Getchell T V
Physiol Rev. 1986 Jul;66(3):772-818. doi: 10.1152/physrev.1986.66.3.772.
The interaction of an odorant with the chemosensitive membrane of olfactory receptor neurons initiates a sequence of molecular and membrane events leading to sensory transduction, impulse initiation, and the transmission of sensory information to the brain. The main steps in this sequence are summarized in Figure 6. Several lines of evidence support the hypothesis that the initial molecular events and subsequent stages of transduction are mediated by odorant receptor sites and associated ion channels located in the membrane of the cilia and apical dendritic knob of the olfactory receptor neuron. Similarly, the membrane events associated with impulse initiation and propagation are mediated by voltage-gated channels located in the initial axonal segment and the axolemma. The ionic and electrical events associated with the proposed sequence have been characterized in general using a variety of experimental techniques. The identification, localization, and sequence of membrane events are consistent with the neurophysiological properties observed in specific regions of the bipolar receptor neuron. The influence of other cells in the primary olfactory pathway such as the sustentacular cells in the olfactory epithelium, the Schwann cells in the olfactory nerve, and the astrocytes in the olfactory nerve layer in the olfactory bulb on the physiological activity of the olfactory receptor neuron is an emerging area of research interests. The general principles derived from the experimental results described in this review provide only a framework that is both incomplete and of necessity somewhat speculative. As noted in the Introduction, the multidisciplinary study of the primary olfactory pathway is undergoing a renaissance of research interest. The application of modern biophysical, cell, and molecular biological techniques to the basic issues of odorant recognition and membrane excitability will clarify the speculations and lead to the establishment of new hypotheses. Three broad areas of research will benefit from such studies. First, the application of biophysical techniques will lead to a detailed characterization of the membrane properties and associated ion conductance mechanisms. Second, the isolation and biochemical characterization of intrinsic membrane and cytosolic proteins associated with odorant recognition, sensory transduction, and the subsequent electrical events will result from the utilization of cell and molecular biological techniques.(ABSTRACT TRUNCATED AT 400 WORDS)
气味分子与嗅觉受体神经元的化学敏感膜相互作用，引发一系列分子和膜事件，导致感觉转导、冲动起始，并将感觉信息传递至大脑。这一过程的主要步骤总结于图6。多条证据支持如下假说：转导的初始分子事件及后续阶段由位于嗅觉受体神经元纤毛膜和顶端树突小球中的气味受体位点及相关离子通道介导。同样，与冲动起始和传播相关的膜事件由位于轴突起始段和轴膜中的电压门控通道介导。与所提出的过程相关的离子和电事件一般已通过多种实验技术得以表征。膜事件的识别、定位及过程与在双极受体神经元特定区域观察到的神经生理特性一致。初级嗅觉通路中其他细胞，如嗅觉上皮中的支持细胞、嗅神经中的施万细胞以及嗅球嗅神经层中的星形胶质细胞，对嗅觉受体神经元生理活动的影响是一个新兴的研究领域。本综述中描述的实验结果所推导的一般原理仅提供了一个既不完整且必然带有一定推测性得框架。如引言中所述，对初级嗅觉通路的多学科研究正经历着研究兴趣的复兴。将现代生物物理、细胞和分子生物学技术应用于气味识别和膜兴奋性的基本问题，将澄清这些推测并导致新假说的建立。三个广泛的研究领域将从这类研究中受益。首先，生物物理技术的应用将导致对膜特性及相关离子传导机制的详细表征。其次，利用细胞和分子生物学技术将实现与气味识别、感觉转导及后续电事件相关的内在膜蛋白和胞质蛋白的分离及生化表征。（摘要截选至400词）
