The Science of Taste

By David Morris

Structure of a taste bud

In 350 BC, the Greek philosopher Aristotle postulated that varying blends of two tastes, sweetness and bitterness, comprised all flavours. As the understanding of taste developed, it was shown that sourness and saltiness were also distinct tastes. In 1908 the Japanese chemist, Kikunae Ikeda, discovered a fifth subtle and now well established taste known as umami. Until recently, these tastes were universally accepted as the five fundamental detectable tastes that made up all flavours that can be experienced by humans.

The role of smell (olfaction) in flavour wasn’t fully appreciated until as late as 2004, when biologists Richard Axel and Linda Buck discovered the role of the nose in detecting and characterising odours. When you breathe in through your nose, millions of odorous molecules activate and inhibit olfactory receptors at the roof of the nasal cavity. Electrical impulses travel from these receptors to the brain, informing you of what you’re eating. This action is supported by taste buds in the mouth.

Molecules within certain foods can chemically activate senses that are responsible for the sensation of heat, pain or touch. This is known as chemesthesis. Despite being different from taste, chemesthesis can contribute to the flavour of a substance. Examples include the ‘tingle’ on the tongue from ingestion of carbonated drinks, the feeling of heat upon eating a chili pepper, and the cooling feeling from eating gum.

 Taste receptors are mounted on papillae, which are structures found on the front and back of the tongue, the roof and sides of the mouth, and even at the back of the mouth and throat. The idea of a ‘tongue map’ whereby certain areas of the tongue detect certain tastes is a myth, although the concentration of certain receptors may vary in different areas of the tongue.

           Saltiness and sourness are the simplest of the tastes. Sourness arises from the donation of hydrogen ions, which is a characteristic feature of acids. It has been postulated that detection of sour foods defends the body from ailments like indigestion. Similarly, saltiness arises from the dissociation of salt on the tongue, forming sodium and potassium ions. The taste response acts as a warning for your body to replenish electrolytes, but not too much, hence why we find salty foods appealing, but also repulsive in large amounts.

                  

           Bitterness, umami and sweetness are more complicated tastes. They all come from the binding of larger, more complex molecules to large proteins in the taste buds that are typically responsible for signal transduction throughout the body. Bitterness receptors can bind with molecules that are usually toxins or poisons. In this way, the bitter taste warns your body against ingesting molecules that can harm your body.

           Similarly, umami receptors detect glutamate (a component of monosodium glutamate, or MSG, a popular salt substitute), giving off a subtle savoury taste. The subtlety arises because the glutamate is usually bound to sodium, giving off a more powerful salty taste. Glutamate is useful to your body as a neurotransmitter and a catalyst to metabolism, so like salt, the taste warns your body to replenish glutamate, but not excessively.

Tomatoes are rich in umami

           In July of this year, academics at the University of Purdue published a paper in Chemical Senses describing the existence of a sixth taste called oleogustus. Usually, when the body ingests oil or fat, it is in the form of triglyceride, a molecule comprised of three fatty acids chemically bound through a glycerol molecule. This triglyceride is too large to fit into oleogustus receptors and thus can’t be tasted. However, when the fat spoils, the triglyceride is broken down into glycerol and the fatty acids. The fatty acid then binds to the oleogustus receptors and acts as a warning that the food is no longer suitable for ingestion, hence it smells and tastes rancid.

                  

           Each of the aforementioned tastes, as well as the olfactory and chemesthetic systems, have proven essential for the body to be able to consume the correct amount of different types of food, and to protect from ingesting harmful toxins and poisons.

Is it safe to reuse plastic bottles?

by Rachel Argo

Typically, I will buy a bottle of water and re-use it until I loose it. We all know that re-using a plastic bottle is good for both the environment and our pockets, but by doing this are we increasing our risk of exposure to ‘dangerous’ chemicals in the plastics? Recently bottles have been designed and marketed as being ‘BPA free’. But what is BPA and why have we never heard of it before?

