Art meets science in Mini Lisa's nanoworld

Was Leonardo Da Vinci the greatest scientist or artist of his time? Perhaps more well known for his artistic talents, his enigmatic painting of the Mona Lisa continues to puzzle generations of art enthusiasts many centuries later.

Now, thanks to a newly published study by PhD student Keith Carroll from Georgia Instiute of Technology, Da Vinci's artistic works can take a tiny place in the world of science. A very, very tiny place indeed....

The 'Mini Lisa' wins the record for the world's smallest replica of Da Vinci's famous painting. The technical terminology adds a layer of complexity that detracts from what simply is a work of art. Published in the journal Langmuir, "Fabricating nanoscale chemical gradients with thermochemical nanolithography" is a complex description of a technology that can perhaps be likened to the painting style pointillism. Whereas the latter refers to a painting created from tiny dots of individually applied paint, 'Mini Lisa's' 'paint' was applied using controlled chemical reactions to create varying shades of grey across 125 nanometer intervals.

The overall image stretches just 30 microns across---that's so small that it's probably not worth splitting hairs over. Let's just say that it's really rather small.

But perhaps in the science of art, size doesn't really matter all that much. In our new world of nanotechnology, perhaps sci-art is the genre of the future? I'm sure that Da Vinci, as an inventor and creator born before his time, would be more than a tiny bit pleased is he could see this painting.

[Image source: Georgia Tech Media Release] 

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The science of happiness - an experiment in gratitude

Have you ever wished you could be happier, if only you could figure out how? Here's a great video that reminds us how expressing a little gratitude can help us unleash our inner happiness.



This experiment suggests that the act of expressing gratitude to a loved one increases our own levels of happiness. 

The use of the scientific method makes me happy. Of course, I couldn't agree more with the conclusions. But the scientist in me wants to know more. Without access to the original scientific publication, I can only speculate...

Personally, I'm a writer, not a speaker, and am familiar with a sensation of happiness after writing about a person I care for. Do you actually need to speak your feelings out loud to experience this boost of happiness, or will just writing them down suffice?

This being a scientific experiment and all, we know that it's important to have the proper controls so that we know exactly where the increases in happiness are coming from. Of course, by comparing a group of "talkers" (people who spoke to their loved ones) versus a group of "writers" (people who only wrote these feelings down), we saw that the act of verbally expressing gratitude produced the greatest increases in happiness. So yes, on face value, the results suggests that telling loved ones your feelings face to face is more responsible for the observed happiness than the act of writing.

If you watch closely however, you will notice that perhaps the differences between the "writers" and the "talkers" is not that dramatic, and perhaps we shouldn't just "trust the guy in the lab coat". The "writers" experienced increases in happiness of 2-4%, whereas the "talkers" experienced from 4-19% increases in happiness. So whilst the difference between 2 and 19% is large, some "talkers" experienced the same 4% increases in happiness as some "writers". To make a proper judgement as to whether there is a true difference between the two groups, we would need to do some kind of statistical testing.

Even if we don't bother too much with all that statistics stuff, perhaps it would be good enough if we could see what the average of each group is. Perhaps most "writers" experienced only 3% increases and most "talkers" experienced 5% increases. Who knows, perhaps the 19% increase comes from just one person, who for whatever reason produced dramatically different results from everyone else. This person would be an outlier, and we would view they contribution to the data with caution.

I'm a little surprised by the only incremental increases in happiness observed for the group of writers, considering the depth of emotion that I experience myself when writing. But this reminds me how science works---by removing those innate biases that may cloud our perception of what is 'real' and what is 'superstition'.

Whilst the experiment suggests (with the acknowledged flaws) that talking is better than writing, unfortunately, this experiment doesn't tell me whether just writing down your feelings produces an increase in happiness on it's own. To answer this question, the experimenters should have completed a second control experiment, to see whether just volunteering for the study itself produced an increase in happiness. So for example, they could have compared the group of "writers" to a group of "thinkers", who were left alone in a room during the study but did not write down their thoughts or speak them aloud. If the "writers" experienced an increase in happiness above what the "thinkers" did, only then could we say that the act of writing can increase our levels of happiness.

