Humans experience many powerful emotions: love, anger, excitement, and fear. The question is why do fearful memories stay with us so strongly when others become increasingly difficult to remember?
Collaborating teams of researchers from Tulane University and Tufts University have been investigating this phenomenon for years now. They recently released a paper in Nature Communications with their findings.
How do fearful memories form?
Their work specifically looked into the formation of fear memories in the amygdala, the emotional hub of the brain. They found that the stress neurotransmitter norepinephrine – or noradrenaline – drives a specific memory processing mechanism when it comes to fear. Here, certain populations of neurons are inhibited in an electrical bursting pattern that arouses the amygdala in a way that strongly promotes the formation of fear memories.
Lead researcher Jeffrey Tasker explained how this would work in an armed robbery. He said: “If you are held up at gunpoint, your brain secretes a bunch of the stress neurotransmitter norepinephrine, akin to an adrenaline rush. This changes the electrical discharge pattern in specific circuits in your emotional brain, centered in the amygdala, which in turn transitions the brain to a state of heightened arousal that facilitates memory formation, fear memory, since it’s scary.”
Why is this research important?
This study is important for understanding diseases where this mechanism goes awry, like in PTSD and anxiety disorder. In these situations, the brain makes it so you cannot forget these traumatic experiences, resurfacing the memory even when the fearful stimulus is not there anymore.
Research such as this increases our understanding of the complex and still mysterious brain, hopefully leading to a future of better treatments to combat these fear-based diseases.
Source study: Nature Communications – Gq neuromodulation of BLA parvalbumin interneurons induces burst firing and mediates fear-associated network and behavioral state transition in mice