UMass medical school professor named Howard Hughes Medical Institute investigator

A leader in the study of glial cells, the brain's most abundant and overlooked cell type, Marc R. Freeman, PhD, associate professor of neurobiology at the University of Massachusetts Medical School, is among 27 new Howard Hughes Medical Institute (HHMI) investigators named today from 19 institutions across the United States. Through one of the most prestigious and sought-after scientific awards in the world, HHMI is committing approximately $150 million to support some of the nation's most innovative scientists over the next five years. Dr. Freeman, one of ten current HHMI Early Career Scientists selected, was chosen for his individual scientific excellence from a group of 1,155 applicants.

Although they comprise 60 percent of all human brain cells, glial cells often take a backseat to their better known cousin, the neuron, among neurobiologists who thought these cells played only supporting roles in the central nervous system. That thinking has begun to change, thanks in part to the work done in the Freeman lab. Experiments by Freeman have shown that glial cells are major players in the development, function and health of the nervous systems. Glia, for example, are responsible for devouring cellular debris after injury, allowing for proper repair and recovery of the brain. This and other findings have shed new light on the basic biology governing neurodegenerative diseases and how the nervous system responds to traumatic injuries. Discoveries made in the Freeman lab are poised to provide critical insights that may one day lead to new treatments and therapeutics for a host of neurological conditions.

"The Howard Hughes Medical Institute recognizes exceptionally creative thinkers and innovative scientists who are pushing the boundaries of scientific knowledge into new and unexpected avenues from which breakthroughs arise," said Michael F. Collins, MD, chancellor of UMass Medical School. "This award allows Dr. Freeman the freedom to take risks and pursue novel ideas that can dramatically change the landscape of neurobiology. All of us at UMMS are incredibly proud of what he has accomplished."

"This is a tremendously exciting moment for me and my lab," said Freeman. "Being named an HHMI investigator provides us the stability to continue chasing down the most interesting questions about basic glia biology. One of the projects we're really excited about involves understanding how glial cells select a neuron's axon for ensheathment," said Freeman explaining that glia help form the insulation that allows neurons to rapidly transmit signals over long distances in the nervous system. "HHMI allows us the freedom to start with no preliminary data but dive headlong into and answer these types of fundamental questions."

HHMI encourages its investigators to push their research into new areas of inquiry. By employing scientists as HHMI investigators—rather than awarding them research grants—HHMI gives scientists the freedom to explore and, if necessary, to change direction in their research. Moreover, they have support to follow their ideas through to fruition—even if that process takes many years.

"HHMI has a very simple mission," says HHMI President Robert Tjian, PhD. "We find the best original-thinking scientists and give them the resources to follow their instincts in discovering basic biological processes that may one day lead to better medical outcomes. This is a very talented group of scientists. And while we cannot predict where their research will take them, we're eager to help them move science forward."

A member of the UMMS faculty since 2004, Freeman received his undergraduate degree in biology from Eastern Connecticut State University and carried out his doctoral training in the laboratory of John Carlson, PhD, at Yale University where he studied Drosophila olfaction. After receiving his PhD from Yale, Freeman trained as a postdoctoral associate with Chris Q. Doe, PhD, at the University of Oregon, studying Drosophila embryonic neurogenesis.

It was as a postdoctoral associate that Freeman became interested in glial cells. Working on a type of neural stem cell division that generated both neurons and glia, he realized how little was actually known about glial cells and saw a tremendous opportunity to explore new territory. "At the time, there were all these new genetic, genomic and computational tools becoming available to study glia in Drosophila," said Freeman. "So about two years into my post doc I went to Chris and told him I wanted to switch from neurons to glia."

Freeman came to UMMS with the intention of answering fundamental questions about glia biology, but his work had unforeseen implications for human diseases and health. His interest in the glial cell's response to injury led to the identification of a suicide mechanism in axons, the projections from neurons that transmit messages to other cells. When injured or severed, the axon activates a program that signals the glia to consume the injured axon. Freeman found that mutations in one gene in this pathway, however, resulted in severed axons surviving about 50 times as long after injury. "When we started out I didn't have any intention of studying any diseases," said Freeman. "But as is often the case when you study fundamental processes in biology, you find connections that are very important for understanding and potentially treating human disease." Freeman now plans to probe this axon degeneration pathway more deeply in the hopes of identifying ways to help neurons survive damage caused by traumatic injuries to the nerves or fend off the effects of neurodegenerative disease.

Through its flagship HHMI Investigator Program, the Institute has joined with more than 70 distinguished U.S. universities, hospitals, institutes, and medical schools to create an environment that provides flexible, long-term support for approximately 330 Hughes investigators and members of their research teams. HHMI investigators are widely recognized for their creativity and research accomplishments: 164 HHMI investigators are members of the National Academy of Sciences and there are currently 15 Nobel laureates within the investigator community.

HHMI will provide each investigator with his or her full salary, benefits and a research budget over their initial five-year appointment. The Institute will also cover other expenses, including research space and the purchase of critical equipment. Their appointment may be renewed for additional five-year terms, each contingent on a successful scientific review.

Provided by University of Massachusetts Medical School