Is expressing your gratitude going to have an effect on happiness for everyone? The experimenter tells us that person who experienced this 19% increase in happiness was the least happy person to start with. So people who are particularly unhappy should be happy to know that expressing their feelings will most likely have a bigger effect on them than their already happy friends. This is an example of a "ceiling" effect, where you don't see any further changes to a variable that is already optimal. So to get good results, it would be important to start with a wide range of people with different levels of happiness---if everyone was happy to start with then we might not have seen this increase in happiness.

"The science of happiness" puts the happiness into science, and encourages us to think about what we are feeling. Sure, perhaps as far as scientific validity goes, there is room for improvement. I imagine it's very likely that simply participating in a study about happiness makes you feel happier over time, just an awareness of the emotion, immediately brings it to our attention. For example, if you're like me, you most likely felt happier just by watching this video and thinking about happiness. This is great news, because even without the pretty numbers and graphs we saw in this experiment, it suggests that all we need to do to be happy is to be aware of our happiness and show it to other people.

So get out there and be grateful to Pollyanna for showing us how to be glad.

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Neuronal Culture: How do brain cells communicate?

If you listen carefully, can you hear your brain cells talking to each other?

In our lab, we eavesdrop on these neuronal conversations. We know that neurons talk to each other in much the same way that we do. Here in the bottom left corner you can see two brain cells doing what any two cultured neurons do these days—hanging out, and discussing the social media they’re growing up in.

But whilst we converse across the cyberspace, brain cells talk to each other across these junctions known as synapses. You can see one illuminated here on the right. During a neuronal conversation, the presynaptic neuron illustrated in green, talks to the red postsynaptic neuron on the opposite side of the synapse. This neuronal conversation is conducted in the language of these grey neurotransmitter molecules that diffuse across the synapse. Their meaning is decoded by these purple receptors that transmit the information to the inside of the neuron. Message received loud and clear.

But in the busy metropolitan environment of the brain, everyone has something to say. A single neuron cannot listen to all the conversations in its noisy surroundings.  We know that when a postsynaptic neuron is not listening, these purple receptor molecules do not decode and transmit the information carried by the neurotransmitter. For people with Autism, this happens too much. We want to know why.

Perhaps I’m not a great listener myself. So during my PhD project, I’m not listening to these neuronal conversations. Instead, I’m watching them in action. I am looking down a microscope at these synapses and studying what the receptors are doing when neurons are talking (or ignoring) each other.

The problem with studying synapses is that they are very, very small. I would have to split hairs many thousands of times to provide an accurate representation of their incredibly small size. If these chattering neurons are like two trees in the far off distance, then their synapses are the leaves that are just too small to see. So let’s get closer.

Unfortunately, neuronal synapses are so small that we need some kind of super powers to see them, even with a microscope. Thankfully, I’m lucky enough to have access to a new type of microscope with super resolution powers that can see the leaves for the trees.

Stretching across the screen in white is a close up image of just a tiny part of a neuron. At this level of detail, we can now see these synapses that form between this green presynaptic neuron and its red postsynaptic, conversational partner. So despite their small size, we can clearly see these synaptic exchanges in progress.

I hope that by watching neuronal conversations, we will see the secrets in the brain.

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Seeing brain plasticity in the environment

Photo credit: Emma Goodman 

You are where you live. If you open your eyes wide enough, you'd see that your environment really is the most important thing in your life.

A paper published this week in the Journal of Neuroscience suggests that the ability of the adult brain to re-wire itself depends on the quality of the environmental stimulus. What's more, perhaps this can occur more quickly than previously thought. [Matthies U et al. J. Neurosci. 2013;33:11774-11778].

