Opioid Agonist Effects on Regulation of Cue-Induced Food Wanting

Several lines of evidence strongly suggest that the MOR system is important for modulating reward processing in the healthy human brain. Indeed, the μ-opioid receptor system is central to reward and pain relief across many species. In rodents, injection of opioids into striatum amplifies "liking" responses to and/or "wanting" for rewards. In the current study we make use of data from a previous psychopharmacological fMRI study to assess whether an opioid agonist can alter the functional connectivity between brain areas known to be involved in hedonia/valuation and regions used in inhibition/regulation. Few studies have studied the effect of MOR agonist drugs on human reward related brain activity in healthy humans. The few that have do not provide conclusive evidence due to very small samples. Data from a randomized, placebo controlled study where a low but clinically significant dose (10mg) of the µ-opioid agonist morphine was administered per-orally in 63 healthy volunteers to stimulate their endogenous MOR system. In one of the tasks administered, participants viewed images of palatable foods and were instructed to either passively observe or actively regulate their food wanting using specific emotion regulation techniques. The primary goal for this project is to investigate the data with a new (secondary) research question: Does morphine influence our ability to down-regulate appetitive motivation?