Effects of Tyr- d-Arg-Phe-β-Ala-NH 2, a novel dermorphin analog, on elevated plus-maze learning and spontaneous alternation performance in mice

Abstract

1. 1. The effects of intracerebroventricular administration of Tyr- d-Arg-Phe-β-Ala-NH 2 (TAPA), a novel dermorphin analog, on plus-maze learning and spontaneous alternation performance were investigated in mice. 2. 2. The pre- or posttraining or preretention administration of TAPA (0.3–3.0 ng) alone failed to affect transfer latency of plus-maze learning, whereas TAPA (3 ng) produced a significant decrease in percent alternation without affecting total arm entries. 3. 3. β-Funaltrexamine (5 μg) almost completely reversed the TAPA (3 ng)-induced decrease in percentage of alternation. 4. 4. These results suggest that stimulation of μ-opioid receptors disrupts spontaneous alternation performance associated with spatial working memory.