Brain Anatomy and Physiology: Commentary

Abstract

Revolutions in science are often connected to unique researchers. In neuroscience such a unique researcher was Ramon y Cajal. Perfecting Golgi’s silver stain and interpreting what he saw in his microscope in an innovative way, he catapulted the understanding of the nervous system to new horizons. Today’s neuroanatomy benefits from the revolutions introduced by powerful microscopes, computers and software, and these revolutions have many fathers and mothers. It is hard to believe that 3D images of neurons and neural nets are available to us only one to two decades. Camera-lucida pictures of neurons still impress us by their structural complexity and beauty, but considering the enormous loss of information by such artistic drawings one wonders what more than just documentation and classification of structural features could be reached by this method. Scientific reports have now to be based on 3D images of segmented structures incorporated into appropriate reference systems. Neurons can be quantified with respect to their real branching patterns, the length components of all branches and their spatial relations. Neural nets can be reconstructed in 3D from multiple single neurons. Neuropils and tracts as well as somata clusters can be composed in 3D and provide the intrinsic landmarks for embedding neural elements into a 3D atlas. Digital neuroanatomy provides us already with the tools for such an endeavor although the necessary software is still not satisfactory and requires a large amount of tedious hand work. Digital neuroanatomy requires segmentation of reference structures, tracing neurons, bridging between large ranges of spatial resolution, registering the structures in a virtual reference system (the atlas) and using this information for ontologies of neuron related information. The first steps in this direction have been done, and insect brains are at the forefront of this endeavor taking advantage of their suitable size for digital microscopy.