Monthly Archives: May 2017

Running away from stress…literally

By Molly Campbell, University of Leeds, @mollyrcampbell

Exercise – for some, it’s a hobby, for others, a burden. We all know exercise is good for us. Yet, ironically, many people feel too busy or stressed to exercise regularly. Particularly during exam time, who wants to swap an hour of revision for an hour of tiring yourself out?

Research actually suggests that committing to exercise when you are experiencing stress can lower your stress response both now, and in the future. Regular exercise can be particularly helpful in boosting your mood, and thus your motivation to do work. Scientific research suggests that exercise elevates molecules in the body associated with the feeling of joy, whilst decreasing those that cause stress.

Post-exercise feelings of bliss

The term ‘runner’s high’ was coined in the 1970’s following an apparent worldwide increase in the number of people running long distance. This feeling of elation was attributed to the increased levels of endorphins in runners’ blood after exercise. Since then, many studies have been conducted that expand on this work to clarify exactly how exercise produces this ‘feel good’ effect.

Exercise also increases the release of endocannabinoids in the body. These are a type of cannabinoid that are endogenous, meaning they are made within our body. Endocannabinoids serve as a message between cells. Cells receive the message when the endocannabinoid attaches to another molecule, called a receptor, on the outside of a receiver cell. The receiver cells for endocannabinoids are in the central nervous system (brain and spinal cord) as well as other parts of the body. This elicits a wide range of beneficial effects.

The chemical anandamide, one type of endocannabinoid, gets its name from the Sanskrit word ‘ananda’ meaning joy. It is created in areas of the brain involved in motivation, memory, and higher cognitive function. Whilst its exact function has not been clarified, increased levels of anandamide are associated with states of heightened happiness. Anandamide can enter the brain through the so-called blood-brain barrier. This means that an increase of anandamide in the blood is followed by an increase of the chemical in the brain.

An experiment by Elsa Heyman and her colleagues demonstrated that, following a period of intense exercise, cyclists have increased levels of anandamide in their blood (1). This increase in anandamide was correlated with the increase of a molecule that is extremely important for the growth and maintenance of neurons in the brain, called brain-derived neurotrophic factor (BDNF).

Johannes Fuss and his colleagues used mouse models to demonstrate that exercising on a running wheel produced a significant increase in anandamide levels, which was correlated with a substantial reduction in anxious behaviours (2). When the researchers gave the mice a drug to block the cannabinoid receptors, to which anandamide binds, this reduction in anxiety was reversed.

Together, these findings therefore suggest an emerging role for the endocannabinoid system in producing the feeling of well-being and stress relief people experience after exercise. However, anandamide is broken down in the body very rapidly, possibly explaining why exercise is most beneficial when done regularly.

Sweat away your stress

Susanne Droste and her colleagues investigated the short-term effects of exercise on stress hormones in mice (3). Adult male mice were provided access to a running wheel for four weeks before undergoing a series of behavioural tests. Exercising mice were found to exhibit a significant decrease in corticosterone (the equivalent of the stress hormone, cortisol, in rodents) responses to a novel environment compared to control animals that had not exercised. These animals were also found to be less anxious in behavioural tests.

Researchers have also found long-term changes in the stress response after repeated exercise. Mindfulness experts suggest exercise, such as running or yoga, can indeed be a meditation practice carried out ‘on the go’. By placing focus on the repetitive movement of our joints and the increase in our heart rate, and the general effects exercise exerts on our body, we are distracted from the thoughts circling through our mind. Repeatedly applying this focus, particularly when high levels of stress cause us to be entangled in our thoughts, can produce long-term changes in the bodily tools we rely on to calm down. Ann Kennedy and her colleagues found that several studies show that this improves breathing rate and depth, lowers heart rate, and increases our ‘rest and digest’ response, or the so-called parasympathetic nervous system (4).

Although it may seem a chore to take time out of the day to get your body in motion, research about our physiology suggests that your brain (and therefore your grades) will benefit from doing so!


