清醒状态下嗅球僧帽细胞的气味编码策略

发布时间：2018-03-19 04:10

本文选题：嗅觉　切入点：僧帽细胞　出处：《中国科学院研究生院(武汉物理与数学研究所)》2014年博士论文　论文类型：学位论文

【摘要】：嗅觉对于动物的生存来说十分重要,觅食、哺乳和躲避天敌等都需要利用嗅觉。嗅球(olfactory bulb, OB)作为嗅觉信息处理的第一级中枢,其编码气味信息的方式与大脑状态紧密相关,尤其是清醒状态下,它对气味信息的编码方式与麻醉状态下的编码方式截然不同。目前对于清醒状态下,OB对气味编码方式的了解还知之甚少。为了揭示清醒状态下,OB对气味的编码方式,我们用电生理细胞外记录的方式,记录了不同大脑状态下,OB僧帽细胞(mitral cell, MC)对气味的反应情况,通过分析和比较得到以下结果：1)通过记录麻醉状态下,嗅球MC对气味信息的编码情况,我们发现该状态下,嗅球MC对气味刺激具有较强的反应,同时也具备选择性。2)通过记录清醒头部固定的小鼠嗅球MC对气味的反应情况,我们发现MC对气味的选择性较强。3)通过比较麻醉状态和清醒状态下获得的数据,我们发现清醒状态下,嗅球MC对同种气味反应的变异系数显著高于麻醉状态下反应的变异系数,该结果提示清醒状态下,嗅球MC对气味的反应是动态变化的。4)通过比较清醒静止和运动状态下,嗅球MC对气味的反应情况,我们发现运动状态不影响MC对气味反应的变异性。5)通过go/no-go训练,使动物处于特定状态中,记录嗅球MC对气味的反应情况,我们发现动物在学会go/no-go任务以后,MC对气味的反应的变异性显著降低。该结果提示,大脑状态的改变可能是影响MC对气味的反应的重要因素之一。6)在清醒头部固定的小鼠的OB内,我们记录到发放的动作电位与θ振荡相偶联的这一类有特点的MC,结果显示,这类MC发放的动作电位在大多数情况也同Y振荡相偶联。在受到气味刺激前后,动作电位在θ或γ振荡上的分布情况以及平均相位没有发生较为显著的变化。但是相位的分布模式受到了气味刺激的影响。该结果提示这类MC的动作电位在θ或γ振荡上的相位分布可能表征了与气味相关的信息。
[Abstract]:Olfactory bulb (OB) is the first stage of olfactory information processing, and the way it encodes smell information is closely related to the state of the brain. Especially in a sober state, The way it encodes odour information is very different from that in anesthetic state. At present, very little is known about the smell coding mode of OB in awake state. In order to reveal how OB encodes smell in awake state, We recorded the responses of OB mitral cells (MCs) to odors in different brain states by electrophysiological extracellular recording, and by analyzing and comparing the following results: 1) under anaesthesia. The encoding of olfactory bulb MC to odor information, we found that in this state, olfactory bulb MC has a strong response to odour stimulation, and also has selectivity. 2) by recording the reaction of olfactory bulb MC to smell in mice with fixed head. We found that MC had stronger selectivity to odors. 3) by comparing the data obtained under anaesthesia and sobriety, we found that the coefficient of variation of the reaction of olfactory bulb MC to the same smell was significantly higher than that of the reaction under anaesthesia. The results suggested that the response of olfactory bulb MC to odour was dynamic. 4) the response of olfactory bulb MC to odor was compared with that of conscious static state and movement state. We found that the state of movement does not affect the variability of MC's response to smell. 5) through go/no-go training, the animals are in a specific state, and the reaction of the olfactory bulb MC to the smell is recorded. We found that the variability of MC response to odor decreased significantly after learning go/no-go task. The results suggested that changes in brain state might be one of the important factors affecting MC response to odor. 6) in OB of mice with fixed head. We have recorded this kind of characteristic MCs in which the emitted action potentials are coupled to theta oscillations. The results show that the action potentials released by this kind of MC are also coupled to Y oscillations in most cases. The distribution of action potential on 胃 or 纬 oscillations and the average phase did not change significantly, but the distribution pattern of phase was affected by odour stimulation. This result suggests that the action potential of this kind of MC is at 胃 or. The phase distribution on 纬-Oscillation may indicate odor-related information.
【学位授予单位】：中国科学院研究生院(武汉物理与数学研究所)
【学位级别】：博士
【学位授予年份】：2014
【分类号】：Q434

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