Laughing gas – or nitrous oxide – is a colourless gas with a sweet odour and taste. Its principle use is as an anaesthetic in surgical operations, however due to its unique properties, it has been used for other non-medical purposes too. Its use as a stimulant – from which it acquired its name – grants the inhaler a short period of insensibility to pain, euphoria and a tendency to mild hysteria (ie laughter). The gas has this effect as it both modulates a broad range of ligand-gated ion channels in the user’s nervous system and partially/fully inhibits NMDAR-mediated currents (the NMDA receptor is the brain’s predominant molecular device for controlling synaptic plasticity and memory function).
Importantly, however, while nitrous oxide is still sold and used for recreational purposes, scientific trials have discovered that it causes neurotoxic damage to the posterior cingulate and retrosplenial cortices of the brain (areas involved with awareness and memory), and that prolonged use will lead to death.