Ohno M, Watanabe S
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
Eur J Pharmacol. 1996 Sep 26;312(2):145-7. doi: 10.1016/0014-2999(96)00580-8.
Rats were tested with a one-trial inhibitory avoidance paradigm in which the latency to enter the shock compartment served as a measure of memory retention. Pretraining administration of the non competitive NMDA receptor antagonist MK-801 (0.3 mg/kg i.p.) significantly reduced the response latency during the retention test given 24 h after rats received a step-through inhibitory avoidance training. MK-801 at 0.1 mg/kg did not affect the retention latency. The muscarinic receptor antagonist scopolamine (1.0 mg/kg i.p.) also interfered with the inhibitory avoidance response in the retention test when administered before the training trial. The lower dose of 0.3 mg/kg scopolamine, which by itself was ineffective, significantly impaired inhibitory avoidance learning when administered simultaneously with the behaviorally subthreshold dose of 0.1 mg/kg MK-801 before the training trial. These results suggest that interactive mechanisms regulated by concurrent activation of NMDA and muscarinic receptors are involved in learning processes of inhibitory avoidance performance in rats.
用单次试验抑制性回避范式对大鼠进行测试，其中进入电击区的潜伏期作为记忆保持的指标。在大鼠接受穿梭式抑制性回避训练24小时后进行的保持测试中，预训练给予非竞争性NMDA受体拮抗剂MK-801（0.3毫克/千克，腹腔注射）显著缩短了反应潜伏期。0.1毫克/千克的MK-801不影响保持潜伏期。毒蕈碱受体拮抗剂东莨菪碱（1.0毫克/千克，腹腔注射）在训练试验前给药时，也会在保持测试中干扰抑制性回避反应。0.3毫克/千克的较低剂量东莨菪碱本身无效，但在训练试验前与行为阈下剂量的0.1毫克/千克MK-801同时给药时，会显著损害抑制性回避学习。这些结果表明，由NMDA和毒蕈碱受体同时激活所调节的交互机制参与了大鼠抑制性回避行为的学习过程。
