Cell . . . Heavyweight released a three-dimensional map of the brains of the third generation of mice.

The mouse brain is an ideal animal model for studying the central nervous system.at present, many major international cooperation is being carried out to collect massive data on neuronal types, neural connections and gene expression in mouse brain from spatial and temporal scales to establish maps.the successful integration, display and analysis of these data require three-dimensional standard brain maps.the two-dimensional brain atlas widely used in brain science is mainly Allen Reference Atlas (released by Allen Institute of brain science in Seattle) and mouse brain in stereo coordinates (MBSC), but the digital three-dimensional map is more in line with the current research needs.the second edition of 3D Atlas of mouse brain has two fatal shortcomings: (1) transforming 2D structure annotated in coronal field into 3D volume in non coronal plane, resulting in image distortion; (2) lack of cell level resolution required for transcriptomic data on brain neurons.on May 7, 2020, Lydia ng and Julie A. Harris team of Allen Institute of brain science published the article the Allen mouse brain common coordinate framework: a 3D reference atlas in the journal Cell. Images of 1675 adult mouse brains were obtained by two-photon tomography, and brain models were constructed and annotated in detail, Finally, the third edition of mouse brain common coordinate framework (ccfv3) was established.due to the slight differences in the volume and structure of each mouse brain, in order to design a model suitable for the mouse brain, the researchers calculated the average value of all mouse brains, and further fused them into a clear average image, showing obvious anatomical details.specifically, first, the average estimation was performed at a resolution of 50 μ m, and then fusion processing was performed at a resolution of 25 μ M. finally, a unique, detailed and anatomic 3D map model was presented at a resolution of 10 μ M.at a 10 micron voxel resolution, this brain model contains 506 million voxels.based on the internal anatomical features of this brain model and the data of transgenic mice, axonal projection, immunohistochemistry, in situ hybridization, Nissl staining and other specific information, Lydia ng and Julie A. Harris team established a three-dimensional data platform, namely ccfv3.how to divide the brain regions in ccfv3? Take the cortex as an example, the cortex is a more complex structure in the brain, and it is also one of the most studied brain regions.the researchers used calb1 CRE (the vast majority of CALB gene is expressed in the superficial epidermis) and Fezf2 creer (fezf is expressed in the deep cortex) mice to distinguish the superficial cortex from the deep cortex; in the coronal section, the dorsal boundary between the cortex and the piriform area; in the sagittal plane, the posterior boundary with the posterior inferior bracket and area protata; on the horizontal plane, the posterior boundary with the olfactory bulb.through further division, the cortex is divided into 43 sub regions.in addition to the division of the cortex, ccfv3 also subdivided the subcortical structure into 329 regions, 81 fiber tracts and 8 ventricular structures.What are the advantages of ccfv3? First, the spatial resolution of ccfv3 (the Third Edition) is more than 1000 times higher than that of the second edition.Second, ccfv3 collects high-resolution images of the whole brain with high signal-to-noise ratio, which makes it easier to distinguish anatomical details.Third, ccfv3 can be viewed in two-dimensional or three-dimensional way through the website for good human-computer interaction. Users can select the target brain area and view the data set according to the purpose (gene expression or projection of brain region, etc.). Fourth, in addition to providing basic functions, ccfv3 also adds two new functions: reverse mapping (notes can be viewed in the original Atlas) and volume estimation. in general, the brain atlas was upgraded by high-resolution reconstruction of the brain anatomical structure of nearly 2000 mice, which provided more convenience for the study of mouse brain. original link: