PUBLICATION

Synaptic plasticity and functionality at the cone terminal of the developing zebrafish retina

Authors
Biehlmaier, O., Neuhauss, S.C.F., and Kohler, K.
ID
ZDB-PUB-030730-5
Date
2003
Source
Journal of neurobiology   56(3): 222-236 (Journal)
Registered Authors
Biehlmaier, Oliver, Neuhauss, Stephan
Keywords
none
MeSH Terms
  • Animals
  • Gene Expression Regulation, Developmental/physiology
  • Lighting
  • Neuronal Plasticity/physiology*
  • Presynaptic Terminals/metabolism*
  • Presynaptic Terminals/ultrastructure
  • Retina/embryology
  • Retina/growth & development
  • Retina/physiology*
  • Retina/ultrastructure
  • Retinal Cone Photoreceptor Cells/embryology
  • Retinal Cone Photoreceptor Cells/growth & development
  • Retinal Cone Photoreceptor Cells/physiology*
  • Retinal Cone Photoreceptor Cells/ultrastructure
  • Zebrafish/embryology
  • Zebrafish/growth & development
  • Zebrafish/physiology*
PubMed
12884262 Full text @ J. Neurobiol.
Abstract
Previous studies have analyzed photoreceptor development, some inner retina cell types, and specific neurotransmitters in the zebrafish retina. However, only minor attention has been paid to the morphology of the synaptic connection between photoreceptors and second order neurons even though it represents the transition from the light sensitive receptor to the neuronal network of the visual system. Here, we describe the appearance and differentiation of pre- and postsynaptic elements at cone synapses in the developing zebrafish retina together with the maturation of the directly connecting second order neurons and a dopaminergic third order feedback-neuron from the inner retina. Zebrafish larvae were examined at developmental stages from 2 to 7dpf ( days postfertilization) and in the adult. Synaptic maturation at the photoreceptor terminals was examined with antibodies against synapse associated proteins. The appearance of synaptic plasticity at the so- called spinule-type synapses between cones and horizontal cells was assessed by electron microscopy, and the maturation of photoreceptor downstream connection was identified by immunocytochemistry for GluR4 ( AMPA-type glutamate receptor subunit), protein kinase beta(1) (mixed rod -cone bipolar cells), and tyrosine hydroxylase (dopaminergic interplexiform cells). We found that developing zebrafish retinas possess first synaptic structures at the cone terminal as early as 3. 5dpf. Morphological maturation of these synapses at 3.5-4dpf, together with the presence of synapse associated proteins at 2.5dpf and the maturation of second order neurons by 5dpf, indicate functional synaptic connectivity and plasticity between the cones and their second order neurons already at 5dpf. However, the mere number of spinules and ribbons at 7dpf still remains below the adult values, indicating that synaptic functionality of the zebrafish retina is not entirely completed at this stage of development.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping