QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dutton, E. K. Articles by Daniels, M. P. Search for Related Content PubMed PubMed Citation Articles by Dutton, E. K. Articles by Daniels, M. P.

 Previous Article  |  Next Article 

Journal of Neuroscience, Vol 15, 7401-7416, Copyright © 1995 by Society for Neuroscience

ARTICLE

Acetylcholine receptor aggregation at nerve-muscle contacts in mammalian cultures: induction by ventral spinal cord neurons is specific to axons

EK Dutton, CS Uhm, SJ Samuelsson, AE Schaffner, SC Fitzgerald and MP Daniels
Laboratory of Biochemical Genetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.

We used a novel mammalian coculture system to study ACh receptor (AChR) redistribution and synaptic structure at nerve-muscle contacts. Ventral spinal cord (VSC) neurons were plated on cultures containing extensive myotubes but few fibroblasts. Neurite-induced redistribution of AChRs occurred within 6 hr after plating neurons and was maximal between 36- 48 hr. This AChR redistribution appeared in two patterns: (1) AChR density at sites directly apposed to the neurite where neurites crossed preexisting AChR patches was sharply reduced, (2) Newly aggregated AChRs formed swaths lateral to the neurite path. VSC neurons induced more AChR aggregation than hippocampal, superior cervical ganglion and dorsal root ganglion neurons. The 43 and 58 kDa postsynaptic proteins were colocalized with AChR-enriched domains in all VSC neurite-induced aggregates whereas the colocalization of laminin was variable. Electron microscopy of regions with neurite-induced AChR aggregation showed postsynaptic membrane specializations characteristic of developing synapses and, in older cultures, features of more mature synaptic structure. Thus, the coculture system is useful for studying early stages of neuromuscular junction (NMJ) formation. Neurites in these cocultures were identified as axons or dendrites by morphological criteria and by their immunoreactivity for synaptophysin and phosphorylated heavy neurofilament subunits or for microtubule associated protein 2 (MAP2), respectively. Axons showed a 10-fold higher induction of AChR aggregation than did dendrites. Thus, at least one essential signaling molecule necessary for the induction of AChR aggregation at sites of interaction with muscle appears to be expressed in a polarized fashion in developing VSC neurons.

This article has been cited by other articles:

				C. E. Torgan and M. P. Daniels Calcineurin Localization in Skeletal Muscle Offers Insights into Potential New Targets J. Histochem. Cytochem., January 1, 2006; 54(1): 119 - 128. [Abstract] [Full Text] [PDF]

				C.-S. Uhm, B. Neuhuber, B. Lowe, V. Crocker, and M. P. Daniels Synapse-Forming Axons and Recombinant Agrin Induce Microprocess Formation on Myotubes J. Neurosci., December 15, 2001; 21(24): 9678 - 9689. [Abstract] [Full Text] [PDF]

				C. E. Torgan and M. P. Daniels Regulation of Myosin Heavy Chain Expression during Rat Skeletal Muscle Development In Vitro Mol. Biol. Cell, May 1, 2001; 12(5): 1499 - 1508. [Abstract] [Full Text]

				C. M. Bose, D. Qiu, A. Bergamaschi, B. Gravante, M. Bossi, A. Villa, F. Rupp, and A. Malgaroli Agrin Controls Synaptic Differentiation in Hippocampal Neurons J. Neurosci., December 15, 2000; 20(24): 9086 - 9095. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help