Category Archives: Events

Physiology 2019: Something for everyone

By Guy Bewick, University of Aberdeen, UK, Member of local organising committee

Whatever your interest in physiology, be it in research of systems (cardiovascular, respiratory, musculoskeletal, neural, etc.), tissues (epithelia, adipose etc.) or nuclear receptors, or be it in teaching, we have it covered at Physiology 2019, our Annual Conference, in Aberdeen. If the Annual Conference does not quench your thirst for knowledge, why not extend your stay in Scotland’s north-east to attend one of the five Satellite Symposia covering fatigue, obesity, cancer drug cardiotoxicity, and renal and placental physiology.

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The Annual Prize Lecture by Silvia Arber (Basel Biozentrum, Switzerland) will describe her elegant work elucidating the function, assembly and plasticity of motor circuits. The Hodgkin-Huxley-Katz Lecture by Stephen Traynelis (Emory University, Georgia, USA) reveals the characteristics of neuronal glutamate receptors in health and disease. In the Joan Mott Prize Lecture, Claire Hills (University of Lincoln, UK) presents important discoveries in diabetic nephropathy and kidney disease mechanisms. And, finally, the Sharpey-Schafer Lecture by endocrinologist Roger Smith (University of Newcastle, Australia), a leading expert on pathophysiology of human pregnancy, will expound on the idiosyncrasies, interactions and inner workings of the body across species but especially in humans.

A particular teaching highlight will be Dee Silverthorn, whose textbook is a staple of many physiology degree programmes, who will provide insights into best teaching practice from an international perspective.

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Aberdeen’s local representation is by Lora Heisler, recent winner of the Outstanding Scientific Achievement Award from the American Diabetes Association. She will present the Annual Public Lecture describing her work on the neural control of appetite, looking for new targets to tackle the current global epidemic of obesity.

So, please come and join these world-class speakers from across the globe and all stages of their careers who are coming to sample the renowned Scottish hospitality. We look forward to welcoming you to Aberdeen for a memorable summer scientific conference.

Attend our specialist Satellite Symposia, free to Physiology 2019 attendees

Our Satellite Symposia increase the involvement of underrepresented sub-disciplines of physiology at our flagship Annual Conference, Physiology 2019. This year, join us for one of the following five Satellite Symposia. Free to Physiology 2019 attendees, they are all held on Sunday, 7 July 2019. Keep reading for more detail about each meeting, and don’t forget to sign up when registering for Physiology 2019 on our website:
physoc.org/physiology2019/satellite-symposia

Cellular Mechanisms of Anticancer-Induced Cardiotoxicity
Organisers: Susan Currie & Margaret Cunningham from the University of Strathclyde, UK

Cardiovascular disease and cancer are the leading causes of death in the industrialised world. Anti-cancer therapies have dramatically improved over recent years with increased patient survival rates following diagnosis. Kinase inhibitors in particular have had a major impact on cancer patient survival. However, a number of these agents have been reported to cause serious adverse effects on cardiac function, leading to increased numbers of cancer patients with cardiovascular complications that can, in some cases, lead to death. The true extent of the overall risk to cancer patients is unknown, and the underlying mechanism(s) responsible for the cardiotoxic effects remain to be fully identified.

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Strategies to prevent or mitigate cardiotoxicity resulting from cancer treatment are urgently needed to ensure the best cancer care possible. Future management of anticancer-drug-related cardiotoxicity will rely on improved understanding of the cellular effects of these agents in the heart. This, combined with improved biomarker identification along with cardiac imaging for monitoring purposes, will be crucial in an overarching strategy to design effective targeted cardioprotective agents. This symposium will be a forum to bring together basic scientists, cardiologists and oncologists to present recent findings that will work towards this overall goal. Ultimately, collaboration across these disciplines will be essential for promotion of evidence-based research that can relate to clinical practice in the area of anticancer cardiotoxicity.

Fatigue as a Limitation to Performance
Organisers: Derek Ball, University of Aberdeen, UK, and Ron Maughan, University of St Andrews, UK

The complex nature of fatigue is a function of single or multiple mechanisms that result in the failure to produce or maintain the required or expected muscle force/power output. Models to explain the underlying causes of fatigue range from single cell, to organ, to whole body examples and bring together the many different aspects of physiology represented through The Physiological Society.

This symposium will discuss potential limitations to performance imposed by the cardiovascular and respiratory systems, muscle metabolism and the central nervous system and how these factors are modulated by training, environment and nutritional status. In addition, a discussion of the strategies aimed at offsetting fatigue from the perspective of training adaptation and nutritional and pharmacological intervention will be invaluable.

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Physiology of Obesity and Diabetes
Organisers: Lora Heisler, University of Aberdeen, UK, Peter Aldiss, University of Nottingham, UK, Daniel Brayson, King’s College London, UK, and Jo Lewis, University of Cambridge, UK

Obesity is an increasingly common disorder of energy homeostasis and has become a leading cause of type 2 diabetes, cardiovascular disease, human morbidity and mortality worldwide. Exciting new scientific discovery continues to propel the understanding of the molecular, cellular and neural mechanisms underlying the control of metabolic health. Dysregulation of these and other processes underpin the development and progression of obesity, type 2 diabetes and cardiovascular disease.

This symposium will bring together breaking research advances from the basic science and clinical realms with the objective of sharing novel insights relevant to human obesity, type 2 diabetes and cardiovascular disease. Specifically, the meeting seeks to integrate existing knowledge with novel discoveries on appetite, cognitive drivers of feeding behaviour, the gut-brain axis, the neurobiology of ingestive behaviour and energy expenditure, adipogenesis and lipolysis, glucose sensing and glycaemic control, cardiovascular disease and the genetics of obesity and type 2 diabetes. Several new areas will also be addressed, including state-of-art technologies for neuroscience and physiological research, ageing, anorexia and metabolic resilience.

The primary goal of this meeting is to provide cutting-edge research related to the control of body weight and glucose homeostasis. The maintenance of stable body weight involves the biological process energy homeostasis that matches cumulative energy intake to expenditure. The discovery of critical integrative systems that underpin energy homeostasis and glucose metabolism has important implications for the future of obesity and type 2 diabetes treatment. This symposium will highlight the latest advances in the cellular and molecular mechanisms whereby brain circuits modulating physiological appetite and the cognition of food intake are integrated with systems controlling gut function and insulin sensitivity. We will explore the cross-regulation of these circuits by adiposity- and nutrient-related signals.

Renal Physiology: Recent Advances and Emerging Concepts
Organisers: Morag K Mansley and Robert W Hunter from the University of Edinburgh, UK

Renal physiology is flourishing in the UK and beyond. In recent years, physiologists have made fundamental advances: we now know the molecular basis of oedema formation in nephrotic syndrome, how renal sodium and potassium excretion can be controlled independently and how glomerular capillary permeability is regulated. We are also learning much about the influence of the kidney on whole-organism physiology, in particular blood pressure homeostasis including advances in understanding the (renal) mechanism underpinning circadian control of blood pressure.

These recent advances have not only allowed us to better understand renal physiology, but have opened up an array of potential targets for novel therapies in a range of kidney diseases and fluid-electrolyte disorders. The clinical impact of renal physiology research has been demonstrated recently where Vallon and colleagues published a series of papers showing that sodium-glucose co-transporter inhibitors (SGLT2i) can attenuate glomerular hyperfiltration in diabetic rodent models. In 2017-2018, large-scale clinical trials demonstrated that these agents can delay progression of diabetic nephropathy, meaning that – in large part because of basic renal physiology research – we now have the first new effective treatment for this common condition in 15 years. This symposium aims to bring together scientists from across the UK and beyond to discuss the latest advances in renal physiology.

The Placenta and Maternal Metabolic Regulation in Health and Disease
Organisers: Luis Sobrevia, Universidad Católica de Chile, Chile, Raheela Khan, University of Nottingham, UK and Abigail Fowden, University of Cambridge, UK

During pregnancy, many physiological changes occur in the mother, which are designed to support fetal growth and to sustain the baby during lactation. These include changes in the cardiovascular, pulmonary, immune and metabolic systems. A failure to appropriately adapt maternal physiology can lead to pregnancy complications, including abnormal birth weight, pre-eclampsia, and gestational diabetes, which can be traced to poor placental development in early pregnancy. The placenta is the place for bidirectional materno-fetal crosstalk involving transfer of metabolic substrates and epigenetic regulation, about which little is known. Amino acids, lipids, glucose and other substrates such as nucleosides and nucleotides are vital for fetal growth and maturation. However, our understanding of the physiological and pathophysiological aspects of placenta transport mechanisms and the potential consequences for fetal physiology in diseases of pregnancy is still fragile.

