Investigating axonal and glial adaptations to sensory manipulations in the olfactory system

项目总结 在嗅球，二尖瓣和簇状细胞的放电频率和协调的放电模式编码 嗅觉信息的各个方面，包括气味识别和气味是否值得注意(气味突出)。 在整个生命过程中，这些燃烧特性会随着动物的学习而发生戏剧性的变化。而本地电路 而调节二尖瓣和簇状细胞输出的离心力输入是相当清楚的，存在 几乎不了解这些细胞如何将气味信息传递到其他感觉处理区域 沿着长长的有髓轴索。轴突域，如轴突起始段和有髓鞘 像Ranvier结节和髓鞘这样的区域在神经元的放电特性和 传导速度，但它们是否适合于促进成人的信息处理尚不清楚。这 该提案由两个目标组成，这两个目标试图测试轴突根域因反应而改变的假设 成年动物的神经活动。第一个目标是使用免疫组织化学和电子显微镜来 成年动物Ranvier轴突起始段、髓鞘和结节的结构观察 感觉剥夺与单侧鼻孔闭塞，以及光遗传版本的Go-no Go 联想学习范式，小鼠学会嗅觉和嗅觉。我会决定是否改编 发生在感觉剥夺和学习之后。第二个目的是调查生理后果。 感觉剥夺和学习从嗅球发出的轴突的功能。一起， 这些实验试图验证髓鞘和轴突区域适应感觉操作的假设。 并参与嗅觉感官处理。

PROJECT SUMMARY In the olfactory bulb, the firing rates and coordinated firing patterns of mitral and tufted cells encode aspects of olfactory information including odor identity and whether an odor deserves attention (odor salience). Throughout life, these firing properties can change dramatically as an animal learns. While the local circuits and centrifugal inputs modulating the output of mitral and tufted cells are reasonably well understood, there is virtually no understanding of how these cells transmit odor information to other sensory processing regions along long, myelinated axonal tracts. Axonal domains such as the axon initial segment and myelinated domains like nodes of Ranvier and the myelin sheath play a vital role in neuronal firing properties and conduction velocity, but whether they adapt to facilitate information processing in adults is not known. This proposal is comprised of two aims which seek to test the hypothesis that axonal domains change in response to neuronal activity in adult animals. The first aim uses immunohistochemistry and electron microscopy to investigate the structure of the axon initial segments, myelin sheaths, and nodes of Ranvier in adult animals following sensory deprivation with unilateral naris occlusion, and an optogenetic version of the go-no go associative learning paradigm where mice learn to detect and odorant. I will determine whether adaptations occur following sensory deprivation and learning. The second aim investigates the physiological consequences of sensory deprivation and learning on the function of axons projecting out of the olfactory bulb. Together, these experiments seek to test the hypothesis that myelin and axonal domains adapt to sensory manipulations in adults and participate in olfactory sensory processing.