MECHANISMS OF OLFACTORY RECEPTOR NEURON ADAPTATION

感官感受器能够检测和区分相关的刺激 刺激质量和数量各不相同的背景。对这些问题的研究 这些事件表明，感官适应对于 受体细胞输出为激活。事实上，刺激计划的进展 受体细胞反应的接受和终止受 转导(激活)和适应(失活)的动力学。在……里面 近年来，利用现代路径夹具进行的研究 电生理和生化技术有了很大的进步 我们对嗅觉受体细胞激活机制的认识 但失活的机制在很大程度上是未知的。建议数 研究将利用这些经过验证的技术来批判性地检查 嗅觉适应的机制。在其他感觉系统中，电压和 钙激活电导、生电泵活性、受体 脱敏和离子成分的变化，已经被牵连到 适应。两种类型的适应，一种是 背景气味环境(背景适应)，另一种是以前 细胞的响应历史(受体细胞疲劳)被提出 影响细胞当前的反应能力。背景适应 被认为对气味激活的电导具有较慢的动力学作用。 受体细胞疲劳被认为是以更快的动力学作用于 编码这一动作的体细胞电压和钙激活的电导 潜力。这项拟议的研究将检查气味的参与程度， 电压和钙离子激活的电导以及生电泵 适应中的活性和受体脱敏。因为适应 发生在嗅觉感受器细胞中，组织暴露在 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疾病有关。 精神障碍(Doty等人，1988年)。因此，关于细胞的知识 适应途径的机制可能有助于阐明糖尿病的病因 不仅是嗅觉，可能还有其他神经疾病。

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.