The overall goal of this Satellite Symposium is to explore the nature and wider biological significance of placental endocrine function in adapting maternal physiology during pregnancy to support fetal growth in both normal and compromised environments. Discussions will cover insights into regulatory epigenetic mechanisms within the placenta, placental structure and vascular/trophoblast function, contribution of the placenta to disease, placental transfer of nutrients and possible translation to the clinic, and potential consequences of human placenta pathophysiological transfer of nutrients for fetus and newborn health.

Life at the Limits: Register now for our extreme environmental physiology conference

By Mike Tipton, @ProfMikeTiptonExtreme Environments Laboratory, Department of Sport and Exercise Science, Portsmouth University

“Ecology”, from the Greek “oikos” meaning home or place to live, is the branch of biology that deals with the relationships of organisms and their physical surroundings. It encompasses the impact of animals on their environment, and the environment on animals. Both sides of the ecology coin are becoming increasingly important and linked.

On one side we are careering, largely unfettered, towards the man-made abyss of the end game of global warming; we are threatening our direct descendants, but at a rate and distance that doesn’t provoke us to action.

On the other side, only 15% of the surface of our planet is not water, desert, ice or mountain. For a tropical, low altitude, air-breathing human, this means most of planet Earth represents an extreme environment, defined as a place where it is difficult to survive. The link between the two is, of course, that global warming will make our planet even more extreme with flooding, erosion, heat waves, cold snaps and desertification.

group of climbers on rope on glacier

Perhaps, therefore, there is no better time for The Physiological Society to plan a specialist conference on Extreme Environmental Physiology (EEP) on 2-4 September.

From origins where EEP research was largely undertaken for occupational groups such as miners and the military, as well as those attempting expeditions to remote parts of the globe, EEP has now become much more “mainstream.” The greatest number of submissions and publications in the journals of The Physiological Society come from the areas of “environmental” and “exercise” physiology; both of which have extreme environmental components.

EEP research continues to examine the responses of humans to environmental stressors such as heat, cold and altitude; these remain important areas in themselves with, for example, at least 1000 people dying from drowning every day around the planet. But EEP research is now also providing insights into a wide range of other conditions such as: responses to hypoxia on intensive care (“survivor phenotypes”); ageing; peripheral vascular disease; osteoporosis; and debilitation caused in critical care patients by bed rest.

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In addition, as we take greater and greater control of our environment through technology, it is becoming increasingly apparent that we need to challenge our homeostatic mechanisms in order to remain functional. At one time we did this naturally by exercise and exposure to the natural world, now we have to employ thermal therapies for a wide range of physiological and mental health pathologies, from microvascular function through autonomic function to depression.

The specialist conference at Portsmouth in September will reflect all of the above, with sessions on cold, heat, hypo- and hyperbaric physiology, micro-gravity and cross-adaptation. To remind us what an eclectic discipline physiology is, each session will include short keynotes on physiology, pathophysiology and comparative physiology, as well as plenty of time for free communications. Finally, it seems appropriate that we should “flip the coin” and spend some time on what the environment might have in store for us if we continue to damage it.

Our exciting keynote speakers include:

References

  1. Martin & McKenna (2017). High Altitude Research and its Relevance to Critical Illness. ICU Management & Practice 17(2): 103-105.
  2. Tipton MJ (2015). GL Brown Lecture: “Extreme Threats” Environmental extremes: origins, consequences and amelioration. Experimental Physiology. doi: 10.1113/EP085362.
  3. Tipton, M. J. (2018) Humans: a homeothermic animal that needs perturbation? Experimental Physiology. https://doi.org/10.1113/EP087450.

Early Career Conference: Join us in December!

Want to run a two-day early career physiology conference? This valuable experience will give you leadership experience and boost your CV! Any Affiliate and/or Undergraduate Members of The Society may apply. Read testimonials from our first Future Physiology conference in 2017 below. 

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Jose L. Areta, Norwegian School of Sport Sciences, Oslo, Norway:

Attending the Future Physiology meeting in Leeds in December 2017, coming all the way from Oslo, Norway, was a privilege I had thanks to a Physiological Society travel grant. I am a post-doctoral researcher in the early stages of what, I think, might turn into a long academic career. I signed up for this conference specifically to get a better overview and insights on what a researcher at my stage could do to make the right choices for his future career. The conference did not fail to provide valuable food for thought.

