µ-opioid receptor in the CA1 involves in tramadol and morphine cross state-dependent memory

Publication date: Available online 30 April 2019Source: Neuroscience LettersAuthor(s): Saba Niknamfar, Setareh Nouri Zadeh-Tehrani, Mitra-Sadat Sadat-Shirazi, Ardeshir Akbarabadi, Afarin Rahimi-Movaghar, Mohammad-Reza ZarrindastAbstractIn the present study, the effect of tramadol – an opioid painkiller drug with abuse potential- on amnesia and state-dependent memory and its interaction with the opioidergic system was investigated in male Wistar rats. Intra CA-1 administration of tramadol (0.5, 1, and 2 µg/rat) before training, dose-dependently decreased the learning ability in passive avoidance task. Amnesia induced by pre-train tramadol administration was significantly reversed by pre-test administration of tramadol (1 µg/rat). Pre-test administration of naltrexone (a µ-opioid receptor (MOR) antagonist) inhibited the effect of tramadol on memory retrieval. In addition, the pre-test administration of morphine (1 µg/rat, intra-CA1) also reversed memory impairment induced by pre-train tramadol administration. Although, pre-train morphine administration (1 µg/rat, intra-CA1), induced memory impairment reversed by pre-test tramadol administration (1 µg/rat, intra-CA1). In addition, the level of MOR in the hippocampus decreased in animals with memory impairment due to using tramadol in the training day. However, state-dependent retrieval using tramadol or cross state-dependent retrieval using morphine enhanced the MOR level in the hippocampus.The results of the s...
Source: Neuroscience Letters - Category: Neuroscience Source Type: research