Tag Archives: animals

Sleep across the animal kingdom

By Kimberley Whitehead, University College London

As creatures that spend a glorious one third of our lives asleep, we might be quick to assume that all animals on earth sleep.  Do they, and if so, how can we actually tell?

To understand the mechanisms of sleep and wakefulness better, physiologists often study animals. This is because their nervous systems are simpler, but still share similarities with ours. For example in animals with fewer genes involved in sleep, such as flies, it is easier to understand genetic effects. In the case of the zebrafish, life is made easier for neuroscientists who use this species because the fish is transparent when young, so the brain is visible and can be imaged in a living fish! However, if scientists study a fly or a fish, how can we tell that they’re asleep, especially if they don’t have eyelids?

Before we can look at differences in sleep between species, we first need to define criteria of sleep that we can apply to even simple animals. Firstly, sleep has to be reversible! If somebody was unconscious and couldn’t ever be roused, that would be a coma state, rather than sleep. Secondly, arousal threshold – i.e. what it would take to get a response – has to be increased during sleep, compared to wakefulness. For example, a cat will let you put all sorts of objects on it while sleeping, which it never would have tolerated when awake! Thirdly, sleep tends to happen at certain times of day, and in certain positions or situations: for us a nice comfy bed, for fish at the bottom of the tank.

In addition to these behavioural differences, if sleep is a distinct state from full consciousness, we would expect brain activity to differ. It turns out that indeed, even in flies, there is a difference in brainwaves between wakefulness and sleep. Brainwaves reduce in size as we fall asleep. Humans then go through cycles in which brainwaves get bigger and slower as sleep deepens whereas this is not apparent in flies for example.


Monica Folgueira and Steve Wilson, Wellcome Collection

Not only does sleep differ from wakefulness, it also varies across our lifespan. The sleep-specific brainwaves of adults are not present in baby rodents and humans. This suggests that sleep in early life may differ from sleep in adults.

Young animals also sleep much more. This extensive sleep in early life might be important for learning; baby flies deprived of sleep don’t learn how to find an appropriate mate. In mammals, there is some evidence that the twitchy movements babies have during sleep might help them to learn how to sense their environment.

Not only is sleep different in early life, it also differs in later life. In the elderly, changes in sleep patterns are seen across the whole animal kingdom. In both flies and humans, their sleep becomes more fragmented and elderly humans are more likely to report sleep problems than young adults.


Robert Hindges, Wellcome Collection

Understanding the criteria of what defines sleep, and the normal changes in sleep across the lifespan, paves the way to understand sleep disorders, such as narcolepsy. The brain circuits involved in narcolepsy are the same between zebrafish and humans. This offers exciting opportunities to understand these circuits better, because they’re so much easier to manipulate in fish. Aside from diseases which primarily affect sleep – like narcolepsy – many neurological disorders eventually affect sleep. This means that researchers using animal models can use sleep as a marker of overall brain health or degeneration.

Since there are ways to tell whether even simple animals are asleep, research about sleep across the animal kingdom can offer fresh insights into the million dollar questions of why we sleep, and what causes sleep problems.

This blog is based on a recent public engagement event at the Grant Museum of Zoology, put on by University College London and The Physiological Society. Surrounded by weird and wonderful pickled and stuffed animals, sleep scientists from University College London studying flies (James Jepson), zebrafish (Jason Rihel) and humans (me – Kimberley Whitehead) each brought a different angle to the discussion.

Follow these links to learn more about the research done by:

Night at the Vet College

Step inside the Royal Veterinary College’s inspiring campus on 22nd November for an evening of animal excitement at ‘Night at the Vet College’, in collaboration with The Physiological Society.

The theme of the night is ‘Wellbeing’, based on The Physiological Society’s 2017 theme of ‘Making Sense of Stress’. Complete with canine scientists, TV stars and a dissection, this event is not to be missed!

