In Defence of Parasites

In Defence of Parasites_elephantisisParasites have a bad reputation. These tiny creatures are responsible for some of the most visually horrifying diseases known. For example, a microscopic worm causes the grotesquely swollen limbs of elephantiasis, while a single-celled parasite, Leishmania, is capable of destroying a victim’s face. However, we humans often concentrate on the worst aspects of certain species – just ask your average wasp or spider – and there is much more to parasites than disease.  Many parasitic infections in fact cause little harm – if we die, so do they – and by concentrating solely on the diseases they cause we miss out on some fascinating underlying biology.

I remember arriving late for one of my first undergraduate parasitology lectures and being pleased to find the lecturer had not yet arrived either.  “Sorry I’m late,” he said when he appeared, “I was on the Tibetan plateau yesterday, looking for tapeworms in foxes”.  This lecture was my first glimpse into the ecology of parasites, and where the elegance and sheer complexity of their life cycles became apparent.  We all marvel at the epic journeys in nature, such as the great wildebeest migration across the Serengeti.  But compared to parasites, those TV regulars have it easy.  Strolling from one part of Africa to another, avoiding the occasional crocodile or lion? Simple.

The life cycles of parasites can be incredibly complex and quite ingenious.  These animals often need to jump between several host species to mature and reproduce and many have evolved amazing ways of completing these unlikely journeys.

In Defence of Parasites_miceToxoplasma gondii is a single-celled parasite that can infect a number of mammals, but which ultimately needs to find its way into a cat to sexually reproduce.  The most common intermediate hosts for Toxoplasma are rodents and the parasite has evolved the remarkable ability to alter the behaviour of these animals in order to maximise its chances of finding a feline.  A mouse or rat that becomes infected with Toxoplasma not only loses its natural fear of cats but can even become actively drawn to their scent, deliberately seeking out catty environments and thereby increasing its chance of being eaten and the parasite’s chance of transmission.

In Defence of Parasites_fluke wormThe Lancet fluke, a flatworm that infects the liver of grazing animals, is also adept at brain washing its host.  This worm has two intermediate hosts, a snail and an ant.  Snails become infected by eating infected animal droppings, after which the parasites develop into cysts and are released in the snail’s slime.  Passing ants then swallow these cysts as they graze on the slime as a source of moisture.  This cycle alone is a beautiful example just how complex parasites’ life cycles can be, but the really clever part comes next…

Following infection of the ant, the Lancet fluke begins to exert its mind control.  The ant’s behaviour becomes peculiar and, like Toxoplasma and its stupidly brave rodents, this behaviour is due to the parasite’s attempts to increase its chance of transmission.  In the evening the ant leaves its colony members and travels to the top of some nearby vegetation.  Once there, it clamps its jaws on tightly and stays until dawn, a ruse by the parasite to increase the likelihood of the ant being accidentally swallowed by grazing cattle.  Clever stuff, but the parasite is cleverer still.  When day breaks, the fluke senses the rise in temperature and relinquishes its control over its insect host, allowing it to continue with its usual anty chores.  This prevents the ant dying in the daytime heat, which would also kill its parasitic puppeteer.

In Defence of Parasites_taxo brainEven within a single host, parasites face extraordinary challenges.  A single individual may have to navigate blindly from the gut to the lungs, from the skin to the eye, or from the liver to the brain.  Tunnelling through organs and hitching a ride in our bloodstream, the travelling parasites must face a relentless barrage from our immune system.  Many have therefore evolved sophisticated ways of dampening down host immune responses to protect themselves.  They are in fact so proficient at this that many scientists believe the lack of parasitic infection in developed countries, and the loss of their calming influence on our immune system, has led to the observed increase in allergies and autoimmune diseases.  Indeed, deliberate infection with parasitic worms has actually been used to successfully treat many such disorders.

The complexity and elegance of parasites is often overlooked, but they are marvels of nature. Parasites can treat as well as cause disease, and can alter host physiology and behaviour; they form important parts of ecosystems and undertake journeys which, though microscopic, are unrivalled in nature.  A single individual must endure environments as diverse and hostile as the bottom of a pond, the gut of a snail and the tissues of a wildebeest. And yet who gets the David Attenborough treatment?

