Roles for ephrins in positionally selective synaptogenesis between motor neurons and muscle fibers.

Full Abstract

Motor axons form topographic maps on muscles: rostral motor pools innervate rostral muscles, and rostral portions of motor pools innervate rostral fibers within their targets. Here, we implicate A subfamily ephrins in this topographic mapping. First, developing muscles express all five of the ephrin-A genes. Second, rostrally and caudally derived motor axons differ in sensitivity to outgrowth inhibition by ephrin-A5. Third, the topographic map of motor axons on the gluteus muscle is degraded in transgenic mice that overexpress ephrin-A5 in muscles. Fourth, topographic mapping is impaired in muscles of mutant mice lacking ephrin-A2 plus ephrin-A5. Thus, ephrins mediate or modulate positionally selective synapse formation. In addition, the rostrocaudal position of at least one motor pool is altered in ephrin-A5 mutant mice, indicating that ephrins affect nerve-muscle matching by intraspinal as well as intramuscular mechanisms.

Author information

Author/s: Feng, G (G); Laskowski, M B (MB); Feldheim, D A (DA); Wang, H (H); Lewis, R (R); Frisen, J (J); Flanagan, J G (JG); Sanes, J R (JR);

Affiliation: Department of Anatomy, Washington University Medical School, St. Louis, Missouri 63110, USA.

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.

Journal: Neuron (Neuron), published in UNITED STATES. (Language: eng)

Reference: 2000-Feb; vol 25 (issue 2) : pp 295-306

Dates: Created 2000/03/30; Completed 2000/03/30; Revised 2008/11/21;

PMID: 10719886, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

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