Firestein S, Shepherd G M
Section of Neurobiology, Yale University School of Medicine, New Haven, CT 06510.
J Steroid Biochem Mol Biol. 1991 Oct;39(4B):615-20. doi: 10.1016/0960-0760(91)90259-8.
The detection of odor molecules by olfactory receptors is a biochemical process, but the neural signal is electrical. The transformation of chemical information into a change in membrane potential, i.e. the process of signal transduction, is accomplished in olfactory receptor neurons by a multi-step second messenger pathway resulting finally in the activation of ion channels by cAMP. Many of the biochemical and physiological details of this process are beginning to be appreciated, giving rise to a comprehensive model of the basic mechanisms of olfactory transduction that has much in common with those of other signal transduction systems. One interesting result of these new insights is that the olfactory neuron may act more as a molecule counter than a concentration detector, as had been believed previously.
嗅觉受体对气味分子的检测是一个生化过程，但神经信号是电信号。化学信息转化为膜电位变化，即信号转导过程，在嗅觉受体神经元中通过多步第二信使途径完成，最终导致离子通道被环磷酸腺苷（cAMP）激活。这一过程的许多生化和生理细节正逐渐为人所知，从而形成了一个嗅觉转导基本机制的综合模型，该模型与其他信号转导系统的模型有很多共同之处。这些新见解的一个有趣结果是，嗅觉神经元可能更像是一个分子计数器，而不是像之前认为的那样是一个浓度探测器。
