DYNORPHIN(1-13) IMPAIRS MEMORY FORMATION FOR AVERSIVE AND APPETITIVE LEARNING IN CHICKS

The opioid peptide dynorphin(1 - 13) impairs memory formation in chick s (5). We examined whether this occurs for both aversively and appetit ively motivated learning. Four-day-old chicks were injected with dynor phin(1-13) into the intermediate medial hyperstriatum ventrale and tra ined on either a peck avoidance (PA) or an appetitive discrimination ( AD) task; 2-day-old chicks were trained on PA. In 2-day-old chicks, dy norphin was amnestic for PA at 0.0 1, 0.03, or 0.1 mM. In 4-day-old ch icks, dynorphin impaired memory formation for PA at 0.1 mM, and for AD training at 0.03 mM. Thus, similar doses of dynorphin impair memory f ormation for both appetitive and aversive conditioning.