This photograph of a young scientist in training is the second in the Who’s That? category here on Webvision. The inaugural post in this category explains the idea behind these posts, but this post shows us, as you’ve deduced from the post title, a young Wolfgang Baehr seen in the Institute for Physical Chemistry at the University of Heidelberg in 1963. Incidentally, one of Wolfgang’s sons is studying at Heidelberg University and looks shockingly like him in this photo.
Wolfgang was born in Mannheim, Germany and studied organic chemistry while at the University of Heidelberg before moving on to graduate school and then where we find him today in vision science.
Continue reading “Who’s That? Wolfgang Baehr”
I remember when the first discussion of intrinsically photosensitive retinal ganglion cells (ipRGCs) started coming out. My thinking at the time was: “Wow, cool concept… but how in the world could you stack enough opsins in two membranes to make for any psychophysical perception?” In short, despite some years of predicting their presence, I did not buy it until the number of papers coming out made it impossible to refute. Now we have different classes of ipRGCs with multiple targets and the whole prospect is really interesting.
A couple of months ago, King Wai Yau gave a talk here at the University of Utah where he talked about some of his work and the number of ideas that came out of that talk were amazing. The idea that there are parallel pathways to conscious vision have been around for some time (blindsight etc…), but new work suggests possible image forming roles.
We’ve had a chapter in Webvision on melanopsin ganglion cells by Dustin Graham for some time, but this review by Gary Pickard and Particia Sollars also does a pretty nice job of summarizing ipRGCs, the discovery of melanopsin, its comparison of invertebrate and vertebrate photoreceptors, the mechanism of drive and some description of subtypes as well as current progress. Continue reading “Interesting Review: Intrinsically Photosensitive Retinal Ganglion Cells”
The desire to restore vision, once lost is as old as man itself.
This article by Noah Shachtman in Wired’s Danger Room documents the discovery of a 250 year old code complete with secret society. Its interesting reading from a variety of perspectives and has some wonderful photographs of the text and “blindfold goggles”, but what piqued my scientific interest was the ritual involving the restoration of sight and the potential evolution of the study of vision.
Sight and the mysteries of how we see is an equally compelling story that has inspired many throughout history to form in groups to discuss and study vision. The Greek Empedocles in the fifth century BC had his “Emission theory” of vision which evolved through the Aristotle and Galen. Plato also maintained that the eye possessed an “inner fire”. But it was not until Alhazen and Leonardo DaVinci that experiments were carried out and documented that we started to establish our understanding of sight. The Oculists mentioned in this article were thought to be early gatekeepers of the study of ophthalmology who would keep “charlatans” at bay that might cause people to lose their sight. These Oculists came after William Briggs Theory of Vision and organized themselves into one of the many secret societies that exploded throughout the world in the 18th century, some of which served as safe houses for the discussion of science and religion which did not necessarily fit within popular belief or practice. Of course modern understanding of vision was due largely to Hermann von Helmoltz in the 19th century which gave us early color theory and perception experiments, but it would be interesting work to follow the study of ophthalmology from the Oculists in the 18th century through Helmhotz work in the 19th century as it appears to be a partially secret history documenting the early study and restoration of vision loss.
Retinal degenerations are accompanied by retinal remodeling events. These events alter the structure and function of the retina and involve to a large extent, Müller cells which seem to serve as pathways for neuronal migration. This paper by Karin Roesch, Michael B. Stadler and Constance L. Cepko looks at gene expression changes in the Müller cells, one of the glial cells of the retina as the rd1 mouse retina degenerates.
While the paper is not terribly conclusive in its definition of genes or pathways involved, (partially I suspect because of the limited time points examined and the late point in the examinations), this paper does however point in a direction that is useful to the retinal degeneration community. Specifically, Müller cells are fundamentally involved in the remodeling process. Intervening there is an opportunity to arrest or slow down the retinal remodeling process to allow for interventions and understanding which genes are involved is a good first step.