Neurite outgrowth and growth cone collapse assays to assess neuronal responses to extracellular cues.

The identification of molecular processes involved in regulating neurite outgrowth is an active area of interest for investigators studying neural development and regeneration. In vitro assays designed to measure growth cone morphology and neurite length are frequently used to assess neuronal responses to developmental guidance cues and inhibitory cues that exist in the adult CNS. Here, we describe the procedures to assess morphological responses of cultured dorsal root ganglion neurons to attractive and repellent cues, with a focus on repellents found in the injured adult CNS. The chapter describes methods to culture the DRGs, apply inhibitory ligands, and assess morphological responses. These assays provide biological readouts to assess the capacity of a molecule to act as an inhibitory or growth promoting cue. The readouts can be used as screening tools to aid in the identification of novel targets or drugs for promoting nerve regeneration.