Mechanosensory transduction of vagal and baroreceptor afferents revealed by study of isolated nodose neurons in culture

Vladislav Snitsarev, Carol A. Whiteis, Francois M. Abboud, Mark W. Chapleau

Research output: Contribution to journalArticleResearchpeer-review

34 Citations (Scopus)

Abstract

Changes in arterial pressure and blood volume are sensed by baroreceptor and vagal afferent nerves innervating aorta and heart with soma in nodose ganglia. The inability to measure membrane potential at the nerve terminals has limited our understanding of mechanosensory transduction. Goals of the present study were to: (1) Characterize membrane potential and action potential responses to mechanical stimulation of isolated nodose sensory neurons in culture; and (2) Determine whether the degenerin/epithelial sodium channel (DEG/ENaC) blocker amiloride selectively blocks mechanically induced depolarization without suppressing membrane excitability. Membrane potential of isolated rat nodose neurons was measured with sharp microelectrodes. Mechanical stimulation with buffer ejected from a micropipette (5, 10, 20 psi) depolarized 6 of 10 nodose neurons (60%) in an intensity-dependent manner. The depolarization evoked action potentials in 4 of the 6 neurons. Amiloride (1 μM) essentially abolished mechanically induced depolarization (15±4 mV during control vs. 1±2 mV during amiloride with 20-psi stimulation, n=6) and action potential discharge. In contrast, amiloride did not inhibit the frequency of action potential discharge in response to depolarizing current injection (n=6). In summary, mechanical stimulation depolarizes and triggers action potentials in a subpopulation of nodose sensory neurons in culture. The DEG/ENaC blocker amiloride at a concentration of 1 μM inhibits responses to mechanical stimulation without suppressing membrane excitability. The results support the hypothesis that DEG/ENaC subunits are components of mechanosensitive ion channels on vagal afferent and baroreceptor neurons.

Original languageEnglish
Pages (from-to)59-63
Number of pages5
JournalAutonomic Neuroscience: Basic and Clinical
Volume98
Issue number1-2
DOIs
StatePublished - 28 Jun 2002

Fingerprint

Cellular Mechanotransduction
Pressoreceptors
Amiloride
Action Potentials
Neurons
Membrane Potentials
Sensory Receptor Cells
Degenerin Sodium Channels
Nodose Ganglion
Epithelial Sodium Channels
Afferent Neurons
Membranes
Carisoprodol
Microelectrodes
Blood Volume
Ion Channels
Evoked Potentials
Aorta
Arterial Pressure
Buffers

Keywords

  • Amiloride
  • Baroreceptors
  • Degenerin/epithelial Na channels
  • Mechanoelectrical transduction
  • Nodose ganglia
  • Vagal afferents

Cite this

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title = "Mechanosensory transduction of vagal and baroreceptor afferents revealed by study of isolated nodose neurons in culture",
abstract = "Changes in arterial pressure and blood volume are sensed by baroreceptor and vagal afferent nerves innervating aorta and heart with soma in nodose ganglia. The inability to measure membrane potential at the nerve terminals has limited our understanding of mechanosensory transduction. Goals of the present study were to: (1) Characterize membrane potential and action potential responses to mechanical stimulation of isolated nodose sensory neurons in culture; and (2) Determine whether the degenerin/epithelial sodium channel (DEG/ENaC) blocker amiloride selectively blocks mechanically induced depolarization without suppressing membrane excitability. Membrane potential of isolated rat nodose neurons was measured with sharp microelectrodes. Mechanical stimulation with buffer ejected from a micropipette (5, 10, 20 psi) depolarized 6 of 10 nodose neurons (60{\%}) in an intensity-dependent manner. The depolarization evoked action potentials in 4 of the 6 neurons. Amiloride (1 μM) essentially abolished mechanically induced depolarization (15±4 mV during control vs. 1±2 mV during amiloride with 20-psi stimulation, n=6) and action potential discharge. In contrast, amiloride did not inhibit the frequency of action potential discharge in response to depolarizing current injection (n=6). In summary, mechanical stimulation depolarizes and triggers action potentials in a subpopulation of nodose sensory neurons in culture. The DEG/ENaC blocker amiloride at a concentration of 1 μM inhibits responses to mechanical stimulation without suppressing membrane excitability. The results support the hypothesis that DEG/ENaC subunits are components of mechanosensitive ion channels on vagal afferent and baroreceptor neurons.",
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Mechanosensory transduction of vagal and baroreceptor afferents revealed by study of isolated nodose neurons in culture. / Snitsarev, Vladislav; Whiteis, Carol A.; Abboud, Francois M.; Chapleau, Mark W.

