Neuritin, A Neurotrophic Factor in Nervous System Physiology

Neuritin (also known as candidate plasticity gene 15, cpg15) is an activity-induced glycosylphosphatidylinositol- anchored axonal protein and is mainly expressed in the brain. Neuritin mRNA expression is modulated by neurotrophic factors, synaptic activity, hormones, sensory experience, and electroconvulsive seizure therapy. Neuritin has several effects in the nervous system, such as promoting neurite outgrowth, modulating neurite outgrowth during neuronal differentiation, protecting motor neuron axons, promoting dendritic growth, shaping dendritic arbors of target neurons, regulating synaptic plasticity, stabilizing active synapses, promoting synaptic maturation and neuronal migration, promoting the development and maturation of visual cortical neurons, regulating apoptosis of proliferative neurons, and regenerating peripheral nerve and spinal axons. Neuritin is also implicated in cerebral ischemia, depression, and cognitive function in schizophrenia, and it upregulates transient outward K+ currents in neurons, suggesting that neuritin may be a potential therapeutic target in peripheral and central nervous system diseases. This review focuses on the expression, distribution, and physiological functions of neuritin in the nervous system.