Electrically stimulated increases in cochlear blood flow: I. Frequency and intensity effects

J. S. Sillman, M. J. LaRouere, R. I. Masta, J. M. Miller, Alfred Nuttall

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Charge-balanced, sinusoidal current was passed differentially between the apex and round window of the guinea pig cochlea. Cochlear blood flow was measured using a laser Doppler flow monitor. Systemic blood pressure was monitored from a cannula with the common carotid artery. Electrical stimulation increased cochlear blood flow, while systemic blood pressure was unaffected. A cochlear blood flow response parameter, normalized for transient changes in systemic blood pressure, was defined. The magnitude of the response parameter was found to be frequency selective and was also found to be an increasing function of current intensity, with maximum responses obtained with 500 Hz sinusoids. This cochlear blood flow response was not observed in dead animals; was present in preparations paralyzed with gallamine hydrochloride; and was correlated with an increase in cochlear red blood cell velocity, as directly observed by intravital microscopy. These observations imply that electrical stimulation induces a local vasodilation within the temporal bone. The fact that decreased cochlear blood flow was never observed with current injection implies that ischemia is not a likely mechanism of electrically induced tissue damage within the inner ear. The mechanism of this cochlear blood flow response is addressed in a companion report.

Original languageEnglish (US)
Pages (from-to)308-316
Number of pages9
JournalOtolaryngology - Head and Neck Surgery
Volume100
Issue number4
StatePublished - 1989
Externally publishedYes

Fingerprint

Cochlea
Blood Pressure
Electric Stimulation
Gallamine Triethiodide
Temporal Bone
Common Carotid Artery
Inner Ear
Vasodilation
Guinea Pigs
Lasers
Ischemia
Erythrocytes
Injections

ASJC Scopus subject areas

  • Otorhinolaryngology

Cite this

Electrically stimulated increases in cochlear blood flow : I. Frequency and intensity effects. / Sillman, J. S.; LaRouere, M. J.; Masta, R. I.; Miller, J. M.; Nuttall, Alfred.

In: Otolaryngology - Head and Neck Surgery, Vol. 100, No. 4, 1989, p. 308-316.

Research output: Contribution to journalArticle

Sillman, J. S. ; LaRouere, M. J. ; Masta, R. I. ; Miller, J. M. ; Nuttall, Alfred. / Electrically stimulated increases in cochlear blood flow : I. Frequency and intensity effects. In: Otolaryngology - Head and Neck Surgery. 1989 ; Vol. 100, No. 4. pp. 308-316.
@article{8d01a93ac1094fdc9378a5c1f8e2e64a,
title = "Electrically stimulated increases in cochlear blood flow: I. Frequency and intensity effects",
abstract = "Charge-balanced, sinusoidal current was passed differentially between the apex and round window of the guinea pig cochlea. Cochlear blood flow was measured using a laser Doppler flow monitor. Systemic blood pressure was monitored from a cannula with the common carotid artery. Electrical stimulation increased cochlear blood flow, while systemic blood pressure was unaffected. A cochlear blood flow response parameter, normalized for transient changes in systemic blood pressure, was defined. The magnitude of the response parameter was found to be frequency selective and was also found to be an increasing function of current intensity, with maximum responses obtained with 500 Hz sinusoids. This cochlear blood flow response was not observed in dead animals; was present in preparations paralyzed with gallamine hydrochloride; and was correlated with an increase in cochlear red blood cell velocity, as directly observed by intravital microscopy. These observations imply that electrical stimulation induces a local vasodilation within the temporal bone. The fact that decreased cochlear blood flow was never observed with current injection implies that ischemia is not a likely mechanism of electrically induced tissue damage within the inner ear. The mechanism of this cochlear blood flow response is addressed in a companion report.",
author = "Sillman, {J. S.} and LaRouere, {M. J.} and Masta, {R. I.} and Miller, {J. M.} and Alfred Nuttall",
year = "1989",
language = "English (US)",
volume = "100",
pages = "308--316",
journal = "Otolaryngology - Head and Neck Surgery (United States)",
issn = "0194-5998",
publisher = "Mosby Inc.",
number = "4",

}

TY - JOUR

T1 - Electrically stimulated increases in cochlear blood flow

T2 - I. Frequency and intensity effects

AU - Sillman, J. S.

AU - LaRouere, M. J.

AU - Masta, R. I.

AU - Miller, J. M.

AU - Nuttall, Alfred

PY - 1989

Y1 - 1989

N2 - Charge-balanced, sinusoidal current was passed differentially between the apex and round window of the guinea pig cochlea. Cochlear blood flow was measured using a laser Doppler flow monitor. Systemic blood pressure was monitored from a cannula with the common carotid artery. Electrical stimulation increased cochlear blood flow, while systemic blood pressure was unaffected. A cochlear blood flow response parameter, normalized for transient changes in systemic blood pressure, was defined. The magnitude of the response parameter was found to be frequency selective and was also found to be an increasing function of current intensity, with maximum responses obtained with 500 Hz sinusoids. This cochlear blood flow response was not observed in dead animals; was present in preparations paralyzed with gallamine hydrochloride; and was correlated with an increase in cochlear red blood cell velocity, as directly observed by intravital microscopy. These observations imply that electrical stimulation induces a local vasodilation within the temporal bone. The fact that decreased cochlear blood flow was never observed with current injection implies that ischemia is not a likely mechanism of electrically induced tissue damage within the inner ear. The mechanism of this cochlear blood flow response is addressed in a companion report.

AB - Charge-balanced, sinusoidal current was passed differentially between the apex and round window of the guinea pig cochlea. Cochlear blood flow was measured using a laser Doppler flow monitor. Systemic blood pressure was monitored from a cannula with the common carotid artery. Electrical stimulation increased cochlear blood flow, while systemic blood pressure was unaffected. A cochlear blood flow response parameter, normalized for transient changes in systemic blood pressure, was defined. The magnitude of the response parameter was found to be frequency selective and was also found to be an increasing function of current intensity, with maximum responses obtained with 500 Hz sinusoids. This cochlear blood flow response was not observed in dead animals; was present in preparations paralyzed with gallamine hydrochloride; and was correlated with an increase in cochlear red blood cell velocity, as directly observed by intravital microscopy. These observations imply that electrical stimulation induces a local vasodilation within the temporal bone. The fact that decreased cochlear blood flow was never observed with current injection implies that ischemia is not a likely mechanism of electrically induced tissue damage within the inner ear. The mechanism of this cochlear blood flow response is addressed in a companion report.

UR - http://www.scopus.com/inward/record.url?scp=0024593568&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0024593568&partnerID=8YFLogxK

M3 - Article

C2 - 2498819

AN - SCOPUS:0024593568

VL - 100

SP - 308

EP - 316

JO - Otolaryngology - Head and Neck Surgery (United States)

JF - Otolaryngology - Head and Neck Surgery (United States)

SN - 0194-5998

IS - 4

ER -