Synaptic innervation density is regulated by neuron-derived BDNF

Neuron. 1997 Feb;18(2):257-67. doi: 10.1016/s0896-6273(00)80266-4.


In this report, we have examined the role of neuron-derived BDNF at an accessible synapse, that of preganglionic neurons onto their sympathetic neuron targets. Developing and mature sympathetic neurons synthesize BDNF, and preganglionic neurons express the full-length BDNF/TrkB receptor. When sympathetic neuron-derived BDNF is increased 2- to 4-fold in transgenic mice, preganglionic cell bodies and axons hypertrophy, and the synaptic innervation to sympathetic neurons is increased. Conversely, when BDNF synthesis is eliminated in BDNF -/- mice, preganglionic synaptic innervation to sympathetic neurons is decreased. Together these results indicate that variations in neuronal neurotrophin synthesis directly regulate neuronal circuitry by selectively modulating synaptic innervation density.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / ultrastructure
  • Brain-Derived Neurotrophic Factor / physiology*
  • Dopamine beta-Hydroxylase / genetics
  • Fluorescent Antibody Technique, Indirect
  • Gene Expression
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Microscopy, Electron
  • Nerve Fibers, Myelinated / ultrastructure
  • Superior Cervical Ganglion / growth & development*
  • Sympathetic Nervous System / growth & development
  • Synapses / ultrastructure*
  • Synapsins / metabolism


  • Brain-Derived Neurotrophic Factor
  • Synapsins
  • Dopamine beta-Hydroxylase