Understanding How the Brain Overcomes Fear

A recent study by scientists from University College London has uncovered mechanisms by which a mouse's brain overcomes instinctive fear. This research holds potential implications for treating human fear-related disorders such as phobias, anxiety, and post-traumatic stress disorder (PTSD).

Key Findings

• Brain Regions Involved:
  • The study identified two brain regions that learn to suppress responses to perceived but harmless threats: the visual cortex and the Ventrolateral geniculate nucleus (vLGN).
  • The visual cortex is responsible for processing visual information and plays a role in learning to suppress fear reactions.
  • The vLGN stores memories that help disregard instinctive fears, bridging the neocortex and the brain stem.

Study Methodology

The researchers conducted a laboratory experiment involving 100 mice exposed to a repeated visual threat, an expanding dark circle mimicking a swooping bird, which proved harmless over time.

• Initially, the mice instinctively ran for shelter when the shadow appeared.
• After 30 to 50 exposures, the mice learned the threat was harmless and suppressed their instinctive fear, continuing normal foraging and exploring.

Scientific Observations

• Silicon probes inserted into the mice’s brains tracked neural mechanisms as they learned to suppress fear.
• This study marks the first recognition of the vLGN’s role in recalling learned behaviors.

Future Implications

Researchers aim to develop treatments targeting the vLGN to help humans manage fear-related disorders, opening new avenues for anxiety and PTSD treatment.