Seeing, hearing, thinking, daydreaming — doing anything at all, in fact — activates neurons in the brain. But for people predisposed to developing brain tumors, the ordinary buzzing of their brains could be a problem. A study by researchers at Washington University School of Medicine in St. Louis and Stanford University School of Medicine shows that the normal day-to-day activity of neurons can drive the formation and growth of brain tumors.
The researchers studied mice genetically prone to developing tumors of their optic nerves, the bundle of neurons that carries visual signals from the eyes to the brain. The mice served as a model for children with the genetic condition neurofibromatosis type 1 (NF1). About one in six children with NF1 develops low-grade optic nerve tumors by age 7. In this study, mice with Nf1 mutations raised under normal lighting developed tumors; those kept in the dark during a critical period of development did not.