The attendees included a wide range of representatives of the academic career continuum, from undergraduates to professors. A majority of these were, seemingly, early career researchers (ECRs) and they belonged to a reasonably wide range of areas within the field of physiology. This showed that the purpose of the conference was to go beyond delving into their specific areas of expertise. A dominant topic of interest seemed to be commonalities irrespective of the specific area of expertise, meaning the ins and outs of working in and growing through academia.

Several of the sessions provided examples of more established researchers showcasing how they built their own academic careers in the context of research in physiology. The take-home message for me was that there is no one way to become an established researcher in any given area. The impression that I got is that love for the work you do followed by dedication and a solid network play a key role, immediately followed by serendipity. This seemed to provide some support to the saying ‘the harder you work, the luckier you get’, that I sometimes remind myself of.

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On that note, it was also nice to feel supported by other researchers going through similar difficulties in a research system that seems to very often put high-pressure on individuals and can lead to sub-optimal life quality and, in many cases, burnout. Uncertainty seems to be a common denominator for many researchers in different stages of their careers (more so ECRs). Making this explicit is important to find a solution for it. I think this conference was a good first step to bridge the gap between ECRs who have a lot of questions on how to progress through the ranks, while making meaningful contributions to science and more experienced researchers talking about their specific experiences or professionals providing advice.

Personally, one of my favourite events was a small grant-writing workshop I had the chance to attend that also turned into a bit of a career advice workshop. Transitioning towards being an independent researcher is very significant milestone for anyone in research, I think. Gathering some tools to do so in the context finding one’s place in the field was a nice addition to the experience of the conference.

In conclusion, I think this conference was a good first step to put the uncertainties that ECRs face throughout their development as researchers in the spotlight, and provide them (us!) with tools and networks for better tackling these.

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Dan Brayson, King’s College London, London, UK:

As a member of the Affiliate Working Group of The Society, I was privileged to have the opportunity to help with the planning and execution of the Future Physiology meeting, an early career researcher (ECR) focussed meeting held at the University of Leeds last month. The meeting was ‘by ECRs for ECRs’. This meant that the Affiliate Working Group was placed at forefront of the brainstorming process to come up with a plan for a meeting which facilitated an engaging experience for early career scientists.

What we hoped for was an opportunity for ECR’s to shed their inferiority complex baggage (we all have it), and to feel invigorated by the conference experience rather than being overwhelmed. To this end 20 ECRs were selected for oral presentations whilst five talks were given by senior scientists (for balance, of course). Of these, three were young PIs and shining examples that we don’t have to wait around for professors to retire in order to make significant progress in our careers. We hoped that this would add a motivational slant for attendees. If they can do it, why can’t we?

On a personal note it was a red letter day. I was charged with sharing the chairing and presentation-marking duties with my fellow Affiliate Working Group members, a first for me, and with this, I got to experience the joy of facilitating meeting proceedings rather than merely taking part. At least this was my perception of it, and I would definitely do it again.

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Reflecting now on the meeting I feel that it was a good first crack at a meeting for ECRs. However, I also feel that there is further scope to create the most engaging and immersive experience for young scientists. One idea would be to have facilitated debate workshops on general topics (neuroscience, cardiovascular physiology, gastrointestinal physiology etc.). This would engage people in a relaxed environment to talk more generally about the big issues/questions facing their chosen fields.

Putting visual information into context

By Nathalie L. Rochefort and Lukas Fischer

The cerebral cortex is the seat of advanced human faculties such as language, long-term planning, and complex thought. Research over the last 60 years has shown that some parts of the cortex have very specific roles, such as vision (visual cortex) or control of our limbs (motor cortex).

While categorizing different parts of the cortex according to their most apparent roles is convenient, it is also an oversimplification. Brain areas are highly interconnected, and studies over the past decade have shown that incoming sensory information is rapidly integrated with other variables associated with a person or an animal’s behavior. Our internal state, such as current goals and motivations, as well as previous experience with a given stimulus shape how sensory information is processed. This can be referred to as the “context” within which a sensory input is perceived. For example, we perceive a small, brightly-colored object differently when we see it in a candy store (where we might assume it is a candy) compared to seeing it in the jungle (where it might be a poisonous animal). In our recent article published in Cell Reports, we investigated the factors that impact the activity of cells in the visual cortex beyond visual inputs as animals learned to locate a reward in a virtual reality environment.

