The roles of neuronal and glial precursors in overcoming chondroitin sulfate proteoglycan inhibition

► NRP-derived axons cross borders between laminin and CSPGs. ► NRP growth cones exhibit lower levels of PTPσ and LAR compared to sensory neurons. ► NRP-derived axons cross onto CSPG independent of GRP contact and secreted factors. ► GRPs secrete factors that promote axon outgrowth of sensory neurons onto CSPG. ► GRP secreted factors decrease the inhibitory properties of the CSPG substrata.