Maybe you have seen strange shaped bottles with coloured filters appearing in people’s handbags, at the gym or on the high street? ‘Bobble’ bottles are an example of these BPA free plastic products. They are made from recycled materials, are recyclable and contain replaceable filters that claim to remove impurities in the water and improve the taste. Bisphenol A (BPA) is a synthetic organic molecule that is used to make certain plastics such as ‘polycarbonate’. Polycarbonate is commonly used to make household items like drinks bottles and tupperware. BPA is also found in epoxy resins that are used to line drinks cans and tins. We come into contact with plastic all the time and admittedly it would be very difficult to exclude from our day-to-day lives. Until recently no one questioned the effect of this plastic heavy lifestyle on our health, so should we stop re-using that water bottle and buy a BPA free one?

Studies have suggested that BPA possesses the ability to pass from the containers to the food or beverages inside. The concern around this possible seeping stems from the chemical’s ability to act as a mimic of the hormone oestradiol and therefore have potential to interrupt hormone patterns and signaling pathways. Animal studies in rats and mice have linked BPA exposure to a range of health problems such as obesity, fertility impairment, respiratory disorders and inflammation, however there is little or no research into the effects on humans and no single study that conclusively proves that BPA is the cause of these diseases. 

A review in 2006 by the European Food Safety Authority (EFSA), concluded that the Tolerable Daily Intake (TDI) of BPA was 0.05 mg/kg body weight/day. This value is an estimation of the amount of BPA that can be ingested per day per kg of body weight daily, over a lifetime without significant risk to health. BPA is licensed by the EU for use in food contact materials, however a directive in January 2011 prevented the use of BPA containing plastics in the manufacture of baby bottles. The most recent review of the molecule’s safety (July 2013) provisionally suggests that diet is the main source of exposure, that the estimation of this exposure is much lower than EFSAs previous estimations and well below the suggested TDIs. 

Due to the lack of conclusive evidence of BPA safety in humans and changing opinion on TDI values, it is hard to decide if it is worth investing in a BPA free bottle. I initially thought that this was a trendy case of false science, but on closer inspection it seems there may be some truth in their safety claims even if we have not established the extent of it.

The Musical Brain

2013 BNA Christmas Symposium overview

by Jonathan Smith

How does the human brain distinguish music from noise? What brain regions are active when we react to music? Do we all share an intrinsic musicality? How do you make a duck into a soul singer?

These important questions were discussed this month in an annual Christmas symposium held by the British Neuroscience Association (BNA). Speakers from all over the UK were invited to present their findings on the special relationship between Homo sapiens and music. These talks were also interspersed with live music, refreshments and humorous ‘Christmas Crackers’ such as the latter question asked above. In this article I summarise the research discussed in this exciting symposium.

Distinguishing music from noise by pattern-detection
It’s rare to be in a completely silent environment, even in university exams! Being able to tell apart rhythm from random noise is very advantageous. This is because we can be alerted to someone’s footsteps for example, which can let us calculate all sorts of useful information such as the proximity, speed and even mood of the walker.

Dr Maria Chait from the University College London (UCL) demonstrated that humans are incredibly sensitive to rhythmic, repeating sounds. This is even the case when our attention is diverted to other tasks - showing that there is continuous, sub-conscious processing that is very effective at detecting rhythms in our auditory inputs. This might go some way to explaining why all human societies feature some form of rhythmic musical tradition, including genres like polyrhythmic African drumming and thumping dance floor beats.

The Beat in society
It’s clear that an important component of most music is a regular pulse, or beat. The beat provides a regular structure on which we can build harmonies, rhythms and melodies. As demonstrated by the audience in a clapping task, humans are very good at detecting the beat of a piece of music and then moving in sync with it - in other words, dancing. Any Youtube video search would also reveal that our fascinating ability starts at an early age. What is happening in the brain when we detect a beat?

