Calif. Psych Study Shows How Brain Encodes Fear

RIVERSIDE COUNTY, CA — Certain neurons flooding several regions of the brain during a traumatic event may explain how humans and animals learn fear and what methods might work in regulating it, opening avenues to the treatment of post-traumatic stress and other disorders, according to UC Riverside researchers.

UCR professor Jun Hyeong Cho, who teaches cell biology, along with post-doctoral researcher Woong Bin Kim, published findings demonstrating how neurons emanating from the hippocampus can encode frightening occurrences to make them permanent memories.

The duo's "fear memory" research, outlined in this month's edition of the Journal of Neuroscience, focused on the influence of hippocampal neurons on the prefrontal cortex and amygdala.

Using mice in lab experiments, Cho and Kim said they were able to map the movement of "double-projecting" hippocampal neurons in relation to upsetting events, identifying how transmissions turned into contextual associations.

"Our study suggests that double-projecting hippocampal neurons can facilitate synchronized neural activity in the prefrontal cortex and amygdala that is implicated in learned fear," Cho said.

"It is by modulating the activity of the prefrontal cortex and basal amygdala that these double-projecting hippocampal neurons contribute to the acquisition and retrieval of fear memory for a context associated with an aversive event," Cho said.

After using stimuli to imprint fear in the lab mice, Cho and Kim examined the rodents' brain activity by tracking neurons that had been color- coded.

"When we repeated the experiments, the same pattern was observed consistently," Kim said. "We realized that this could be an exciting finding that may account for how contextual information is processed and conveyed between brain areas for the formation of fear memory."

The outlying prospect is for the research to translate into methods of regulating, and therefore curbing, fear responses.

Cho specifically mentioned the potential for the "development of novel therapeutics to reduce pathological fear in post-traumatic stress disorder."

In the next phase of their research, efforts will be made to "silence" the double-projecting neurons to dampen contextual fear and determine the extent to which neural manipulation can occur, the researchers said.

— By City News Service / Image via Shutterstock