Micromanipulators and Microscope Isolation Stage

巴克实验室正在研究允许一些物种，如淡水龟、金鱼和蜗牛在冬季数月无氧生存的细胞机制。我们使用肝脏和脑细胞模型来研究缺氧耐受的机制。缺氧生存的关键是关闭利用细胞活动的能量，如蛋白质合成和维持细胞膜上的离子梯度。我们之前的研究表明，蛋白质合成减少了90%，维持离子梯度的泵减少了75%，离子通道活性（离子穿过膜的途径）减少（在一种情况下增加）。哺乳动物（人类）缺乏降低这些能量消耗反应速率的能力。然而，基本的生化途径对几乎所有物种都是共同的，当然在爬行动物、鱼类、鸟类和哺乳动物中也是如此。我们的目标是确定负责关闭耐缺氧物种的能量消耗过程的自然细胞途径。我们已经确定了几种可能的途径，并发现在缺氧时，涉及谷氨酸的脑兴奋性信号减少，而涉及GABA的抑制活性增加。这些结果与挥发性麻醉剂减少人类大脑活动的方式非常相似，我们可能已经发现了一种天然的麻醉机制。大脑是一种可电兴奋的组织，我们也在研究肝脏中离子通道的缺氧调节，这是一种不可兴奋的组织。我们将继续探索脑和肝组织的电生理特性，以更好地了解哪些离子通道受到调节，从而减少能量需求并允许缺氧生存。本提案所要求的设备是Buck实验室探索缺氧耐受机制的基本电生理技术的基础；然而，它是一个双电极系统，需要两个电动微机械臂来实现电极的精细定位，并需要一个坚固的显微镜隔离台来连接机械臂。新设备将维持和提高我的研究效率，并支持越来越多的学生和博士后的研究和培训。

The Buck lab is investigating cellular mechanisms that permit some species, such as freshwater turtles, goldfish and snails to survive without oxygen (anoxia) for months during winter. We use both a liver and brain cell model to study the mechanisms of anoxia tolerance. Key to surviving anoxia is the shutting off of energy utilizing cellular activities, such as the synthesis of proteins and maintaining ion gradients across cell membranes. We have previously shown that protein synthesis decreases by 90%, the pump that maintains ion gradients decreases by 75%, and ion channel activity (pathways for ions to cross membranes) decreases (in one case increases). The ability to reduce the rate of these energy consuming reactions is something that mammals (humans) lack. However, basic biochemical pathways are common to almost all species, certainly amongst reptiles, fish, birds and mammals. Our goal is to determine the natural cellular pathways responsible for shutting off energy consuming processes in anoxia-tolerant species. We have already identified several possible pathways and discovered that brain excitatory signaling involving glutamate decreases, while inhibitory activity involving GABA is increases during anoxia. These results are remarkably similar to the way in which volatile anesthetics reduce brain activity in humans and we may have uncovered a natural anesthetic mechanism. Brain is an electrically excitable tissue and we are also investigating anoxic regulation of ion channels in liver, a non-excitable tissue. We will continue to explore the electrophysiological properties of brain and liver tissue to better understand which ion channels are regulated in a way that reduces energetic demands and permits anoxic survival. The equipment requested in this proposal is the basis of a fundamental electrophysiological technique in the Buck Lab to explore mechanisms of anoxia tolerance; however, it is a dual electrode system that requires two motorized micromanipulators for the fine scale positioning of electrodes and a sturdy microscope isolation stage to attach the manipulators. The new equipment will maintain and increase my research productivity and support the research and training of an increased number of students and postdoctoral fellows.