Discusses research on chemotropic responses of retinal growth cones mediated by rapid local protein synthesis and degradation with reference to a study led by D.S. Campbell and C. E. Holt, which appeared in the 2001 issue of "Neuron." Response to netrin 1; Details of the collapse response to L-alpha-lysophosphatidic acid; Implications of the study for future studies related to axon guidance.