Ventrolateral Origin of Each Cycle of Rhythmic Activity Generated by the Spinal Cord of the Chick Embryo

Hdl Handle:
http://hdl.handle.net/10675.2/534
Title:
Ventrolateral Origin of Each Cycle of Rhythmic Activity Generated by the Spinal Cord of the Chick Embryo
Authors:
Arai, Yoshiyasu; Mentis, George Z.; Wu, Jiang-young; O'Donovan, Michael J.
Abstract:
Background: The mechanisms responsible for generating rhythmic motor activity in the developing spinal cord of the chick embryo are poorly understood. Here we investigate whether the activity of motoneurons occurs before other neuronal populations at the beginning of each cycle of rhythmic discharge.; Methodology/Principal Findings: The spatiotemporal organization of neural activity in transverse slices of the lumbosacral cord of the chick embryo (E8-E11) was investigated using intrinsic and voltage-sensitive dye (VSD) imaging. VSD signals accompanying episodes of activity comprised a rhythmic decrease in light transmission that corresponded to each cycle of electrical activity recorded from the ipsilateral ventral root. The rhythmic signals were widely synchronized across the cord face, and the largest signal amplitude was in the ventrolateral region where motoneurons are located. In unstained slices we recorded two classes of intrinsic signal. In the first, an episode of rhythmic activity was accompanied by a slow decrease in light transmission that peaked in the dorsal horn and decayed dorsoventrally. Superimposed on this signal was a much smaller rhythmic increase in transmission that was coincident with each cycle of discharge and whose amplitude and spatial distribution was similar to that of the VSD signals. At the onset of a spontaneously occurring episode and each subsequent cycle, both the intrinsic and VSD signals originated within the lateral motor column and spread medially and then dorsally. By contrast, following a dorsal root stimulus, the optical signals originated within the dorsal horn and traveled ventrally to reach the lateral motor column.; Conclusions/Significance: These findings suggest that motoneuron activity contributes to the initiation of each cycle of rhythmic activity, and that motoneuron and/or R-interneuron synapses are a plausible site for the activity-dependent synaptic depression that modeling studies have identified as a critical mechanism for cycling within an episode.
Editors:
Mei, Lin
Citation:
PLoS ONE. 2007 May 2; 2(5):e417
Issue Date:
2-May-2007
URI:
http://hdl.handle.net/10675.2/534
DOI:
10.1371/journal.pone.0000417
PubMed ID:
17479162
PubMed Central ID:
PMC1855078
Type:
Article
ISSN:
1932-6203
Appears in Collections:
Department of Neurology: Faculty Research and Presentations

Full metadata record

DC FieldValue Language
dc.contributor.authorArai, Yoshiyasuen_US
dc.contributor.authorMentis, George Z.en_US
dc.contributor.authorWu, Jiang-youngen_US
dc.contributor.authorO'Donovan, Michael J.en_US
dc.contributor.editorMei, Lin-
dc.date.accessioned2012-10-26T16:26:33Z-
dc.date.available2012-10-26T16:26:33Z-
dc.date.issued2007-05-2en_US
dc.identifier.citationPLoS ONE. 2007 May 2; 2(5):e417en_US
dc.identifier.issn1932-6203en_US
dc.identifier.pmid17479162en_US
dc.identifier.doi10.1371/journal.pone.0000417en_US
dc.identifier.urihttp://hdl.handle.net/10675.2/534-
dc.description.abstractBackground: The mechanisms responsible for generating rhythmic motor activity in the developing spinal cord of the chick embryo are poorly understood. Here we investigate whether the activity of motoneurons occurs before other neuronal populations at the beginning of each cycle of rhythmic discharge.en_US
dc.description.abstractMethodology/Principal Findings: The spatiotemporal organization of neural activity in transverse slices of the lumbosacral cord of the chick embryo (E8-E11) was investigated using intrinsic and voltage-sensitive dye (VSD) imaging. VSD signals accompanying episodes of activity comprised a rhythmic decrease in light transmission that corresponded to each cycle of electrical activity recorded from the ipsilateral ventral root. The rhythmic signals were widely synchronized across the cord face, and the largest signal amplitude was in the ventrolateral region where motoneurons are located. In unstained slices we recorded two classes of intrinsic signal. In the first, an episode of rhythmic activity was accompanied by a slow decrease in light transmission that peaked in the dorsal horn and decayed dorsoventrally. Superimposed on this signal was a much smaller rhythmic increase in transmission that was coincident with each cycle of discharge and whose amplitude and spatial distribution was similar to that of the VSD signals. At the onset of a spontaneously occurring episode and each subsequent cycle, both the intrinsic and VSD signals originated within the lateral motor column and spread medially and then dorsally. By contrast, following a dorsal root stimulus, the optical signals originated within the dorsal horn and traveled ventrally to reach the lateral motor column.en_US
dc.description.abstractConclusions/Significance: These findings suggest that motoneuron activity contributes to the initiation of each cycle of rhythmic activity, and that motoneuron and/or R-interneuron synapses are a plausible site for the activity-dependent synaptic depression that modeling studies have identified as a critical mechanism for cycling within an episode.en_US
dc.rightsThis is an open-access article distributed under the terms of the Creative Commons Public Domain declaration which stipulates that, once placed in the public domain, this work may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose.en_US
dc.subjectResearch Articleen_US
dc.subjectDevelopmental Biologyen_US
dc.subjectNeuroscienceen_US
dc.subjectPhysiologyen_US
dc.titleVentrolateral Origin of Each Cycle of Rhythmic Activity Generated by the Spinal Cord of the Chick Embryoen_US
dc.typeArticleen_US
dc.identifier.pmcidPMC1855078en_US
dc.contributor.corporatenameDepartment of Neurology-
dc.contributor.corporatenameCollege of Graduate Studies-

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