Category: Education

Ellena GrilloLeave a comment

The crucial cortex

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University of Oxford PhD student Lance Millar recently ran one of our Brain Spotlight events as part of the Brain Diaries exhibition programme. Here, Lance explains his research into neurodevelopmental disorders and possible treatments.

The brain has always been a fascinating organ for me. It is the site of our intelligence, our problem-solving and social skills, and it allows us to connect our senses to the world around us.

The large, folded outer part of the human brain is called the cortex, and is responsible for decision-making, language, face recognition, and a lot of the other things that I like to think are what make us human. The word cortex comes from the Greek for husk or outer shell, which underestimates the importance of what the cortex does.

Humans can survive with damage to the cortex, but depending on the part of the cortex that is damaged, a range of disabilities can result. People who have had a stroke can lose part of their cortex, leading to limb paralysis, loss of speech, or loss of memory, depending on the site of the damage.

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Cerebral cortex – Professor Michael R Peres – Wellcome Images

Some people are also born with a developmental problem in the cortex, and are said to have a neurodevelopmental disorder. Such conditions are thought to include autism, schizophrenia, ADHD, and even dyslexia – all fairly common conditions. The damage to the cortex is subtle and complex in these conditions, and scientists are still working out exactly what happens to the brain during its prenatal development.

I am studying one particular neurodevelopmental disorder caused by lack of oxygen at birth. It is known to medical specialists as neonatal hypoxia ischaemia. The image on the right shows a cross-section MRI scan of a normal newborn human brain, alongside some babies who have been damaged by oxygen deprivation. You can see that the brains are smaller, the cortex is less folded and it takes up less space inside the skull.

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MRI scans of normal newborn brains alongside those of babies who have been damaged by oxygen deprivation. Image: Woodward et al., New England Journal of Medicine, 2006

Scientists still don’t know how to protect the newborn brain from these injuries. Some are caused by inflammation which is a normal response to illness, but can wreak havoc in the confined space of the skull. Some is caused by the presence of free radicals, which are thought to contribute to ageing and organ failure, as the newborn brain doesn’t have many antioxidants to fight these chemicals. It’s also possible that the electrical signals that neurons within the brain send to each other contribute to the damage when there isn’t enough oxygen to feed them.

So what can we do to treat oxygen deprivation at birth? One breakthrough treatment currently available is known known as hypothermia. In this technique, the baby is cooled to 33℃ which slows down the brain-damaging chemical reactions which in turn protects the brain. This is currently the only treatment available, but I am involved in the study of possible alternatives.

We don’t want to introduce any drugs to the baby’s system as they might be harmful to normal development. So scientists are currently working on treatments which help the baby’s natural body proteins to protect the brain. I do this by looking at neurons under the microscope, and identifying proteins expressed by these neurons using fluorescent probes known as antibodies.

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An example of neurons under the microscope. Image: Lancelot Millar

These neurons are expressing neuroserpin, a natural brain protein which decreases inflammation and cell death. I’m looking at exactly where neuroserpin is expressed in the brain, how it can be upregulated in response to oxygen deprivation, and how its chemical reactions could be used to protect the brain.

Another way to help people with neurodevelopmental disorders is to better understand how the cortex connects to other parts of the brain and how it can carry out complicated decisions. There is still so much to understand about the complexity of the human brain, and what seems like fundamental research could generate the springboard for new ideas for neurodevelopmental disorder treatments.

To explore the structure of the human brain and compare it to that of other animals see the Brain Diaries Brain Explorer below.

 

More than a Dodo2 Comments

Is it real? – models, casts and replicas

One of the most common questions asked about our specimens, from visitors of all ages, is ‘Is it real?’. This seemingly simple question is actually many questions in one and hides a complexity of answers. 

