Mechanisms of transduction of olfactory signals: the possible role of the contractive apparatus of the olfactory ciliae
A hypothesis is proposed whereby the activation of Cl-channels in the chain of olfactory transduction is activated indirectly with respect to the activation of the contractive apparatus of the olfactory cilia. At the first stage, activation of the olfactory elements of the fibrils of the olfactory cilia with Са2+-ions provide smooth fluctuations of the signals of the olfactory receptors, G-proteins, adenylatecyclase of type III and cation cATP-dependent channels. In this case, the Са2+ current signal is transformed integrally into mechanical stress of fibril along the length of the olfactory cilium. At the second stage the integral change of fibril contraction by mechanical effect on the sensory membrane caused activation of Cl-channels grouped in the membrane of the basal portion of the cilium directly in the zone of the development of the generator potential. The mechanism under discussion throws a new light on the role on the olfactory cilia in transduction of the olfactory signals and, as based on the integral function of their contractive apparatus, interpret rationally some fundamental and mutually contradictory properties of olfactory reception as rapidity of action, sensitivity and selectivity.