Abe Hiroshi, Tani Toshiki, Mashiko Hiromi, Kitamura Naohito, Miyakawa Naohisa, Mimura Koki, Sakai Kazuhisa, Suzuki Wataru, Kurotani Tohru, Mizukami Hiroaki, Watakabe Akiya, Yamamori Tetsuo, Ichinohe Noritaka
Ichinohe Group, Laboratory for Molecular Analysis of Higher Brain Function, RIKEN Brain Science Institute, Saitama, Japan.
Ichinohe Group, Laboratory for Molecular Analysis of Higher Brain Function, RIKEN Brain Science Institute, Saitama, Japan.
J Neurosci Methods. 2017 Jul 15;286:102-113. doi: 10.1016/j.jneumeth.2017.04.016. Epub 2017 May 31.
The brain of the common marmoset (Callithrix jacchus) is becoming a popular non-human primate model in neuroscience research. Because its brain fiber connectivity is still poorly understood, it is necessary to collect and present connection and trajectory data using tracers to establish a marmoset brain connectivity database.
To visualize projections and trajectories of axons, brain section images were reconstructed in 3D by registering them to the corresponding block-face brain images taken during brain sectioning. During preprocessing, autofluorescence of the tissue was reduced by applying independent component analysis to a set of fluorescent images taken using different filters.
The method was applied to a marmoset dataset after a tracer had been injected into an auditory belt area to fluorescently label axonal projections. Cortical and subcortical connections were clearly reconstructed in 3D. The registration error was estimated to be smaller than 200 μm. Evaluation tests on ICA-based autofluorescence reduction showed a significant improvement in signal and background separation.
Regarding the 3D reconstruction error, the present study shows an accuracy comparable to previous studies using MRI and block-face images. Compared to serial section two-photon tomography, an advantage of the proposed method is that it can be combined with standard histological techniques. The images of differently processed brain sections can be integrated into the original ex vivo brain shape.
The proposed method allows creating 3D axonal projection maps overlaid with brain area annotations based on the histological staining results of the same animal.
普通狨猴（Callithrix jacchus）的大脑正成为神经科学研究中一种受欢迎的非人类灵长类动物模型。由于其脑纤维连接性仍未得到充分了解，因此有必要使用示踪剂收集并呈现连接和轨迹数据，以建立狨猴脑连接数据库。
为了可视化轴突的投射和轨迹，通过将脑切片图像与脑切片过程中拍摄的相应块面脑图像进行配准，对其进行三维重建。在预处理过程中，通过对使用不同滤光片拍摄的一组荧光图像应用独立成分分析，降低了组织的自发荧光。
在将示踪剂注入听带区域以荧光标记轴突投射后，该方法应用于狨猴数据集。皮质和皮质下连接在三维中清晰重建。配准误差估计小于200μm。基于独立成分分析的自发荧光降低评估测试显示，信号和背景分离有显著改善。
关于三维重建误差，本研究显示的精度与先前使用磁共振成像和块面图像的研究相当。与连续切片双光子断层扫描相比，该方法的一个优点是它可以与标准组织学技术相结合。不同处理的脑切片图像可以整合到原始离体脑形状中。
所提出的方法允许基于同一动物的组织学染色结果创建覆盖有脑区注释的三维轴突投射图。