This post, by author Dr. Andy Turner, was kindly donated by the Scouse Science Alliance and the original text can be found here.SSA

Pint of Science 3 day festival comes to Manchester!

Pint-of-Science-logo-with-glasses-528x746What better way to enjoy a sprinkle of scientific banter than down your local pub complete with pint in hand! For three days only, this summer we have enticed some of Manchester’s finest academic researchers out of the lab and into the pub to talk to you about their work. Events are taking place across Manchester on the 19th to the 21st of May and cover a wide range of topics, with enough variety to keep even the pickiest scientific dabbler satisfied. So have a look at our line-up and pick your favourite night, if you’re lucky you may even spot a brainbanker or two, but be quick tickets are selling fast.

Matters of the mind @ The Albert Club in West Didsbury – Click here for tickets

Monday the 19th: Mental health: breaking the stigma

1We’ve all experienced the feeling of being unwell with the accompanying trips to the GP, time off work and medication. Coughs and colds are common and well understood, but what happens when our minds become unwell? One in four of us will be affected by mental illness, the effects of this are no less real than a bout of the flu, but are often much harder to understand. Despite the extent of mental health problems, those affected still experience stigma and discrimination – a burden which can be even worse than the symptoms themselves. This evening, join Dr Rebecca Elliott and mental health experts from the University of Manchester for an evening of discussion where we hope to break down barriers and challenge stigma.

Tuesday the 20th : Understanding stroke.

2With around 152,000 strokes occurring in the UK every year, it’s never been more important for us to understand the ins and outs of this devastating condition. As part of the Stroke Association’s Action on Stroke Month, speakers from the University of Manchester and the Stroke Association will give us a window into the brain and the lives of stroke survivors. Professor Stuart Allan will introduce the workings of the brain, how strokes occur and what makes them so destructive, including how targeting inflammation could offer a brighter future for survivors. A real highlight will be provided by stroke survivor and nurse Christine Halford and her daughter Natalie who will offer moving first-hand accounts of what happens when a carer becomes the cared for. We will have an interactive activity provided by the wonderful artist Amanda McCrann to bring together a fascinating night of information and discovery.

Wednesday the 21st : The ups and downs of sleep and circadian biology (sold out)

3Have you ever wondered why it’s so hard to function when you just wake up or what really drives us to spend almost a third of our lives tucked up in bed? This evening we will address these questions and more as we explore the ups and downs of circadian biology. Join Professor Andrew Loudon and Dr Penny Lewis from the University of Manchester as they take us on a journey through the mysterious landscape of circadian rhythms and sleep. We will explore what makes our biological clocks tick, how our hectic 24-hour lifestyle affects our internal rhythms, how snoozing is vital to our memories and uncover the difference between morning larks, night owls and the indecisive humming bird with a live science experiment!

Understanding our bodies @ Solomon Grundy in Withington – Click here for tickets

Monday the 19th : Unlocking the Sense of Smell – The Scent of A Maggot

4Professor Matt Cobb’s lab studies how the sense of smell works. To do this they use a rather unusual animal – a maggot. You and I have about 4 million smell cells in our noses. A maggot has just 21, and by using genetics they can make a maggot with just a single smell cell. By studying the behaviour of these animals, and the electrical activity of their smell cells, we can understand how smells are processed in the nose and in the brain. Not only does a maggot have a brain, but the bits of its brain that process smells are also wired up just like ours. So by studying something as simple as a maggot we hope to understand how the sense of smell works in all animals, including humans.

Tuesday the 20th : Nanotechnology & the Role of graphene

5Manchester is leading the way in graphene research, with a nobel prize being given to two of its researchers in 2010. The material has some exceptional properties: tougher than diamond, stretchier than rubber, and better able to conduct electricity than anything else. It also has a myriad of possible uses: bendy touchscreens for mobiles, super-light batteries, artificial retinas, more effective drug delivery … and that’s just for starters. Graphene could become as much a part of our daily lives as plastic, and its implications will be huge!

Wednesday the 21st : Personalised medicine and the future of cancer treatment

6This talk will provide a fascinating introduction to personalised medicine, and the future of cancer treatment. No two cancers are the same. So, even patients with the same ‘type’ of cancer will respond differently to treatment. Personalised medicine aims to understand each person’s individual cancer at a molecular level, so doctors can match patients with the treatments that will work best for them. This aim of treating every patient as an individual is still some way off, but Professor Caroline Dive, from the Manchester Cancer Research Centre, will discuss how scientists in Manchester are playing a pivotal role in bringing forward this era of personalised medicine.

Chemistry and Physics @ The English Lounge in the Northern Quarter – Click here for tickets

Monday the 19th : Ocean circulation – the awkward bits


The heat capacity of the ocean is around one thousand times that of the atmosphere, and the ocean circulation plays a crucial role in climate change. For long term model simulations one needs to average over space and time to make the computations feasible, but important processes happen over relatively small time and length scales. In this talk, Dr Gregory Lane-Serff will explain some of these processes, including mixed-later deepening, flow over sills and through straits, and flows of dense water into the deep ocean. He will show results from observations, and explain how insights from laboratory models can help our understanding – with some experiments for the audience to do!

Tuesday the 20th : A sonic wonderland


What are the sonic wonders of the world? Trevor Cox, a renowned professor who engineers concert halls, has made a career out of eradicating bizarre and unwanted sounds. But after an epiphany in the London sewers, Trevor now revels in exotic noises – creaking glaciers, whispering galleries, stalactite organs, musical roads, humming dunes, seals that sound like alien angels, and a Mayan pyramid that chirps like a bird. Join him and discover what insights these remarkable effects give us into how sound is made, altered by the environment and perceived by listeners.

Wednesday the 21st : Waste not, want not – A Radioactive Reality


Radioactive waste can be one of the most sensitive issues regarding the production of nuclear energy. However, are we too quick to jump to conclusions without considering all the evidence? Matt will talking about the preconceptions that most people have when they hear about radioactive waste and the scale of the problem in the UK. He’ll also talk about what we’re trying to do to solve the problem, while binding all these topics together with some anecdotes about his experiences regarding the topic.

Planet Earth @ Odder bar on Oxford Road – Click here for tickets

Monday the 19th : Unlocking ancient DNA

10Michael is a Royal Society University Research Fellow based in the Faculty of Life Sciences, University of Manchester. His main research interests are in the recovery of genetic information from extinct animals. Due to the age and environmental conditions of the remains of the more poorly understood species, this usually takes the form of cutting-edge techniques in proteomics. In this talk he highlights some of the key areas that ‘palaeoproteomics’ has helped improve our understanding of mammal evolution.

Hunting dinosaurs in the 21st Century…

Dr Philip Manning

Phil is Reader in Palaeobiology and Head of the Palaeontology Research Group at the University of Manchester. He is also an STFC Science in Society Fellow, a Research Associate at the American Museum of Natural History (USA) and a Visiting Scholar at the University of Pennsylvania (USA). In 2014 Phil was elected a Fellow of the Explorer’s Club (New York). His research is both broad and interdisciplinary with active research topics from biomechanics of dinosaurs to the synchrotron-based imaging of both extant and extinct organisms. He and his team have worked extensively in the Hell Creek Formation of South Dakota and Montana, but their field program also includes sites in South America, Europe, Asia, Africa and Australia.

Tuesday the 20th : Taking volcanoes to the IMAX

11Kate Dobson is a geologist who applies the latest cutting edge 3D and 4D imaging techniques across a wide range of geological research, to capture and quantify the spatially and temporally variable processes that control how our planet works. She has been at the University of Manchester since 2011.

From Core to Crust: A journey through the interior of the Earth

Michael Ward Broadley

Michael Ward Broadley is a PhD student at the University of Manchester, and his research revolves around the use of noble gases and halogens as tracers of volatile movement between the Earth’s geological reservoirs. Studying magmas erupted from deep within the Earth’s mantle, by means of analysing their unique geochemical signatures rich in primordial noble gases, it is possible to understand how the Earth obtained its volatiles. The theories that are being put to the test include impacts with primitive meteorites and solar wind influence, among other fascinating mechanisms. Michael is also a regular contributor to his research group’s outreach program.

