Conditional dendritic oscillators in a lobster mechanoreceptor neurone.
1. Intra- and extracellular recordings were made from in vitro preparations of the lobster (Homarus gammarus) stomatogastric nervous system to study the nature and origin of pacemaker-like activity in a primary mechanoreceptor neurone, the anterior gastric receptor (AGR), whose two bilateral stretch...
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ftpubmed:oai:pubmedcentral.nih.gov:1159344 2023-05-15T16:34:44+02:00 Conditional dendritic oscillators in a lobster mechanoreceptor neurone. Combes, D Simmers, J Moulins, M 1997-02-15 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1159344 http://www.ncbi.nlm.nih.gov/pubmed/9061647 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1159344 http://www.ncbi.nlm.nih.gov/pubmed/9061647 Research Article Text 1997 ftpubmed 2013-08-30T11:03:59Z 1. Intra- and extracellular recordings were made from in vitro preparations of the lobster (Homarus gammarus) stomatogastric nervous system to study the nature and origin of pacemaker-like activity in a primary mechanoreceptor neurone, the anterior gastric receptor (AGR), whose two bilateral stretch-sensitive dendrites ramify in the tendon of powerstroke muscle GM1 of the gastric mill system. 2. Although the AGR is known to be autoactive, we report here that in 20% of our preparations, rather than autogenic tonic discharge, the receptor fired spontaneously in discrete bursts comprising three to ten action potentials and repeating at cycle frequencies of 0.5-2.5 Hz in the absence of mechanical stimulation. Intrasomatic recordings revealed that such rhythmic bursting was driven by slow oscillations in membrane potential, the frequency of which was voltage sensitive and dependent upon the level of stretch applied to the receptor terminals of the AGR. 3. Autoactive bursting of the AGR originated from an endogenous oscillatory mechanism in the sensory dendrites themselves, since (i) during both steady, repetitive firing and bursting, somatic and axonal impulses were always preceded 1:1 by dendritic action potentials, (ii) hyperpolarizing the AGR cell body to block triggering of axonal impulses revealed attenuated somatic spikes that continued to originate from the two peripheral dendrites, (iii) the timing of burst firing could be phase reset by brief electrical stimulation of either dendrite, and (iv) spontaneous bursting continued to be expressed by an AGR dendrite after physical isolation from the GM1 muscle and the stomatogastric nervous system. 4. Although a given AGR in vitro could switch spontaneously from dendritic bursting to tonic firing and vice versa, exogenous application of micromolar (or less) concentrations of the neuropeptide F1 (TNRNFLRFamide) to the dendritic membrane could rapidly and reversibly switch the receptor firing pattern from repetitive firing to the bursting mode. Exposure of the somatic ... Text Homarus gammarus PubMed Central (PMC) |
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Research Article Combes, D Simmers, J Moulins, M Conditional dendritic oscillators in a lobster mechanoreceptor neurone. |
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Research Article |
description |
1. Intra- and extracellular recordings were made from in vitro preparations of the lobster (Homarus gammarus) stomatogastric nervous system to study the nature and origin of pacemaker-like activity in a primary mechanoreceptor neurone, the anterior gastric receptor (AGR), whose two bilateral stretch-sensitive dendrites ramify in the tendon of powerstroke muscle GM1 of the gastric mill system. 2. Although the AGR is known to be autoactive, we report here that in 20% of our preparations, rather than autogenic tonic discharge, the receptor fired spontaneously in discrete bursts comprising three to ten action potentials and repeating at cycle frequencies of 0.5-2.5 Hz in the absence of mechanical stimulation. Intrasomatic recordings revealed that such rhythmic bursting was driven by slow oscillations in membrane potential, the frequency of which was voltage sensitive and dependent upon the level of stretch applied to the receptor terminals of the AGR. 3. Autoactive bursting of the AGR originated from an endogenous oscillatory mechanism in the sensory dendrites themselves, since (i) during both steady, repetitive firing and bursting, somatic and axonal impulses were always preceded 1:1 by dendritic action potentials, (ii) hyperpolarizing the AGR cell body to block triggering of axonal impulses revealed attenuated somatic spikes that continued to originate from the two peripheral dendrites, (iii) the timing of burst firing could be phase reset by brief electrical stimulation of either dendrite, and (iv) spontaneous bursting continued to be expressed by an AGR dendrite after physical isolation from the GM1 muscle and the stomatogastric nervous system. 4. Although a given AGR in vitro could switch spontaneously from dendritic bursting to tonic firing and vice versa, exogenous application of micromolar (or less) concentrations of the neuropeptide F1 (TNRNFLRFamide) to the dendritic membrane could rapidly and reversibly switch the receptor firing pattern from repetitive firing to the bursting mode. Exposure of the somatic ... |
format |
Text |
author |
Combes, D Simmers, J Moulins, M |
author_facet |
Combes, D Simmers, J Moulins, M |
author_sort |
Combes, D |
title |
Conditional dendritic oscillators in a lobster mechanoreceptor neurone. |
title_short |
Conditional dendritic oscillators in a lobster mechanoreceptor neurone. |
title_full |
Conditional dendritic oscillators in a lobster mechanoreceptor neurone. |
title_fullStr |
Conditional dendritic oscillators in a lobster mechanoreceptor neurone. |
title_full_unstemmed |
Conditional dendritic oscillators in a lobster mechanoreceptor neurone. |
title_sort |
conditional dendritic oscillators in a lobster mechanoreceptor neurone. |
publishDate |
1997 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1159344 http://www.ncbi.nlm.nih.gov/pubmed/9061647 |
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Homarus gammarus |
genre_facet |
Homarus gammarus |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1159344 http://www.ncbi.nlm.nih.gov/pubmed/9061647 |
_version_ |
1766024716977438720 |