PUBLICATION

Nicotinic acetylcholine receptors (nAChRs) at zebrafish red and white muscle show different properties during development

Authors
Ahmed, K.T., Ali, D.W.
ID
ZDB-PUB-151121-9
Date
2016
Source
Developmental Neurobiology   76(8): 916-36 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Animals
  • Embryo, Nonmammalian/physiology*
  • Muscle Fibers, Fast-Twitch/physiology*
  • Muscle Fibers, Slow-Twitch/physiology*
  • Neuromuscular Junction/physiology*
  • Patch-Clamp Techniques
  • Polymerase Chain Reaction
  • Receptors, Nicotinic/physiology*
  • Time Factors
  • Zebrafish
PubMed
26585318 Full text @ Dev. Neurobiol.
Abstract
Nicotinic acetylcholine receptors (nAChRs) are highly expressed at the vertebrate neuromuscular junction (NMJ) where they are required for muscle activation. Understanding the factors that underlie NMJ development is critical for a full understanding of muscle function. In this study we performed whole cell and outside-out patch clamp recordings, and single-cell RT-qPCR from zebrafish red and white muscle to examine the properties of nAChRs during the first 5 days of development. In red fibers miniature endplate currents (mEPCs) exhibit single exponential time courses at 1.5 days post fertilization (dpf) and double exponential time courses from 2 dpf onwards. In white fibers, mEPCs decay relatively slowly, with a single exponential component at 1.5 dpf. By 2 and 3 dpf, mEPC kinetics speed up, and decay with a double exponential component, and by 4 dpf the exponential decay reverts back to a single component. Single channel recordings confirm the presence of two main conductance classes of nAChRs (∼45 pS and ∼65 pS) in red fibers with multiple time courses. Two main conductance classes are also present in white fibers (∼55 pS and ∼73 pS), but they exhibit shorter mean open times by 5 dpf compared with red muscle. RT-qPCR of mRNA for nicotinic receptor subunits supports a switch from γ to ε subunits in white fibers but not in red. Our findings provide a developmental profile of mEPC properties from red and white fibers in embryonic and larval zebrafish, and reveal previously unknown differences between the NMJs of these muscle fibers.
Genes / Markers
Figures
Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Errata and Notes