Laboratory of Preclinical MRI, Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal.
PLoS Biol. 2023 Aug 17;21(8):e3002229. doi: 10.1371/journal.pbio.3002229. eCollection 2023 Aug.
Understanding the dynamics of stability/plasticity balances during adulthood is pivotal for learning, disease, and recovery from injury. However, the brain-wide topography of sensory remapping remains unknown. Here, using a first-of-its-kind setup for delivering patterned visual stimuli in a rodent magnetic resonance imaging (MRI) scanner, coupled with biologically inspired computational models, we noninvasively mapped brain-wide properties-receptive fields (RFs) and spatial frequency (SF) tuning curves-that were insofar only available from invasive electrophysiology or optical imaging. We then tracked the RF dynamics in the chronic visual deprivation model (VDM) of plasticity and found that light exposure progressively promoted a large-scale topographic remapping in adult rats. Upon light exposure, the initially unspecialized visual pathway progressively evidenced sharpened RFs (smaller and more spatially selective) and enhanced SF tuning curves. Our findings reveal that visual experience following VDM reshapes both structure and function of the visual system and shifts the stability/plasticity balance in adults.
理解成年期稳定性/可塑性平衡的动态变化对于学习、疾病和损伤恢复至关重要。然而，感觉再映射的大脑整体拓扑结构仍然未知。在这里，我们使用一种首创的设置，在啮齿动物磁共振成像 (MRI) 扫描仪中提供模式化视觉刺激，结合受生物启发的计算模型，非侵入性地绘制了大脑整体特性——感受野 (RFs) 和空间频率 (SF) 调谐曲线——这些特性迄今为止只能通过侵入性电生理学或光学成像获得。然后，我们在可塑性的慢性视觉剥夺模型 (VDM) 中跟踪 RF 动态，发现光暴露逐渐促进了成年大鼠的大规模地形再映射。在光暴露后，最初非特化的视觉通路逐渐表现出锐化的 RFs（更小且更具空间选择性）和增强的 SF 调谐曲线。我们的发现表明，VDM 后的视觉体验重塑了视觉系统的结构和功能，并改变了成年人的稳定性/可塑性平衡。
