Human brain connections

The Atlas of Human Brain Connections by Catani and Thiebaut de Schotten (2012) covers the long association, commissural and projection systems of the cerebral hemispheres as studied with diffusion tensor tractography. The atlas begins with an extensive and well-illustrated historical survey of these systems and the disconnection syndromes that result from their interruption. This is followed by chapters on the individual systems, including an atlas of each in serial axial, coronal and parasagittal sections, and an atlas of all the systems combined. The book ends with an overview of diffusion tensor imaging tractography and its applications.I must have dissected the long association systems of the cerebral hemispheres numerous times during lab courses for students or neurological residents. Blunt dissection of fibre systems is a method of great antiquity, but became more precise with the preservation of the brain in alcohol. The 1840s witnessed an important change in methodology, with blunt dissection of fibre systems replaced by microscopy of serial sections, as introduced by Benedict Stilling in his atlases of the brainstem (1846). This method allowed nuclei and the components of white matter to be distinguished with much greater precision and solved the problem inherent in blunt dissection, namely its inability to trace fibre bundles beyond the point where they merge or are crossed by other fascicles (Voogd and van Baarsen, 2013).![Graphic][1] Stilling (1846) used wet unstained sections, relying on the differential refraction of myelin to obtain contrast. However, his method was greatly improved with the subsequent development of fixation and staining techniques. The first systematic microscopical study of the long association systems was published by Dejerine, and was followed by the atlases of Wernicke, and then Jelgersma. Wernicke’s atlas is remarkable because it consists of original photographic prints of sections in the three major planes; however, even before … [1]: /embed/inline-graphic-1.gif