A Window to the Brain-The Enduring Impact of Vision Research.

The visual system has served as an expeditious entry point for discerning the mechanism of action of many brain systems, spearheading multiple fields of neuroscience in the process. It has additionally launched the careers of countless scientists, as we have crafted new means to understand neuronal structures and their functions, leading to advances in many areas of the sciences. Indeed, one can readily mark the onset of the scientific examination of the visual system with the 1851 invention of the ophthalmoscope by Hermann von Helmholtz, and the trichromatic theory of color vision in 1802. The Young-Helmholtz understanding the red-green-blue nature of color vision became the foundation to understanding sensory system function that visual artists and also contemporary flat panel displays rely on. It is fascinating to realize that the paintings of Georges Seurat and an iPhone display share a commonality of this application of the trichromatic theory. While it was not until 1956 that the existence of cells responsive to three different ranges of wavelengths was proven with the work of Gunnar Svaetichin, this proof in many ways marked the advancement of tools to visualize at a microscopic level, a full century after the Young-Helmholtz theory was developed. Just a decade later, in 1966, the person widely considered as the founder of modern neuroscience, Stephen Kuffler, founded the Harvard neurobiology department. It was from Kuffler's work with his post-doctoral students that many new fields of study were created and from whom many of the neuroscience programs across the US were founded. In terms of the visual system, Kuffler and his team were key in detailing areas of retinal neuroanatomy, neurochemistry, neurophysiology, and developmental neurobiology. This paper traces areas in visual system research that provide our understanding of the disparate areas of brain sciences. As such, there are six categories that are evaluated, each of which spawned work in multiple areas that have become mainstays in neuroscience. These range from fields that were dominant a half century ago to ones that have their origins in this decade. The commonality is that all of these owe their origin to Helmholtz and Kuffler, polymaths of the nineteenth and twentieth centuries. We will examine the impact of vision research across the following fields of neuroscience: sensory system function, neuroanatomy, neurochemistry, neurophysiology, developmental neurobiology, and neurological health and disease.