PUBLICATION

Mutations in deadly seven/notch1a reveal developmental plasticity in the escape response circuit

Authors
Liu, K.S., Gray, M., Otto, S.J., Fetcho, J.R., and Beattie, C.E.
ID
ZDB-PUB-030908-3
Date
2003
Source
The Journal of neuroscience : the official journal of the Society for Neuroscience   23(22): 8159-8166 (Journal)
Registered Authors
Beattie, Christine, Fetcho, Joseph R., Gray, Michelle, Liu, Katharine S.
Keywords
none
MeSH Terms
  • Animals
  • Axons/physiology
  • Behavior, Animal/physiology
  • Biomechanical Phenomena
  • Calcium/metabolism
  • Cell Count
  • Escape Reaction/physiology*
  • Homeodomain Proteins/genetics*
  • Mutation*
  • Nerve Net/cytology
  • Nerve Net/embryology
  • Nerve Net/physiology*
  • Nerve Tissue Proteins/genetics*
  • Neuronal Plasticity/physiology*
  • Neurons/physiology
  • Reaction Time/physiology
  • Receptor, Notch1
  • Spinal Cord/cytology
  • Spinal Cord/embryology
  • Spinal Cord/physiology
  • Synapses/physiology
  • Zebrafish
  • Zebrafish Proteins
PubMed
12954879
Abstract
The relatively simple neural circuit driving the escape response in zebrafish offers an excellent opportunity to study properties of neural circuit formation. The hindbrain Mauthner cell is an essential component of this circuit. Mutations in the zebrafish deadly seven/notch1a (des) gene result in supernumerary Mauthner cells. We addressed whether and how these extra cells are incorporated into the escape-response circuit. Calcium imaging revealed that all Mauthner cells in desb420 mutants were active during an elicited escape response. However, the kinematic performance of the escape response in mutant larvae was very similar to wild-type fish. Analysis of the relationship between Mauthner axon collaterals and spinal neurons revealed that there was a decrease in the number of axon collaterals per Mauthner axon in mutant larvae compared with wild-type larvae, indicative of a decrease in the number of synapses formed with target spinal neurons. Moreover, we show that Mauthner axons projecting on the same side of the nervous system have primarily nonoverlapping collaterals. These data support the hypothesis that excess Mauthner cells are incorporated into the escape-response circuit, but they divide their target territory to maintain a normal response, thus demonstrating plasticity in the formation of the escape-response circuit. Such plasticity may be key to the evolution of the startle responses in mammals, which use larger populations of neurons in circuits similar to those in the fish escape response.
Genes / Markers
Figures
Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes