Evaluation of a Postoperative Pain-Like State on Motivated Behavior in Rats: Effects of Plantar Incision on Progressive-Ratio Food-Maintained Responding

摘要: There has been recent interest in characterizing the effects of pain-like states on motivated behaviors order to quantify how pain modulates goal-directed behavior and persistence that behavior. The current set experiments assessed an incisional postoperative manipulation food-maintained responding under a progressive-ratio (PR) operant schedule. Independent variables included injury state (plantar incision or anesthesia control) reinforcer type (grain pellet sugar pellet); dependent were tactile sensory thresholds response breakpoint. Once stabilized PR schedule, separate groups rats received single ventral hind paw (control condition). Incision significantly reduced breakpoints for grain, but not sugar. In sugar, hypersensitivity recovered within 24 hr, indicating faster recovery incision-induced compared which demonstrated at PD2. NSAID analgesic, diclofenac (5.6 mg/kg) completely restored incision-depressed sensitivity 3 hr following incision. schedule differentiated between sucrose suggesting relative reinforcing efficacy may be important determinant detecting pain-induced changes