Long-term survival of olfactory sensory neurons after target depletion.

Life-long addition and elimination of neurons within the adult olfactory epithelium and olfactory bulb allows for adaptive structural responses to sensory experience, learning, and recovery after injury. The interdependence of the two structures is highlighted by the shortened life span of sensory neurons deprived of bulb contact, and has prompted the hypothesis that trophic cues from the bulb contribute to their survival. The specific identity and source of these signals remain unknown.