To learn what different cells do, scientists switch them on and off and observe the effects. There are many methods that do this, but they all have problems: too invasive, too slow, or not precise enough. Now, a new method to control the activity of neurons in mice, devised by scientists at Rensselaer and Rockefeller University, avoids these downfalls by using magnetic forces to remotely control the flow of ions into specifically targeted cells.

Jonathan Dordick, the Isermann Professor of Chemical and Biological Engineering and vice president for research at Rensselaer, and colleagues successfully employed this system to study the role of the central nervous system in glucose metabolism. The findings suggest that a group of  neurons in the hypothalamus plays a vital role in maintaining blood glucose levels. Glucose metabolism is fundamental to human health, and a mechanism for controlling metabolism through remote activation of specific regions of the brain may provide new routes to therapies for a range of important diseases.

“These results are exciting  because they provide a broader view of how blood glucose is regulated —they emphasize how crucial the brain is in this process,” said Jeffrey Friedman ’77, Marilyn M. Simpson Professor and head of the Laboratory of Molecular Genetics at Rockefeller.

“We can imagine adapting this method in a number of in vitro applications in drug discovery,” said Dordick. “Depending on the type of cell type we target, and the gene expression we enhance or decrease within that cell, this approach holds potential in development of therapeutic modalities, for example, in metabolic and neurologic diseases.”

Previous work led by Friedman and Dordick tested a similar method to turn on insulin production in diabetic mice. The system couples introduction of a natural iron storage particle, ferritin, and a fluorescent tag to an ion channel called TRPV1.