Brain Altering Parasites

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Jonathan Cooke

Fans of The Last of Us might be familiar with brain-altering parasites. These little critters and fungi are slowly creeping into the popular imagination thanks in part to media using them as the instigator of the ever-popular zombie apocalypse genre. The ‘bad guy’ of choice in The Last of Us is the parasite Cordyceps; a fungus that is represented by multiple species which ‘zombify’ their hosts, turning them into vessels for their reproduction.

Fortunately for you, Cordyceps; or more precisely Ophiocordyceps only prey on tiny insects found on the forest floor. In fact, they are quite an effective pest control, helping to keep insect populations in check.

Generally, whether or not the parasite kills their host, it will manipulate the host into a situation that is more advantageous for the parasite. For instance, if the current host is merely an intermediary for the parasite can reach their final host they will manipulate the current host’s behaviour to make it more likely they will come into contact with the final host.

Such parasites include the protozoan Toxoplasma gondii; which infect rodents, but reproduce in cats, alter the behaviour of their rodent hosts. Several behavioural experiments have found that rats infected by the parasite are much more likely to take risks than their non-infected counter-parts. This leaves them more susceptible to eaten by their feline predators, thereby continuing the parasites lifecycle.

These behavioural changes are usually brought about by manipulating the hosts brain chemistry, either increasing or decreasing the brains response to signals it is receiving. In the case of the rodents, T.gondii ‘makes’ encourages risk-taking behaviour by ignoring environmental stimuli that work to make them dive for cover, such as the scent of cats. In several experiments that exposed rats to the smell of various different organisms, rats infected with T.gondii tended to frequent areas that smelled of cats and were not scared of cats when they were in the area. This is part of the parasite’s ‘extended phenotype’; where the behaviour of the host changes to maximise the survival chances of the parasites genes.

Again and again these manipulations have been observed in the animal kingdom (although for the most part the actual mechanisms are not fully understood, I should know, I wrote my dissertation on it) but what if they do affect humans?

Are humans manipulated in the same way that others are, to benefit those organisms that are so much smaller than us?

Humans are parasitized by many different organisms, tapeworms being a well-known example. However, most parasites we know steal nutrients from the food we eat, or feed off us directly, like ticks. In both cases, they don’t kill us, and don’t need to do something as energy consuming as manipulating their host’s behaviour.

Manipulating your host’s behaviour typically indicates that you want your host to move somewhere or do something that would be out of the ordinary for them; but is advantageous for you as the parasite, e.g. in the case with Cordyceps, which want their spores to be better distributed, or you want your host to be eaten, such as with T.gondii.

Neither of those strategies would be viable in humans. We don’t tend to get eaten by other organisms until we die naturally and unless the parasite only breeds around beach resorts in Tenerife, there’s not much point in changing our behaviour.

So, what if it’s accidental? What if we get infected by something were not supposed to? How might a parasite, not realising its reached a reproductive dead-end, affect us? Well ever since humanity has been looking after our feline friends we’ve run the risk of accidental infection by T.gondii, although no one is quite clear as what this infection might do to us. Infection rates vary widely across the country and for the vast majority of the population infection is completely asymptomatic, though infection can also trigger toxoplasmosis which can have lethal consequences.

Some observational evidence from studies, seem to suggest that infection has a demonstrable effect on the behaviour of those who have picked up the parasite, although the consequences do differ between males and females. Women seemingly become more intelligent, affectionate, and more likely to follow rules, whilst men tend to mellow out, becoming more loyal and mild-tempered when compared against other males.

The only trait that those who are infected share across both genders is a higher level of neuroticism, being more likely to blame themselves for problems in their lives and to have a high sense of insecurity.

However, these correlations are just that – correlations. No work has been done to prove that T.gondii is what is causing these behavioural changes in people – if they are changes at all.

Perhaps the reverse is happening; those of us with these traits are more prone to getting infected. Very little work – for obvious ethical reasons – has been done to see T.gondii interacts with the human body. However, perhaps we can take small pleasure in the idea that it is going to be convincing us to get eaten by lions anytime soon.

Behaviour altering parasites is a new, emerging field in biology; its effects are rarely documented and even more rarely understood in how they work. For many years, however, there has been a fundamental view that humans are not affected by such parasites and that we are apart from the animal kingdom in this regard.

Perhaps it’s time we address this view?

The ‘Tetris Effect’

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Jess Jarvis

Tetris – a game we’ve all played at some point throughout our childhood. A frustratingly addictive, yet somewhat simplistic game, involving aligning falling blocks in horizontal lines, to gain points.

But whom would’ve thought that a game which stamped out hours of our summer holiday boredom, could hold such valuable, therapeutic properties?

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The BBC reported recently that Tetris may actually be beneficial to our physical and mental health. Helping to ease patient suffering in Post-Traumatic Stress Disorder (PTSD), curb cravings for addictive substances and even treat lazy eyes!

Scientists have suggested that it is the captivating and immersive ease of playing Tetris which ‘makes it potentially powerful as a therapeutic tool’.

Prof. Emily Holmes, a previous visiting professor in Clinical Psychology at the University of Oxford, has spent many years of her career studying the potential use and effectiveness of Tetris in therapy and medicine. She suggests that it is the visual aspect of Tetris that makes it so absorbing. Unlike other games, the diversity in colour, shape and movement taps into the visual memory. The ‘Tetris Effect’ can be so intense, that people often report seeing the ‘falling blocks in their thoughts and dreams’ after playing.

Easing Suffering in PTSD

Prof. Holmes and her colleagues published a study in 2017, which showed how intrusive memories and ‘flashbacks’ – characteristic of PTSD – could be significantly reduced by playing Tetris. This study was one of the first to look at the use of Tetris as a therapeutic intervention. It suggested that the high ‘visuospatial demands’ of Tetris occupied the sensory elements of memory, preventing the consolidation of traumatic memories in the mind.

6 hours following a motor vehicle trauma, participants were delivered either a control intervention (writing a log for 20 minutes) or a Tetris intervention (20 minutes of game play). A week later, compared to the control group, those whom had played Tetris were significantly less affected by intrusive memories. Furthermore, their incidence of intrusions was significantly lower too!

From analysing previous research, Tetris seems to be the only game which has a positive effect on preventing intrusive memories following trauma. Not only is the intervention extremely effective, it is also very simple and helpful for people to use. It is low in intensity and the game itself, creates minimal distress. It reduces the symptoms of PTSD, whilst still allowing the ability to make sense of the event.

Further studies with more participants could show whether Tetris might have a real impact on the quality of life for sufferers following trauma. This research is only in the early stages though, and has a long way to go before it can be implemented into clinical situations.

Curbing Addiction and Cravings

Scientists from Plymouth University and Queensland University of Technology, have said playing Tetris can also help control cravings for addictive substances.

31 students took part in this experience sampling study. They were sent text messages throughout the day which asked them to rate their current level of cravings for drugs (e.g. cigarettes), food and drink (e.g. coffee, alcohol), and activities such as exercise and sex.

Half of the students were given a device to play short games of Tetris throughout the day. This mini intervention showed Tetris to have an effect, whereby cravings reduced more in those who played the game.

Prof. Jackie Andrade believes Tetris has an effect on curbing addictive cravings, because cravings involve imagining an intense experience of indulging in the use of a particular substance. Therefore, the demanding nature of Tetris on the sensory mental processes in the brain, makes it extremely difficult to imagine cravings vividly and make sense of them, whilst playing Tetris at the same time.

Treating a Lazy eye (Amblyopia)

Dr. Robert Hess, from McGill University in Canada (2013), completed a small study to see whether Tetris could help treat a condition known as lazy eye or amblyopia.

Previous treatments have only focused on retraining the ‘lazy eye’ alone. In the past doctors had recommended “covering the “good” eye with a patch to make the “lazy” one work harder.”

However, it became apparent to the researchers that the only way to help solve amblyopia was to solve the disruption to binocular vision and encourage the two eyes to work together.

Dr. Robert Hess, used headset-video goggles to display an adapted version of Tetris. Through these goggles Tetris was displayed dichoptically, ‘where one eye was allowed to see only the falling objects, and the other eye was allowed to see only the ground plane objects.’ This adaptation required the eyes to work simultaneously.

Results showed half of the participants played regular Tetris with the stronger eye patched up, while the other half of the participants played the adapted game with both eyes open. At the end of the study both groups improved, but those who used both eyes and played the game through the headset, showed a dramatic improvement.

Many people play Tetris just to pass the time. However, it seems as though Tetris may have therapeutic benefits; showing an amazing and captivating effect on the mental and physical processes in the body and enabling interventions for many kinds of disorders and conditions.

 

The Science of Jet Lag

airplaneJonathan James

It’s only been in the last few decades that long distance travel has become commonplace in our lives. With it has come the phenomenon of desynchronosis, a combination of symptoms including headaches, fatigue, and loss of concentration. This is better known as Jet Lag. Resulting from the disruption of our bodies circadian rhythms –  the collection of processes that ensure that all our body functions follow a roughly 24-hour clock, Jet Lag can make travelling on holiday or to a business meeting on the other side of the world a nightmare for even the most seasoned traveler. But what exactly is it about travelling across multiple time zones that so badly disrupts our systems, and are there ways to minimise its impact?

What is Jet Lag?

Our bodies internal clocks are regulated by a hormone,melatonin, in an area of the brain called the pineal gland. As night time approaches, the pineal gland produces more melatonin, which has lots of effects on our body – the most obvious being that we become tired, triggering us to sleep. This system relies on us being exposed to different light levels during the day – as light levels begin to fall in the early evening, different genes are switched on or off, getting us ready for sleep. This is all overseen by an area of the brain called the hypothalamus, which scientists refer to as the ‘master clock.’

Travelling across multiple time zones completely messes up the regular system going on in our brains by either extending or reducing the amount of time we are exposed to daylight. As an example, a Flight from London to New York can take around eight hours. Because you are flying ‘backwards’ against time zones, you’ll arrive in the United States only three or four hours later than you left London, effectively creating a time ‘lag’ of over four hours.

For longer flights, these delays become even more significant, but it is ‘forward’ travel that has the greatest impact. As you travel eastward, you are shortening your day, resulting in your brain having to process the idea that it must sleep much sooner than it would normally have to. This results in a lot of internal ‘confusion’ – processes regulating everything from sleeping patterns to digestion are thrown out of kilter, resulting in the typical symptoms we associate with Jet Lag.

How might we minimise its effects?

Research carried out by a group of scientists at the Nuffield Laboratory in Oxford in mice has shown that a protein, SIK1 plays a role as a kind of natural brake mechanism in the mouse, responding to light exposure and stopping the mouse’s body clock. By inactivating this protein, the scientists could produce mice which can adjust to changes in time zones much quicker. Work done by these scientists, as well as research carried out in Japan, has opened the door to the idea of a jet lag ‘cure’ – a medication able to block a similar protein found in humans. However, with much of their work in the experimental stage, the idea of a wonder cure to jet lag is some way off.

Is it possible that there might be other, more easily adopted ways to minimise the effects of Jet Lag? One way might be to take melatonin orally in small quantities – work at Rush University Chicago has been exploring the impact of giving small doses (0.5milligrams) along with exposure to ‘light boxes.’ They’ve demonstrated remarkable results, resetting subject’s circadian rhythms and minimising the impact of Jet Lag. Since then, there’s been an explosion in mobile apps and programmes such as Entrain, designed to help travelers adjust to crossing time zones by telling them when to expose themselves to bright light. Many of these programs have had limited testing, so it’s good to be wary of so called ‘miracle cures.’

