What if one neural pathway could determine whether or not you developed an anxiety disorder based on a bad memory? The Notch pathway, which is used in the embryo to decide what cells become nerves, skin, and bone also aid in fear memory formation later in life, according to a new study publishing in Neuron. The research, which examined the microRNA in mice, is key to developing more effective medications and therapy for anxiety disorders like Post-Traumatic Stress Disorder (PTSD).

More on the Study

While examining the brains of mice after they had learn to fear a sound paired with a mild foot shock, researchers took a closer look at a microRNA called miR-34A, which signals the Notch pathway. They found that Notch was present in the amygdala, one of the brain's fear centers, but was not activated often. Initially, Notch was thought to be used less because its primary function—to aid in deciding what cells become which part of the body—had already passed. Upon closer inspection, though, researchers found that though Notch was used less, it was contributing to fear learning in the amygdala. Notch is present in insects, worms and vertebrates.

"We are finding that developmental pathways that appear to be quiescent during adulthood are transiently reactivated to allow new memory formation to occur," said Kerry Ressler, MD, PhD and senior author of the paper.

Applying Notch Knowledge to Anxiety Treatment

This discovery is fundamental to the medication and therapy for anxiety disorders that are based in memory, like PTSD and specific phobias. If scientists can discover a drug that alters Notch pathways in the brain, then the fear learning which helps create these mental health concerns could be deactivated. Such a change could lead to a completely new treatment plan for PTSD and phobias by treating fear learning at the source. If administered early on, veterans of war and others prone to PTSD and phobias could avoid mental health problems altogether. Before that can happen, though, scientists need to have a greater understanding of Notch, its effects on the brain, and find ways to positively alter the pathway.

Date of original publication:


Brian George Dias, Jared Vega Goodman, Ranbir Ahluwalia, Audrey Elizabeth Easton, Raül Andero, Kerry James Ressler. Amygdala-Dependent Fear Memory Consolidation via miR-34a and Notch Signaling. Neuron, 2014; DOI: 10.1016/j.neuron.2014.07.019