Neuronal plasma membrane has been thought to retain a lot of lipid raft components which play important roles in the neural function. Although the biochemical analyses of lipid raft using brain tissues have been extensively carried out in the past 20 years, many of their experimental conditions do not coincide with those of standard neuroscience researches such as neurophysiology and neuropharmacology. Hence, the physiological methods for lipid raft analysis that can be compatible with general neuroscience have been required. Herein, we developed a system to physiologically analyze ganglioside GM1-enriched lipid rafts in brain tissues using the “Enzyme-Mediated Activation of Radical Sources (EMARS)” method that we reported (Kotani N. et al. Proc. Natl. Acad. Sci. U S A 105, 7405–7409 (2008)). The EMARS method was applied to acute brain slices prepared from mouse brains in aCSF solution using the EMARS probe, HRP-conjugated cholera toxin subunit B, which recognizes ganglioside GM1. The membrane molecules present in the GM1-enriched lipid rafts were then labeled with fluorescein under the physiological condition. The fluorescein-tagged lipid raft molecules called “EMARS products” distributed differentially among various parts of the brain. On the other hand, appreciable differences were not detected among segments along the longitudinal axis of the hippocampus. We further developed a device to label the lipid raft molecules in acute hippocampal slices under two different physiological conditions to detect dynamics of the lipid raft molecules during neural excitation. Using this device, several cell membrane molecules including Thy1, known as a lipid raft resident molecule in neurons, were confirmed by the EMARS method in living hippocampal slices.

人们认为神经元质膜保留了许多脂筏成分，这些脂筏成分在神经功能中起着重要的作用。尽管使用脑组织对脂质筏进行生化分析已经在过去的20年中进行了广泛的研究，但它们的许多实验条件与标准神经科学研究（例如神经生理学和神经药理学）的实验条件并不吻合。因此，需要可以与一般神经科学兼容的用于脂筏分析的生理学方法。本文中，我们开发了一种系统，该系统使用我们报道的“酶介导的自由基来源激活（EMARS）”方法对脑组织中富含神经节苷脂GM1的脂质筏进行生理分析（Kotani N.等人，Proc。Natl。Acad。Sci 。 美国105，7405–7409（2008）。EMARS方法适用于使用ACSRS探针（识别神经节苷脂GM1的HRP缀合的霍乱毒素亚基B）在aCSF溶液中从小鼠大脑制备的急性脑切片。然后在生理条件下用荧光素标记富含GM1的脂质筏中存在的膜分子。荧光素标记的脂筏分子称为“ EMARS产物”，在大脑的各个部位之间分布不同。另一方面，在沿海马纵轴的节段之间未检测到明显的差异。我们进一步开发了一种设备，可以在两种不同的生理条件下标记急性海马切片中的脂质筏分子，以检测神经兴奋过程中脂质筏分子的动力学。使用此设备，