Effects of proteasome inhibitor MG132 on memory acquisition and retrieval in one-trial passive avoidance in mice / 中华行为医学与脑科学杂志

Objective To investigate the effects of proteasome inhibitor MG132 on memory acquisition and memory retrieval in one-trail passive avoidance for mice.Methods MG132 (25 mg/kg) was administrated at different time points to analyze the time-dependent effects of MG132 on hippocampus proteasome activity.MG132 (25 mg/kg) was administrated 3 hours before-training or 1.5 hours pre-test to investigate the effect on memory acquisition and retrieval.The interaction of low dose (12 mg/kg) of MG132 and novelty interference on memory retrieval to studied.Results Hippocampus proteasome activity was significantly blocked when MG132 (25 mg/kg) was administrated 0.5-1.5 hours before analysis.The inhibition recovered as time passing and backed to normal state 24 hours later.A significant difference was showed between vehicle and pre-training,pre-test group (pre-training vehicle (296.03 ± 3.97) s,pre-training (173.30 ± 47.51) s ; pre-test vehicle (199.23 ± 43.01) s,pre-test (44.10 ± 11.16) s).Proteasome inhibitor did not produce a significant effect on memory retrieval (vehicle (174.19 ± 30.54)s,lower dose (174.19± 30.54)s),then only together with a novelty task the retrieval was significantly altered(vehicle (164.02 ±35.26)s,MG132 +novelty group (84.70 ±23.92)s).Conclusion Proteasome inhibitor MG132 can inhibit memory acquisition and memory retrieval.Thereby the effect on memory retrieval is enhanced by novelty.Thus,a physiological proteasome activity is essential for learning abilities.

Studies on Pharmacodynamics of Duodongan Oral Solution and Its Acute Toxicity / 中成药

Objective: To investigate the pharmacodynamics and acute toxicity of Duodongan Oral Solution. Methods: The test of walking time and raising the front limbs of mice Step down test were used to observe the improvement of Duodongan Oral Solution on the spontaneous activity inhibition and memory acquisition disturbance of mice. Results: Duodongan Oral solution could obviously inhibit the spontaneous activity of mice, and its action is strengthened with the increase of dosage. The step down test showed that the oral solution could prolong the latent peroid and decrease the error rate in 5 minites, which indicated that the drug obviously improved memory acquisition disturbance. The acute toxic test indicated that the maximum tolerance dose is 159 times as much as the clinical dose a day. Conclusion: This oral solution has much low toxicity, and is safety for oral administration.