Bright lights, big hormone surge

摘要

The bright light at the end of the tunnel which some people close to death describe may result from a flood of serotonin in the brain. Near-death experiences (NDEs) are reported by around 1 in 5 critically ill people, and their cause is a mystery. Alexander Wutzler's team at the Charite University of Medicine in Berlin, Germany, wondered if serotonin -a neurotransmitter involved in mood regulation and processing vision and sound - plays a role. They gave six rats an overdose of anaesthetic and found that serotonin levels in their brains had tripled by the time they died (Neuroscience Letters, DOI: 10.1016/j.neulet.2011.04.051).