Reinforcing effects of morphine are reduced in tissue plasminogen activator-knockout mice

Y. Yan, K. Yamada, H. Mizoguchi, Y. Noda, T. Nagai, A. Nitta, T. Nabeshima

研究成果: Article

13 引用 (Scopus)

抜粋

Tissue plasminogen activator (tPA) plays a key role in neuroplasticity. We have recently demonstrated that the tPA-plasmin system is involved in the rewarding effects of drugs of abuse by regulating the release of dopamine in the nucleus accumbens. In the present study, we investigated whether tPA is involved in the reinforcing properties of morphine in a paradigm of drug self-administration. Eight-week-old tPA knockout and wild-type control mice were subjected to a single 24-h session of morphine self-administration under a fixed ratio (FR) 2 or a progressive ratio (PR) schedule of reinforcement after eight daily 30-min sessions of nose-poke training. tPA knockout mice responded significantly more often for morphine self-administration in a dose-dependent manner as compared with wild-type control mice. Under the PR schedule of morphine reinforcement, however, tPA knockout mice showed a lower breaking point than wild-type control mice. There was no significant difference in food-reinforced operant behavior, breaking points to food pellets, and saline self-administration between the two genotypes. The increased responding in tPA knockout mice under the FR2 schedule was significantly attenuated by the dopamine D1 receptor antagonist SCH23390 (0.3 mg/kg), whereas SCH23390, at a dose range of 0.03-2.0 mg/kg, demonstrated biphasic effects on morphine self-administration in wild-type control mice. Our findings suggest that the reinforcing effects of morphine are reduced in tPA knockout mice. Modulation of the tPA system in the brain may be a potential target against drugs of abuse.

元の言語English
ページ(範囲)50-59
ページ数10
ジャーナルNeuroscience
146
発行部数1
DOI
出版物ステータスPublished - 25-04-2007
外部発表Yes

    フィンガープリント

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)

これを引用

Yan, Y., Yamada, K., Mizoguchi, H., Noda, Y., Nagai, T., Nitta, A., & Nabeshima, T. (2007). Reinforcing effects of morphine are reduced in tissue plasminogen activator-knockout mice. Neuroscience, 146(1), 50-59. https://doi.org/10.1016/j.neuroscience.2007.01.011