SIGNAL RECOGNITION AND CHEMO-ELECTRICAL TRANSDUCTION IN OLFACTION

The mimicking of olfaction is considered to be a promising approach fo r the construction of artificial odour-sensing systems. In the nose, t he detection of volatile odorants begins when the odorant ligands inte ract with specific odorant receptors in the ciliary membrane of the ol factory neurons. A large family of genes encoding putative odorant rec eptors has been identified recently. Individual receptor types are exp ressed in subsets of cells distributed in distinct zones of the olfact ory epithelium. Ligand-receptor interaction triggers a rapid multistep reaction cascade, resulting in a ''pulse'' of second messengers that initiates an electrical response from the receptor neuron. Olfactory s ignalling is terminated by phosphorylation of receptors via a negative feedback reaction, catalyzed by specific kinases.