EFFECT OF PEPTIDE YY (PYY) ON FOOD-ASSOCIATED CONFLICT

Peptide YY (PW) administered centrally in rats induces powerful overea ting. PW also occurs endogenously in humans and is elevated in abstain ing bulimic patients. To examine the effect of PW in an environment th at parallels some aspects of bulimia, rats were tested in a paradigm a ssociated with approach-avoidance behavior, choosing a preferred (swee t) food paired with shock, over regular food safe from shock. PW-treat ed rats chose to sustain shock to retrieve and consume the preferred f ood, at a significantly greater speed and quantity. The number of appr oaches that were met without retrieval of food due to anxiety after PW treatment indicates that PYY increased motivation towards feeding, ra ther than anxiolysis. This effect of PW in a model of conflict associa ted with food choice resembles aspects of bulimic binge-eating, which is characterized by the repetitive, rapid intake of food, despite anxi ety associated with this behavior.