Researchers Identify the Neural Circuit Associated with Fear in Miceadmin
A study, recently published in Nature, outlines the identification of a specific area of olfactory cortex involved in the stress hormone responses of mice when they are exposed to odors related to their predators. This understanding, IFLScience author Ben Taub writes, “provides a fascinating insight into how certain neural circuits have played a role in their survival, revealing key information about the importance of fear in the evolution of all complex life forms.”
Reserachers at the Howard Hughes Medical Institute injected mice with neural activity markers and investigated how neurons in the olfactory cortex (the part of the brain that processes smells) responded to the presence of bobcat urine and a fox odor known as TMT. The team found that corticotropin-releasing hormone neurons in a tiny area of the olfactory cortext appeared to be responsible for modulating the fear response to these odors. Activity increased almost six-times when exposted to TMT and five-times when bobcat urine was present.
“Interestingly,” Taub points out, “this TMT in the wild – and therefore knew not of the dangers posed by these predators – experienced the same increase in stress hormone levels when encountering these odors, leading the the stereotypical freezing response.”