Center for Life Sciences & IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Haidian District, Beijing, China.
Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA.
Adv Neurobiol. 2024;38:29-43. doi: 10.1007/978-3-031-62983-9_3.
One of the most fascinating aspects of the brain is its ability to acquire new information from experience and retain it over time as memory. The search for physical correlates of memory, the memory engram, has been a longstanding priority in modern neurobiology. Advanced genetic approaches have led to the localization of engram cells in a few brain regions, including the hippocampus and cortex. Additionally, engram cells exhibit learning-induced, persistent modifications and have at least two states, active and silent. However, it has been hypothesized that engrams for a specific memory are distributed among multiple brain regions that are functionally connected, referred to as a unified engram complex. Recent tissue-clearing techniques have permitted high-throughput analyses of intact brain samples, which have been used to obtain a map of the engram complex for a contextual fear memory. Careful examination of these engram complex maps has revealed a potentially underappreciated contribution of subcortical regions, specifically thalamic nuclei, to memory function. These more holistic studies support the unified engram complex hypothesis for memory storage and have important implications for understanding dysfunctional engrams in the context of human disease.
大脑最迷人的特点之一是其能够从经验中获取新信息，并将其作为记忆长时间保留。寻找记忆的物理相关物，即记忆印痕，一直是现代神经生物学的长期重点。先进的遗传方法已经将印痕细胞定位在几个脑区，包括海马体和皮质。此外，印痕细胞表现出学习诱导的、持久的修饰，并具有至少两种状态，活跃和沉默。然而，人们假设，特定记忆的印痕分布在多个功能连接的脑区中，被称为统一的印痕复合物。最近的组织清除技术允许对完整的脑组织样本进行高通量分析，这些分析被用于获得上下文恐惧记忆的印痕复合物图谱。对这些印痕复合物图谱的仔细检查揭示了皮质下区域，特别是丘脑核，对记忆功能的潜在贡献。这些更全面的研究支持了记忆存储的统一印痕复合物假说，并对理解人类疾病背景下功能失调的印痕具有重要意义。
