Synaptic innervation density is regulated by neuron-derived BDNF.
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.
Causing
C G
CG
Center for Neuronal Survival, Montreal Neurological Institute, McGill University, Canada.
Gloster
A
A
Aloyz
R
R
Bamji
S X
SX
Chang
E
E
Fawcett
J
J
Kuchel
G
G
Miller
F D
FD
D000818:Animals; D001369:Axons / Q000648:ultrastructure; D019208:Brain-Derived Neurotrophic Factor / Q000502:physiology*; D004299:Dopamine beta-Hydroxylase / Q000235:genetics; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008854:Microscopy, Electron; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure; D017783:Superior Cervical Ganglion / Q000254:growth & development*; D013564:Sympathetic Nervous System / Q000254:growth & development; D013569:Synapses / Q000648:ultrastructure*; D016704:Synapsins / Q000378:metabolism
D019208:Brain-Derived Neurotrophic Factor; D016704:Synapsins; D004299:Dopamine beta-Hydroxylase