Researchers have known since the 1960s that cells in the primary visual cortex exhibit striking responses to specific features of the visual environment such as bars moving across our visual field or edges of a given orientation. The traditional view of a hierarchical organization of the visual system was that primary visual cortex encodes elementary visual features of our environment, and then forwards this information to higher cortical areas which, in turn, take these individual visual elements and combine them to represent objects and scenes. Our understanding of how an animal’s current behavior influences information processing, however, was limited. Recent studies have started to address this question directly and found that neurons in primary visual cortex show more complex responses than expected. We have set out to use cutting-edge technological advances in systems neuroscience to understand what type of information is processed in the primary visual cortex of awake animals as they learn to find rewards.

A window into the brain, literally

We have combined two recent technologies to record from a large number of individual neurons in primary visual cortex while mice were awake and free to run. An advanced microscopy technique, two-photon calcium imaging, allowed us to visualize the mouse brain and record the activity of hundreds of neurons through a small implanted window.

A key challenge with this technique, however, is that the mouse head has to remain fixed. We, therefore, constructed a virtual reality system in which an animal was placed atop a treadmill, surrounded by computer screens displaying a virtual environment within which they can freely move while their head remains in the same place. The virtual environment consisted of a linear corridor with a black-and-white striped pattern on the wall and a black wall section (visual cue) in which the mouse could trigger a reward (sugar water) by licking a spout. This allowed us to train animals to find rewards at a specific location within the virtual environment while simultaneously recording the activity of neurons in the visual cortex.

More dedicated neurons, more reward

Our first, unexpected, finding was that after learning the task, a large proportion of neurons (~80%) in the primary visual cortex were responding to task-specific elements, with many cells becoming specifically more active when the animal approached the reward area. Interestingly, the number of these “task-responsive” cells strongly correlated with how well the animals performed the task. In other words, the more precisely animals were able to locate the reward location, the more cells we found to be active around that location of the virtual corridor in the visual cortex. This was surprising as neurons in the visual cortex clearly seemed to be as interested in where the animal could get a drop of sugar water, as the visual features of their surroundings. To test the impact that the visual reward cue (black wall section) itself had on the activity, we removed this cue and found that some neurons still responded at the rewarded location. This suggests that these neurons in the visual cortex were no longer only depending on visual information to elicit their responses.

Visual inputs matter, but sometimes motor-related inputs matter more

These results opened up a number of interesting questions about what is driving these responses as it was clearly not only visual inputs. We wanted to understand the factors driving this activity in the visual cortex. Mice could use two strategies to locate the reward when no visual cue was present to indicate the reward point. The first strategy relies on their internal sense of distance based on feedback from the motor systems (motor feedback). In other words, an estimate of how far a mouse has traveled based on how many steps they have taken since the beginning of the corridor. The second strategy would be to rely on an estimate of position based on the way the visual world moves past the animal, known as “optic flow.”

We took advantage of the unique opportunities in experimental design afforded by a virtual reality system to test which information is driving those reward-location specific responses. By creating a mismatch between the animal’s own movement on the treadmill and the visual movement of the external virtual environment, we were able to test whether it is motor feedback or visual flow that determines where the animal thinks it is along the corridor, and, correspondingly, where these neurons representing the reward location become active. The results showed that animals expected the reward location primarily based on motor feedback. This means that there are some neurons in the primary visual cortex that encode information related to the location of a reward, based on an animal’s motor behavior rather than purely visual information.

However, in our final experiment, the importance of visual inputs became clear again: when the visual cue indicating the reward location was put back in, while still maintaining the mismatch between treadmill and virtual movement, the animal’s behavior, as well as the neuronal responses, snapped back to the visual cue, disregarding the number of steps it had taken. This suggests that motor feedback is available to and used by the primary visual cortex, but in a conflict situation, the visual cues indicating a specific location, override other types of information to correctly locate a reward.

Conclusion

These results demonstrate the importance of behavioral context for sensory processing in the brain. The primary visual cortex, a region that was once thought to primarily represent our visual world by detecting elementary visual features such as edges, is also influenced by prior experience, learning, and interactions with our environment. A prominent model proposed to explain sensory cortical function, posits that the cerebral cortex creates a representation of what we expect, based on current sensory inputs and previous experience.