Wednesday the 21st : Secrets of the Moon

13Katherine Joy is a senior research fellow at the University of Manchester SEAES. Her research focuses on studying the geological history of the Moon throughout lunar samples returned by the Apollo astronauts, and lunar meteorites that are found here on Earth. She analyses these samples in the laboratory to investigate their chemistry, mineralogy and age. With the contribution of data collected by satellites orbiting the Moon it’s possible to reveal its fascinating geological evolution, as well as explore the wider history of the Solar System. Her work may one day help guide people planning to send astronauts back to the lunar surface.

Cooking Up A Comet – Francesca McDonald

Francesca is a first year PhD student and her research concerns determining and comparing the volatile budgets of the lunar and terrestrial mantles. This will make us understand the volatile behaviour during the formation and evolution of Earth-Moon system. The rock samples she studies are Apollo lunar basalts and terrestrial komatiites. She also partakes in outreach work where she talk about comets whilst having her glamorous assistant Alex Clarke cook her up a comet.

Hope you see you there!

the Brain Bank Team.

The Science of Procrastination

Procrastination, or ‘the action of delaying or postponing something’ is a widespread habitual weakness common to most people in the world (unless you are super human, then this article does not apply to you). Specifically, it involves the pursuit of activities that provide short-term gratification while simultaneously delaying any task which is particularly laborious or unpleasant. Procrastination often manifests as a coping mechanism for dealing with pressure and anxiety surrounding personal trials; for example revising for exam1s or writing a novel. Although procrastination has acquired the characteristics of laziness, avoidance and sloth; stressed out students may now take heart to learn that scientists are attempting to understand the neurological and psychological underpinnings of task avoidance and whether it may actually confer cognitively beneficial effects on intelligence, creativity and development.

From a psychological perspective, procrastination is a problem of self-control which leads the procrastinator towards behaviours that provide short-term relief by making a stressful or boring task immediately avoidable. Task avoidance may be easier to understand if we look at another model of self-control, for example, in a dieter. Before going to a restaurant the dieter may be set on not ordering dessert but, once the time comes, they may give in to the lure of a moist sticky toffee pudding. Inevitably, following this decision the would be dieter is likely to regret their choice and may be racked with feelings of guilt and self-hatred. This behaviour stems from a disproportionate preference for immediate gratification (a sugary snack) over, more beneficial, long-term rewards (better health) and is known as ‘systematic preference reversal’. These brief but powerful lapses in self-control govern the brain’s preference for behaviours that provide instant gratification and avoids pursuing goal-directed achievement.

The amygdala brain region (highlighted in red).

Procrastination on a neurobiological level actually appears to be emotionally driven, stemming from an internal desire to protect ourselves from negative feelings associated with the fear of failure. The amygdala is a brain region which has been associated with mediating a diverse number of normal behavioural functions including fear, emotion, memory and decision-making and is also involved in a number of psychological disorders including anxiety and phobias. This complex aggregation of brain cells has also been implicated in the neurobiology of procrastination, due to its role in establishing what is known as the ‘fight or flight’ response. This physiological reaction is most commonly linked to situations involving a threat to survival, but has also been applied as an explanation for task avoidance and procrastination. When we start to feel emotionally overwhelmed by an activity that is particularly challenging, or by the accumulation of multiple demanding projects, the amygdala induces this fight or flight emotional reaction in an attempt to protect us from negative feelings of panic, depression or self-doubt. When the amygdala detects a threat, i.e. when you begin to panic about how much you have to do before your exam tomorrow, it floods your system with the hormone adrenaline. Adrenaline can dull the responses of brain regions involved in planning and logical reasoning, leaving you at the mercy of more impulsive brain systems which may convince you that sitting on facebook for the next few hours is really not such a bad idea, even though you have an exam tomorrow. Short term gratification, can immediately relax us and improve our mood via the production of the neurotransmitter dopamine. Dopamine has a major role in reward-motivated behaviour, indeed, most behaviours that make us happy increase the levels of dopamine in the brain. This is when emotional memory comes into play. Specifically, because the brain will stimulate you to repeat an activity that has increased your happiness (and thus dopamine levels) in the past. Therefore, the amygdala encourages you to pursue such behaviours, despite the seemingly short-term advantages of doing so.