In studies by Dr Katie Overy of the University of Edinburgh, participants were tested to see if they could tell if the beat was repeated in patterns of fours, threes or twos, corresponding to 4/4, 3/4 and 2/4 times for musicians. Using fMRI scans to show active brain regions, Dr Katie Overy showed that groups of neurons deep inside the brain called the Basal Ganglia are very active when carrying out this task. The Basal Ganglia are highly connected regions that are really important in both sensory and motor processing, so this might be an interesting link between listening and moving to a beat. Not only this, but diseases involving the Basal Ganglia, such as Parkinson’s Disease, result in impaired beat detection. Perhaps by using music in more therapies we can provide better ways of treating Parkinson’s Disease and other Basal Ganglia disorders.

The emotional response to music
As most would agree, the soundtrack to a film deeply influences how a scene is portrayed. For instance, dissonant melodies convey discomfort and fear whereas smooth, major keys give a sense of calm and peace. At its most extreme, a piece of music can literally make our hairs stand up on end and give us the ‘chills’. This strong emotional response was measured by Dr Alan Watson of Cardiff University.

Dr Alan Watson’s lab used lie detectors to find out when we get the chills from a piece of music. This is due to the fact that lie detectors are very sensitive to changes in autonomic nervous system activity, such as sweating and pulse rate. Since our autonomic nervous system changes in response to strong emotions, the lie detector is a nifty way of showing when we get the chills! Using various imaging studies, the researchers were able to show that the chills are accompanied by a huge release of dopamine in the ‘pleasure’ circuits in the brain. This thus helps to explain why we can react so strongly to music.

Congenital Amusia and musicality
Some individuals are unable to enjoy music. Some, for example, even have trouble distinguishing between Happy Birthday and the National Anthem. These people may suffer from a condition called Congenital Amusia, a disorder of interpreting musical patterns. Yet, studies of these unique individuals may uncover just how innate musicality can be in the human brain. Dr Lauren Stewart from UCL collaborated with the BBC to carry out some of these studies.

Using a test called the Montreal Battery, the researchers found that people with this disorder have difficulty distinguishing musical tones compared with controls. They even have some trouble in detecting changes in speech tones, such as a question or a command. The research got more elaborate. The experimenters designed an artificial nonsense language and asked participants to detect if they heard a particular word in a phrase e.g. Pa-ti-ba. Interestingly, amusics were no different to controls, even when the ‘language‘ was replaced by musical tones! This indicates that amusia-sufferers may not have an absolute deficit in distinguishing pitches, but rather a lower confidence when doing so. This also indicates that a form of musicality is present in all individuals but can be honed by constant practice.

Dementia and music
Most of us are acquainted with someone who is going through the pain of dementia. It’s a very isolating ordeal for all involved and it’s expected to get much more common within the next few decades. Is music a good way of maintaining contact with sufferers who are gradually losing other precious memories?

Dr Jason Warren from UCL began by emphasising the complexity of music as a cognitive function. It’s encoded in many brain regions and evokes strong emotional and associative memories of events of that concert, party etc. All types of dementia have unique patterns of brain region damage. For example, Frontotemporal dementia (FTD) has specific damage in the knowledge-encoding temporal regions and the motor and emotion-encoding frontal regions of the brain. It turns out that FTD patients have selective impairments in identifying scary and angry music. This may prove to be an effective diagnostic tool because music is a much more robust memory than current tests using the memory of faces.

Peter Todd of the Alzheimer’s Society gave a fascinating talk about his experiences. He organises weekly singing groups called Singing for the Brain. The only difference here is that the participants are dementia sufferers at all stages of the disease. While it might not seem easy to pull off a group session with this requirement, the results of these groups are very encouraging. The groups have even performed at festivals and for BBC Radio 4! The aim of the groups is to include everyone at a personal level, no matter what level of dementia they are suffering. One heartwarming example of the good effects of these groups is of one patient who had lost his short-term memory. He couldn’t even remember that he had been in a singing group for the last hour! However, after every session, it was clear from his posture and manner that he was very upbeat from singing with the group, despite not being able to remember why! Examples like this emphasise the importance of music in social bonding for potentially lonely individuals going through dementia.