Wellbeing 2017 image crop

Go behind the scenes at the RVC’s 226 year old Camden campus, admiring animal skeletons and specimens which have shaped the study of thousands of veterinary students. In the main Anatomy Museum you have the chance to get up close and personal with your favourite specimen for a drawing session, with artist Tim Pond.  Tim has drawn every animal under the sun, and will be showcasing his animal anatomy studies, which are fundamental for understanding animal wellbeing.

At 6 pm, move into the Great Hall for an exciting talk by the star of ‘Trust Me I’m A Vet’, Judy Puddifoot, who will be discussing the work behind the scenes of the programme, in particular her work with dogs, guinea pigs and tortoises!


Judy Puddifoot on Trust Me I’m a Vet. ©BBC Two

Throughout the college you will find stands dedicated to different professions who care for animal wellbeing, including staff from our Hertfordshire Queen Mother Animal hospital talking about how your dog could save lives by giving blood. Check out visiting animal charities and community teams to see how their work with animals benefits both human and animal wellbeing. For instance, hear about how dogs are trained to become assistance animals, from The Dogs for Good team. Try on surgical gowns and develop your clinical skills in our mock clinic area; our neighbours the Beaumont Sainsbury Animal Hospital will be showcasing their accredited dog and cat waiting rooms, complete with research-approved classical music for the cats!

At 7 pm, get ready for a dissection conducted by the Head of Anatomy services, Andrew Crook MBE. He can assure you that “this will be a fantastic opportunity to witness a real dissection and learn about anatomical structures first hand.” You can either watch the dissection first hand (max 100 spaces in the theatre, first come first served), or if you prefer, the whole thing will be being live streamed to the Great Hall lecture theatre, for you to watch the process without the olfactory component.


©Royal Vet College

By taking part in our activities you can learn about the world–class science being produced by our researchers, including ferret preferences and how fractures relate to neurobiology. Postdoctoral Researcher Dr Rowena Packer and her team will be talking about stress levels in Border Collie dogs, how it is affected by neurological disorders, and how they can measure it. You will find out how this cutting-edge research will benefit the wellbeing of dogs with epilepsy!

Manager of the Grant Museum of Zoology and author Jack Ashby is also joining us with his new book – Animal Kingdom: A Natural History in 100 Objects.

You’ll have to try and remember all you heard about throughout the evening, because our student bar will be hosting a Pub Quiz. Time to use your new animal knowledge to win prizes!

Night at the Vet College is on November 22nd, 5.30-10pm, at the Royal Veterinary College’s Camden Campus: 4 Royal College Street, NW1 0TU (10 mins walk from Kings Cross, Mornington Crescent or Camden Town tube stations). You can book your free place here, however there is limited capacity so early booking is encouraged: https://www.eventbrite.co.uk/e/night-at-the-vet-college-wellbeing-tickets-38770001117

Making sense of stress in the wild

By Kimberley Bennett, Abertay University

Imagine leaning forward over the edge of a precipice. Lurching back to safety, you picture the forest hundreds of metres below. Is your heart racing? Are your palms sweating? Our body’s stress response to an ever-changing environment enables us to survive and flourish.

Physiologists play a crucial role in developing our understanding of the mechanisms involved. To highlight the exciting work that they do, our 2017 theme is ‘Making Sense of Stress’. Follow the conversation on Twitter using #YearOfStress.

Launching the theme will be Dr Kimberley Bennett’s talk, ‘Making sense of stress in the wild’, at the Association for Science Education’s (ASE’s) Annual Conference on 6 January 2017. Read a teaser to her talk below!

Coping with stress is a major issue in modern society, but it’s easy to forget that wildlife experiences stress too. Without enough water, plants wilt and die and whole crops fail; without the right habitat, a small population of rare animals dwindles and dies out, causing extinction of the species; a whole coral reef bleaches when the water temperature gets too high, causing catastrophe for the ecosystem, and massively increasing flooding risk for people living by the coast. We really need to pay attention to stress in the wild because the consequences can herald disaster.

