Abstract: The disclosure relates to isolated nucleic acids comprising opioid receptor promoter regions and methods and compositions comprising said isolated nucleic acids. In one aspect the invention provides an isolated nucleic acid comprising a first region that encodes a Opioid Receptor promoter (ORP) region operably linked to a second region encoding an exogenous protein; wherein the opioid receptor promoter is selected from the group consisting of a mu opioid receptor promoter (MORP), a delta opioid receptor promoter (DORP), and a kappa opioid receptor promoter (KORP).

Abstract: An ensemble of neurons in the basolateral amygdala (BLA) has been identified that encodes nociceptive information across pain modalities, including pain evoked by noxious thermal and mechanical stimuli. Methods are provided for screening candidate agents for inhibition of neural activity of the BLA nociceptive ensemble. Screening assays further include determining the effectiveness of candidate agents in alleviating pain and reducing aversive pain avoidance behavior.

Abstract: Methods are provided for attenuating or preventing ?-opioid receptor mediated tolerance and opioid-induced hyperalgesia in a subject in need of acute or chronic opioid treatment for pain or in need of opioid anesthesia.