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Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus

Varicosities immunoreactive for nitric oxide synthase (NOS) make synaptic connections with submucosal neurons in the guinea-pig small intestine, but the effects of nitric oxide (NO) on these neurons are unknown. We used intracellular recording to characterize effects of sodium nitroprusside (SNP, NO...

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Autores principales: Bornstein, Joel C., Marks, Kathryn A., Foong, Jaime Pei Pei, Gwynne, Rachel M., Wang, Zhi Hong
Formato: Texto
Lenguaje:English
Publicado: Frontiers Research Foundation 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904599/
https://www.ncbi.nlm.nih.gov/pubmed/20589236
http://dx.doi.org/10.3389/fnins.2010.00030
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author Bornstein, Joel C.
Marks, Kathryn A.
Foong, Jaime Pei Pei
Gwynne, Rachel M.
Wang, Zhi Hong
author_facet Bornstein, Joel C.
Marks, Kathryn A.
Foong, Jaime Pei Pei
Gwynne, Rachel M.
Wang, Zhi Hong
author_sort Bornstein, Joel C.
collection PubMed
description Varicosities immunoreactive for nitric oxide synthase (NOS) make synaptic connections with submucosal neurons in the guinea-pig small intestine, but the effects of nitric oxide (NO) on these neurons are unknown. We used intracellular recording to characterize effects of sodium nitroprusside (SNP, NO donor) and nitro-l-arginine (NOLA, NOS inhibitor), on inhibitory synaptic potentials (IPSPs), slow excitatory synaptic potentials (EPSPs) and action potential firing in submucosal neurons of guinea-pig ileum in vitro. Recordings were made from neurons with the characteristic IPSPs of non-cholinergic secretomotor neurons. SNP (100 μM) markedly enhanced IPSPs evoked by single stimuli applied to intermodal strands and IPSPs evoked by trains of 2–10 pulses (30 Hz). Both noradrenergic (idazoxan-sensitive) and non-adrenergic (idazoxan-insensitive) IPSPs were affected. SNP enhanced hyperpolarizations evoked by locally applied noradrenaline or somatostatin. SNP did not affect slow EPSPs evoked by single stimuli, but depressed slow EPSPs evoked by stimulus trains. NOLA (100 μM) depressed IPSPs evoked by one to three stimulus pulses and enhanced slow EPSPs evoked by trains of two to three stimuli (30 Hz). SNP also increased the number of action potentials and the duration of firing evoked by prolonged (500 or 1000 ms) depolarizing current pulses, but NOLA had no consistent effect on action potential firing. We conclude that neurally released NO acts post-synaptically to enhance IPSPs and depress slow EPSPs, but may enhance the intrinsic excitability of these neurons. Thus, NOS neurons may locally regulate several secretomotor pathways ending on common neurons.
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spelling pubmed-29045992010-08-20 Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus Bornstein, Joel C. Marks, Kathryn A. Foong, Jaime Pei Pei Gwynne, Rachel M. Wang, Zhi Hong Front Neurosci Neuroscience Varicosities immunoreactive for nitric oxide synthase (NOS) make synaptic connections with submucosal neurons in the guinea-pig small intestine, but the effects of nitric oxide (NO) on these neurons are unknown. We used intracellular recording to characterize effects of sodium nitroprusside (SNP, NO donor) and nitro-l-arginine (NOLA, NOS inhibitor), on inhibitory synaptic potentials (IPSPs), slow excitatory synaptic potentials (EPSPs) and action potential firing in submucosal neurons of guinea-pig ileum in vitro. Recordings were made from neurons with the characteristic IPSPs of non-cholinergic secretomotor neurons. SNP (100 μM) markedly enhanced IPSPs evoked by single stimuli applied to intermodal strands and IPSPs evoked by trains of 2–10 pulses (30 Hz). Both noradrenergic (idazoxan-sensitive) and non-adrenergic (idazoxan-insensitive) IPSPs were affected. SNP enhanced hyperpolarizations evoked by locally applied noradrenaline or somatostatin. SNP did not affect slow EPSPs evoked by single stimuli, but depressed slow EPSPs evoked by stimulus trains. NOLA (100 μM) depressed IPSPs evoked by one to three stimulus pulses and enhanced slow EPSPs evoked by trains of two to three stimuli (30 Hz). SNP also increased the number of action potentials and the duration of firing evoked by prolonged (500 or 1000 ms) depolarizing current pulses, but NOLA had no consistent effect on action potential firing. We conclude that neurally released NO acts post-synaptically to enhance IPSPs and depress slow EPSPs, but may enhance the intrinsic excitability of these neurons. Thus, NOS neurons may locally regulate several secretomotor pathways ending on common neurons. Frontiers Research Foundation 2010-05-21 /pmc/articles/PMC2904599/ /pubmed/20589236 http://dx.doi.org/10.3389/fnins.2010.00030 Text en Copyright © 2010 Bornstein, Marks, Foong, Gwynne and Wang. http://www.frontiersin.org/licenseagreement This is an open-access article subject to a non-exclusive license between the authors and Frontiers Media SA, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and other Frontiers conditions are complied with.
spellingShingle Neuroscience
Bornstein, Joel C.
Marks, Kathryn A.
Foong, Jaime Pei Pei
Gwynne, Rachel M.
Wang, Zhi Hong
Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus
title Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus
title_full Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus
title_fullStr Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus
title_full_unstemmed Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus
title_short Nitric Oxide Enhances Inhibitory Synaptic Transmission and Neuronal Excitability in Guinea-Pig Submucous Plexus
title_sort nitric oxide enhances inhibitory synaptic transmission and neuronal excitability in guinea-pig submucous plexus
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904599/
https://www.ncbi.nlm.nih.gov/pubmed/20589236
http://dx.doi.org/10.3389/fnins.2010.00030
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