In Brief Doh!

Deleting a certain gene in mice can make them smarter by unlocking a mysterious region of the brain.

Mice with a disabled RGS14 gene are able to remember objects they had previously explored and learn to navigate mazes better than regular mice, suggesting that the gene’s presence limits some forms of learning and memory. Since RGS14 appears to hold mice back mentally, Emory pharmacologist John Hepler and his colleagues have dubbed it the “Homer Simpson gene.”

RGS14 regulates several molecules that process brain signals known to be important for learning and memory. RGS14 is primarily turned on in one particular part—the CA2—of the hippocampus, a region of the brain known to consolidate new learning and form new memories. But very little is known about the CA2 region, says Hepler. Neurons in the hippocampus will strengthen their connection after a new memory forms, but CA2 neurons do not. The loss of certain CA2 neurons is known to play a role in schizophrenia.

Hepler and his team were surprised to find that, in mice with a disabled RGS14 gene, the CA2 region was capable of robust long-term potentiation. In response to electrical stimulation, neurons there had stronger connections.

“A big question this research raises is why would we have a gene that makes us less smart?”

Hepler says. “I believe that we are not really seeing the full picture. RGS14 may be a key gene that, when missing or disabled, knocks brain signals important for learning and memory out of balance.”—Quinn Eastman

‘Homer’ gene limits mouse memory a safer way to regenerate blood vessels

A patient’s own blood cells may regenerate blood vessels damaged by heart attack or peripheral artery disease, and the method may be safer and less arduous than using rare stem cells.

Recent trials have shown that a patient’s bone marrow cells support the growth of nearby blood vessels. “Based on this idea, we wanted to identify a population of cells enriched with the capacity to regenerate blood vessels,” says Emory cardiologist Young-sup Yoon.

Yoon and his team focused on the molecule CD31, found on the surface of some endothelial cells lining the inside of blood vessels. Using donated blood from volunteers or mouse bone marrow cells, the researchers showed that cells with CD31 secrete hormones that support the growth of blood vessels. In the lab, cells with CD31 formed tubular structures that mimicked the growth of blood vessels.

Harvesting cells with CD31 may have several advantages over stem cells, Yoon says. The cells can be prepared without the need to grow them in a dish for several days, and large volumes of patient’s blood or bone marrow may not be necessary.