Neuritin 1 (NRN1) is a member of the neuritin family. Neuritin is a glycosylphosphatidylinositol-anchored protein induced by neural activity. It is expressed in postmitotic-differentiating neurons of the developing nervous system and a population of small-diameter neurons in the dorsal root ganglia and was anterogradely and retrogradely transported. Neuritin message is induced by neuronal activity and by the activity-regulated neurotrophins BDNF, nerve growth factor (NGF), and NT-3. Purified recombinant neuritin promotes neurite outgrowth and arborization in primary embryonic hippocampal and cortical cultures. Thus, neuritin is considered as a downstream effector of activity-induced neurite outgrowth. In clinical, neuritin levels in diabetes were reduced in both dorsal root ganglia and sciatic nerve of rats, and these deficits were reversed in vivo by treatment with NGF. This manipulation of neuritin levels in diabetes may provide a potential target for therapeutic intervention in the management of neuropathy.