Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.
CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina.
Sci Rep. 2019 Aug 21;9(1):12157. doi: 10.1038/s41598-019-48340-9.
Memories are a product of the concerted activity of many brain areas. Deregulation of consolidation and reprocessing of mnemonic traces that encode fearful experiences might result in fear-related psychopathologies. Here, we assessed how pre-established memories change with experience, particularly the labilization/reconsolidation of memory, using the whole-brain analysis technique of positron emission tomography in male mice. We found differences in glucose consumption in the lateral neocortex, hippocampus and amygdala in mice that underwent labilization/reconsolidation processes compared to animals that did not reactivate a fear memory. We used chemogenetics to obtain insight into the role of cortical areas in these phases of memory and found that the lateral neocortex is necessary for fear memory reconsolidation. Inhibition of lateral neocortex during reconsolidation altered glucose consumption levels in the amygdala. Using an optogenetic/neuronal recording-based strategy we observed that the lateral neocortex is functionally connected with the amygdala, which, along with retrograde labeling using fluorophore-conjugated cholera toxin subunit B, support a monosynaptic connection between these areas and poses this connection as a hot-spot in the circuits involved in reactivation of fear memories.
记忆是许多大脑区域协同活动的产物。恐惧相关心理病理的产生可能是由于记忆痕迹的巩固和再处理失调，这些记忆痕迹编码了恐惧经历。在这里，我们使用正电子发射断层扫描的全脑分析技术，在雄性小鼠中评估了预先建立的记忆是如何随经验而变化的，特别是记忆的不稳定/再巩固。与没有重新激活恐惧记忆的动物相比，我们发现经历不稳定/再巩固过程的小鼠的外侧皮质、海马体和杏仁核的葡萄糖消耗存在差异。我们使用化学遗传学来深入了解皮质区域在这些记忆阶段中的作用，并发现外侧皮质对于恐惧记忆的再巩固是必要的。在再巩固过程中抑制外侧皮质会改变杏仁核的葡萄糖消耗水平。使用基于光遗传学/神经元记录的策略，我们观察到外侧皮质与杏仁核在功能上是相连的，逆行标记使用荧光素标记的霍乱毒素亚单位 B 支持这些区域之间的单突触连接，并将该连接作为涉及恐惧记忆重新激活的回路中的热点。