In this FAQ mini-series we’ll unpack the ‘Is it real?’ conundrum by looking at different types of natural history specimens in turn. We’ll ask ‘Is it a real animal?’, ‘Is it real biological remains?’, ‘Is it a model?’ and many more reality-check questions. Here’s your final installment…

There’s nothing like standing under a huge T.rex skeleton, staring up at its ferocious jaws, to get the blood pumping. Visitors often ask “Is it real?” and look rather deflated when they find out it’s a cast. So why do we include casts, models or replicas in our displays, if they don’t have the same impact as the real deal? The truth is that they’re valuable additions to museum displays, allowing the public to engage with specimens that would otherwise be hidden behind the scenes.

Please touch! A cast of the famous Oxford Dodo helps visitors explore this fragile specimen.

On any visit to the Museum, you’ll come across labels that tell you the object you’re looking at is a cast. It could be a dinosaur skeleton, a brightly coloured fish, an amphibian specimen or even the head of the Oxford Dodo. But what is a cast? Casts are made by taking a mould of bones, or sometimes whole animals, then filling that mould with resin, plaster or fibre glass to make a copy. They can be incredibly accurate or lifelike.

It’s extremely rare to find whole dinosaur skeletons, and very difficult to mount heavy fossils (weighing tonnes) onto large armatures. Our Tyrannosaurus rex is a cast of the famous Stan, found in South Dakota, USA, and one of the best preserved skeletons of its kind in the world. But the “real” Stan is kept at the Black Hills Institute of Geological Research, so the only way we can offer the breath-taking experience of standing beneath a T. rex here in Oxford is by using a cast.

The Dodo Roadshow in 2015 would have been a lot less fun without our life-size dodo model

Even Stan has some bones missing, so sometimes casts are made up of several individual skeletons. Copies can also be made to give the impression of a more complete skeleton. For example, if a left bone is missing, a mirror of the right hand bone can be created. We call these specimens “composites”.

Animals such as fish and frogs aren’t easy to taxidermy; their skins shrivel, dry out, lose their colour and crack. Painted casts are a good way to show what these animals look like.

A model allows us to show the intricate scales of this Blue Morpho butterfly up close.

Models, such as the giant insects on the upper gallery and the Archaeopteryx in the Evolution of Flight display (at the top of this post), are very clearly not real. These are made by model makers to show something that can’t be seen or shown with real specimens. The giant insects are a way of showing the detail of very small creatures. The palaeontological models show what we think extinct animals might have looked like in life. They’re hypothetical models based on the latest scientific research, which can change very quickly, and always have an element of artistic assumption or speculation in the details.

In this series we’ve talked about taxidermy, skeletons, fossils and more, but these are just a few of the kinds of specimens we have on display. There are also nests, plastinated models, microscope slides and dioramas, which all have a mix of real and non-real elements. When you are looking around the Museum try to think about which specimens are real and which aren’t… and how does that make you think about the specimen?

Read the other posts in the Is it real? series here.

Ellena GrilloLeave a comment

Drawing amongst the dinosaurs

For the past few years the Museum has been working with second year students on the BA (Hons) Illustration course at the University of Plymouth. As part of a module on interpreting information, students are given information on research that is going on in the Museum or related departments and asked to interpret this information visually. This year one of the students, Sally Mullaney, took on the project ‘Key to the Past: exploring the life and work of Charles Lyell’. Sally continued her work with the museum on a week’s placement during the summer, and was supervised by Eliza Howlett, Earth Collections Manager.

Sally Mullaney talks about how she interpreted the project and her experience here at the Museum.

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Illustrated map of Lyell’s European travels on which we can mark the fossil localities by Sally Mullaney

“For the past two months on my illustration course at Plymouth University, I’ve been working with the Museum of Natural History on an illustrated timeline of geologist Charles Lyell. At first I was pretty daunted at the amount of travelling and ‘geologising’ he did in his life throughout the Victorian era. But after I spent time reading his letters and journals, I really got a feel for what Lyell was like. His musings and good humour shine through in his many letters to various siblings, professors and his wife, Mary. This really made the Charles Lyell project a pleasure for me to do, and I was thrilled when the museum asked me back to work for a week’s placement continuing with Lyell.”

