Tag: science

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Movers and settlers

Our new exhibition Settlers, which opens today, shows that the history of the people of Britain is one of movement, migration and settlement. Here, exhibition writer Georgina Ferry finds that Britain has been receiving new arrivals since the last Ice Age.  

In Britain following the Brexit vote, the word ‘migration’ has taken on an emotional and political charge. A new exhibition opening today takes a long-view of the movement of people, looking in particular at how migration has formed the British population.

Settlers: genetics, geography and the peopling of Britain tells the story of the occupation of Britain since the end of the last Ice Age, about 11,600 years ago. From this perspective, today’s pattern of movement into and out of the country is only the latest in a long history of alternating change and stability that has made the people of Britain who they are today.

Hand axes from Wolvercote, Oxford
About 340,000 – 300,000 years ago, when conditions were slightly warmer than at present, Neanderthal hunters lived alongside a channel of the Thames near Oxford where the village of Wolvercote now stands. They made flint hand axes – all-purpose butchering, digging and chopping tools. They hunted animals now extinct in Britain.

Tracing these movements has been a fascinating detective story, with clues coming from many different types of evidence. The starting point for Settlers is a remarkable study carried out by Oxford scientists, who used DNA samples from contemporary British volunteers to trace the origins of the people who settled Britain between the end of the Ice Age and the Norman Conquest of 1066. One striking finding is that the bonds that unite Celtic communities in Cornwall, Wales and Scotland are largely cultural – genetically these groups are quite distinct.

Drinking horn finial of copper alloy and glass, 9th century – Northern Ireland. The Ashmolean Museum, University of Oxford

The genetic evidence adds a new dimension to the archaeological story, based on artefacts left behind by our ancestors, or other historical signposts such as place names. For example, although occupying Roman armies left us the names of their forts and cities, they don’t seem to have left much of their DNA. They came, saw and conquered, but didn’t stay in large enough numbers to make a genetic impact on the native British population. In contrast the Anglo-Saxons, who arrived after the Romans withdrew, left a strong genetic signature everywhere except Wales and the Scottish Highlands.

It took 2,000 volunteers and software that can distinguish tiny differences to arrive at the various regional clusters that came out of the study. When you visit the exhibition, you can play a fascinating interactive lottery game to see just how unlikely it is that genes from any specific ancestor of more than a few generations will still be in your DNA.

This map, created by the People of the British Isles study, is the result of comparing patterns in the DNA of a carefully selected sample of around 2,000 modern British people. It provides new evidence about links between genetic ancestry and geographical origins.

The story of movement and settlement doesn’t stop in 1066. Researchers in Oxford’s School of Geography have plotted census data since 1841 against global events, from the persecution of Russian Jews to the enlargement of the European Union, to illustrate the ebb and flow of people from and to Britain that has produced the current population mix. Another interactive lets you compare your own family’s journey with those of all the other visitors.

We will have to wait until the census of 2021 to know what a difference Brexit will make, but we can be sure that people will be arriving and leaving for a lot longer than that.

www.oum.ox.ac.uk/settlers

Ellena GrilloLeave a comment

The crucial cortex

Lance Millar_Developmental Anatomy_14Oct2017.jpg-large

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.

B0009564 Human brain, coronal section, LM
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.

Neurons under the microscope
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.

 

Ellena GrilloLeave a comment

All about Alzheimer’s

University of Toronto research fellow Jacqueline Zimmermann recently ran one of our Brain Spotlight events as part of the Brain Diaries exhibition programme. To mark World Alzheimer’s Day today, here Jacqueline tells us about the neurophysiology of Alzheimer’s disease and the risk factors we can actively reduce to lead happier, healthier, and longer lives.

Almost all of us have in some way been affected by Alzheimer’s disease, which makes the quest for a cure that much more personal. An estimated one in nine people over the age of 65 will develop the disease, and this risk also increases with age, according to the World Alzheimer’s Report in 2015.

Brain Spotlight
Jacqueline Zimmerman’s Brain Spotlight on Saturday 16 September as part of the Brain Diaries exhibition series of events.

Due to chemical toxins, and increased longevity, the incidence for Alzheimer’s disease is on the rise. But the good news is that there is a lot that you can do to reduce your risk. At the John Radcliffe Hospital in Oxford, hundreds of scientists are currently working towards identifying the cause and the solution to the disease.

