Neurite growth on different substrates: permissive versus instructive influences and the role of adhesive strength

• Published in: The Journal of neuroscience Vol. 12; no. 3; pp. 818 - 826
• Main Authors: Lemmon, V, Burden, SM, Payne, HR, Elmslie, GJ, Hlavin, ML
• Format: Journal Article
• Language: English
• Published: Washington, DC Soc Neuroscience 01-03-1992; Society for Neuroscience
• Subjects: Adhesiveness; Animals; Biological and medical sciences; Cadherins - chemistry; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; Chick Embryo; Fundamental and applied biological sciences. Psychology; Laminin - chemistry; Laminin - pharmacology; Microscopy, Electron, Scanning; Molecular and cellular biology; Neurites - physiology; Neurites - ultrastructure; Cell culture; Vertebrata; Adhesive strength; Laminin; Neurite; Neuron; Growth; Cell adhesion molecule; Extracellular matrix; Chicken; Aves; Artificial substrate
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/JNEUROSCI.12-03-00818.1992

Growing axons use environmental cues to guide them to their targets. One class of cues is thought to be adhesion molecules on cells and in the extracellular matrix that axons interact with as they grow to their targets. In choosing between two possible pathways, the relative adhesiveness of the two substrates could be an important factor in controlling neurite growth. We conducted experiments in vitro to study how naturally occurring adhesion molecules influence neurite growth. Neurite growth rates, the degree of neurite fasciculation, the choices neurites make between two substrates, and the relative adhesiveness of different substrates were examined. We found that the relative adhesiveness of a substrate was a poor predictor of either axon growth rate or the degree of fasciculation. Furthermore, neurites showed little selectivity between three different naturally occurring substrates, L1, N-cadherin, and laminin. These results suggest that some adhesion molecules may serve as permissive substrates in that they can define axonal pathways but they do not provide information about which path to take at a choice point or about which direction to go along the path. Finally, these results suggest that substrates in vivo may not exert their effects on axon guidance principally via relative adhesiveness.