Our results are congruent with this model while emphasizing the large role of contextual factors, such as motor feedback and prior knowledge of a location. Future studies are necessary to determine how different types of inputs to sensory regions of the brain influence the activity of individual neurons and how they shape our perception of the world.

These findings are described in the article entitled The Impact of Visual Cues, Reward, and Motor Feedback on the Representation of Behaviorally Relevant Spatial Locations in Primary Visual Cortex, recently published in the journal Cell ReportsThis work was conducted by Janelle M.P. Pakan from the University of Edinburgh, the Otto-von-Guericke University, and the German Center for Neurodegenerative DiseasesStephen P. Currie and Nathalie L. Rochefort from the University of Edinburgh, and Lukas Fischer from the University of Edinburgh and the Massachusetts Institute of Technology.

This blog originally appeared on the website Science Trends.

Nathalie L. Rochefort has been awarded the 2018 R Jean Banister Prize Lecture. The prize is awarded to early career physiologists in the late stages of a PhD, postdoc or who are in an early faculty position. It was established in 2016 in memory of a former Member of The Physiological Society, (Rachel) Jean Banister who left a legacy to The Society when she passed away in 2013.

Seeing Depth in the Brain – Part II

By Andrew Parker, Oxford University

Stereo vision may be one of the glories of nature, but what happens when it goes wrong? The loss of stereo vision typically occurs in cases where there has been a problem with eye coordination in early childhood. Developmental amblyopia, or lazy eye, can persist into adulthood. If untreated, this often leads to a squint, or a permanent misalignment of the left and right eyes. One eye’s input to the brain weakens and that eye may even lose its ability to excite the visual cortex. If the brain grows up during a critical, developmental period with uncoordinated input from the two eyes, binocular depth perception becomes impossible.

My lab’s work supports a growing tide of opinion that careful binocular training may prove to be the best form of orthoptics for improving the binocular coordination of the eyes. Recent treatment of amblyopia has tended to concentrate on covering the stronger eye with a patch to give the weaker eye more visual experience with the aim of strengthening the weaker eye’s connections to the visual cortex. Now we understand from basic research like ours that there is more to stereoscopic vision than the initial connection of left and right eyes into the primary visual cortex.

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Figure 2: Ramon y Cajal’s secret stereo writing, see Text Box

Secret Stereo Writing. The great Spanish neuroanatomist Ramon y Cajal developed this technique for photographically sending a message in code. The method uses a stereo camera with two lenses and two photographic plates on a tripod at the left. Each lens focuses a slightly different image of the scene in front of the camera. The secret message is on plate B, whereas plate A contains a scrambled pattern of visual contours, which we term visual noise. The message is unreadable in each of the two photographic images taken separately because of the interfering visual noise. Each photograph would be sent with a different courier. When they arrive, viewing the pair of photos with a stereograph device as in Figure 1, the message is revealed because it stands out in stereo depth, distinct from the noisy background. Cajal did not take this seriously enough to write a proper publication on his idea: “my little game…is a puerile invention unworthy of publishing”. He could not guess that this technique would form the basis of a major research tool in modern visual neuroscience.

Our lab is investigating the fundamental structure of stereoscopic vision by recording signals from nerve cells in the brain’s visual cortex. One of the significant technical developments we use is the ability to record from lots of nerve cells simultaneously. Using this technique, I am excited to be starting a new phase of work that aims to identify exactly how the visual features that are imaged into the left eye are matched with similar features present in the right eye.

The neural pathways of the brain first bring this information together in the primary visual cortex. Remarkably there are some 30 additional cortical areas beyond the primary cortex, all in some way concerned with vision and most of them having a topographic map of the 2-D images arriving on the retinas of the eyes. The discovery of these visual areas started with Semir Zeki’s work in the macaque monkey’s visual cortex. Our work follows that line by recording electrical signals from the visual cortex of these animals. To achieve this, we are using brain implants in the macaques very similar to those being trialed for human neurosurgical use (where implants bypass broken nerves in the spinal cord to restore mobility).

