Anterograde trophic signaling in the olfactory system: neurotrophin-3 expressed by olfactory sensory neurons is transported to target bulb neurons in adult mice

The adult rodent olfactory system provides an excellent model for the study of the
developing nervous system due to its constant integration of new neurons and
establishment of new synapses throughout life. This allows for adaptive structural
responses to sensory experience that continuously shape functional circuits to fit the
behavioral needs of the animal. The cellular mechanisms underlying the anatomical
plasticity of the adult olfactory system are not well understood, but neurotrophins, long
recognized as crucial to the early development of neuronal circuits, are attractive
candidate molecules in this capacity. Brain-derived neurotrophic factor (BDNF) and
nerve growth factor (NGF), two members of the neurotrophin family, have received
attention in terms of their anatomical distribution and physiological functions in the olfactory system.