Anterograde trafficking of neurotrophin-3 in the adult olfactory system in vivo

► Endogenous neurotrophin-3 is expressed by olfactory sensory neurons in adult mice. ► Epitope-tagged NT3 is expressed by sensory neurons after viral-mediated gene transfer. ► NT3 fusion proteins are sorted to the secretory pathway in olfactory sensory neurons. ► Tagged NT3 is transported in sensory axons to the adult olfactory bulb in vivo. ► The epitope tag is detected in some bulb neurons, suggesting postsynaptic transfer.