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Figure 3: A very odd form of binocular vision in the animal kingdom. The young turbot grows up with one eye on each side of the head like any other fish, but as adulthood is reached one eye migrates anatomically to join the other on the same side of the head. It is doubtful whether the adult turbot also acquires stereo vision. Human evolutionary history has brought our two eyes forward-facing, rather than lateral as in many mammals, enabling stereo vision.

My lab is currently interested in how information passes from one visual cortical area to another.  Nerve cells in the brain communicate with a temporal code, which uses the rate and timing of impulse-like events to signal the presence of different objects in our sensory world. When information passes from one area to another, the signals about depth get rearranged. The signals successively lose features that are unrelated to our perceptual experience and acquire new properties, corresponding closer to perceptual experience. So, these transformations eventually come to shape our perceptual experience.

In this phase of work, we are identifying previously unobserved properties of this transformation from one cortical area to another. We are examining how populations of nerve cells use coordinated signals to allow us to discriminate objects at different depths. We are testing the hypothesis that the variability of neural signals is a fundamental limit on how well the population of nerve cells can transmit reliable information about depth.

To be specific, we are currently following a line of enquiry inspired by theoretical analysis that identifies the shared variability between pairs of neurons (that is, the covariance of neural signals) as a critical limit on sensory discrimination. Pursuing this line is giving us new insights into why the brain has so many different visual areas and how these areas work together.

It is an exciting time. We still need to determine whether our perceptual experiences are in any sense localised to certain regions of the brain or represent the activity in particular groups of neurons. What are the differences between types of neural tissue in their ability to deliver conscious perception?

There are many opportunities created by the newer technologies of multiple, parallel recording of neural signals and the ability to intervene in neural signaling brought by the use of focal electrical stimulation and optogenetics. By tracking signals related to specific perceptual decisions through the myriad of cortical areas, we can begin to answer these questions. The prospect of applying these methods to core problems in the neuroscience of our perceptual experience is something to look forward to in the forthcoming years.

Seeing Depth in the Brain – Part I

By Andrew Parker, Oxford University

The Physiological Society set up the annual, travelling GL Brown Prize Lecture to stimulate an interest in the experimental aspects of physiology. With predecessors such as Colin Blakemore and Semir Zeki, following in their footsteps is a tall order. They are not only at the very top scientifically but also superb communicators.

My lecture series on stereo vision has already taken me around the UK, including London, Cardiff, and Sheffield. I’ll be at the University of Edinburgh on 15 November and Oxford University on 23 November. It’s a nice touch that GL Brown’s career took him around the country too, including Cambridge, Manchester, Mill Hill and central London, before he became Waynflete Professor in my own department in Oxford. The other pleasurable coincidence of giving lectures on stereo vision this year is that there is a 50th anniversary since fundamental discoveries were made about how the brain combines the information from the two eyes to provide us with a sense of depth.

In his 1997 book How the Mind Works Steven Pinker wrote, “Stereo vision is one of the glories of nature and a paradigm of how other parts of the mind might work.” I can’t claim to have written this inspiring sentence myself, but I can at least claim to have chosen stereo vision as my field well before Steven Pinker wrote his sentence.

Stereo vision is, in a nutshell, three-dimensional visual perception. It is the use of two eyes in coordination to give us a sense of depth: a pattern of 3-D relief or 3-D form that emerges out of 2-D images arriving at the left and right eyes. These images are captured by the light-sensitive surface of the eye called the retina. Stereo vision gives us the ability to derive information about how far away objects are, based solely on the relative positions of the object in the two eyes.

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Figure 1: “The stereograph as an educator,” illustrating the virtual reality technology of the Victorian era.

The Victorians amused themselves with stereo vision (see Figure 1). Virtual reality is our modern day version of this, but what comes next? The next generation will probably enjoy “augmented reality” rather than virtual reality. With augmented reality, extra computer-generated imagery is projected onto objects in the real world. The aim is to create a perceptual fusion of real objects with virtual imagery. For example, in one prototype I have seen, surgeons perform their operations with virtual imagery (acquired with diagnostic imaging devices) superimposed upon the surgical field in the operating theatre. Needless to say, this places much higher demands on the quality and stability of the virtual imaging systems.

What causes people like Pinker, who are outside the field, to get so excited about stereo vision? Partly it’s just the experience itself. If you’ve been to the 3-D movies or put on a virtual reality headset, you will have the sense of stereoscopic depth. It is vivid and immediate. The other thing that excites Pinker is the way in which the brain is able to create a sense of a third dimension in space out of what are fundamentally two flat images. As a scientific problem, this is fascinating.

