/j.heares.2017.12.015

M3 - Article

VL - 359

SP - 50

EP - 63

JO - Hearing Research

JF - Hearing Research

SN - 0378-5955

ER -