Pharma firms are developing drugs that avoid the brain’s opioid receptors to minimise the risks of dependence and overdoses, but not all experts are convinced

Nature Methods - A DREADD for the periphery

Kang et al. present HCAD, a peripherally restricted DREADD based on HCA2, with a chemical actuator that avoids crossing the blood-brain barrier and selectively reduces pain in mice. This system will enable the study of peripheral physiology without affecting the central nervous system.

Pain is meant to be a defense mechanism. It creates a strong sensation to get us to respond to a stimulus and prevent ourselves from further harm

Kang et al. present HCAD, a peripherally restricted DREADD based on HCA2, with a chemical actuator that avoids crossing the blood-brain barrier and selectively reduces pain in mice. This system will enable the study of peripheral physiology without affecting the central nervous system.