RT Journal Article
SR Electronic
T1 Positionally Selective Growth of Embryonic Spinal Cord Neurites on Muscle Membranes
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4984
OP 4993
DO 10.1523/JNEUROSCI.19-12-04984.1999
VO 19
IS 12
A1 H. Wang
A1 S. R. Chadaram
A1 A. S. Norton
A1 R. Lewis
A1 J. Boyum
A1 W. Trumble
A1 J. R. Sanes
A1 M. B. Laskowski
YR 1999
UL http://www.jneurosci.org/content/19/12/4984.abstract
AB Motor neurons from distinct positions along the rostrocaudal axis generally innervate muscles or muscle fibers from corresponding axial levels. These topographic maps of connectivity are partially restored after denervation or transplantation under conditions in which factors of timing and proximity are eliminated. It is therefore likely that motor neurons and some intramuscular structures bear cues that bias synapse formation in favor of positionally matched partners. To localize these cues, we studied outgrowth of neurites from embryonic spinal cord explants on carpets of membranes isolated from perinatal rat muscles. Neurites from rostral (cervical) and caudal (lumbar) spinal cord slices exhibit distinct growth preferences. In many instances, rostrally derived neurites grew selectively on membranes from forelimb muscles or from a single thoracic muscle (the serratus anterior) when given a choice between these membranes and membranes from hindlimb muscles or laminin. Caudally derived neurites almost never exhibited such rostral preferences, but instead preferred membranes from hindlimb muscles or a single hindlimb muscle (the gluteus) to rostral muscles or laminin. Likewise, spinal neurites exhibited distinct position-related preferences for outgrowth on membranes of clonal myogenic cell lines derived from specific rostral and caudal muscles. Taken together these results suggest that the membranes of motor axons and myotubes bear complementary labels that vary with rostrocaudal position and regulate neuromuscular connectivity.