A lesson in FEAR.

PhysOrg reveals the anatomy of terror… in zebrafish:

A new study on the behavior of the zebrafish by Japanese researchers at the RIKEN Brain Science Institute has uncovered a key role for a region of the brain called the habenula nucleus in the development of fear responses.

Published in Nature Neuroscience, the findings for the first time connect the experience-dependent selection of fear responses to a specific region of the brain, opening new paths for research and promising insights into related mental disorders such as PTSD.

Their methodology was… terrifying. They bred fish without the neurological pathway. Then scared them.