Section of Soft Matter Physics, Faculty of Physics and Geosciences, University of Leipzig, Linnéstr. 5, 04103, Leipzig, Germany.
Institute for Physical Chemistry, Faculty of Chemistry and Physics, Technical University Freiberg, Leipziger Str. 29, 09599, Freiberg, Germany.
Sci Rep. 2023 Aug 7;13(1):12774. doi: 10.1038/s41598-023-39277-1.
Knowledge of the brain's structure and function is essential for understanding processes in health and disease. Histochemical and fluorescence-based techniques have proven beneficial in characterizing brain regions and cellular compositions in pre-clinical research. Atomic force microscopy (AFM) has been introduced for mechanical tissue characterization, which may also help investigate pathophysiological aspects in disease-related models such as stroke. While combining AFM and fluorescence-based techniques, this study explored the mechanical properties of naive and ischemic brain regions in mice. Ischemia-affected regions were identified by the green signal of fluorescein isothiocyanate-conjugated albumin. A semi-automated protocol based on a brain atlas allowed regional allocations to the neocortex, striatum, thalamus, hypothalamus, hippocampus, and fiber tracts. Although AFM led to varying measurements, intra-individual analyses indicated a gradually increased tissue stiffness in the neocortex compared to subcortical areas, i.e., the striatum and fiber tracts. Regions affected by ischemia predominantly exhibited an increased tissue stiffness compared to those of the contra-lateral hemisphere, which might be related to cellular swelling. This study indicated intra-individual differences in mechanical properties among naive and ischemia-affected brain regions. The combination of AFM, semi-automated regional allocations, and fluorescence-based techniques thus qualifies for mechanical characterizations of the healthy and disease-affected brain in pre-clinical research.
了解大脑的结构和功能对于理解健康和疾病过程至关重要。组织化学和荧光技术已被证明在临床前研究中有助于描述大脑区域和细胞组成。原子力显微镜（AFM）已被引入用于组织的力学特性分析，这也有助于研究与疾病相关的模型中的病理生理方面，如中风。本研究结合 AFM 和荧光技术，探索了小鼠正常和缺血脑区的力学特性。通过异硫氰酸荧光素标记的白蛋白的绿色信号来识别缺血影响的区域。基于脑图谱的半自动方案允许将区域分配到新皮层、纹状体、丘脑、下丘脑、海马体和纤维束。尽管 AFM 导致了不同的测量结果，但个体内分析表明，与皮质下区域（即纹状体和纤维束）相比，新皮层的组织硬度逐渐增加。与对侧半球相比，受缺血影响的区域表现出更高的组织硬度，这可能与细胞肿胀有关。本研究表明，正常和缺血脑区的力学特性存在个体内差异。因此，AFM、半自动区域分配和荧光技术的结合可用于临床前研究中健康和患病大脑的力学特性分析。