  1. Heyman, E. Gamelin, F.X., Goekint, M., Piscitelli, F., Roelands, B., Leclair, E., Di Marzo, V. and Meeusen, R. 2012. Intense exercise increases circulating endocannabinoid and BDNF levels in humans—possible implications for reward and depression. 37(6), pp. 844-851.
  2. Fuss, J. Steinle, J., Bindila, L., Auer, M., Kirchherr, H., Lutz, B. and Gass, P. Runners high depends on cannabinoid receptors in mice. PNAS. 112(42).
  3. Droste, S.K., Gesing, A., Ulbricht, S., Muller, M.B., Linthorst, A.C and Reul, J.M. 2003. Effects of long-term voluntary exercise on the mouse hypothalamic-pituitary-adrenocortical axis. Endocrinology. 144(7), pp. 3012-3023.
  4. Kennedy, A. and Resnick, P. 2015. Mindfulness and Physical Activity. American Journal of Lifestyle Medicine. 9(13), pp. 221-223.


The Glastonbury of Neuroscience

By Anjanette Harris, University of Edinburgh, @anjiefitch

I have been to many music festivals in my time, but last month I went to my first Neuroscience Festival. Every two years, the British Neuroscience Association holds the Festival of Neuroscience, which boasts a jam-packed program of research talks from experts across many disciplines within neuroscience, as well as workshops and discussion forums. It is quite simply the national celebration of neuroscience.

Last month, nestled amongst the canals of Birmingham, the International Conference Center provided the perfect backdrop for over 1500 scientists from around the world to get together, share their latest data, and enthuse one another. This year, The Physiological Society hosted a strand running through the festival called The Neurobiology of Stress as part of their annual theme Making Sense of Stress. One of the symposia, organised by Professor Megan Holmes, brought together researchers from around the world, including myself, to present our work on imaging the emotional brain.

What puts us at risk of depression?


Dr Stella Chan, a lecturer in clinical psychology from the University of Edinburgh, kicked off with the staggering statistic that half of all cases of depression first occur in adolescence. Stella reminded us that adolescence is a tricky time in which teenagers struggle with intense emotions on the road to self-discovery. But why do some youngsters develop depression while others don’t?

To answer this question, Stella studies how young people perceive themselves and the world around them. One startling finding is that those at risk of depression find it harder to see joy in other people’s faces. Because Stella uses teenagers at risk of, but not yet suffering from, depression she is able to see if there are changes in perception that may flag up that a youngster is likely to develop depression. If Stella can untangle whether a negative self-opinion is the cause or consequence of depression, she may be able to develop mind-training techniques to prevent depression in those at risk.

Untangling cause and effect using mice


Dr Marloes Henckens, a post-doctoral researcher from the Donders Institute at Radboud University, presented her work on the effects of stress on brain function. She uses both human and mouse subjects to help her distinguish between cause and effect. Marloes began by setting her work in context; she highlighted that the brain is a collection of networks and that brain disorders are probably caused by disorders of the connections between different networks.

With that in mind, Marloes showed that stressing humans or giving them stress hormones caused the connections that make up the fear network to become stronger. While this is useful for priming a person to tackle danger, it may lead to an anxiety disorder, such as post traumatic stress disorder (PTSD) in which suffers are haunted by intense unpleasant memories. Marloes takes pictures of the brains of mice with PTSD-like symptoms and has shown that reduced activity at the front of the brain (important for reducing unpleasant memories) is a consequence and not the cause of PTSD. It remains to be seen how connections between different networks are affected in mice with PTSD.

Hormonal influences on brain activity in rats

The following speaker, Professor Craig Ferris of Northeastern University, is the pioneer of imaging rats’ brains while they are awake. Craig began with a whistle-stop tour of the groundbreaking technology that he and his team have developed. His special scanning technology allows researchers to monitor brain activity while the rats are responding to things. For example, Craig showed changes in brain activity in mother rats as their pups start to suckle. It comes as no surprise that the brain areas involved in reward and motivation are active with breast-feeding. In fact, in these rats, breast-feeding is more rewarding than cocaine!

Craig then presented images of brain activity involved in aggression. To observe this, he first took pictures of the brain of a male rat that was happily lying in the scanner with its girlfriend, and then introduced an unfamiliar male rat and observed the changes in the first rat’s brain. The abrupt change in brain activity that was seen in the male rat’s brain might be described as blind rage, as it is similar to that observed with the onset of a seizure. Craig’s ambition knows no bounds: he finished his talk with musing on whether he could fit a killer whale into his brain scanner!