Stress is the biological response to a major challenge, whether it’s at the whole organism or cell level. A gazelle in the Serengeti chased by a lion experiences the same stress responses that we do – a surge of adrenaline and cortisol that cause increased heart rate and blood pressure and a release of glucose. These changes make sure there is enough fuel and oxygen to cope with increased demand at the tissue and cell levels. Sudden change or mismatch in the supply of oxygen and fuel leads to increased production of reactive molecules called ‘free radicals’ that can damage cells. If the temperature gets too hot too fast or if the acidity of the cell changes too much, proteins (the molecules that catalyse reactions, transport substances and provide structure) can fall apart or unravel. So cells have to increase their defence mechanisms too. Cellular defences include antioxidants that mop up the free radicals, and heat shock proteins, which refold damaged proteins and stop them forming a sticky mess inside the cell.

The old adage that what doesn’t kill you makes you stronger is often true: short term ‘good stress’ builds up these defences and makes organisms better able to deal with stress later on. However, sometimes defences can be overwhelmed or can’t be maintained for long periods. The organism then experiences the same sorts of problems as people under chronic stress: lower immunity, altered metabolism, anxiety and tissue damage (like ulcers). In wildlife, this can have major consequences for breeding success or even survival. By affecting whether organisms survive and thrive, stress dictates which individuals contribute to the next generation. Stress shapes population dynamics, lifestyle and adaptations, and is therefore a powerful agent of natural selection.


I work on seals, top marine predators that are used to stress as a normal part of their existence. Their individual and population level health is an indicator of ecosystem health. Seals are air breathing mammals that feed underwater, but need to come to the surface to breathe, and to come ashore to rest, breed and moult. Diving on a single breath hold means they need to conserve oxygen; to do this, blood flow is restricted mostly to the heart and brain, so that other tissues may experience free radical production while oxygen levels are low. On land, seals need to fast, often while they are doing energy-demanding activities i.e. shedding and replacing hair, producing milk, defending pups or territory, or undergoing rapid development. Injury and infection can occur from skirmishes or trampling. Seals may have to reduce their defences to deal with all these demands on their energy when food is not available. In addition to their ‘lifestyle stressors’, seals face stress from competition for access to fish, disturbance on haul out or displacement from foraging grounds as a result of human activity, and the accumulation of contaminants in their blubber.

We need to understand natural and man-made causes of stress in wild populations, distinguish good stress from bad stress, and understand how multiple stressors at the same time can create problems. That means we have to have effective tools to measure stress and its consequences in organisms that can’t tell us how they feel. But can we measure stress responses in wildlife? What do they mean in context? And can they help in managing stress in the wild?

I will address all these questions and more at the ASE’s Annual Conference on Friday 6 January 2017, as part of the annual Biology in the Real World (#BitRW) lecture series. Please drop by the Knight Building, LT 135, at the University of Reading, at 1.30pm to find out more!


Horse or Human: who will win the race?

Place your bets now! Because tomorrow, on 11 June, the 36th annual Horse vs Man Marathon will take place in Llanwrtyd Wells, Wales, where humans will test their mettle against horses on 22 miles of mountainous terrain. Who will win this year?

On flat terrain, it would be a no-brainer: horses clearly have a significant advantage over humans. With their lean and muscular physique, thoroughbreds can reach speeds of up to 55 mph, while the world’s fastest human, Usain Bolt, lags behind with a top speed of only 27 mph. So how do horses reach such impressive speeds? We can find some clues by studying their anatomy and physiology.

The first proper studies began over 200 years ago, after the death of a particularly special racehorse, Eclipse, who was never beaten throughout his racing career from 1769 to 1770. His extraordinary success prompted the founding of the Royal Veterinary College in 1791 and ever since then, veterinary scientists have been making great strides in finding out what it is that allows horses to run so fast. It turns out that several factors play a role, including a big heart and the ability to increase heart rate to a remarkable degree:


Horses’ ability to increase the amount of blood pumped by the heart around the body to the muscles makes all the difference in a race, and that is helped by the spleen, which contains a store of oxygen-carrying red blood cells that are released into the bloodstream during exercise. They have other tricks up their sleeve too:  compared to humans, they have a far greater tolerance of increased body temperature and blood acidity, both of which go up fast during intense exercise.

