ZFIN ID: ZDB-PUB-010807-22
Paralytic zebrafish lacking acetylcholine receptors fail to localize rapsyn clusters to the synapse
Ono, F., Higashijima, S., Shcherbatko, A., Fetcho, J.R., and Brehm, P.
Date: 2001
Source: The Journal of neuroscience : the official journal of the Society for Neuroscience   21(15): 5439-5448 (Journal)
Registered Authors: Fetcho, Joseph R., Higashijima, Shin-ichi
Keywords: zebrafish; mutant; neuromuscular junction; acetylcholine receptor; dihydropyridine receptor; rapsyn; clustering
MeSH Terms:
  • Acetylcholine/pharmacology
  • Action Potentials/drug effects
  • Action Potentials/genetics
  • Animals
  • Bungarotoxins/pharmacology
  • Caffeine/pharmacology
  • Calcium Channel Blockers/pharmacology
  • Calcium Channels, L-Type/metabolism
  • Electric Stimulation
  • Fluorescent Dyes
  • Green Fluorescent Proteins
  • In Vitro Techniques
  • Ion Channel Gating/drug effects
  • Luminescent Proteins/biosynthesis
  • Luminescent Proteins/genetics
  • Motor Neurons/drug effects
  • Motor Neurons/metabolism
  • Motor Neurons/pathology
  • Muscle Contraction/drug effects
  • Muscle Proteins/metabolism*
  • Mutation*
  • Paralysis/physiopathology*
  • Patch-Clamp Techniques
  • Protein Transport/physiology
  • Receptor Aggregation/physiology
  • Receptors, Cholinergic/deficiency*
  • Receptors, Cholinergic/genetics
  • Spinal Cord/physiopathology
  • Synapses/drug effects
  • Synapses/metabolism*
  • Synapses/pathology
  • Synaptic Transmission/drug effects
  • Zebrafish
PubMed: 11466415
Physiological analysis of two lines of paralytic mutant zebrafish, relaxed and sofa potato, reveals defects in distinct types of receptors in skeletal muscle. In sofa potato the paralysis results from failed synaptic transmission because of the absence of acetylcholine receptors, whereas relaxed mutants lack dihydropyridine receptor-mediated release of internal calcium in response to the muscle action potential. Synaptic structure and function appear normal in relaxed, showing that muscle paralysis per se does not impede proper synapse development. However, sofa potato mutants show incomplete development of the postsynaptic complex. Specifically, in the absence of ACh receptors, clusters of the receptor-aggregating protein rapsyn form in the extrasynaptic membrane but generally fail to localize to the subsynaptic region. Our results indicate that, although rapsyn molecules are capable of self-aggregation, interaction with ACh receptors is required for proper subsynaptic localization.