Pools of neurons (red and green) fail to segregate when a cadherin is misexpressed (right).

Jessell/Elsevier

Pools of motor neurons use cadherin combinations to sort themselves into discrete units, say Stephen Price, Thomas Jessell (Columbia University, New York, NY), and colleagues.

Differential expression of cadherins has been seen in the brain, so Jessell looked to see which cadherins are made in chick spinal cord. He studied defined motor pools, each of which innervates a single limb muscle, and found 15 cadherins, 7 of which were expressed in different subsets of the motor pools. Combinations of these cadherins could easily account for the 40 pools needed to innervate the 40 muscles in one limb.

Two of the pools—EF and A—were well suited to further analysis. These two pools shared expression of three different cadherins, but only the A pool expressed the additional MN-cadherin. When...

The Rockefeller University Press
2002
The Rockefeller University Press
2002
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