Micromanipulators and Microscope Isolation Stage

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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.