Oct. 24, 2013

Neurobiology's Warden receives $1.5M stem cell award

Melissa Warden
Warden

Melissa Warden hopes to better understand behavior and psychiatric conditions by probing the brains of rodents – using pond scum and pulses of light.

The newest addition to the Department of Neurobiology and Behavior, Warden will be aided in her efforts with a $1.5 million award from the New York Stem Cell Foundation (NYSCF).

The assistant professor and Miriam M. Salpeter Fellow has been named by the nonprofit one of seven “most promising scientists” engaged in novel neuroscience and translational stem cell research. The 2013 NYSCF–Robertson Investigator designation was created to aid researchers as they make the transition from the postdoctoral phase of their careers to the establishment of their own laboratories.

“These young investigators are on the cutting edge of high-risk, high-reward research that no one else is doing. We are all honored to support the careers and future investigations of these promising talents,” said Susan L. Solomon, NYSCF chief executive officer.

Warden will start her Cornell lab in November, after working as a postdoctoral researcher in the lab of Karl Deisseroth, a pioneer in optogenetics at Stanford University.

She will use the technique to conduct research into the neural circuitry underlying normal and pathological patterns of action selection, motivation and learning in rats and mice, with potential therapeutic applications for humans with depression and psychiatric diseases.

Optogenetics uses light to target and manipulate certain cells and neural pathways in the brain. It is more precise than the electrodes that are sometimes used in “deep brain stimulation” treatment for patients with Parkinson’s diseases and other disorders.

In Deisseroth’s lab, researchers discovered that they could use proteins from a single-celled algae and archaebacteria from Egyptian salt lakes to make the cells sensitive to certain light patterns. Using viral vectors, neurons were genetically engineered to produce these algal proteins, which caused these neurons to be sensitive to blue light; bathing the cells in blue light triggered them to open channels and allow for the flow of positive ions, stimulating activity in the cells. The bacterial proteins caused sensitivity to yellow light, which triggered the flow of negative ions, inhibiting activity in the cells.

By using thin fiberoptic threads – 200 micrometer diameter – researchers can send pulses of blue or yellow light into the brains of mice. Only the cells containing the algal or bacterial proteins will respond.

Warden has already used the technology to locate and boost the brain cells responsible for motivation in rats, a discovery reported in the November 2012 Nature.

Potential projects at Cornell include determining how different kinds of serotonin neurons contribute to different facets of depression and deconstructing how reward-related signals are created in the mammalian brain.

The NYSCF “will allow me to pursue high-risk, transformative research from day one, and will accelerate our progress toward understanding the neural circuitry underlying motivated behavior, reward and depression,” Warden said.

“The work of Melissa Warden is a beautiful example of the technical wizardry that is fueling the ‘explosion’ in 21st-century behavioral neuroscience,” said Thomas Seeley, the Horace White Professor of Biology and chair of the Department of Neurobiology and Behavior.

Warden received her A.B. in molecular biology from Princeton University in 1996 and her Ph.D. in systems neuroscience from the Massachusetts Institute of Technology in 2006.

Stacey Shackford is staff writer at the College of Agriculture and Life Sciences.