crossing the border molecular control of motor axon exit穿越边境的分子控制电动机的轴突退出.pdfVIP

Int. J. Mol. Sci. 2011, 12, 8539-8561; doi:10.3390/ijm OPEN ACCESS International Journal of Molecular Sciences ISSN 1422-0067 /journal/ijms Review Crossing the Border: Molecular Control of Motor Axon Exit Arlene Bravo-Ambrosio 1 and Zaven Kaprielian 1,2,* 1 Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; E-Mail: Arlene.Bravo@ 2 Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA * Author to whom correspondence should be addressed; E-Mail: Zaven.Kaprielian@; Tel.: +1-718-430-2162; Fax: +1-718-430-3758. Received: 17 October 2011; in revised form: 5 November 2011 / Accepted: 8 November 2011 / Published: 29 November 2011 Abstract: Living organisms heavily rely on the function of motor circuits for their survival and for adapting to ever-changing environments. Unique among central nervous system (CNS) neurons, motor neurons (MNs) project their axons out of the CNS. Once in the periphery, motor axons navigate along highly stereotyped trajectories, often at considerable distances from their cell bodies, to innervate appropriate muscle targets. A key decision made by pathfinding motor axons is whether to exit the CNS through dorsal or ventral motor exit points (MEPs). In contrast to the major advances made in understandi