Regeneration in the olfactory system of vertebrates.

The olfactory sensory neurons, which are of placodal origin, maintain in adult vertebrates, including mammals, a neurogenetic matrix that allows for their replacement without impairment of function, both in normal circumstances (turnover) and after experimental intervention. The unique characteristics of these "disposable" neurons have recently led to a number of experiments whose results may have some importance in our understanding of the olfactory system and of the nervous system as a whole.