We also see parallels between stereo vision and how other important functions of the brain are realised. One straightforward example of that is visual memory. Gaining a sense of stereoscopic depth from two images (left and right) requires matching of visual features from one image to another. Remembering whether or not we have seen something before requires matching of a present image to a memory trace of a previously seen image. Both processes require the nervous system to match visual information from one source to another.

Another aspect that Pinker is highlighting is the way in which the two flat images in stereo are fused to form with a new perceptual quality, binocular depth. A great deal of spatial perception works this way. One obvious example is our ability to use the two ears in combination to form an impression of sound localised in space, based just on the vibrations received by the left and right ear canals.

What is the world like without stereo vision? While you can partly experience this by placing an eyepatch over one eye (try playing a racket sport or carefully making a cup of tea), the difference is most strongly highlighted by the very rare cases when stereo vision appears to have been lost but is then recovered. Susan Barry, professor of neurobiology at Mount Holyoke College, was stereoblind in early life but eventually gained stereo vision with optometric vision therapy.

In a New Yorker article by Oliver Sacks (Stereo Sue, A Neurologist’s Notebook, June 19 2006) Barry describes her newly acquired perception of the world. “Every leaf seemed to stand out in its own little 3-D space. The leaves didn’t just overlap with each other as I used to see them. I could see the SPACE between the leaves. The same is true for twigs on tree, pebbles on the road, stones in a stone wall. Everything has more texture.”

Check back next Wednesday for Part II of Andrew Parker’s blog on stereo vision.

Europhysiology 2018: What’s in it for early career researchers

By Yvoni Kyriakidou, University of Westminster

As an early career researcher, presenting part of my PhD at Europhysiology 2018 will not only provide me with an opportunity to share my research, but it will also help me meet people in related fields to exchange information and expand my network. As this meeting will bring together some of the biggest physiological societies in Europe, I look forward to discussing work from many other institutions across the world. I hope to gain critical feedback on my work from the experts.

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I am currently a Doctoral Researcher in Bradley Elliott’s team, who is the leader of the Translational Physiology Research Group at the University of Westminster, London. I am studying the physiological pathways that lead to decreased performance and how these can be affected or induced by performing specific exercise protocols. My research also explores how ageing affects muscle function, human performance and health. Furthermore, I am investigating the impact of different nutritional strategies on offsetting this.

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This well-established conference is also an opportunity to learn more about the latest techniques and developments in the field of exercise physiology. I can also develop science communication strategies with other experts who also want to increase the impact of our research and inform the general public. Finally, at this interdisciplinary event, I will learn about different career pathways.

Europhysiology 2018 will provide me with extra motivation to gain deeper knowledge for and beyond my PhD journey.


By Pardeep Pabla, University of Nottingham

Europhysiology 2018 will be the biggest joint-society meeting that I have attended so far. As a young scientist, I always look forward to seeing the biggest names in our field present high quality science. It helps to put into perspective exactly what it takes to have a career in science, but it also serves as a timely reminder of how rewarding such a career can be.

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The coming together of experienced and enthusiastic academics with young, and equally enthusiastic, early career scientists alwaysprovides excellent opportunities to network, share ideas and gain new insights into each other’s work.

When possible, I try to steal a few moments of time from some of the more senior researchers and have found them very forthcoming with their advice and knowledge. I find that these moments help renew the excitement and enthusiasm I have for my research, qualities I believe are essential to longevity and success in an academic career.

I also greatly appreciate (and am guilty of taking for granted in the past) just how many opportunities these societies provide for early career researchers to showcase their work, and to witness new and emerging methodologies in physiology.

Having been a member of The Physiological Society for some time now, I can gladly say that I have made some friends along the way whom I look forward to catching up with at Europhysiology 2018. It is great to share stories from the lab and we always find some comfort in knowing that others share the same day-to-day challenges; the empathy that only fellow researchers can provide is warmly welcomed. A great thing about networking and talking to others is the realisation that our work utilises an extremely broad range of techniques and methodologies. Consequently, the wider impact of our work is astounding.

From a personal point of view, I am looking forward to the atmosphere of a big meeting. There is often a sense of excitement around these meetings, balanced with a welcoming and relaxed vibe.