First published online June 8, 2006
Development 133, 1302e (2006)
© The Company of Biologists Limited
New technique for guiding axons
Axons navigate to their targets during brain development by interacting
with gradients of guidance molecules. Exactly how they read these gradients is
unclear. Now on p.
2487, Friedrich Bonhoeffer, Martin Bastmeyer and co-workers propose
that chick retinal axons stop growing in response to the combined effect of
the total amount of ephrin5A that they have encountered during their outgrowth
and its local concentration. The researchers investigated the response of
chick retinal growth cones to different gradients and local concentrations of
ephrin5A by using a new technique - microcontact printing - to prepare
reproducible and quantifiable, discontinuous gradients of this guidance
molecule on coverslips. They found that the growth cones stopped at distinct
zones within these gradients but remained active rather than collapsing. The
position at which they stopped depended on both the steepness of the gradient
and the local concentration of substrate-bound ephrin. Whether a similar
mechanism acts in vivo - where growth cones are reading several gradients
simultaneously - remains to be investigated.
Related articles in Development:
- Growth cone navigation in substrate-bound ephrin gradients
- Anne C. von Philipsborn, Susanne Lang, Jürgen Loeschinger, André Bernard, Christian David, Dirk Lehnert, Friedrich Bonhoeffer, and Martin Bastmeyer
Development 2006 133: 2487-2495.
[Abstract]
[Full Text]