The impact of stress on emotional memory in rats


The final speaker was me, Dr Anjanette Harris. I’m a post-doctoral researcher from the laboratory of Megan Holmes at the University of Edinburgh. I want to understand how stress affects brain function. This is particularly tricky to study in humans, especially if we want to look at the effects of early life stress on the brain, so we use rats (read more on the importance of using rodents in psychiatric research in my previous blog post). The work that I presented uses the technology of Craig Ferris coupled with memory exercises for rats that we specialize in designing. We have shown that rats that experience stress in early life form stronger memories of unpleasant experiences. These rats also have stronger activity in brain areas involved in fear when recalling unpleasant experiences in adulthood. This mirrors what is found in humans and means that we may be able to test potential therapies for human memory disorders on rats, ensuring that the treatments target appropriate areas in the brain.

Practical Innovations in Life Science Education

By Nick Freestone, Kingston University

On 27- 28 April, The Physiological Society held a workshop under the auspices of the Education and Teaching Theme. The workshop was held at The Society’s HQ, Hodgkin Huxley House, and in somewhat of a departure for such an event, extended an invite to those unsung heroes of the Higher Education environment – technical support staff.  Thus, in the weeks leading up to the event, to encourage participation from this under-represented group (in The Physiological Society participation terms anyway) various inducements were proffered to our technical colleagues. Primary amongst these was the offer of an all-expenses paid trip to London contingent upon the submission of an abstract as a prelude to a poster presentation at the event itself. Who could refuse such a generous offer?

Equally heartening from the point of view of your cynical correspondent was the presence of a number of new faces to the physiological pedagogical arena. This served to greatly enliven the proceedings and ensured that the event wasn’t merely an echo chamber reverberating to the well-worn axioms of the usual suspects.

Happily the event kicked off with lunch, which served as a great prompt for punctuality. This was followed by Session 1 chaired with great aplomb by Sarah Hall (Cardiff University) where the audience was blown away by fantastic contributions from Iain Rowe (Robert Gordon University) on teaching pharmacokinetics, Viv Rolfe (University of the West of England) on Open Educational Resources, Michelle Sweeney (Newcastle University) on the use of LabTutor and our very own Derek Scott (Aberdeen) on developing a renal physiology practical for large groups – no urine required!.

This left the audience so energised that a refreshment break was necessary to recover. After this much-needed pause, Session 2 included contributions from Frances Macmillan (University of Bristol), on developing experimental design skills in first and second year students and Rachel Ashworth (Queen Mary University of London) on using technology to teach respiratory physiology from a clinical perspective.

Given so much food for thought it was an opportune time for the participants to form smaller discussion groups facilitated by the Education and Teaching Theme Leads and tireless organisers to discuss a variety of questions posed by The Physiological Society around the general question of “how can The Society help?”. Having set the world to rights in this format, and having provided The Physiological Society with an extensive to-do list, heroically noted down in real time by Chrissy Stokes, the formal part of the day was rounded off by a message from our sponsors, ADInstruments, who reported on upcoming initiatives involving their widely used educational wares. Rather more informal was a wine and poster session which melded seamlessly into a later gathering at a local hostelry.

Day 2 kicked off with a plenary lecture by Peter Alston of Liverpool University. While Peter is not a physiologist, his talk, “Technology-informed curriculum design” was received with rapt attention by an appreciative audience. At this stage of the proceedings, Professor Judy Harris (Bristol University) exerted her considerable crowd control skills and marshalled the next batch of contributions expertly and smoothly. These included talks from Dave Lewis (University of Leeds) on Open Educational Resources, Hannah Moir (Kingston University) who did a livestream of her lecture to us to her own students via an app called Periscope (Think about that for a while! Hannah lectured to us, whilst showing students that she was lecturing to us whilst giving us a demonstration of a technique to enhance student engagement. There’s too many layers there for me to unpack into a coherent story!), Louise Robinson (Derby University) and our very own Sheila Amici-Dargan on how online tools can be used to enhance the learning and teaching environment. Louise Robinson’s talk deserves a special mention here covering as it did a topic close to my own heart, lecturing using gamification techniques. This caused an appreciative hubbub from the assembled throng.