At the Brain Spotlight event at the Museum I presented images of ageing brains, and explained how brains affected by Alzheimer’s have reduced volume in the temporal lobe and the hippocampus, regions critical for language and memory respectively. Diseased brains will also often show reduced frontal lobe volume, which may reflect the changes in personality and the ability to engage in planning which area associated with Alzheimer’s. The overall volume of the brain is also reduced in sufferers because cellular changes lead to the death of neurons.

Brain Atrophy in Alzheimer’s disease
Brain Atrophy in Alzheimer’s disease. Note: overall brain volume is reduced, hippocampal regions and frontal regions are particularly affected, and ventricles are enlarged. Image: http://www.lookfordiagnosis.com

Recently, a number of genes have been identified that are related to early onset Alzheimer’s, which is quite rare and much more hereditary than late-onset Alzheimer’s. At the Nuffield Department of Clinical Neurosciences, where I am a visiting researcher, we are investigating a late-onset Alzheimer’s risk gene called Apolipoprotein 4 (APOE4), looking at how it relates to subtle cognitive impairments in middle-aged people. Working with the Oxford Biobank we are trying to determine which cognitive assessments may be most effective in predicting these impairments.

Jacqueline Zimmerman
Functional brain imaging using electroencephalography at Rotman Research Institute in Toronto. Image: Rotman Research Institute

Although some of us may be more susceptible to Alzheimer’s than others, there are a number of environmental factors that contribute, including air pollution or additives in our food, like nitrogen-based chemicals which are used to preserve and flavour processed foods. It is important to reduce cholesterol in the diet, eat plenty of fruits and leafy greens, and engage in frequent physical and mental exercise.

Though there is speculation about the effectiveness of ‘brain games’ and how they translate into improvements in cognition in the real world, there are certainly large benefits of keeping your brain active.

 

Ellena GrilloLeave a comment

Amber time capsules

New Museum Research Fellow Dr. Ricardo Pérez-de la Fuente talks about his fascinating work with a special collection at the Museum of Comparative Zoology, Harvard University, and what he’ll be getting up to at the Museum of Natural History. 

Amber, fossilised resin, has fascinated humanity since prehistoric times due to its mesmerising colour, shine, and fragrance when burned. From a scientific viewpoint however, what makes amber unique is the ability that the resin has to capture small portions of the ecosystem and the organisms living within almost instantaneously, in an unaltered way, preserving them for tens of millions of years. This has an unmatched fidelity among the fossiliferous materials.

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Holotype of Fibla carpenteri Engel, 1995, a snake-fly. Credit: President and Fellows of Harvard College.

During a four-year postdoctoral fellowship at the Museum of Comparative Zoology (MCZ) at Harvard University, I had the chance to curate, identify and digitise one of the premier fossil insect collections worldwide. It holds about 50,000–60,000 specimens, including around 10,000 amber inclusions. One of the unexpected outcomes of my time there was helping to rediscover a forgotten loan of about 400 Baltic amber samples that had been brought to the MCZ from the University of Königsberg during the 1930’s.  This loan ended up sparing the specimens from being destroyed during the bombardment of the city of Königsberg (renamed Kaliningrad thereafter) in World War Two. The full-story as showcased by the Harvard Gazette can be found here.

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Holotype of Lagynodes electriphilus Brues, 1940, a megaspilid wasp. Credit: President and Fellows of Harvard College.

As a researcher specialising in fossil arthropods, one of the most remarkable challenges for me during the digitisation project at the MCZ was to overcome the thrill to learn more about the specimens that we were imaging. In what way were they different from their modern relatives? Were they perhaps new to science? What information were they providing from the ecosystem in which they lived? At present, I can fully embrace these questions and many more thanks to becoming a Museum Research Fellow at the Museum of Natural History.

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Cotype of Hypoponera atavia (Mayr, 1868), an ant. Credit: President and Fellows of Harvard College.

My research at the museum focuses on studying interactions between organisms in deep time and their behaviours, particularly in Cretaceous amber, such as plant-insect pollination relationships around 100 million years ago. During that time, a major shift was taking place in terrestrial ecosystems due to the diversification of angiosperms (flowering plants), which ended up replacing gymnosperms (non-flowering plants) as the dominant flora. There was also the appearance of key groups of organisms from the ecological perspective — ants and bees in the case of insects, for instance.

