Brainbow Hippocampus

I feel it is only fair to talk about Greg Dunn whose beautiful microetchings have been a continuous reminder of how amazing the brain actually is. My logo for this blog is based on one of Greg Dunn and Brian Edwards microetchings titled the Brainbow Hippocampus.

Greg Dunn also happens to have a PhD in Neuroscience and combines his two passions, Asian Art & Neuroscience, seamlessly in these beautiful etchings. But what is the Hippocampus and what does it have to do with rainbows?

Well first off, the Hippocampus is this C shape structure found deep in the centre of the brain and is mainly involved in learning, memory and sensory integration (in other words, our brain interprets and integrates the information we get from our senses). Ever heard of Alzeihmer’s disease? This disease affects the Hippocampus, which is why people with Alzheimer’s disease can’t remember who they are, where they are, and get really confused in familiar surroundings. So it’s a pretty important structure, which is probably why it’s buried so deeply in the brain’s centre (imo).

the-limbic-lobe

Now for the Brainbow part.

Brainbow is a genetic technique used to trace each neuron in the brain. What this cool technique does is use genes from corals, bacteria and jellyfish, which contain fluorescent red, green and blue proteins. These genes are inserted into the neurons and then the neurons express different combinations of red, green and blue giving you all these wonderful different colours. Neuroscientists can then follow the different colours and track the activity of each neuron and see how they are connected to one another. In other words, they’ve colour-coded the brain. So you get a Brainbow; a brain that looks like a rainbow. Brilliant!

I’d also recommend watching the video on building a brainbow, and the one on fluorescent proteins. They’re only a few minutes long.

But why do this technique at all, I hear you ask, when there are other techniques out there like fMRI or DTI?

And it’s a fair enough question. This Brainbow method has so far only been tested on rodents and this etching of the Hippocampus is therefore a rodent’s Hippocampus. But whether it’s from a rodent or a human, it looks incredible! What makes it distinctive from other techniques like fMRI and DTI is the following:

Functional Magnetic Resonance Imaging (fMRI) is possibly the most fashionably used technique at the moment and here’s why. When you want to look at which parts of the brain are active, for example, when you’re reading this blog post about the Brainbow Hippocampus, many Neuroscientists and Psychologists would use fMRI (they’d probably use some other stimuli instead of this blog, but you get the point). fMRI looks at the differences in blood oxygen levels, blood flow and blood volume in the brain to detect which areas are active. The more oxygen-rich blood, the greater the activity. The images are taken over a short period of time (which is why they stuck the functional name part in there), so you can see what parts of the brain are activated first, then second and so on. Now, what you get from an fMRI session is black and white images of the brain and red-orange-white blobs, which show the areas of the brain that are active. You can then compile these images into a 3D brain activity flip book. Pretty cool stuff. So cool that it won a Noble Prize for its revolutionary sensing technique.

fig

Now for the Diffusion Tensor Imaging (DTI) stuff. I don’t have any practical experience with using DTI, but I’ll do my best to explain it without going into too much anatomy stuff. Our brain is made up of grey matter and white matter. The grey matter contains most of the neurons and is found both in the centre and around the outside of the brain. The white matter is the bit in between the grey matter parts and contains lots of white matter tracts. These tracts are important because they connect the different parts of the grey matter so that the brain can carry out its different functions, such as make new memories. What DTI does is detect how water travels along these white matter tracts in the brain and maps it. This way we can see the connections between the different areas of the brain, and it’s colour-coded.

diffusion-tensor-imaging

The problem with fMRI is that the images can be somewhat blurry, and both fMRI and DTI cannot (thus far) identify any individual neuron structures or individual neuron activity. This is why Brainbow is the talk of the town because it does exactly that.

mouse-hippocampus

If you’re lucky enough to be in Philadelphia, USA, I’d recommend going to the Mütter Museum to see these amazing microetchings. You won’t be disappointed.

Written by Alison Holland

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References

Kwon, D., & Tormes, L. (2015). The Brainbow Connection. Scientific American Mind, 26(6), 52-55.