Do the Kappa Opioid Receptors Really Work?

The Kappa receptor is a big component of this. We don't know with 100% certainty why the Kappa receptor works like this because mapparidine as a clinically used drug has been abandoned. There's some good strong research that shows that maperedine decreases the shiver threshold in humans. The second idea is that Kappa opioid receptor might affect somehow how we sense temperature.