Now if you thought gamification was a bit outré in the august setting of The Physiological Society HQ then you would have been astonished by the contribution of Emma Hodson-Tole (Manchester Metropolitan University) who gave a talk on teaching physiology through the medium of interpretative dance!

I told you this was a different kind of conference. This presentation, in the batch of talks after refreshments, focussed on motor neurone disease and provided evidence on how learning can be facilitated across different groups using unconventional teaching techniques. Other talks in this section included my own (Kingston University) on Outreach and Public Engagement by the use of a “Lab in a Lorry”-initiative funded by HEFCE, and Dawn Davies (Bristol University) who talked about her work using patient simulators in public arenas such as shopping centres. This looked fantastic, if rather daunting fun!

Now I started off talking about how this wasn’t your usual run-of-the-mill academic event, with the old hands nodding sagely while trying not to fall asleep after lunch. No! This event included actual live students! These were Patrick Evans and Elodie Cox also of Bristol University (Judy’s enthusiasm for learning and teaching is obviously infectious). Their talk “Engaging the public with final year undergraduate projects” definitely proved one thing once and for all. Our students are a FANTASTIC resource, capable of giving much better talks than even the most seasoned academic. Suitably humbled and chastened by this demonstration of youthful excellence, the excited crowd networked over lunch whilst perusing some of the items of equipment one can put on the road in a “Lab in a Lorry”.

Feedback from the event was uniformly and overwhelmingly positive. Ideas are being gestated as we speak as a result of this inspirational event. Watch this space for more positive, energising educational stuff in the near future.

Just Take A Breath

By Molly Campbell, University of Leeds, @mollyrcampbell

Take deep breaths. Try to relax. Stay calm. In stressful situations, this is the advice we often receive. More often than not, this tends to work.

What you might not be aware of is that this advice is thousands of years old, and is also supported by extensive scientific research. You’ve heard of the Buddha, right? At the core of the Buddhist teachings of mindfulness, meaning focusing on the present moment, is placing attention and focus on the breath. This has beneficial effects on our nervous system and subsequently our health.


Picture this. You are revising a particularly hard topic, perhaps a subject that you desperately need to ace to secure your college or university place. A train of thoughts frantically rushes through your brain and you panic. I’m not going to get the grade I want! I’m not going to get my college place and this will ruin everything for me! Sound familiar?

In these situations, our ‘fight or flight response’ (the sympathetic nervous system) can go into overdrive. Our heart rate increases, as does our blood pressure. This stress response actually limits the function of some of our vital organs – most notably the digestive system. It also limits our cognitive abilities, making it difficult to focus on the task at hand. So where does breathing come into the equation?


The breath is interesting because we can control it despite it being a function of the autonomic (or subconscious) nervous system. Pranayama, or ‘yogic breathing’ involves manipulating and deepening the breath; by doing so we cultivate awareness and consciousness that actually allows us to take the reins and stimulate our ‘rest and digest’ response (the parasympathetic nervous system), inducing relaxation.

How does this work? The vagus nerve, coined the ‘mind-body’ connection, is the longest nerve in the body. To avoid delving too deep into its anatomical route, let’s just say it innervates many organs and regulates many important functions. In the early 1900s, the German physiologist Otto Loewi found that simulating the vagus nerve reduces heart rate by releasing a substance that he called ‘Vagusstoff’. We now know that ‘Vagusstoff’ is actually the chemical acetylcholine that affects brain activity.

When we breathe deeply using our diaphragm, we create pressure in our abdomen that stimulates the vagus nerve to secrete acetylcholine. Acetylcholine slows down the heart and increases the activity of the digestive system.

Stimulating our ‘rest and digest’ response also inhibits our ‘fight or flight response’. One effect of this is decreasing the release of adrenaline from the adrenal medulla. This then reduces the action of adrenaline in the brain. This is another mechanism behind the physiological workings of breathing for relaxation.