Research by Laura Rabin of Brooklyn College also implicates frontal regions of the brain, involved in what is known as ‘executive functioning’, in the induction of procrastination. Executive functioning is a term that encompasses a number of different processes, including problem-solving, changing actions in response to new information, planning strategies for approaching and completing complex tasks and most importantly regulating self-control of our own emotions, behaviours and cognition. Despite only demonstrating a correlative link (i.e. it is unclear if changes in executive functioning directly cause procrastination), this study suggests that procrastination may emerge as a result of a dysfunction of the executive function producing systems of the brain.

But does procrastination deserve its bad reputation, or may task avoidance actually confer some benefit? Some studies suggest that day dreaming, a well-known form of procrastination, may in fac3t be beneficial in terms of the developing mind. Research, by Daniel Levinson of the University of Wisconsin-Madison, demonstrated that children who are regular daydreamers actually have better ‘working memory’, i.e. the ability to juggle multiple thoughts simultaneously than their less dreamy counterparts. Working memory capacity has been positively correlated with reading comprehension and even IQ score, and may represent a cognitive advantage in the ability to handle multiple complex thought processes all at once. Further to this, daydreaming and procrastination have been argued to be beneficial as a type of rest for the brain. However, these potential benefits remain highly controversial, and are obviously subject to individual trait and personality differences.

So, if you are reading this instead of revising, writing your dissertation, or composing a report, don’t despair. Neuroscience offers us several ways we can tackle our tendency to procrastinate.

As procrastination stems from a split second emotional reaction that represses our reasonable thought processes (i.e. to be productive) and yearns for a happiness boost, we need to train our brains to see the completion of a task itself as the dopamine-producing experience rather than the procrastination. So, we should be focusing on rewarding ourselves for completing steps of a challenging project, rather than punishing ourselves for not getting it done. If a reward (no matter how small) is in sight, the amygdala, and the rest of your brain will encourage working towards receiving that reward, and will therefore be less likely to initiate behaviours that will distract you from achieving your goals. As dopamine release is triggered by things that makes us happy, dividing your work into small sections with a reward at the end of each step may be beneficial, so for every chapter you read or 100 words you write, maybe reward yourself with a YouTube clip of a cat singing, or a sneezing panda?

eAnother key element of procrastination is that we often set ourselves unrealistic goals, and when we fail to complete these we panic – and so does the amygdala – setting in motion a series of neurochemical reactions that will, quite literally, stimulate us to do anything else but the task at hand. So, throw those unrealistic goals out the window, break your work down to smaller manageable pieces and make sure you reward yourself each time you complete one. Finally, if you start to panic about the enormity of the task ahead, stop, take a breather, and give your rational mind the time to remind you that there is light at the end of the tunnel and the less you avoid it, the faster you will get there!

Post by: Isabelle Abbey-Vital

Your nose sniffs out friends, foes, and sickness

Image by ‘great_sea’ (Wikicommons)

The sense of smell is often unfairly overlooked, but it is becoming more and more obvious that it’s essential for a huge number of really important functions. Recently, the average human nose was estimated to be able to discriminate between more than 1 trillion different smells, each of which are mixtures of odorant molecules recognised by the nose. Of the ~24,000 genes in every person’s genetic make-up, around 400 code for smell receptors that reside in the nose. These receptors bind to these odorant molecules and trigger neural activity to the brain.

Our sense of smell  – or ‘olfaction’ – has long been known to be closely associated with our emotions. Strongly emotional memories often involve elements of smell (e.g. the smell of sun cream reminding you of holidays, or associating the smell of cut grass with sports day), so perhaps it isn’t surprising that a lot of emotional relationships can be helped (or hindered!) by our sense of smell too.

