#SfN14: Art of Neuroscience, a conversation with Greg Dunn

Image credit: Greg Dunn

Image credit: Greg Dunn

Greg Dunn needs no introduction. With a PhD in Neuroscience and a passion for Asian art, Greg Dunn's shockingly beautiful deceptions of the brain are a must-see feature at every Society for Neuroscience conference. I'll admit that I'm a fan: I bought one of his prints (Hippocampus II) two years ago, and it's been one of my most prized possessions ever since.

Greg began experimenting with combining his two interests halfway through his PhD studies at the University of Pennsylvania. I did a lot of microscopy those days, and I was heavily inspired by the sparse beauty of neurons, particularly after Golgi staining, he told me. The wispy, delicate, half-realistic yet half-abstract nature of stained neurons heavily reminded him of the works of Japanese master painters, such as Kano Sanetsu. "They have a very Zen-like quality to them, you know?" It's the conscious use of negative space that really makes the object stand out, he explained. I choose to use enamel – which is black – on gold leaf for the same reason, he said, showing me a gorgeous minimalistic painting of pyramidal cells. The contrast in colour and the reflectivity of the surface really makes the subject "pop", and the viewer focuses more on the lines, forms and shapes of the delicate neuronal processes and less on potential distractions.

The chaotic, random branching patterns of neurons have a lot in common with the way trees are depicted in Asian art, and Greg finds this unpredictable feature incredibly appealing. Fundamentally, the shape of dendritic branches are fractal, he said, like the branches of trees (or the coastline of England - SF). Fractal shapes surround us in nature, and maybe that's why dendritic trees are so viscerally beautiful. "They're not easy to paint though!", he added.

To limit the spread of ink, Greg coats his papers (Xuan) in gelatin. This lets the drops bead up, which I then blow across the paper, he explained. This lets the drop naturally elongate, and as it encounters the nooks-and-crannies on the paper, it naturally branches out into dendritic, fractal-like shapes. "When you think about it it's not that dissimilar to biology", he said. During development, axons and dendrites also respond to outward signals – physical obstructions or chemical signals – that causes them to grow into unique shapes. Randomness is very hard to paint, he said, much easier to let nature do the work.

There's also something attractive about the juxtaposition between the chaotic structure of neurons and the (somewhat) predictable rules that govern their functions, he said. But to Greg, perhaps the most intriguing feature of the brain is its "overwhelming complexity". It's something you have to look at from afar to appreciate the intricacies of neural networks, he said. So I wanted to depict the complexity of the brain, but I didn't want to loose any delicate details either. Greg wanted the viewer to be able to interact with the paining and choose how they want to experience it: the forest as a whole or the individual trees.

The thousand-year old painting techniques he inherited from Asian masters just weren't going to do it, so Greg teamed up with Dr. Brian Edwards, an optics and electrical engineer expert at UPenn. Together, they devised a new artistic tool called reflective microetching, a technique similar to "making silicon microchips". You break an image into different reflective channels, which are controlled by microscopic ridges engraved on your work material (a "photoresist" – SF), he explained, the way light interacts with these ridges determines how light is reflected. We then coat the photoresist with gold.

When you move around the painting, you'll see some parts light up and other parts dim down, "it's actually quite striking", he said, "but you'll need a dark room to see the full effect." The finished artwork is thus a synthesis of multiple images, and viewers can choose which images to highlight by simply moving around. It preserves the delicate beauty of neural processes and allows you to distinguish them from their neighbouring counterparts, Greg said, it breaks the brain down into digestible pieces, but you can also take a step back and see the whole thing.

Having a new tool in hand, the next step was to pick a worthy subject. "Simple – the brainbow." Greg said. Devised in 2007, the brainbow is the work of Jeff Lichtman and colleagues, who genetically expressed different colour combinations of fluorescent proteins in individual neurons that resulted in a rainbow-coloured brain. Because the microetched surface doesn't contain any pigments, the colour is controlled by lights mounted on the edge of the picture frame, he said, so by changing the colours of the lights you're essentially changing the colours of the painting. It's no longer stagnant, said Greg, now there're infinite possibilities.

Greg and his collaborator Brian have recently received a fund from the National Science Foundation to mircoetch a giant section of the human brain with as much detail and complexity as possible – a project predicted to take two years. Unlike many other works of art, the Big Brain project strives for anatomical correctness in hopes of offering neuroscientists a beautiful – if unorthodox – reference to consult. "Is that goal what drives you?" I asked Greg. That, he said, and the ability of paintings to reach out to the public and potentially inspire a new generation of neuroscientists. Art is a visceral method of science communications, he said, and our goal is bypass charts and tables to get that gut reaction, a strong emotional response that'll inspire people to look deeper into the mysteries of the brain.


I'd like to thank Greg for taking the time to chat with me. (One burning question left unanswered is "how do you balance scientific accuracy and freedom of artistic expression?" I have a feeling his answer will be very different than all the artists I've talked to so far.)  I sincerely hope everyone enjoyed the Art of Neuroscience series. It's been incredibly inspiring to me talking to the artists and learning about their creative process, and I'd love to continue the series. So please leave me a note if you know any neuroscience-themed #sciArtist that would like a chat and a profile about them and their work.

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