The phrase "brain ventricles" refers to cavities or hollow spaces found inside the brain. These ventricles are filled with a fluid called cerebrospinal fluid, which helps protect and nourish the brain. Full definition
When the one of these lincRNA, called megamind, is reduced in zebrafish, the embryos have abnormally shaped heads and enlarged brain ventricles, as indicated by the arrow. (wi.mit.edu)
Though faster brain ventricle enlargement is a marker for cognitive decline and the development of neurodegenerative diseases such as Alzheimer's, the effects of sleep on this marker have never been measured. (sciencedaily.com)