Department of Cognitive Neuroscience, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands.
Donders Institute for Brain, Cognition and Behaviour, Radboud University, 6525 EN Nijmegen, The Netherlands.
Proc Natl Acad Sci U S A. 2019 Apr 2;116(14):7077-7082. doi: 10.1073/pnas.1901513116. Epub 2019 Mar 15.
Extensive evidence indicates that the basolateral amygdala (BLA) interacts with other brain regions in mediating stress hormone and emotional arousal effects on memory consolidation. Brain activation studies have shown that arousing conditions lead to the activation of large-scale neural networks and several functional connections between brain regions beyond the BLA. Whether such distal interactions on memory consolidation also depend on BLA activity is not as yet known. We investigated, in male Sprague-Dawley rats, whether BLA activity enables prelimbic cortex (PrL) interactions with the anterior insular cortex (aIC) and dorsal hippocampus (dHPC) in regulating glucocorticoid effects on different components of object recognition memory. The glucocorticoid receptor (GR) agonist RU 28362 administered into the PrL, but not infralimbic cortex, immediately after object recognition training enhanced 24-hour memory of both the identity and location of the object via functional interactions with the aIC and dHPC, respectively. Importantly, posttraining inactivation of the BLA by the noradrenergic antagonist propranolol abolished the effect of GR agonist administration into the PrL on memory enhancement of both the identity and location of the object. BLA inactivation by propranolol also blocked the effect of GR agonist administration into the PrL on inducing changes in neuronal activity within the aIC and dHPC during the postlearning consolidation period as well as on structural changes in spine morphology assessed 24 hours later. These findings provide evidence that BLA noradrenergic activity enables functional interactions between the PrL and the aIC and dHPC in regulating stress hormone and emotional arousal effects on memory.
大量证据表明，基底外侧杏仁核（BLA）与其他大脑区域相互作用，介导应激激素和情绪唤醒对记忆巩固的影响。大脑激活研究表明，唤醒条件会导致大规模神经网络的激活，以及大脑区域之间的几个功能连接，超出了 BLA 的范围。这种远距离的相互作用是否也依赖于 BLA 的活动，目前还不得而知。我们在雄性 Sprague-Dawley 大鼠中研究了 BLA 活动是否能够使前额皮质（PrL）与前岛叶皮质（aIC）和背侧海马（dHPC）相互作用，从而调节糖皮质激素对不同物体识别记忆成分的影响。糖皮质激素受体（GR）激动剂 RU 28362 在物体识别训练后立即注入 PrL，但不是在边缘下皮质内，通过与 aIC 和 dHPC 的功能相互作用，分别增强了 24 小时对物体身份和位置的记忆。重要的是，BLA 的去甲肾上腺素能拮抗剂普萘洛尔在训练后对 BLA 的失活消除了 GR 激动剂在 PrL 中的给药对物体身份和位置记忆增强的影响。普萘洛尔对 BLA 的失活也阻止了 GR 激动剂在 PrL 中的给药对诱导学习后巩固期间 aIC 和 dHPC 内神经元活动变化以及 24 小时后评估的棘突形态结构变化的影响。这些发现提供了证据，表明 BLA 去甲肾上腺素能活性使 PrL 与 aIC 和 dHPC 之间的功能相互作用能够调节应激激素和情绪唤醒对记忆的影响。