In March of this year, scientists in Italy measured the physiological and psychological responses of students who performed deep breathing (Perciavalle et al., 2017). Considering that the 38 volunteers were university students, the findings are particularly relevant to exam stress. Half of the 38 volunteers did deep breathing exercises once a week for 10 weeks.

The exercises included paying attention to how one breath differs from another, and contracting and releasing the muscles. After 10 weeks, students had lower levels of the stress hormone cortisol, and lower heart rates.

In focusing on deepening the breath, we calm the nervous system and prevent our body going into ‘fight or flight’ overdrive. This sense of calm and clarity can help bring our attention to the present moment. Our anxiety about exams is regarding the future (What will happen if I fail?) or based on a mistake we made in the past. Using the breath to be present and aware allows us to focus on the now, on the task at hand. So, in times of stress – just take a breath!


Nezlek, J., Holas, P., Rusanowska, M., Krejtz, I. 2016. Being present in the moment: Event-level relationships between mindfulness and stress, positivity, and importance. Personality and individual differences. 93(2016), pp. 1-5.

Bordoni, B and Zanier, E. 2013. Anatomic connections of the diaphragm: influence of respiration on the body system. Journal of Multidisciplinary Healthcare. 6(281-289)

McCoy, A. and Tan, Y. 2014. Otto Loewi  (1873-1961): Dreamer and Nobel Laureate. Singapore Medicine Journal. 55(1), pp. 3-4.

Perciavalle, V., Blandini, M., Fecarotta, P., Buscemi, A., Di Corrado, D., Bertolo, L., Fichera, F. and Coco, M. 2017. The role of deep breathing on stress. Neurological Sciences. 38(3), pp.451-458.

Breath of the Sith: a case study on respiratory failure in a galaxy far, far away

Excerpt from a Physiology News feature by Ronan Berg, Department of Clinical Physiology & Nuclear Medicine, Frederiksberg and Bispebjerg Hospitals & Ronni Plovsing, Department of Intensive Care 4131, University Hospital Rigshospitalet, both in Copenhagen, Denmark.

While the latest instalments in the Star Wars saga have thrilled physiologists and non-physiologists alike, it may be worthwhile to take a look back at what we as respiratory physiologists have learned from the venerated space opera so far. It remains indisputable – at least between the authors of this paper – that the first six episodes’ protagonist-turned-villain-turned-saviour Anakin Skywalker/Darth Vader is the most fascinating case study on respiratory failure in the history of cinema. […]

Health hazards of volcanic fumes

Figure 1. An advanced bi-level positive airway pressure system integrated in a whole-body armoured suit for the treatment of acute and chronic respiratory failure in a Sith Lord. © LucasArts

In the Star Wars saga, the highly talented Jedi knight, Anakin Skywalker, choses to abandon the monastic Jedi Order and instead join his father figure Sheev Palpatine in the more exclusive and politically involved Sith Order. As he does this, he assumes a new identity as Darth Vader, and earns the title Dark Lord of the Sith. For a number of reasons, this change of careers does not impress a former Jedi Master of his, and the two soon clash in a light sabre duel on the volcanic planet Mustafar. The confrontation results in a near-fatal outcome for Darth Vader who loses several limbs in the fight, and while he is incapacitated on the volcanic shore, he furthermore suffers inhalational injury and third degree burns. However, before he passes away, Palpatine comes to the rescue, and organises timely medical intervention. […] After the incident, Darth Vader is unable to breathe freely at all; outside his personal meditation  chamber, which also appears to function as some kind of a fancy hyperbaric oxygen facility, he continually relies on a mobile life-support system, which is integrated in a whole-body armoured suit, in order to survive (Figure 1).

Darth Vader’s acute respiratory failure appears to be the consequence of a number of factors, including direct thermal injury to the airways, chemical damage to the lung parenchyma caused by inhalation of smoke and volcanic dust particles, carbon monoxide poisoning, as well as secondary effects to his severe third degree burns, which seems to cover ~100 % of his total body surface area. […]

Due to his quite severe facial burns, it is difficult to determine whether Darth Vader exhibits ‘cherry-red cheeks’ at this stage, a typical clinical finding associated with carbon monoxide poisoning.

