Molecular mechanisms in dizocilpine-induced attenuation of development of morphine dependence: An association with cortical Ca2+/calmodulin- dependent signal cascade

Moustafa Mahmoud Hamdy, Yukihiro Noda, Masayuki Miyazaki, Takayoshi Mamiya, Ayumu Nozaki, Atsumi Nitta, Merfat Sayed, Abdel Azim Assi, Adel Gomaa, Toshitaka Nabeshima

研究成果: Article

22 引用 (Scopus)


We investigated how dizocilpine, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist, affects the development of morphine dependence in mice. Co-administration of dizocilpine (0.25 mg/kg) and morphine (10 mg/kg) for 5 days attenuated the development of tolerance to the antinociceptive effects of morphine. The withdrawal manifestation induced by the naloxone-challenge (5 mg/kg) was significantly reduced in mice that were treated with a combination of dizocilpine and morphine, compared to the mice treated with morphine and saline. The present study revealed a significant increase in c-Fos protein expression in the cortex and thalamus of mice showing naloxone-precipitated withdrawal syndrome. The combination of dizocilpine and morphine prevented the increase of c-Fos protein expression in the cortex and thalamus. Interestingly, repeated co-administration of dizocilpine and morphine prevented the withdrawal-induced phosphorylation of Ca2+/calmodulin kinase II (p-CaMK II) in the cortex, but not in the thalamus. Acute dizocilpine treatment prior to the naloxone-challenge and repeated treatment with dizocilpine alone had no effect on analgesia, withdrawal manifestations, p-CaMK II levels or c-Fos protein levels. These results showed that co-administration of dizocilpine and morphine prevented the development of morphine tolerance and dependence and suggested that the preventive effect of dizocilpine results from the regulation of c-Fos protein expression, which is possibly involved in the activation of the Ca2+/calmodulin-dependent signal cascade in the cortex.

ジャーナルBehavioural Brain Research
出版物ステータスPublished - 09-07-2004


All Science Journal Classification (ASJC) codes

  • Behavioral Neuroscience