Sniffing out friends

Pheromones in guys’ and girls’ sweat can help give a clue as to their gender for the heterosexual members of the opposite sex, or for homosexual people of the same sex. In one experiment, smelling the male hormone androstadienone made it easier for women and homosexual men to identify a ‘gender neutral’ light point walker as ‘male’. By contrast, the smell of the female hormone estratetraenol made it easier for heterosexual men to identify a walk as ‘female’. The responses of bisexual people and homosexual women to the smell of estratetraenol were, on average, between those of heterosexual men and women. So a sense of smell can alert us generally to members of the sex we find more attractive.

In fact, a person’s smell may even determine how attractive they are to potential mates. Major Histocompatibility Complex (MHC) molecules are produced by the immune system and detect chemical labels on the surface of all cells, bacteria and infected cells. They determine whether a cell belongs to you, or to a pathogen (a parasite or bacterium) or an infected cell. If an MHC-carrying cell comes across anything dodgy, they initiate the immune response to get rid of the pathogen/diseased cell. What’s amazing is that the genes that code for MHC molecules are the most variable of any of the sets of genes in the genome. That is, most of the genetic differences between any two people are found in the MHC genes.

Image from Bayonetblaha (Wikicommons)

Fascinatingly, the level of MHC similarity between two people may influence how attractive they find one another – and that this is mediated by a sense of smell. A study from 1995 discovered that women found the smell of a T-shirt worn for two days by men who had more dissimilar MHC genes to them more attractive than the smell of men with more MHC alleles in common with their own. (Weirdly, women on the contraceptive pill showed more or less the opposite effect, implying the pill could either affect sense of smell, or choice of mate). This study led to a whole load of hypotheses about how smelling out potential mates’ MHC molecules could prevent inbreeding between genetically similar people, or increase their potential babies’ defences against infections.

What’s more, babies use smell to identify their mothers, in order to start suckling. Whereas people previously thought that babies start suckling in response to their mothers’ pheromones – which are perceived by a different sensory organ to that of regular ‘smelling’ – instead experiments in mice suggest that babies learn the unique smell of their mother.  This is interesting because it means that babies don’t instinctively know the scent of their mother through the pheromone system, which is innately programmed; rather, recognising ‘mum’ must be learned in order for the baby to start suckling and therefore survive.

Sniffing out foes and illness

Image by Aaron Logan

A recent report from a neuroscience lab at McGill University suggests that laboratory mice used in pain research respond differently depending on the sex of the researcher. Specifically, male mice showed more signs of stress when handled my male researchers, and this stress response interfered with the feelings of pain that the researchers were trying to measure. This means that the mice appeared to feel less pain whenever male researchers were around. In fact, this happened not only when the male researchers were around, but also when the male mice were given bedding that carried the scent of the male researchers, or other male mammals that were unfamiliar to the mice. So different smells can affect stress, pain and the smells that cause these responses aren’t necessarily specific to other animals of the same species.

Your sense of smell may also help you to avoid catching illnesses. When people are injected with a substance called lipopolysaccharide (LPS) they get a fever as if they have an infection, and have an increase in immune-system chemicals called cytokines in their blood. In one experiment, people were asked to rate the smell of T-shirts that had been worn by people who were injected with LPS, or saline (which wouldn’t have the same effect on the immune system but would involve an injection – something which can make some people sweat!). Individuals tended to rate the LPS group’s T-shirts as less pleasant, more intense and ‘less healthy’ than the control groups’ T shirts. Amazingly, these T-shirts were only worn for 4 hours, and the ratings of ‘unhealthy’ smells correlated with the level of cytokines in the T-shirt wearer’s blood.

So our sense of smell can guide us towards people we might have more biological ‘chemistry’ with, and guards us from sick people (and male scientists!). But why is knowing about our sense of smell useful? Well, in addition to there being a condition where individuals can’t smell anything (called anosmia), there’s some evidence that people with other, more common, disorders have deficient senses of smell. For instance, psychopaths – who show less empathy, and tend to be more manipulative and callous than other individuals – have a reduced ability to identify or discriminate smells. People with depression are also less able to smell faint odours than non-depressed people. People who are more at risk from developing schizophrenia misidentify different smells. Knowing about how our sense of smell relates to the rest of brain function, might help scientists to develop ways of diagnosing, treating or measuring improvement in disorders where this crucial sense goes wrong.

Post by Natasha Bray