Chunk #69 — 5. Procedures for evaluating pharmacological treatments targeting alcohol abuse and dependence — 5.8. Models of ethanol-craving and -seeking in the operant chamber — 5.8.1. Pavlovian Spontaneous Recovery (PSR) of responding
Several weeks to months after the last extinction session, animals can be placed back into the operant chamber to assess PSR of responding. PSR is the spontaneous recovery, of the previously extinguished, lever-pressing behavior due to time spent away from the cues associated with extinction (Rodd et al., 2004b). However, it should be remembered that it is virtually impossible to separate the effect of cue-induced reinstatement of responding (Koob, 2000) from the PSR phenomenon. Similar to extinction, during PSR-testing lever presses are recorded but are not reinforced. As such, like extinction, PSR can measure craving by looking at the persistence of responding in the absence of ethanol reward (Rodd et al., 2004b). Different pharmacotherapies can be used to try to decrease responding indicative of craving during extinction and PSR. Moreover, the differential effects of a compound across different operant parameters can be delineated when assessed within the same animals. For example, in a study examining the maintenance of ethanol responding, ethanol seeking behavior (PSR), and relapse self-administration (ADE), it was found that LY404039, an mGluR2/3 agonist, reduced both ethanol-seeking behavior