We can find other clues to horses’ speed in their long and light-weight legs, which have very springy tendons that save energy needed to move quickly. So where does the muscular power come from?  The leg muscles aren’t in the lower legs as humans’ are, but tucked up close to the body, connected to the lower legs by very long tendons, which also generate  ‘springiness’. As with all four-legged animals, the muscles in the back, neck and abdomen also contribute to the ability to gallop. The quickest racehorses have lots of fast twitch fibres in these muscles, helping them to generate more energy for movement via both aerobic and anaerobic respiration.

Also unlike humans, the stride in galloping directly controls the timing of breathing: the huge weight of the hindgut acts like a piston on the lungs at the front, sucking in the maximum amount of air possible and then expelling it rapidly, as the torso moves with each step. This neat trick means that horses can move large volumes of air in and out of the lungs very quickly, helping to maintain their performance for longer.

And, of course, no racehorse is complete without its rider – who also plays a key role in the horse’s performance. Have you ever wondered why jockeys ride crouching over the horse, rather than sitting upright? Well, this is known as the ‘monkey crouch’ and was invented by Americans in the 1890s in order to improve horse speeds. This position separates the stride of the horse from the rider i.e. as the horse moves forward, the rider moves back, and vice versa. In this way, the rider takes up some of the effort required to move forward, enabling the horse to save some much needed energy for the race.

But what about humans? How can we possibly measure up to all this? By levelling the playing field, to something less level – which is exactly what the Horse vs Man Marathon has done, by holding the race on mountainous terrain. This gives humans a fighting chance – so while it’s true that horses have dominated the Marathon so far, there have been two occasions when a human has won the race. How come?  On rough hilly ground, the horses’ ability to reach and maintain their peak speed is severely reduced. Humans are much lighter, so the changes in direction needed on rough ground take less energy than for the much larger horses.

If we look at the cases where humans have won the race, one factor immediately jumps out, and that is: hot weather. It’s not immediately clear why that favours humans. Our ability to sweat, which cools us down in hot weather, is shared with horses. But, being smaller, we have relatively more skin to sweat from than do horses, and that may be a greater benefit than horses’ greater tolerance of high body temperature. And humans can take on extra fluid during the race, replacing that lost in sweat, without having to stop – something their equine competitors can’t do.

So, who will win tomorrow? The weather forecast predicts maximum temperatures of 19°C, so the human participants will have to draw on all of their abilities, to be in with a chance of winning.

Who will you place your bet on?


Ode to Physiology: Animal Olympics! The Winners!

animal olympics

We are delighted to announce Charlie Toogood, Vismaya Kharkar and Rose McKerell  are the winners of our poetry competition ‘Ode to Physiology: Animal Olympics’, each coming up top out of their age groups.

We received over 100 entries to our science poetry competition which challenged participants to explore physiology through the medium of poetry. With some artistic licence entrants discussed the biological basis of elite performance using rhythm and rhyme. While the poems haven’t been checked for accuracy, we are delighted so many people engaged with the competition and expressed an interest in the science of life. A big thank you to everyone who took part!

Our expert judges Kelly Swain, poet in residence at Oxford University Museum, and Sian Hickson, previously an English teacher and now Director of Eureka Edinburgh, whittled down the entries to just one winner from the under 10s, 11-18s and the over 18s categories.

“Big and blue, can you guess who?” by Charlie Toogood (Under 10’s)

The cheetah would never have met this creature;
A massive blowhole is its best feature.
This is the nostril of the great beast,
Who usually adores a krill feast.
Every day it eats 8000 pounds,
 If I ate that much, I would be round!
The milk tastes like liver and chalk, people say,
But the babies still drink 50 gallons a day!
150 tons is its weight, It’s the biggest animal, isn’t that great?
With a life span 110 years long,
It’s the BLUE WHALE! Did you guess right or wrong?

