Izquierdo I, Medina J H, Bianchin M, Walz R, Zanatta M S, Da Silva R C, Bueno e Silva M, Ruschel A C, Paczko N
Departamento de Bioquimica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Behav Brain Res. 1993 Dec 20;58(1-2):91-8. doi: 10.1016/0166-4328(93)90093-6.
Experiments using localized infusions into selected brain structures of agonists and antagonists of various synaptic receptors, given before or after behavioral training, have led to the following conclusions: (1) Memory is processed shortly after training in the amygdala, medial septum and hippocampus by glutamatergic NMDA and AMPA receptors activated in that sequence. Cholinergic muscarinic receptors are activated concurrently with the former. GABAA receptors modulated by brain benzodiazepines and by beta-noradrenergic receptors inhibit the process. (2) The sequential involvement of NMDA and AMPA receptors suggests that long-term potentiation (LTP) of the synapses activated by the learning experiences in the hippocampus and/or amygdala and medial septum is the crucial event. Expression of this LTP at the time of testing is necessary for retrieval: AMPA receptor blockade in the hippocampus and amygdala at the time of testing hinders retrieval. This suggests that the LTP underlies the memory process itself. (3) The amygdala, medial septum and hippocampus mediate different types of memory and/or different components of memories. The entorhinal cortex, through mechanisms that require intact NMDA receptors and are inhibited by GABAA receptors, intervenes in post-training memory processing 90-180 min after the other limbic regions. The entorhinal cortex integrates consecutively acquired memories; this role could be maintained by the LTP that is generated after training in the amygdala, hippocampus and medial septum. Post-training intervention of the entorhinal cortex does not occur if this region is inhibited at the time of training.
在行为训练之前或之后，向选定的脑结构局部注入各种突触受体的激动剂和拮抗剂进行实验，得出了以下结论：(1) 训练后不久，杏仁核、内侧隔区和海马体中的记忆由按该顺序激活的谷氨酸能NMDA和AMPA受体处理。胆碱能毒蕈碱受体与前者同时被激活。受脑内苯二氮䓬类药物和β-去甲肾上腺素能受体调节的GABAA受体抑制该过程。(2) NMDA和AMPA受体的相继参与表明，海马体和/或杏仁核以及内侧隔区中由学习经历激活的突触的长时程增强 (LTP) 是关键事件。测试时这种LTP的表达是检索所必需的：测试时海马体和杏仁核中的AMPA受体阻断会阻碍检索。这表明LTP是记忆过程本身的基础。(3) 杏仁核、内侧隔区和海马体介导不同类型的记忆和/或记忆的不同组成部分。内嗅皮质通过需要完整NMDA受体且受GABAA受体抑制的机制，在其他边缘区域之后90 - 180分钟介入训练后的记忆处理。内嗅皮质整合相继获得的记忆；这一作用可由杏仁核、海马体和内侧隔区训练后产生的LTP维持。如果训练时抑制该区域，则内嗅皮质不会在训练后进行干预。
