Opioid mechanisms are involved in the disruption of arcaine-induced amnesia by context pre-exposure

► The amnestic effect of arcaine is novelty-dependent. ► Naloxone reinstated the amnesic effect of arcaine on training apparatus. ► Anti beta-endorphin allowed the amnestic effect of arcaine on training apparatus. ► Opioids are involved in the disruption of arcaine-induced amnesia.