Inhalation-induced acute respiratory distress syndrome in a Sith Lord

Darth Vader’s immediate respiratory distress on the volcanic shore is probably caused by volcanic gaseous irritants with high water solubility in the volcanic fumes, which cause immediate symptoms of tracheobronchitis, and impair pulmonary gas exchange (Nemery 2006; Mlcak et al., 2007). Since Darth Vader may concurrently be exposed to high levels of carbon monoxide, which both impairs the red blood cell uptake of oxygen in the lungs due to its higher affinity for haemoglobin than oxygen, and furthermore shifts the oxygenhaemoglobin saturation curve to the left, so that the release of oxygen from the red blood cells to tissue mitochondria (and perhaps also the conceivably similar midi-chlorians) in various organs is impaired; severe tissue hypoxia therefore ensues. Due to his quite severe facial burns, it is difficult to determine whether Darth Vader exhibits ‘cherry-red cheeks’ at this stage, a typical clinical finding associated with carbon monoxide poisoning, but his rather agitated emotional state is characteristic of the cerebral dysfunction often encountered in this clinical condition.

We deem it irrefutable that Darth Vader fulfils the diagnostic criteria for acute respiratory distress syndrome within a few hours after the incident on Mustafar.

Within a few hours, that is, after Darth Vader has been evacuated by Palpatine, the effects of direct thermal injury on the central parts of the lungs, as well as the effects of the volcanic water soluble gaseous irritants and aerosols set in. These give rise to acute chemical pneumonitis with non-cardiogenic pulmonary oedema and induce a reduction in ventilatory capacity with increased pulmonary ventilation-perfusion inequality, thus severely impairing pulmonary gas exchange (Nemery 2006). At this stage, the systemic inflammatory response to the severe skin burns may furthermore disseminate from the blood stream to the alveolar compartment, and thus exaggerate the pulmonary inflammatory response. Although appropriate diagnostic imaging would be required to establish the diagnosis here on Earth, we deem it irrefutable that Darth Vader fulfils the diagnostic criteria for acute respiratory distress syndrome within a few hours after the incident on Mustafar, which is a common complication both after inhalation injury and severe skin burns (Mlcak et al., 2007).

Figure 2. Respiratory rate according to activity level in a Sith Lord (n =1). Data are obtained from Plovsing & Berg (2014) and presented as mean (± standard deviation). ‘Rest’ includes recreational activities in a meditation chamber; ‘Normal everyday activities’ include various friendly encounters as well as torture of enemies, colleagues, and employees; ‘Stressful situations’ includes increased alertness and arousal; ‘Exercise’ includes running, combat and light sabre duels.

Following extensive robotic surgery, the medical droids choose to treat Darth Vader’s respiratory condition by means of the iconic whole-body armoured suit. The suit contains a mobile life-support system, and from a careful analysis of Episodes IV-VI, we have concluded that it functions as an advanced bi-level positive airway pressure (BPAP) system that supports Darth Vader’s intrinsic breathing both during in- and expiration, while preventing airway collapse, and continually supplying him with oxygen (Plovsing & Berg 2014). Accordingly, his respiratory rate varies with his activity level (Figure 2), and pressure equalisation with the surroundings can clearly be heard when his helmet is detached. Other scientists have noted that Darth Vader’s whole-body armoured suit may furthermore function as a means of preventing infections, which is notably relevant in the immediate aftermath of the events on Mustafar, due to Darth Vader’s extensive skin burns (Perrella et al., 2015).

Read the full article in Physiology News.


Mlcak RP, Suman OE, Herndon DN (2007). Respiratory management of inhalation injury. Burns 33, 2-13

Nemery B (2006). Chemical-induced lung injury and its long-term sequelae. In: Imaging of Occupational and Environmental Disorders of the Chest. Springer Berlin Heidelberg, pp. 67-75.

Perrella A, Russo C, Giuliani A, Esposito C, Saturnino P (2015). Infection control in a far, far away Galaxy: new and alternative learning tool from popular culture to improve the antimicrobial stewardship. North Am J Med Sci 7, 236-7

Plovsing RR, Berg RMG (2014). Pulmonary pathophysiology in another galaxy. Anesthesiology 120, 230-2