BACKGROUND: Long-distance axonal growth relies on the precise interplay of guidance cues and cell adhesion molecules. While guidance cues provide positional and directional information for the advancing growth cone, cell adhesion molecules are essential in enabling axonal advancement. Such a @entity734 on adhesion as well as guidance molecules can be well observed in dorsal commissural interneurons, which follow a highly stereotypical growth and guidance pattern. The mechanisms and molecules involved in the attraction and outgrowth towards the ventral midline, the axon crossing towards the contralateral side, the rostral turning after midline crossing as well as the guidance along the @entity2270 have been intensely studied. However, little is known about molecules that provide the basis for commissural axon growth along the anterior-posterior @entity2270 . RESULTS: @entity45255 , a recently discovered cell adhesion molecule of the IgCAM superfamily, is highly expressed in dorsolaterally located ( @entity70168 ) spinal interneurons. Functional studies inactivating @entity45255 by RNA interference (RNAi) or function-blocking antibodies demonstrate that either treatment results in a lack of commissural axon growth along the @entity2270 . Moreover, results from RNAi experiments targeting the contralateral side together with binding studies suggest that homophilic @entity45255 interactions between ipsilaterally projecting axons and post-crossing commissural axons may be the basis of axonal growth along the @entity2270 . CONCLUSIONS: Directed axonal growth of dorsal commissural interneurons requires an elaborate mixture of instructive (guidance) and permissive (outgrowth supporting) molecules. While Wnt and Sonic hedgehog (Shh) signalling pathways have been shown to specify the growth direction of post-crossing commissural axons, our study now provides evidence that homophilic @entity45255 interactions are essential for axonal extension along the @entity2270 . Interestingly, so far each part of the complex axonal trajectory of commissural axons uses its own set of guidance and growth-promoting molecules, possibly explaining why such a high number of molecules influencing the growth pattern of commissural interneurons has been identified.

Rostral growth of commissural axons requires the cell adhesion molecule XXXX .

@entity2270 :: ('MESH:C566610', 'Disease') :: ['axis', 'longitudinal axis'] @entity734 :: ('MESH:D019966', 'Disease') :: ['dependence'] @entity70168 :: ('48693', 'Gene') :: ['dI1'] @entity45255 :: ('161357', 'Gene') :: ['MDGA2']
@entity45255 :: (161357,Gene) :: ['MDGA2']