Wrap-up

It’s clear that music has been an integral part of human history. This shown by the presence of music in every human culture on Earth and the sheer amount of processing power devoted to music in our brains. The brain is a pattern-seeking machine and it has progressed from interpreting primitive vocalisations in forests to sophisticated music forms. Our emotional connection to music and musicality is preserved to a certain extent in everyone. It also proves to be an effective tool for identifying dementia symptoms and also encourages social inclusion for dementia sufferers.

Oh, and if anyone was curious about how you turn a duck into a soul singer, the answer is: Put it in the microwave until its Bill Withers.

Transplanting Memories?

by Rhema Anderews

George Bernard Shaw once said, “All great truths begin as blasphemies.” In the realm of heart transplantation technology, none has posed greater uproar than the controversial concept of cellular memory.

Cellular memory is the notion that the brain is not the only organ capable of storing memories. In fact, all living cells possess “memory”. Evidence for this has been found predominantly in heart transplant patients. Studies on cellular memory from transplant patients are often conducted by scientists with the aid of the hospital system which forbids the recipient to know or communicate with the donor’s family with most cases without the mention of names.

On May 29, 1988, Claire Sylvia received both the heart and lung of an 18-year-old man killed in a motorcycle accident. After the surgery, Sylvia claimed an intense craving for beer, chicken nuggets and green peppers, all of which she never liked before. She began to assume a masculine walk (peculiar for the dancer), started swearing in conversations, and for no apparent reason took up motorcycle riding at dangerous speeds, which was totally out of character. Sylvia even started having recurring dreams of a mysterious man. In her book entitled “A Change of Heart”, she recounted a dream where she kissed a boy thought to be named Tim L. and inhaled him into her. Upon meeting the “family of her heart” as she put it, Sylvia learned the name of her donor was in fact Tim L., and all of the changes she experienced closely mirrored that of Tim L. who strangely at the point of death had chicken nuggets in his pockets. Sylvia’s story quickly captured media attention and soon after, many other transplant recipients came forward with similar testimonies.

The most striking example is that of an eight-year-old girl who received the heart of a ten year-old-girl. Post-surgery, she was consistently plagued with distressing dreams of an attacker and a girl being murdered. Her nightmares proved so vivid that even her psychiatrist believed them to be genuine memories. As it turns out, the donor was a murder victim and as a result of the recipient’s violent recurring dreams, she was able to describe the horrifying incident and the murderer to such great detail that the police eventually apprehended, arrested and convicted the killer.

Ongoing research has shown that neuropeptides and receptors previously known to exist exclusively in the brain have been discovered in places throughout the body, especially in major organs such as the heart. These neuropeptides are a means for the brain to communicate with other organs and for these organs to send feedback to the brain. However, little is known about whether these neuropeptides can store memory; due to the amount of peptides in the heart, there seems to be a strong correlation between the two. But if this were the case, then why don’t all patients go through this experience?

There is no solid evidence that the reports are nothing more than coincidence and fantasy. Even so, the stories are intriguing and we should expect some serious investigation into the matter in the near future. Until then let’s keep an open heart.

Freestyle Rap: Where in the Brain is Creativity?

Jonathan Smith

Creativity, according to blogger and The Oatmeal comics creator Matthew Inman, is like a river that has input constantly flowing in and out of it. Rather than being a finite ‘container’ of ideas, it is a dynamic entity that changes throughout your waking day. 

Despite being a trait that is central to many professions, such as writing, art, and music, creativity is not well understood in cognitive neuroscience. Where do ideas come from? How is inspiration encoded in neuronal networks? One recent study in Nature (summarized here) set out to investigate aspects of these questions by performing functional magnetic resonance imaging (fMRI) on freestyle rappers. The fMRI imaging used in this study detected blood flow (increased blood flow corresponds with increased brain activity) to regions in the brains of twelve male freestyle artists in two scenarios. In the first scenario, they performed memorized predetermined lyrics to a backing track as a non-creative control and in the second, they performed freestyle rap and the differences in brain region activity were measured. 