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Charles Lyell and Captain Cooke spend a night in a shepherd’s hut in the Pyrénées, 1830 by Sally Mullaney

After a weekend of sightseeing Oxford’s many attractions (the museum being one of them!), Jade, a fellow student from Plymouth, and myself reported to the front desk to begin our week.  We were welcomed warmly with a cup of tea overlooking the main court of the museum, and were briefed about the week to come. I was also given the opportunity to work with the Public Engagement team to create a new logo for the Family Friendly Sunday events, as well as the continued work on Lyell which would be a map illustrating his travels and collections.

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New logo for family friendly activities by Sally Mullaney

 

The week really flew by and I managed to complete the projects with a little time to spare, which I spent sketching in the court amongst the dinosaurs! The building is such an incredible place to work in, and it has been a pleasure to be working in such a fantastic museum – I’ll definitely be visiting again!”

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Pianist and the T. rex, 30 July 2017 by Sally Mullaney

Sally’s characterful and charming illustrations of Charles Lyell’s bring his geological travels across Europe to life. Charles Lyell (1797-1875) was a student of William Buckland at Oxford, and went on to become the foremost geologist of his day. The Museum is lucky to house a large proportion of the Charles Lyell Collection, comprising of over 16,000 documented fossil specimens. A number of the specimens in the collection would have been collected in Europe during his travels. LBEC004 small

Lyell was a close and influential friend of Charles Darwin. Lyell’s important Principles of Geology was one of the few geological books that Darwin took with him on his voyage with HMS Beagle, and it helped shape his hypothesis for the mechanism of coral atoll formation amongst other things.

Last year the Museum undertook the large task of starting to make Lyell’s collection publicly accessible by cataloging and taking high resolution images of the specimens. The collection will be available online via a user-friendly database in the foreseeable future – watch this space!

You can learn all about the project, the collection and the man himself via this dedicated blog.

 

 

More than a Dodo2 Comments

Is it real? – Fossils

One of the most common questions asked about our specimens, from visitors of all ages, is ‘Is it real?’. This seemingly simple question is actually many questions in one and hides a complexity of answers. 

In this FAQ mini-series we’ll unpack the ‘Is it real?’ conundrum by looking at different types of natural history specimens in turn. We’ll ask ‘Is it a real animal?’, ‘Is it real biological remains?’, ‘Is it a model?’ and many more reality-check questions.

This time: Fossils, by Duncan Murdock

Whether it’s the toothy grin of a dinosaur towering over you, an oyster shell in the paving stone beneath you, or a trilobite in your hand, fossils put the prehistory into natural history collections. Anyone who has spent a day combing beaches for ammonites, or scrabbling over rocks in a quarry will attest that fossils are ‘real’. It is the thrill of being the only person to have ever set eyes on an ancient creature that drives us fossil hounds back to rainy outcrops and dusty scree slopes. But fossils, unlike taxidermy and recent skeletons, very rarely contain any original material from living animals, so are they really ‘real’?

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The Museum’s famous Megalosaurus jaw

Fossils are remains or traces of life (animals, plants and even microbes) preserved in the rock record by ‘fossilisation’.

This chemical and physical alteration makes fossils stable over very long timescales, from the most ancient glimpses of the first microbes billions of years ago to sub-fossils of dodos, mammoths and even early humans just a few thousand years old. They can be so tiny they can only be seen with the most high-powered microscopes or so huge they can only be displayed in vast exhibition halls, like our own T. rex. Among this is a spectrum of how much of the ‘real’ animal is preserved, and how much preparation and reconstruction is required to be able to display them in museums.

Trace fossils include footprint trackways like these, made by extinct reptile Chirotherium.

Generally, the more there is of the original material and anatomy, the rarer the fossils are. Among the most common fossils found are ‘trace fossils’: burrows, footprints, traces, nests, stomach contents and even droppings (known as ‘coprolites’). Most ‘body’ fossils also contain nothing of the living creature, rather they are impressions of hard parts like teeth, bones and shells.

This ammonite fossil, Titanites titan, was formed when a mould was filled with a different sediment, which later turned to rock.