 ‘Ode to the Hummingbird’ by Vismaya Kharkar (11-18s)

Just lighter than a copper pence,
With ropy muscle and wings of gold he floats,
His beak is sharp and needle-thin,
Soft feathers thinner than waves make up his coat.
From flower to flower he hovers and glides
Sucking sweet nectar from each in turn
For whenever he stops, from life he slides
Falling into a torpor
Deep and slow.
His heart flutters, powerful.
Nearly twenty beats a second, but at what cost?
He is founded upon excellence, and without it, he will sleep.
A modern aurora – tiny, gold, and shining
To awaken at the touch of nectar or a new day.

Ode to Physiology: Who am I? by Rose McKerrell (Over 18’s)

To give you a clue to my chosen athlete
Here are some features which make it elite
Its heart is amazing in strength, size and rate
When running flat out- pulse can increase times eight!
The lungs can expand to fill most of the chest,
Oxygenating blood is what they do best,
When running the guts move forward and back.
Like a piston they help fill those little air sacs…
The limb bones are reduced to run on one toe
And the lack of a collarbone lets the front leg just flow
The muscles are huge at the top they must go
When the fibres contract- some are fast , some are slow
The ligaments stretch to take all the strain
Then act like a catapult- forward again
Narrow in front with an elegant head
The air rushes past- for speed they are bred
But what is most clever is it isn’t just fast
This animal has stamina- it really can last It can win at eight furlongs or stay for the course.
Because as you’ve guessed- my favourite’s the horse!
Adapted for speed. Adapted to stay
 The horse is my winner every day
And there’s one other feature of which science hasn’t told
The horses second heart- the one made of gold!

Night at the Vet College: Animal Athletes

Have you ever visited the Royal Veterinary College? Not many people realise our central London campus is only a 10-minute walk from King’s Cross or Camden Town. At the RVC, leading scientists and vets carry out research and teaching as part of our role as a specialist college for veterinary medicine, nursing and biosciences, in the University of London.

Whilst the campus is not usually open to the public, on Thursday 17 March 2016, we opened our doors to welcome visitors to see behind the scenes at our ‘Night at the Vet College’ event. Kindly funded by The Physiological Society, we focused on ‘Animal Athletes’, looking at elite physiological adaptations.

795 tickets were booked for this free event, and the night started off with a buzz and a queue that reached down the street. The first lecture was Professor Renate Weller’s ‘The Horse as the Ultimate Athlete’, which filled our Great Hall lecture theatre. Renate showed how horse legs can be compared to pogo sticks – of course there was one for a willing volunteer to try out!

Between lectures, visitors took part in hands on science activities such as our Physiology Challenge, where they could measure their heart rate, grip strength, reaction time and jump height, and compare them to different species. This was complemented by scientists explaining different aspects of animal physiology; such as Dr Sarah Channon showing muscle properties, Dr Amy Barstow showing how tendons work (both using real samples); and Dr Anna Walker demonstrating how she has developed innovative lameness sensors.

Paul Pollard from the Beaumont Sainsbury Animal Hospital demonstrated how vet nurses use physiological measures when caring for patients and visitors could have their ECG measured. We also had heart rate monitors on display, demonstrating how the same technology can be used for humans as well as horses to monitor performance.

The dissection event was a real highlight, and once again, Andrew Crook MBE gave a fantastic demonstration by showing a horse dissection to a live audience (which was completely full) and via live-streaming. Peter Day, our farrier, showed visitors how to use corrective shoes, and people were able to try out shoeing for themselves. We also had bone models that had previously been on display for the Ri Christmas lectures and art in the anatomy museum with our student art society and the Royal Society of Biology. Not only did visitors enjoy seeing the anatomy of extant species, they were also treated to a lively talk about extinct species presented by Professor John Hutchinson, explaining how giant animals were able to move in prehistoric landscapes.

The night ended with science comedy from Simon Watt in the Haxby bar, followed by a pub quiz probing the knowledge visitors, complete with animal themed prizes.

By Dr Grace Sim