In: Autonomic Neuroscience: Basic and Clinical, Vol. 98, No. 1-2, 28.06.2002, p. 59-63.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Mechanosensory transduction of vagal and baroreceptor afferents revealed by study of isolated nodose neurons in culture

AU - Snitsarev, Vladislav

AU - Whiteis, Carol A.

AU - Abboud, Francois M.

AU - Chapleau, Mark W.

PY - 2002/6/28

Y1 - 2002/6/28

N2 - Changes in arterial pressure and blood volume are sensed by baroreceptor and vagal afferent nerves innervating aorta and heart with soma in nodose ganglia. The inability to measure membrane potential at the nerve terminals has limited our understanding of mechanosensory transduction. Goals of the present study were to: (1) Characterize membrane potential and action potential responses to mechanical stimulation of isolated nodose sensory neurons in culture; and (2) Determine whether the degenerin/epithelial sodium channel (DEG/ENaC) blocker amiloride selectively blocks mechanically induced depolarization without suppressing membrane excitability. Membrane potential of isolated rat nodose neurons was measured with sharp microelectrodes. Mechanical stimulation with buffer ejected from a micropipette (5, 10, 20 psi) depolarized 6 of 10 nodose neurons (60%) in an intensity-dependent manner. The depolarization evoked action potentials in 4 of the 6 neurons. Amiloride (1 μM) essentially abolished mechanically induced depolarization (15±4 mV during control vs. 1±2 mV during amiloride with 20-psi stimulation, n=6) and action potential discharge. In contrast, amiloride did not inhibit the frequency of action potential discharge in response to depolarizing current injection (n=6). In summary, mechanical stimulation depolarizes and triggers action potentials in a subpopulation of nodose sensory neurons in culture. The DEG/ENaC blocker amiloride at a concentration of 1 μM inhibits responses to mechanical stimulation without suppressing membrane excitability. The results support the hypothesis that DEG/ENaC subunits are components of mechanosensitive ion channels on vagal afferent and baroreceptor neurons.

AB - Changes in arterial pressure and blood volume are sensed by baroreceptor and vagal afferent nerves innervating aorta and heart with soma in nodose ganglia. The inability to measure membrane potential at the nerve terminals has limited our understanding of mechanosensory transduction. Goals of the present study were to: (1) Characterize membrane potential and action potential responses to mechanical stimulation of isolated nodose sensory neurons in culture; and (2) Determine whether the degenerin/epithelial sodium channel (DEG/ENaC) blocker amiloride selectively blocks mechanically induced depolarization without suppressing membrane excitability. Membrane potential of isolated rat nodose neurons was measured with sharp microelectrodes. Mechanical stimulation with buffer ejected from a micropipette (5, 10, 20 psi) depolarized 6 of 10 nodose neurons (60%) in an intensity-dependent manner. The depolarization evoked action potentials in 4 of the 6 neurons. Amiloride (1 μM) essentially abolished mechanically induced depolarization (15±4 mV during control vs. 1±2 mV during amiloride with 20-psi stimulation, n=6) and action potential discharge. In contrast, amiloride did not inhibit the frequency of action potential discharge in response to depolarizing current injection (n=6). In summary, mechanical stimulation depolarizes and triggers action potentials in a subpopulation of nodose sensory neurons in culture. The DEG/ENaC blocker amiloride at a concentration of 1 μM inhibits responses to mechanical stimulation without suppressing membrane excitability. The results support the hypothesis that DEG/ENaC subunits are components of mechanosensitive ion channels on vagal afferent and baroreceptor neurons.

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KW - Baroreceptors

KW - Degenerin/epithelial Na channels

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DO - 10.1016/S1566-0702(02)00033-4

M3 - Article

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EP - 63

JO - Autonomic Neuroscience: Basic and Clinical

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