microscopic image of brain cellsICYMI: This March 2020 story by Rachel Tompa (@Rachel_Tompa) for the Allen Institute explains how researchers demonstrated that asymmetry in neurons’ connections within the brain, established by chance in early development, explains why individual flies behave very differently from one another. The story was given an honorable mention in the 2021 Excellence in Institutional Writing Awards competition sponsored by the National Association of Science Writers. Image by N. Gupta, National Institute of Child Health and Human Development