A TINY peptide called nociceptin may play a key role in feeling pain. Makoto
Inoue and his colleagues at Osaka University applied the peptide to the foot
pads of lightly anaesthetised mice. They found that nociceptin was 10 000 times
better at inducing muscle twitches that indicate pain sensation than another
pain signalling molecule, 鈥淪P鈥�. They then showed that nociceptin works by
causing cells to release SP (Proceedings of the National Academy of
Sciences, vol 95, p 10 949).
Drugs that block the peptide鈥檚 action could provide powerful pain relief
without side effects.