Scientists Uncover Secrets to Reduce Fear Once and For All

There's a reason we naturally flinch at surprise shadows or movement overhead—our brains are wired to be protective, even when the threat isn't actually there. What if we were able to silence false alarms, though? Researchers recently made some progress toward making that a possibility.

There has been a new study with mice that has found how the brain learns to shut down fear response and offers the promise of learning how to better cope with anxiety, PTSD, and other fear disorders. The discovery can change our understanding of fear, learning, and control of mental illness.

Fear is not an emotion—it's a neural reflex hard-wired into the brain. Researchers targeted the ventrolateral geniculate nucleus (vLGN), which is the area of the brain that deals with visual threat.

Mice subjected to the test were initially scared by shadows from above, naturally scurrying for cover—a survival response designed to flee aerial assaults. But after repeatedly colliding with the same innocuous stimulus, something was changed.

Their visual cortex, which translates what the eyes see, stopped overreacting. The brain essentially reprogrammed itself: "This isn't really a threat." Piece by piece, the mice no longer ran away in terror.

This anxiety response re-mapping suggests that patients with anxiety and PTSD will also be able to "unlearn" their hyperresponsive fear reaction—a discovery that holds out hope for better treatments.

The study concluded that learning to overcome fear is a result of exposure but not the sole factor—instead, it's deeper brain adjustments. Scientists, using optogenetics, a technique of driving neurons with light, found that after mice learned to recognize the presence of danger as harmless, the visual cortex transferred control over to the vLGN.

This shift meant that subcortical regions—regions deeper in the brain—had the ability to switch rapidly, effectively restarting the processing of sensory input.

The single most crucial factor in such a change? Endocannabinoid messengers—naturally occurring brain chemicals that fine-tune neuron communication. The messengers worked to calm the panic response, replacing fear with tranquility, modulated the reactions.

This finding could be the solution to enhancing the efficacy of treatments for anxiety and PTSD. Exposure therapy and other interventions accomplish this by gradually exposing patients to triggers in controlled environments. But they do not always work, and progress is incremental.

Aiming at the particular fear-controlling neural pathways, researchers hope to speed up and enhance the treatments. If humans have the same ability to "turn off" the circuits of fear, then it would open the doors for novel medical treatments, such as:
- Ultrasound therapy with targeted treatment to switch on the brain's fear control centers
- Non-invasive brain stimulation to speed up exposure therapy benefits
-[ New medications enhancing endocannabinoid signaling, which enhances fear suppression

Even though the study is just underway, scientists already are considering methods for testing these findings in human subjects. Their goal? To allow people to retrain their brains not to overreact when sensing danger, perhaps revolutionizing the treatment of phobias, anxiety disorders, and PTSD.

As the co-author of the research Sara Mederos explains, "If we can achieve the same effects in people, this could unveil totally new clinical strategies to fear-related diseases."

It appears that fear isn't as cemented in place as previously believed. And that's a thing to look forward to.