Comparing natural- and morphine-induced reward in conditioning place preference paradigm

Introduction: Suitable response to natural rewards is one of the most important human needs for survival and reproduction. Addiction is one of the major issues with which mankind faces that is mainly due to reward system activity enhancement. There is a high degree overlap between brain regions associated with processing natural and drugs induced reward.Objective: We designed this study to enhance our understanding of how natural and synthetic rewards are processed in the brain. Our goal is to investigate the behavior of natural and morphine-induced reward.Method: We compared conditioning in morphine and food-induced reward rats (as a natural reward model) using conditioning place preference (CPP). The protocol for reward induction in all groups (foods and morphine) consisted of three phases: pre-test, conditioning duration, and post-test. In morphine groups, we injected morphine and saline and in natural reward groups, we used two rat favorite foods (Popcorn or Biscuit).Results: CPP didn’t induced in food-deprived rats. The groups that experienced food restriction could induce reward. Interestingly the CPP score of which group received popcorn for 5 days was more than the morphine group. Food-induced CPP of groups which received biscuit or popcorn during 5 and 7 days was more than animals experience 3 days conditioning.Conclusions: Food deprivation could not facilitate CPP while food restriction (Popcorn and Biscuit as reward’s cue in conditioning period) induced reward as well as morphine. Therefore restriction is better than protocol compare to deprivation. Both morphine and food-induced reward.

کلیدواژه ها:

Natural-reward ، Morphine-reward ، Addiction ، Conditioning Place Preference