Pervasive Synaptic Branch Removal in the Mammalian Neuromuscular System at Birth
Name
Tapia-2012-Pervasive Synaptic B.pdf
Size
2.15 MB
Format
Adobe PDF
Checksum (MD5)
56f06ddd466d36783ce48ad0909842f3
Author(s)
Tapia, Juan C.
Wylie, John D.
Kasthuri, Narayanan
Hayworth, Kenneth J.
Schalek, Richard
Berger, Daniel R.
Guatimosim, Cristina
Seung, H. Sebastian
Lichtman, Jeff W.
Date Issued
June 2012
Journal
Neuron
Publisher
Elsevier
Citation
Tapia, Juan C., John D. Wylie, Narayanan Kasthuri, Kenneth J. Hayworth, Richard Schalek, Daniel R. Berger, Cristina Guatimosim, H. Sebastian Seung, and Jeff W. Lichtman. “Pervasive Synaptic Branch Removal in the Mammalian Neuromuscular System at Birth.” Neuron 74, no. 5 (June 2012): 816–829. © 2012 Elsevier Inc.
Version
Final published version
Abstract
Using light and serial electron microscopy, we show profound refinements in motor axonal branching and synaptic connectivity before and after birth. Embryonic axons become maximally connected just before birth when they innervate ~10-fold more muscle fibers than in maturity. In some developing muscles, axons innervate almost every muscle fiber. At birth, each neuromuscular junction is coinnervated by approximately ten highly intermingled axons (versus one in adults). Extensive die off of terminal branches occurs during the first several postnatal days, leading to much sparser arbors that still span the same territory. Despite the extensive pruning, total axoplasm per neuron increases as axons elongate, thicken, and add more synaptic release sites on their remaining targets. Motor axons therefore initially establish weak connections with nearly all available postsynaptic targets but, beginning at birth, massively redistribute synaptic resources, concentrating many more synaptic sites on many fewer muscle fibers. Analogous changes in connectivity may occur in the CNS.
MIT Department
Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.neuron.2012.04.017
