Analysis of embryonic rat motor neurons demonstrates that these cells express a gene encoding 
agrin. The agrin molecule is secreted by the nerve cell axons as they contact the muscle fibers. The 
agrin protein plays a role in organizing the synapse and may be important in regeneration 
following nerve or muscle damage. 
From Rupp, F., Payan, D.G., Magill-Solc, C, Cowan, D., and Scheller, R.H. 1991. Neuron 
6:811-823. 
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