Our brains are plastic organs that are capable of moulding and re-wiring themselves in response to the changing environment. The visual cortex is a great example of this 'brain plasticity'. Young children deprived of vision to eye one during a certain critical period of their growth often develop 'lazy eye', or amblyopia. This occurs because without anything to 'look at', the brain region responsible for vision in this eye does not develop properly. Young children's brains are incredibly adaptable, and this problem can be easily fixed just by correcting the eye problem. Of course, we've all heard that old dogs can't learn new tricks. Unfortunately, after a certain age in childhood, the brain not longer has the capacity to re-wire itself and fix the problem, making untreated lazy eye a problem for the rest of adult life.

However, scientists are now learning that adult brains are far more plastic that we traditionally gave them credit for. We now know that it is possible to encourage this 'plasticity', or brain re-wiring, in the adult animal, even after this critical period has ended. So hopefully one day we will have effective treatments for lazy eye, or any other disorders that the brain could fix itself if it just new how.

This study wanted to find ways to enhance this adult brain plasticity. To do this, the researchers needed to induce the visual cortex to undergo plasticity in the first place. To do this, they covered one eye of adult rats for 4 days so that not visual stimulation reached this eye (similar to what happens with lazy eye).

How did they know if the brain re-wired itself? Thankfully, neuroscientists have access to some great modern imaging technologies. Using our understanding of how light interacts with brain tissue, we can 'look inside' a living brain. Here's a great lecture that explains these technologies and what we can use them for, if you have an hour spare to devote to your own brain plasticity:

Figure 2: 'Ocular Dominance Index' (ODI) changes from day 2 onwards, indicating plasticity is taking place at this time.

These researchers used 'optical imaging' to measure brain activity. They saw more activity in  the brain region responsible for the open eye compared to the closed eye, indicating that plasticity was taking place and the brain had re-wired itself in favour of the open eye. What's more, this occurred after just two days. So, ta-dah! Don't give up on your noggin just yet. Here's an example of how old rats can learn new tricks!

But whilst adult brain plasticity does occur, it needs a little bit of assistance... In this case, the researchers were testing whether a particular type of visual stimulus could induce adult plasticity. During their monocular deprivation, the rats were placed in a box with special mirrors so that all they could see was an organised, repeatedly-moving stimulus. The idea was to test whether the timing of the stimulus is what allowed the brain to re-wire itself.

So does your environment really matter? Yes it does! Adult rats that were exposed to a grey background or randomly moving circles, instead of these moving square gratings did not show the same amount of brain plasticity. So compared to the random firing of neurons that comes from the deprived eye, using this type of organised visual stimulus produces a much clearer signal that clearly tells the brain it should re-wire in favour of the open eye.

This study suggests that the mechanisms that allow the adult brain to re-wire itself are perhaps not so different from those of young brains... All you need it the right environment.

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Nanoscale communication

What would it be like to occupy the cities inside cells? Imagine if we could peer inside cells and watch the tiny proteins go about their daily lives. We'd see the tradesmen hard at work building structures and taking them down again in response to the changing needs. We'd see personalised taxi drivers and hoards of buses transporting goods to other regions, doctors and nurses fixing damage, and factory workers busily pumping out energy for the whole city. These tiny proteins must communicate with each other for the cell to work efficiently as a whole.

Unfortunately we can't peer inside cells with this much detail. Using a standard confocal microscope available to most scientists, we can see major structures inside a cell. This is perhaps equivalent to looking at large factory buildings using a telescope from the international space station. These protein doctors and factory workers are hidden from our view, inside the blur that marks the limit of resolution. So scientists must use creative technologies to infer where these proteins are and how they function, rather than directly watching their actions.

In the last 5 years, new imaging techniques have allowed us to see beyond these major structures and peer inside these large-scale factories. One really great example of this technology is 'Super Resolution Imaging of Chemical Synapses in the Brain', published in 2010 in the scientific journal 'Neuron'. These authors use a new imaging technique known as STORM to see up to 10 times more detail than is possible with a typical confocal microscope.

