Science In Action

Fentanyl is a powerful morphine substitute, but it is also incredibly addictive – millions struggle with weaning themselves off it. And of the 600,000 drug deaths worldwide each year, the World Health Organisation estimates 80% are due to opioids in general, with synthetic opioids like fentanyl being a growing part of the problem. New work with genetically manipulated mice suggests that fentanyl affects two parts of the brain, one associated with the high, but also another that regulates fear. This knowledge could aid in the development of treatments to reduce addiction to the opioid. Early developers: Long before a developing implants into a mother's uterus, in fact as the fertilised egg divides for the first time into a pair of cells, which line becomes the future baby and which will become the 'life support' system of the placenta has been decided. Embryologist Magdalena Zernicka-Goetz explains why this early unfolding of the genetic programme is important, and why it's taken so long to discover it. Gett