PUBLICATION

alx, a zebrafish homolog of Chx10, marks ipsilateral descending excitatory interneurons that participate in the regulation of spinal locomotor circuits

Authors
Kimura, Y., Okamura, Y., and Higashijima, S.
ID
ZDB-PUB-060616-5
Date
2006
Source
The Journal of neuroscience : the official journal of the Society for Neuroscience   26(21): 5684-5697 (Journal)
Registered Authors
Higashijima, Shin-ichi
Keywords
neural development, locomotion, spinal cord, zebrafish, Chx10, GFP
MeSH Terms
  • Animals
  • Efferent Pathways/physiology*
  • Excitatory Postsynaptic Potentials/physiology
  • Eye Proteins/metabolism*
  • Feedback/physiology
  • Homeodomain Proteins/metabolism*
  • Interneurons/physiology*
  • Locomotion/physiology*
  • Nerve Net/physiology*
  • Spinal Cord/physiology*
  • Tissue Distribution
  • Zebrafish/physiology*
  • Zebrafish Proteins/metabolism*
(all 13)
PubMed
16723525 Full text @ J. Neurosci.
Abstract
Recent molecular genetic studies suggest that the expression of transcription factors in the developing spinal cord helps determine the morphological and physiological properties of neurons. Using the zebrafish preparation, we have examined the properties of neurons marked by alx, a zebrafish homolog of mammalian Chx10. We performed morphological and physiological studies using transgenic zebrafish expressing fluorescent reporter constructs in cells that had at any time point expressed alx (alx neurons). Our data reveal that zebrafish alx neurons are all ipsilateral descending neurons that are positive for vesicular glutamate transporter 2, suggesting that they are glutamatergic excitatory interneurons. Patch recordings show that earlier-born neurons are active during stronger movements such as escapes and fast swimming (strong movement class), whereas later-born ones are involved in sustained weak swimming (weak movement class). Paired recordings between alx neurons and motoneurons show that neurons of the strong movement class make frequent monosynaptic excitatory connections onto motoneurons. Thus, neurons of this class are likely premotor interneurons that regulate motoneuron activity during escapes and fast swimming. We also show the existence of a monosynaptic connection between an alx neuron of the weak movement class and a motoneuron. Collectively, our data demonstrate that alx marks ipsilateral descending neurons that are involved in the regulation of motoneuron activity during forms of locomotion, such as escape and swimming.
Genes / Markers
Marker Marker Type Name
isl1aGENEISL LIM homeobox 1a
lhx3GENELIM homeobox 3
nkx6.1GENENK6 homeobox 1
slc17a6aGENEsolute carrier family 17 member 6a
slc17a6bGENEsolute carrier family 17 member 6b
slc32a1GENEsolute carrier family 32 member 1
vsx2GENEvisual system homeobox 2
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Figures
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Expression
Phenotype
No data available
Mutations / Transgenics
Allele Construct Type Affected Genomic Region
nns1TgTransgenic Insertion
    nns2TgTransgenic Insertion
      nns3TgTransgenic Insertion
        1 - 3 of 3
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        Human Disease / Model
        No data available
        Sequence Targeting Reagents
        No data available
        Fish
        Antibodies
        Orthology
        Engineered Foreign Genes
        Marker Marker Type Name
        DsRedEFGDsRed
        EGFPEFGEGFP
        GFPEFGGFP
        KaedeEFGKaede
        1 - 4 of 4
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        Mapping
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        Citation
        Kimura, Y., Okamura, Y., and Higashijima, S. (2006) alx, a zebrafish homolog of Chx10, marks ipsilateral descending excitatory interneurons that participate in the regulation of spinal locomotor circuits. The Journal of neuroscience : the official journal of the Society for Neuroscience. 26(21):5684-5697.