Interactive effects of morphine and scopolamine, MK-801, propanolol on spatial working memory in rhesus monkeys

► Interactive effect of morphine + scopolamine (MK-801, propanolol) on monkey's memory. ► Morphine + scopolamine deteriorated spatial working memory. ► Morphine + MK-801 restored impairment caused by morphine and MK-801. ► Morphine (0.01 mg/kg) + propranolol reversed impaired memory induced by single drug.