Potentiation of developing synapses by postsynaptic release of neurotrophin-4

Neuron. 1997 Oct;19(4):825-35. doi: 10.1016/s0896-6273(00)80964-2.

Abstract

The hypothesis that synaptic functions can be regulated by neurotrophins secreted from the postsynaptic cell was examined in Xenopus nerve-muscle cultures. Neuromuscular synapses formed on myocytes overexpressing neurotrophin-4 (M+ synapses) exhibited a higher level of spontaneous synaptic activity and enhanced evoked synaptic transmission as compared to those formed on normal control myocytes (M- synapses). The NT-4 effects involve a potentiation of presynaptic transmitter secretion as well as a lengthening of the mean burst duration of postsynaptic low conductance acetylcholine channels. Repetitive stimulation of either the presynaptic neuron or the postsynaptic myocyte led to a potentiation of synaptic transmission at M+ synapses. All potentiation effects of NT-4 overexpression were abolished by the extracellular presence of TrkB-IgG but not by the presence of TrkA-IgG, indicating that postsynaptic secretion of NT-4 was responsible for the synaptic modification.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Cells, Cultured
  • Electric Stimulation
  • Embryo, Nonmammalian / physiology
  • Evoked Potentials
  • Female
  • Fertilization in Vitro
  • Green Fluorescent Proteins
  • Luminescent Proteins / biosynthesis
  • Male
  • Muscles / physiology*
  • Nerve Growth Factors / biosynthesis
  • Nerve Growth Factors / physiology*
  • Neuromuscular Junction / physiology*
  • Neurons / physiology*
  • Patch-Clamp Techniques
  • Proto-Oncogene Proteins / physiology
  • RNA, Messenger / metabolism
  • Receptor Protein-Tyrosine Kinases / physiology
  • Receptor, Ciliary Neurotrophic Factor
  • Receptor, trkA
  • Receptors, Nerve Growth Factor / physiology
  • Recombinant Fusion Proteins / biosynthesis
  • Synapses / physiology*
  • Synaptic Transmission
  • Transcription, Genetic*
  • Xenopus

Substances

  • Luminescent Proteins
  • Nerve Growth Factors
  • Proto-Oncogene Proteins
  • RNA, Messenger
  • Receptor, Ciliary Neurotrophic Factor
  • Receptors, Nerve Growth Factor
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • Receptor Protein-Tyrosine Kinases
  • Receptor, trkA
  • neurotrophin 4