The riddle of slow transport - an introduction.

The three articles in this debate section are intended to be read as a unit. Dennis Bray's introduction sets the scene, then Baas and Brown (pages 380-384) and Hirokawa et al. (pages 384-388) argue in favour of two different models for the mechanism by which the microtubules, microfilaments and neurofilaments that make up the neuronal cytoskeleton are transported along axons. These discussions frequently involve very different interpretations of the same experiments, and finding the real answer is a complicated task. As Dennis Bray says, it's a fascinating riddle, and we hope that you will enjoy thinking about possible solutions.