The peripheral olfactory system: from wiring to signal adaptation

In the first section of this work, we studied how olfactory sensory neuron axons are guided towards the brain during development. In the second part of this work, we focused on a phenomenon recently discovered by our laboratory: activated olfactory sensory neurons exhibit a decrease in mRNA concentration of the olfactory receptor gene they express upon odorant stimulation. This observation, thought to reflect an adaptation mechanism, was used as a technique to identify which olfactory receptors respond to a given chemical. This method, called DREAM, employs a simple experimental paradigm: a prolonged odorant exposure followed by the quantitation of the olfactory receptor mRNAs extracted from the total olfactory epithelium. In this work, we addressed the mechanistic bases of this stimulation-dependent mRNA downregulation.