Ferreira M B, Da Silva R C, Medina J H, Izquierdo I
Departamento de Bioquimica, Instituto de Biopciencias, U.F.R.G.S., Porto Alegre RS, Brazil.
Pharmacol Biochem Behav. 1992 Apr;41(4):767-71. doi: 10.1016/0091-3057(92)90225-5.
The NMDA receptor antagonist, D-2-amino-5-phosphonopentanoic acid (AP5) (5 micrograms) and the GABAA receptor agonist, muscimol (0.03 microgram) were infused bilaterally into the entorhinal cortex of rats 0, 90, 180, or 360 min after training in habituation to a novel environment or in step-down inhibitory avoidance. Animals were tested for retention 22 h after training in each task. AP5 and muscimol were amnestic for both tasks when given 90 or 180 min after training, but had no effect when given 0 or 360 min after training. In contrast, intraamygdala injections or AP5 or muscimol were amnestic when given 0 but not 90 min after inhibitory avoidance training. The results indicate that the entorhinal cortex plays a late but important role in posttraining memory processing; this role involves glutamatergic NMDA receptors and is inhibited by GABAA receptors. The intervention of the entorhinal cortex in posttraining memory processing is subsequent, and could be secondary, to that of the amygdala and other limbic structures.
在大鼠对新环境的习惯化训练或阶梯式抑制性回避训练后0、90、180或360分钟，将NMDA受体拮抗剂D - 2 - 氨基 - 5 - 膦酰基戊酸（AP5，5微克）和GABAA受体激动剂蝇蕈醇（0.03微克）双侧注入大鼠的内嗅皮层。在每项任务训练后22小时对动物进行记忆保持测试。训练后90或180分钟给予AP5和蝇蕈醇时，对两项任务均有遗忘作用，但在训练后0或360分钟给予时则无影响。相比之下，在抑制性回避训练后0分钟而非90分钟杏仁核内注射AP5或蝇蕈醇会导致遗忘。结果表明，内嗅皮层在训练后记忆处理中起后期但重要的作用；这一作用涉及谷氨酸能NMDA受体，并受到GABAA受体的抑制。内嗅皮层对训练后记忆处理的干预是继杏仁核和其他边缘结构之后的，可能是次级的。
