University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, 33000 Bordeaux, France.
University of Bordeaux, Laboratoire Photonique Numérique et Nanosciences (LP2N), UMR 5298, 33400 Talence, France; Institut d'Optique & CNRS, LP2N UMR 5298, 33400 Talence, France.
Cell Rep. 2023 May 30;42(5):112478. doi: 10.1016/j.celrep.2023.112478. Epub 2023 May 5.
The extracellular space (ECS) and its constituents play a crucial role in brain development, plasticity, circadian rhythm, and behavior, as well as brain diseases. Yet, since this compartment has an intricate geometry and nanoscale dimensions, its detailed exploration in live tissue has remained an unmet challenge. Here, we used a combination of single-nanoparticle tracking and super-resolution microscopy approaches to map the nanoscale dimensions of the ECS across the rodent hippocampus. We report that these dimensions are heterogeneous between hippocampal areas. Notably, stratum radiatum CA1 and CA3 ECS differ in several characteristics, a difference that gets abolished after digestion of the extracellular matrix. The dynamics of extracellular immunoglobulins vary within these areas, consistent with their distinct ECS characteristics. Altogether, we demonstrate that ECS nanoscale anatomy and diffusion properties are widely heterogeneous across hippocampal areas, impacting the dynamics and distribution of extracellular molecules.
细胞外空间（ECS）及其组成部分在大脑发育、可塑性、昼夜节律和行为以及脑部疾病中发挥着关键作用。然而，由于这个隔室具有复杂的几何形状和纳米级尺寸，因此在活组织中对其进行详细研究一直是一个未满足的挑战。在这里，我们使用单纳米颗粒跟踪和超分辨率显微镜方法的组合，来绘制整个啮齿动物海马体中 ECS 的纳米级尺寸。我们报告说，这些尺寸在海马体区域之间存在异质性。值得注意的是，CA1 和 CA3 层状放射状 ECS 在几个特征上存在差异，这种差异在细胞外基质消化后消失。细胞外免疫球蛋白的动力学在这些区域内变化，与它们不同的 ECS 特征一致。总的来说，我们证明了 ECS 的纳米级解剖结构和扩散特性在海马体区域广泛存在异质性，这影响了细胞外分子的动力学和分布。