When an organism is buried the soft parts quickly decay away. The hard parts decay much more slowly, and can leave space behind, creating a fossil mould. If this later gets filled with different sediment, it forms a cast.

These sediments are buried further still and eventually turned into rocks. Alternatively, the hard parts can be replaced by different minerals that are much more stable over geological time. Essentially bone becomes rock one crystal at a time.

3D reconstruction of 430 million year old fossil, Aquilonifer spinosus. Found in Herefordshire Lagerstätte, which preserves ancient remains with superb detail.

Very rarely the soft parts of an organism get preserved, but in the most exceptional cases skin, muscles, guts, eyes and even brains can be preserved. If buried quickly enough an animal can be compressed completely flat to leave behind a thin film of organic material, or even soft parts themselves can be replaced by minerals, piece-by-piece. These mineralized fossils can be exquisitely preserved in three dimensions, even down to individual cells in some cases. This is about as ‘real’ as most fossils can be, except the few special cases where the remains of an organism are preserved virtually unaltered, entombed in amber, sunk into tar pits or bogs, or frozen in permafrost. The latter push the boundaries of what can really be called a fossil.

Bambiraptor feinbergi

The final step in the process, from the unfortunate demise of a critter to its eventual study or display, involves preparation. In most cases the fossil has to be removed from the surrounding rock with hammers, chisels, dental tools and sometimes acids. This preparation can be quite subjective, a highly skilled preparator has to make judgements about what is or isn’t part of the fossil. The specimen may also need to be glued together or cracks filled in, so not everything you see is always original.

As with modern skeletons, there are often missing parts, so a fully articulated dinosaur skeleton may be a composite of several individuals, or contain replica bones. This is, of course, not a problem as long as it is clear what has been done to the fossil. This is not always the case, and there are examples of deliberately forged fossils, carved into or glued onto real rocks, or forgeries composed of several different fossils to make something ‘new’, like a ‘cut n shut’ car.

So, if you see a fossil that looks too good to be true, then it just might be worth asking, “is it real”?

Next time… Models, casts and replicas
Last time… Skeletons and bones

More than a Dodo3 Comments

A model ancestor

This bizarre creature, somewhere between fish and early four-legged land animals, is called Tiktaalik. The more scientists learn about this 375 million year-old beast, now long extinct, the more it intrigues them. Recent discoveries suggest its strong pelvis and hind limbs allowed it to move effectively through water, but also to clamber on the river bed and possibly onto mud flats.

Education Officers here at the Museum often use Tiktaalik as an example of how animals moved out of water and onto land and how that relates to the history of life on Earth. Until now, this has been a bit of a challenge: our education activities all focus on using specimens, but only a few fossilized bones remain from this ancient animal. Enter Robyn Hill, model maker! Here she explains how she tackled the task of bringing Tiktaalik to life:

Robyn brandishes her Tiktaalik model

For the last 3 years I have been studying model-making at Arts University Bournemouth. For a final year project we were required to find a client and create a model in 7 weeks. One of my fellow students put me in contact with Chris Jarvis, an Education Officer at the Museum of Natural History, who gave me the project. He’s been very supportive and incredibly enthusiastic about the collaboration. The whole experience has been a boost in confidence as this was the first model of this type and scale I had made.

The model will be used as a tool to illustrate the story of the Tiktaalik during schools workshops. The Tiktaalik is important in the evolutionary timeline as it is the cross over between historic fish, such as the Coelacanth, and the first four-legged animals, the tetrapods.

Robyn used clay to flesh out an armature she made from steel, aluminium wire and chicken wire.

I decided to make the model out of fibreglass as it would withstand more wear and tear, such as being stroked by school children, and it is light enough to be carried by a single person when holding up and demonstrating.

The head was probably the easiest part to model, because I could use the direct evidence from fossil remains. Then it was a case of imagining where the muscles and flesh would lie over the skull. I used written explanations of the creature alongside illustrations to help me create the final look.

To make this mould, Robyn applied silicon to the clay sculpture, followed by a fibreglass jacket to add support. She then filled them with fibreglass for the final model.