The presynaptic neuron communicates with the postsynaptic neuron by releasing neurotransmitter than diffuses across the synaptic cleft.

Synapses are the parts of neurons that talk to each other---the ultimate example of cell communication. The presynaptic neuron releases molecules of neurotransmittor that diffuse across the synaptic cleft and bind the postsynaptic neuron, which responses appropriately according to the messages received. Synapses are where all the action is at, where memories are formed and strengthened, and where learning takes place. Unfortunately for people with debilitating diseases such as Alzheimer's or Autism, their synapses do not function as they should.

The synapses are very small, at only half a micron, or 1/2000th of a millimetre across. This is beyond the capabilities of our confocal microscopes, making it difficult for scientists to study these synapses. But thanks to super resolution imaging, we can now zoom in just a little bit more on these tiny cellular cities and see what's going on in a normal cell, or what's going wrong in a diseased cell.

Dani, A., Huang, B., Bergan, J., Dulac, C., & Zhuang, X. (2010). Superresolution Imaging of Chemical Synapses in the Brain. Neuron, 68(5), 843–856. doi:10.1016/j.neuron.2010.11.021. (Figure 1)

With confocal imaging (left), the synapse is blurred and unstructured. We cannot see the details of the two neurons synapsing onto each other, and we cannot make out the synaptic cleft that we know must be there. In comparison, using super resolution STORM imaging (right), we can now make up the details of the synapse. The green and red colours show two different neurons, talking to each other across the synaptic cleft that lies in between.

Here we are looking at nanoscale communication taking place. Imagine what cellular secrets we would find if we could see deeper into cells...

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Do seahorse neurons exist?

Yesterday, I stared down the microscope at some rat neurons, labelled with fluorescent mouse, chicken, and goat antibodies, and saw a seahorse staring back at me. I called him anti-Noah: an antibody concoction of animals gathered together at the end of their lives, without a Savior.



 

When I think of seahorses (which I admit is not very often) I imagine them to exist only inside the glistening waters of my imagination. Like some kind of ethereal, transient being that only comes into existence when my neurons fire together in such a way as to conjure them into existence.

What must life be like, as the figment of someone's imagination? But seahorses must be real. I saw them for probably the very first time the other day at a public Aquarium where I took this overexposed image through layers of glass and water. I admired the way they drifted aimlessly through the water, clutching at seaweed with their tails to change direction, just for something to do.

Nature has conjured up some funny creatures through the process of evolution. Is Darwin's theory of natural selection any less amazing than my own ability to imagine these beautiful creatures inside my mind? How do I know that we haven't evolved an imagination just so that seahorses have a place to live?

This seahorse neuron was real to me. But seahorses don't live in microscopes, silly.

 

 

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Penguins - Spy in the Huddle

Image Source: BBC

I like a good David Attenborough doco as much as the next biologist and animal lover. But sometimes you're just not in the mood for watching nature at its harshest and bloodiest.

The BBC's 'Penguins - Spy in the Huddle' is the most captivating heart-warming nature documentary that I have ever seen. We follow the early lives of Rockhopper, Humboldt, and Emperor penguin, as they grow up in this dangerous world.

Luckily, we have an insider's view. 'Egg cam', 'chick cam', and 'rock cam' show us the Penguins' world through hidden cameras. The technical expertise is inspiring, with imitation penguin robots able to right themselves when toppled over by over-zealous feathered admirers. 'Rockhopper cam' in particular resembles something out of one of the 'Saw' videos, so who can blame the penguins for questioning the intrusion.

This bird's eye view of the birds adds an element of humour. We see childless Rockhoppers attempting to nuture egg cam, and single birds flirting with the imposters. Here we see the first ever footage of a penguin colony filmed from a camera hidden inside a fake egg, flown through the sky by a bird.

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