A New Clue to Anxiety

By Jane Farrell

Researchers have discovered a new pathway in the brain that controls “fear memories and behavior” – and that may be good news for the nearly 40 million adults who suffer from anxiety disorder.

Scientists from Cold Spring Harbor Laboratory had already discovered that “fear learning and memory are orchestrated by neurons in the central amygdala,” a region of the brain, explains CSHL Associate Professor Bo Li, who led the team of researchers who conducted the latest study.

For this study, the scientists turned to the question of what controls the central amygdala? They found the link to be a cluster of neurons that form the region of the brain known as PVT, or paraventricular nucleus of the thalamus. PVT is sensitive to both physical and psychological stress.

As the scientists studied mouse models, Li said, “we found that the PVT is specifically activated as animals learn to fear or as they recall fear memories.” And disrupting that connection meant a reduction in fear learning.

The scientists also found that a molecule called BDNF, which has been linked to anxiety disorders, is a messenger between PVT and the central amygdala.

The discovery of these connections represents “an ideal target for potential drugs to treat anxiety disorders,” according to a CHSL news release.

“Our work provides mechanistic insight into a novel circuit that controls fear in the brain, and provides a target for the future treatment of anxiety disorders,” Li said.

The study was published in the journal Nature.