It is a well-accepted fact that preservation in amber is biased towards small organisms because the larger ones tend to escape the sticky resin more easily. But how easy it is for one to get lost in amber when examining its secrets and trying to unravel its mysteries! Becoming forever trapped within.

Some of the most remarkable Baltic amber specimens (about 40 million years old) returned to the Königsberg collection from the MCZ. Pictures: RPF. Credit: President and Fellows of Harvard College.

Ellena Grillo3 Comments

Calling all artists

We’re happy to announce an exciting opportunity to coincide with our  new exhibition – Settlers, opening at the Museum of Natural History in February 2018.

Settlers is the upcoming exhibition in our Contemporary Science and Society series. The latest of the series, Brain Diaries: Modern Neuroscience in Action is currently running until 1 January 2018.

The history of the people of Britain is one of movement, migration and settlement. Tracing patterns revealed by genetics, archaeology and demography, Settlers: Genetics, Geography and the peopling of Britain will tell the dynamic story of Britain’s ever-changing population.

DNA image for call out blog post

Planning for Settlers is going well and we’re happily getting to grips with the science and archaeology, but we’d also love to have some artistic input. Can you help us?

The Museum would like to commission up to two pieces of contemporary art that explore themes such as genetics, DNA, migration, settlement and ancestry.

We’re particularly interested in work that will provoke thought and discussion and engages with 18-25 year olds, and we welcome all media, including digital and installation art.

The artwork could be displayed in the gallery itself, in the main court or even on the museum lawn.

centre-court
The Museum’s centre court

If you like the sound of adding some artistic flair to Settlers, you can find out more here:.  Don’t delay, though; the deadline for applications is Friday 1 September 2017.

Ellena GrilloLeave a comment

The Big Brain Competition

What happens in your brain when you receive compliments? And what’s going on in your mind when you watch your football team win a match? Does the brain respond differently when recalling music, compared to listening to it? All these questions, and more, have been posed in our Big Brain Competition…

Coinciding with the Museum’s Brain Diaries exhibition, the Wellcome Centre for Integrative Neuroimaging is inviting you to ask your own question about the brain to be in with a chance to have it tested by neuroscientists using Oxford’s state-of-the art Magnetic Resonance Imaging (MRI) scanner.

The advanced MRI scanner at the John Radcliffe Hospital in Oxford is one of the strongest in the world. It allows scientists to carry out functional MRI (fMRI) scans to see the brain in action. This mind-blowing procedure can reveal how the brain changes when learning a new skill or how it compensates when someone recovers from brain damage. It can also reveal which areas are used when people speak, move or laugh, to give just a few examples.

This fMRI scan shows how blood flows to the visual cortex region at the back of the brain when viewing a visually-stimulating checkerboard pattern
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Dr Stuart Clare of the Nuffield Department of Clinical Neurosciences is asking you for questions about the brain

Functional MRI shows when a brain area is more active by detecting the changes in blood oxygen levels and blood flow that happen in response to neural activity. The technique can be used to produce activation maps showing which parts of the brain are involved in a particular mental process.

The scientist behind the Big Brain Competition is Dr Stuart Clare, whose research involves pushing the technological boundaries of the fMRI technique to reveal new insights about how the brain functions normally and how it is affected by disease. There is still so much that the fMRI scans can bring to light, so Stuart is asking you for ideas!

Over several years of inviting people in to see the beautiful pictures that our MRI scanner can produce, I’ve been fascinated by the questions they have about the brain and whether you can see this thing or that thing in our fMRI scans.  With this competition we want to give people the unique access to our scanner and the chance to try an idea out for themselves.

When coming up with an idea for investigation there are a few practical things to bear in mind. Any activity has to be something people can do when lying down in the scanner and it has to be clear when they start and stop doing the activity. But Stuart is very open to ideas for experiments that they haven’t come across before – something that scientists really don’t already know the answer to.

The animation below explains how fMRI works and what it can do. So take a look, think up an experiment of your own and enter your idea via this form. The best one will be put into action by the research team and you will be able to watch the scans take place at the John Radcliffe Hospital yourself!