Further characterization of the prototypical nociceptin/orphanin FQ peptide receptor agonist Ro 64-6198 in rodent models of conflict anxiety and despair

Rationale Ro 64-6198, the prototypical non-peptide nociceptin/orphanin FQ peptide (NOP) receptor agonist, has potent anxiolytic-like effects in several preclinical models and species. However the effects of Ro 64-6198 on distinctive anxiety-provoking conditions related to unconditioned conflict behavior as well as its role in despair-like behavior remain to be addressed.