Rakowska Martyna, Lazari Alberto, Cercignani Mara, Bagrowska Paulina, Johansen-Berg Heidi, Lewis Penelope A
Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom.
Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
Imaging Neurosci (Camb). 2025 Aug 22;3. doi: 10.1162/IMAG.a.104. eCollection 2025.
Memory reactivation during sleep is known to have an impact upon the gradual consolidation of memory traces, but the nature of plastic changes induced by such reactivation remains unclear. Here, we use diffusion-weighted imaging to track the location and timescale of microstructural changes associated with behavioural effects of Targeted Memory Reactivation (TMR) 20 days post-manipulation, when the behavioural effect first became significant. Because we used a serial reaction time task that is known to draw on the sensorimotor system as well as both medial temporal and striatal memory systems, we included all these areas as regions of interest. We also included precuneus, a structure known for plasticity relating to the neural engram. Our analysis was based on correlations between behavioural benefit of TMR and microstructural plasticity over early (first 24 h) and late (24 h to 10 days) consolidation periods. This showed significant TMR-related microstructural plasticity in the striatum over the early period. Over the late period, we observed TMR-related microstructural changes in both sensorimotor cortex and precuneus. Taken together, these findings demonstrate that TMR-related microstructural changes correlate with subsequent memory benefits across multiple brain regions.
睡眠期间的记忆再激活已知会对记忆痕迹的逐渐巩固产生影响，但这种再激活所引发的可塑性变化的本质仍不清楚。在此，我们使用扩散加权成像来追踪与靶向记忆再激活（TMR）行为效应相关的微观结构变化的位置和时间尺度，该行为效应在操作后20天首次变得显著。由于我们使用了一个已知会利用感觉运动系统以及内侧颞叶和纹状体记忆系统的序列反应时任务，我们将所有这些区域都纳入了感兴趣区域。我们还纳入了楔前叶，这是一个因与神经记忆痕迹相关的可塑性而闻名的结构。我们的分析基于TMR的行为益处与早期（最初24小时）和晚期（24小时至10天）巩固期的微观结构可塑性之间的相关性。这表明在早期纹状体中存在与TMR相关的显著微观结构可塑性。在晚期，我们在感觉运动皮层和楔前叶均观察到了与TMR相关的微观结构变化。综上所述，这些发现表明，与TMR相关的微观结构变化与多个脑区随后的记忆益处相关。
