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ZFIN ID: ZDB-PUB-090828-2
Zebrafish motor neuron subtypes differ electrically prior to axonal outgrowth
Moreno, R.L., and Ribera, A.B.
Date: 2009
Source: Journal of neurophysiology   102(4): 2477-2484 (Journal)
Registered Authors: Ribera, Angie
Keywords: motor neuron, spinal cord, electrical excitability, neuronal subtype, voltage-dependent current
MeSH Terms:
  • Action Potentials/physiology
  • Aging/physiology*
  • Animals
  • Animals, Genetically Modified
  • Axons/physiology*
  • Cell Membrane/physiology*
  • Green Fluorescent Proteins/genetics
  • Membrane Potentials/physiology
  • Motor Neurons/physiology*
  • Patch-Clamp Techniques
  • Potassium Channels, Voltage-Gated/metabolism
  • Sodium Channels/metabolism
  • Zebrafish
PubMed: 19692510 Full text @ J. Neurophysiol.
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ABSTRACT
Different muscle targets and transcription factor expression reveal the presence of motor neuron subtypes. However it is not known whether these subtypes also differ with respect to electrical membrane properties. To address this question, we studied primary motor neurons in the spinal cord of zebrafish embryos. Primary motor neuron genesis occurs during gastrulation and gives rise to a heterogeneous set of motor neurons that differ with respect to transcription factors expression, muscle targets and soma location within each spinal cord segment. The unique subtype-specific properties of two primary motor neurons, MiP and CaP, allowed their identification in situ as early as 17 hours post fertilization (hpf), prior to axogenesis. Between 17-48 hpf, CaPs and MiPs displayed subtype-specific electrical membrane properties. Voltage-dependent inward as well as outward currents differed significantly between MiPs and CaPs. Moreover, by 48 hpf, CaPs and MiPs displayed subtype-specific firing behaviors. Our results demonstrate that motor neurons that differ with respect to muscle targets and transcription factor expression also differentiate subtype-specific electrical membrane properties. Moreover, the differences are evident prior to axogenesis.
ADDITIONAL INFORMATION