Typically, emotionally charged events are better remembered than neutral ones. This paper reviews data indicating that the amygdala is responsible for this facilitation of memory by emotional arousal. Pharmacological and behavioral studies have shown that the release of adrenal stress hormones facilitates memory consolidation. The available evidence suggests that this effect depends on a central action of stress hormones involving the release of the neuromodulators noradrenaline (NA) and acetylcholine in the basolateral complex of the amygdala (BLA). Indeed, BLA lesions block the memory modulating effects of stress hormones. Moreover, microdialysis studies have revealed that BLA concentrations of NA and acetylcholine are transiently (2h) elevated following emotionally arousing learning episodes. Last, post-learning intra-BLA injections of beta-adrenergic or muscarinic receptor antagonists reduce retention. These results have led to the hypothesis that NA and acetylcholine increase the activity of BLA neurons in the hours after the learning episode. In turn, the BLA would facilitate synaptic plasticity in other brain structures, believed to constitute the storage sites for different types of memory. Consistent with this, post-learning treatments that reduce or enhance the excitability of BLA neurons respectively decrease or improve long-term retention on various emotionally charged learning tasks. However, a number of issues remain unresolved. Chief among them is how the BLA facilitates synaptic plasticity elsewhere in the brain. The present review concludes with a consideration of this issue based on recent advances in our understanding of the BLA. Among other possibilities, it is suggested that rhythmic BLA activity at the theta frequency during arousal as well as the uniform conduction times of BLA axons to distributed rhinal sites may promote plasticity in co-active structures of the temporal lobe.

中文翻译：

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基底外侧杏仁核在记忆巩固中的作用。

通常，情绪激动的事件比中立的事件更容易记住。本文对数据进行了研究，这些数据表明杏仁核是通过情绪唤起促进这种记忆的原因。药理和行为研究表明，肾上腺应激激素的释放促进记忆巩固。现有证据表明，这种作用取决于应激激素的中心作用，该激素涉及杏仁核（BLA）基底外侧复合物中神经调节素去甲肾上腺素（NA）和乙酰胆碱的释放。确实，BLA损伤会阻断应激激素的记忆调节作用。此外，微透析研究表明，在情绪激动的学习发作后，NA和乙酰胆碱的BLA浓度会短暂升高（2h）。持续，学习后BLA内注射β-肾上腺素或毒蕈碱受体拮抗剂会降低保留率。这些结果导致了这样的假设：NA和乙酰胆碱会在学习发作后的数小时内增加BLA神经元的活性。反过来，BLA将促进其他大脑结构中的突触可塑性，据信这些大脑结构构成了不同类型记忆的存储位点。与此相一致，减少或增强BLA神经元兴奋性的学习后治疗分别减少或改善了对各种充满情感的学习任务的长期保留。但是，许多问题仍未解决。其中最主要的是BLA如何促进大脑其他部位的突触可塑性。本文以我们对BLA的最新理解为基础，对这一问题进行了总结。在其他可能性中，建议在唤醒过程中以theta频率进行节律性BLA活性，以及​​BLA轴突到分布的鼻位的均匀传导时间，可能会促进颞叶的共同结构中的可塑性。