Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
Japan Science and Technology Agency, CREST, University of Toyama, Toyama 930-0194, Japan.
Science. 2018 Jun 15;360(6394):1227-1231. doi: 10.1126/science.aat3810.
Memories are integrated into interconnected networks; nevertheless, each memory has its own identity. How the brain defines specific memory identity out of intermingled memories stored in a shared cell ensemble has remained elusive. We found that after complete retrograde amnesia of auditory fear conditioning in mice, optogenetic stimulation of the auditory inputs to the lateral amygdala failed to induce memory recall, implying that the memory engram no longer existed in that circuit. Complete amnesia of a given fear memory did not affect another linked fear memory encoded in the shared ensemble. Optogenetic potentiation or depotentiation of the plasticity at synapses specific to one memory affected the recall of only that memory. Thus, the sharing of engram cells underlies the linkage between memories, whereas synapse-specific plasticity guarantees the identity and storage of individual memories.
记忆被整合到相互连接的网络中；然而，每个记忆都有自己的身份。大脑如何从存储在共享细胞集合中的混杂记忆中定义特定的记忆身份，一直难以捉摸。我们发现，在小鼠完全逆行性听觉恐惧条件反射记忆缺失后，光遗传学刺激外侧杏仁核的听觉输入不能诱导记忆回忆，这意味着记忆印痕不再存在于该回路中。特定恐惧记忆的完全遗忘并不影响在共享集合中编码的另一个相关联的恐惧记忆。对一个记忆特定突触的可塑性进行光遗传学增强或失活会影响仅该记忆的回忆。因此，记忆印痕细胞的共享是记忆之间联系的基础，而突触特异性可塑性则保证了单个记忆的身份和存储。