In retrospect,  Jet Lag is unavoidable, with the advent of long distance travel in the last few decades meaning we’ve had little time to evolve to the challenge, and whilst we might try to avoid light exposure at certain times and try to maintain a normal sleep cycle, overcoming our own natural body clocks is a pretty big ask all the same.

Are Mobile Phones Safe?

Ellen Moye

Most of us would agree that a mobile phone is an essential part of our lives today. We use them not only for texting and calling, but also as a calculator, a weatherman, a games console, a compass, a camera, a watch and to access the internet. In fact, some of you may be reading this article on a mobile phone!

But how many of you have stopped to think about the possible dangers of this little, radiation-emitting box you’re willing to hold so close to your head?

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Image Credit: Pexels

The World Health Organisation takes the potential dangers of mobile phone transmissions very seriously, because of their widespread use. Their potential effects on human health have been the subject of many a scientific study with most of them looking at the potential links with cancer.

So far, most research has found mobile phone transmissions (both from the phone itself and from the telephone masts) insufficiently powerful enough to cause cancer.  However, some suggest that this little amount of radiation may interact with natural electrical oscillations in the body and still have detrimental effects including; headaches, sleep disturbances, epileptic fits and tumours. Research remains inconclusive, and, thus, mobile phones remain classified as a “possible carcinogen”.  

The International Agency for the Research on Cancer comments that any link that is found between mobile phone use and cancer could also be explained by a common factor. For example, someone that lives a sedentary lifestyle is more likely to get cancer but also more likely to use their mobile phone a lot. The cause of cancer could be the sedentary lifestyle, rather than the mobile phone use.

Other, potential health effects that have been investigated include; an increase in reaction time, effects on the brain’s ability to absorb sugars near the site of the mobile phone antenna, interference with pacemakers and effects on sperm motility and quality. Although, most of the studies that lead to the above observations are hard to replicate and we cannot be sure that the results are not just down to coincidence.

Social effects are also apparent. With the increased use of the mobile phone people are more contactable than ever. We can be contacted by our spouses at work and our bosses on the weekends. This increased contact may explain the rise in telephone phobia. The second, most obvious social effect is using mobile phones at inappropriate times. We’ve all seen the adverts and we all know the dangers of using a mobile phone when driving. Mobile phones provide a distraction that is not always welcome and can have devastating consequences.

It’s not just human health that is under investigation; visual pollution and environmental effects are also very real problems related to mobile phone use. The reason most people protest the construction of a mobile phone mast is not the potential health risks but the blight to the landscape. Masts are big, metal and – in most people’s opinion – ugly.

The potential environmental effects are as vast and varied as the potential health effects. There are potential problems with the mobile phones themselves, in that they contain heavy metals which, if disposed of incorrectly, can be introduced into the environment and affect the food chain. There may be problems with the telephone masts too, as studies are being conducted into the effects on surrounding wildlife and tree density. The effects on the environment, like the effects on health, are not certain and require further research.

Mobile phones have not been in popular use for very long they are a recent invention and we cannot be sure of the consequences of long term use. No one generation has lived a full life with regular mobile phone use and with some scientists suggesting the risk is amplified in children how can we be sure that there will be no effects in someone who has used a mobile phone from a young age when they reach their 60’s or 70’s?  

One thing is clear, though, driving whilst fiddling with your mobile phone is a real danger.

NHS recommendations for mobile phone use:

  • Only make short calls and do not use it more than necessary.
  • Children should only use mobile phones for essential purposes.
  • Keep your mobile phone away from your body when you are not using it.
  • Only use your phone when the reception is strong.
  • Use a hands-free kit to keep your phone away from your head whenever possible.

Department for Transport guidelines for safe use of mobile phones in cars:

  • It is illegal to use a hand held mobile phone when you are driving.
  • Keep your mobile phone switched off when you are driving.
  • If you need to use your mobile phone, stop in a safe place.
  • Avoid using a hands free device – they can still be distracting.