Rashid Asim J, Yan Chen, Mercaldo Valentina, Hsiang Hwa-Lin Liz, Park Sungmo, Cole Christina J, De Cristofaro Antonietta, Yu Julia, Ramakrishnan Charu, Lee Soo Yeun, Deisseroth Karl, Frankland Paul W, Josselyn Sheena A
Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Department of Psychology, University of Toronto, Toronto, ON M5G 3G3, Canada. Institute of Medical Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada. Department of Physiology, University of Toronto, Toronto, ON M5G 1X8, Canada.
Program in Neurosciences and Mental Health, Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
Science. 2016 Jul 22;353(6297):383-7. doi: 10.1126/science.aaf0594.
Collections of cells called engrams are thought to represent memories. Although there has been progress in identifying and manipulating single engrams, little is known about how multiple engrams interact to influence memory. In lateral amygdala (LA), neurons with increased excitability during training outcompete their neighbors for allocation to an engram. We examined whether competition based on neuronal excitability also governs the interaction between engrams. Mice received two distinct fear conditioning events separated by different intervals. LA neuron excitability was optogenetically manipulated and revealed a transient competitive process that integrates memories for events occurring closely in time (coallocating overlapping populations of neurons to both engrams) and separates memories for events occurring at distal times (disallocating nonoverlapping populations to each engram).
被称为记忆印记的细胞集合被认为代表着记忆。尽管在识别和操纵单个记忆印记方面已经取得了进展，但对于多个记忆印记如何相互作用以影响记忆却知之甚少。在外侧杏仁核（LA）中，训练期间兴奋性增加的神经元会在分配到记忆印记时胜过其相邻神经元。我们研究了基于神经元兴奋性的竞争是否也控制着记忆印记之间的相互作用。小鼠接受了两个由不同时间间隔分开的不同恐惧条件反射事件。通过光遗传学操纵LA神经元的兴奋性，揭示了一个短暂的竞争过程，该过程整合了在时间上紧密发生的事件的记忆（将重叠的神经元群体共同分配到两个记忆印记中），并分离了在较远时间发生的事件的记忆（将不重叠的群体分配到每个记忆印记中）。