When posing Tiktaalik I looked into how much the body would realistically curve. I referred to the fossil remains and animations of how it would have moved, alongside images of preserved footprints. Tiktaalik was one of the first animals with a neck, which is something I hope I illustrated in my design.

Once it was released from the mould, Robyn sanded and filled the model, then sprayed it with colour.

The Coelacanth is a living relative of Tiktaalik and has a similar type of scales, so I used images of this animal to help my research. I also looked at fish which live in similar conditions. I was experimental with the paint, as no one is certain what colour its scales would have been. I used changing pigments over a detailing layer of airbrushed cellulose paint.

On the final model, you may see a few scars: some of these I made on purpose, some made by mistake, but I believe it gives the creature more character, because it was a predator and would have had to fight for its place!

More than a Dodo2 Comments

Is it real? – Skeletons and bones

One of the most common questions asked about our specimens, from visitors of all ages, is ‘Is it real?’. This seemingly simple question is actually many questions in one and hides a complexity of answers. 

In this FAQ mini-series we’ll unpack the ‘Is it real?’ conundrum by looking at different types of natural history specimens in turn. We’ll ask ‘Is it a real animal?’, ‘Is it real biological remains?’, ‘Is it a model?’ and many more reality-check questions.

This time: Skeletons and bones, by Mark Carnall

Them bones, them bones… They are all over the place in most museums of natural history: suspended above you, parading around you, or towering menacingly over you in the case of the attention-grabbing Tyrannosaurus rex. When it comes to skeletons you might think the ‘Is it real?’ question is pretty easy to answer; the bones are there, tangibly real, right?

The articulated skeleton of a Barn Owl

Bones are only found in fish, amphibians, reptiles, birds, and mammals. Other animals possess hard parts which can confusingly be named using similar language, such as the cuttlebone of cuttlefish, or the ‘skeletons’ of corals. These hard parts may resemble bone but are formed in different ways to true bone like the ones we possess.

Unlike taxidermy, discussed in the previous instalment, on the face of it bones are less easy to manipulate and so less likely to be subjectively represented. But individual bones did not exist individually in life, and articulated skeletons, where bones have been attached together, have been manually reassembled to illustrate the shape of the whole animal. The accuracy of an articulated skeleton can depend on a number of things, including the skill and knowledge of the person doing the assembly, the completeness of the bone material, and even the preparation of the bones themselves.

The skeleton of an Atlantic Bluefin Tuna, on display in the Museum

In life, the skeletons of the bony animals are also supported by hard but spongy cartilage and tendons which are not so easily preserved after death. Yet it is the support of the cartilage and tendons, and the form of the surrounding muscle tissue, which gives an animal its natural appearance.

Some articulated skeletons do not account for this non-bony connective tissue. For example, all of the vertebrae in an articulated backbone may be touching each other, whereas in life there would actually be a disc in between each vertebra. Articulated skeletons are often positioned so that parts of the skeleton can be easily seen and accessed, even if the positioning is not realistic or even physiologically possible.

The Museum’s parade of articulated mammal skeletons – no cartilage or tendons in sight…

There are also lots of smaller bones which often aren’t preserved as they are too fragile or don’t attach to other bones in life. Examples include clavicles, or collar bones, penis bones, and the hyoid, a bony structure in the neck that supports the tongue. Some skeletons are composite specimens, so they may be made up of bones from multiple individuals to replace missing or damaged parts. Other parts of skeletons on display in museums may have been reconstructed with plaster or filler.

The way that a specimen is ‘skeletonised’ – the processes used to prepare a skeleton from a carcass – can also have a huge effect on the size and shape of bones, altering the size by up to 10 per cent, which can introduce errors in bone measurement, especially for small-boned bats, rodents, lizards, frogs, and fish.

So while there’s a tendency to assume that skeletons are more ‘real’ than other kinds of preserved specimens, they too have their biases. The next time you look at a skeleton try to imagine what is natural and unnatural about its construction, and ask yourself – is it real?

Next time… Fossils
Last time… Taxidermy