Effect of glycine site/NMDA receptor antagonist MRZ2/576 on the conditioned place preference and locomotor activity induced by morphine in mice / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To study the effect of glycine site/NMDA (N-methyl-D-aspartate) receptor antagonist MRZ2/576 on the conditioned place preference (CPP) and locomotor activity induced by morphine in mice.</p><p><b>METHODS</b>Different doses (1.25, 2.5 and 5 mg/kg, i.p.) of MRZ2/576 were used to evaluate the effect of MRZ2/576 on the acquisition and expression of CPP induced by morphine (5 mg/kg) in mice. In addition, we examined the locomotor activity of mice in conditioning and testing phase of CPP paradigm.</p><p><b>RESULTS</b>MRZ2/576 alone could not establish place preference, but a 5 mg/kg dose of MRZ2/576 could block both acquisition and expression of morphine-induced CPP. In testing phase of CPP, there was no statistical difference for locomotor activity between the groups; injection of MRZ2/576 showed a dose-dependent decrease of locomotor activity on both control and morphine-treated mice, especially 5 mg/kg of MRZ2/576 significantly suppressed the locomotor activity of mice.</p><p><b>CONCLUSION</b>Based on the present results, we assume that MRZ2/576 can antagonize the rewarding effect of morphine, suggesting that this glycine site/NMDA receptor antagonist could be used to treat addictions due to its light side effect profile.</p>

Establishment of computer-based video-tracking conditioned place preference experiment system in mice / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To establish the computer-based video-tracking conditioned place preference (CPP) system in mice.</p><p><b>METHODS</b>The CPP system was composed of computer, camera, soundproof box, shuttle box and analytical software. The results of morphine-induced conditioned place preference were used to evaluate the experiment system. And the effect of morphine-induced locomotor activity in drug-paired compartment was studied in mice.</p><p><b>RESULTS</b>Low (1 mg/kg, i.p.), moderate (3 mg/kg, 5 mg/kg, i.p.) and high (10 mg/kg, i.p.) dose of morphine significantly prolonged the time mice spent in drug-paired compartment compared with saline, but there was no dose-response relation. Moderate and high dose of morphine significantly enhanced locomotor activity, among which 5 mg/kg and 10 mg/kg morphine induced behavior sensitization in drug-paired compartment during the conditioning sessions.</p><p><b>CONCLUSION</b>The computer-based video-tracking conditioned place preference experiment system in mice established successfully is reliable and stable.</p>