Abstract
Gustatory and olfactory cells are typical chemical sensors in biological systems, which recognize various species of chemicals in external environments. This paper reviews recent progress in receptor mechanisms of taste and olfaction. It is considered that the initial event of olfactory reception is the binding of odorants to GTP-binding protein (G-protein) coupled receptors in olfactory cilia. The data presented, however, suggest that lipid layers of the receptor membranes also play an important role in odor reception. For example, membrane fluidity changes induced by a temperature increase of up to 40°C abolished the ability of olfactory receptors to discriminate odorants having similar structures. The transduction mechanisms of odor reception was also discussed. Odorants induced odor responses when the G-protein dependent pathway was completely blocked. The paper also deals with characteristics of receptor sites for taste stimuli and transduction mechanisms.
