Selective δ-Opioid Receptor Agonist, KNT-127, Facilitates Contextual Fear Extinction Infralimbic Cortex and Amygdala in Mice.

Facilitation of fear extinction is a desirable action for the drugs to treat fear-related diseases, such as posttraumatic stress disorder (PTSD). We previously reported that a selective agonist of the δ-opioid receptor (DOP), KNT-127, facilitates contextual fear extinction in mice. However, its site of action in the brain and the underlying molecular mechanism remains unknown.