Gut Microbes Key to Fish Social Behavior.

Microorganisms play a critical role in the neural pruning and social behavior of zebrafish larvae, according to a study published in PLOS Biology. The absence of microbiota early in development led to inhibited social behavior and denser neural connections, but the addition of intestinal bacteria restored normal development. The study is the first to demonstrate that microglia are required for pruning of neural connections in zebrafish larvae, and that an intact microbiota is essential for normal pruning and fish social behavior.