MECHANISMS OF OLFACTORY RECEPTOR NEURON ADAPTATION

感觉受体能够检测和区分相关的刺激， 在刺激的质量和数量不同的背景。 研究这些 这些事件表明，感官适应对于 受体细胞输出激活。 事实上，从刺激到 受体细胞反应的接收到终止由 转导（激活）和适应（失活）的动力学。 在 近年来，研究利用当代路径钳 电生理学和生物化学技术已经有了实质性的进步， 我们对嗅觉受体细胞激活机制的理解 但是失活的机制在很大程度上是未知的。 拟议 研究将利用这些经过验证的技术来严格检查 嗅觉适应机制。 在其他感觉系统中，电压和 钙激活电导，生电泵活性，受体 脱敏和离子组成的变化，已经牵连到 适应 两种类型的适应，一种是由于 背景气味环境（背景适应），其他以前 响应历史的细胞（受体细胞疲劳），提出了 影响细胞当前的反应潜力。 背景适应 提出以较慢的动力学作用于气味激活的电导。 受体细胞疲劳被认为是以更快的动力学作用于 体细胞电压和Ca+2激活的电导编码的行动 潜力 这项拟议中的研究将研究气味的参与， 电压和Ca+2激活电导，以及生电泵 活性和受体脱敏，在适应。 因为适应 发生在嗅觉感受器细胞中， 外部环境，适应的细胞机制可能是 特别容易受到有毒物质和感染的影响。 事实上，嗅觉缺陷与几种神经系统疾病有关。 疾病（Doty等人，1988年）。 因此，细胞的知识 适应途径的机制可能有助于阐明 不仅是嗅觉，可能还有其他神经系统疾病

Sensory receptors are able to detect and discriminate relevant stimuli from backgrounds that vary in stimulus quality and quantity. Studies of these events revealed that sensory adaptation is as fundamentally important to receptor cell output as activation. Indeed, the progression from stimulus reception to termination of receptor cell response is governed by the kinetics of transduction (activation) and adaptation (inactivation). In recent years, investigations utilizing contemporary path clamp electrophysiological and biochemical techniques have substantially advanced our understanding of the mechanisms of olfactory receptor cell activation but the mechanisms of inactivation are largely unknown. The proposed research will utilize these proven techniques to critically examine the mechanisms of olfactory adaptation. In other sensory systems, voltage and Ca+2-activated conductances, electrogenic pump activity, receptor desensitization and changes in ion composition, have been implicated in adaptation. Two types of adaptation, one the result of changes in the background odor environment (background adaptation), the other the previous response history of an cell (receptor cell fatigue), are proposed to influence the cell's current potential to respond. Background adaptation is proposed to act with slower kinetics on odor-activated conductances. Receptor cell fatigue is proposed to act with faster kinetics on the somatic voltage and Ca+2-activated conductances encoding the action potentials. The proposed research will examine the involvement of odor, voltage and Ca+2-activated conductances, as well as, electrogenic pump activity and receptor desensitization, in adaptation. Because adaptation occurs in the olfactory receptor cell, tissue which is exposed to the external environment, the cellular mechanisms of adaptation may be particularly vulnerable to the effects of toxic substances and infection. Indeed, olfactory deficits are correlated with several neurological disorders (Doty et al., 1988). Consequently, knowledge of the cellular machinery of adaptation pathways may aid in elucidating the etiologies of not only olfactory, but possibly other neurological disorders.