An interesting finding of the study was that the cortex at the front of the brain (prefrontal cortex) showed different changes according to which region it was. Prefrontal cortex close to the line separating the two hemispheres of the brain (medial) was activated whereas prefrontal cortex further from the middle of the brain (dorsolateral) was largely deactivated. One explanation for this might be that the imposing executive functions of the dorsolateral cortex are reduced, allowing the flow of ideas from other parts of the cortex. It is a bit like stern parents going away for the weekend and leaving their wild child in charge of the house.

A similar pattern was seen in another study investigating the brain patterns of jazz musicians. Would this pattern of activity happen in other creative processes such as painting a picture? This is not known, but it would be pretty interesting to find out.

Other findings from this study suggested that a large amount of the creative processes are in fact below the conscious level as activity could increase long before lyrics were being generated. This seems to agree with the experiences of improvisational performers who often cannot pinpoint an exact source of their ideas. So in conclusion, if you are searching for an innovative idea for your next project or essay, just stay away from your parents for a while and let the inspiration flow! 

Evolution of the athlete

Felicity Russell

As the London 2012 Olympics draw to a close and we have watched how our athletes push their bodies to the extreme to achieve award winning performances, it is easy to see what an amazing species we are. A species more advanced compared to the many other living creatures that we share our planet with. Especially as our closest living relative happens to be the chimpanzee, that split from us 6-8 million years ago. How is it that tree dwelling apes evolved into a species capable of such athleticism? Only recently numerous fragmentary fossils have been discovered which start to reveal our origins and how we came to evolve.

Sahelanthropus

The oldest suspected hominin species found is Sahelanthropus, thought to be 6-7 million years old. The skull appears ape-like but has a distinctive browridge like other identified hominin species. The hole at the base of the skull where the spinal cord passes (foramen magnum) is horizontally orientated suggesting a bipedal posture. Another indication of a hominin species is provided by the shape of its teeth, Sahelanthropus has small canines unlike the larger sharp ape-like canines. Ardipithecus ramidus and Ardipithecus kadabba, thought to have lived between 5.8-4.3 million years ago, are two more examples of hominins where tooth shape indicates a more human like function. However, clues found from Ardipithecus toe bones controversially suggests bipedalism, as joint surfaces are different in humans whose feet flex up to a greater extent than chimpanzees.

Australopithecus species, such as Australopithecus afarensis, Australopithecus anamensis and Australopithecus africanus, lived approximately 3 million years ago. They have thicker tooth enamel compared to apes and the shape of their canines and premolars suggest a more human function. The presence of shorter, broader hips is indicative of a more human like posture and leg bones have revealed human like features. The Paranthropus group, often thought as part of the Australopithecus group, existed 2.5 million years ago. They are also described as bipedal and interesting dental evidence suggests they were especially well adapted to eating nuts and seeds.

Early Homos, such as Homo habilis, Homo rudolfensis and Homo erectus are thought to have lived within the last 2.5 million years, coincident with discoveries of stone tools. A bigger brain size has often been associated with early Homos, suggesting they are more like Homo sapiens (‘intelligent man’). Three new fossils have recently been discovered supporting claims that Homo rudolfensis is a separate species from Homo habilis. Later Homos include Homo heidelbergensis, Homo neanderthalensis and Homo floresiensis. Homo heidelbergensis lived 300,000 to 700,000 years ago and wooden spears have been found nearby indicating that they hunted large animals. Homo neanderthalensis are thought to have used more advanced stone tools to carve meat from larger mammals. They had a large browridge and a human-sized brain. They are also known to have buried their dead and the more recent Neanderthals also made simple jewellery from animal teeth. They may have gone extinct as recent as 30,000 years ago. Homo floresiensis is the most recent distinct species, living up to just 17,000 years ago. They were short, often referred to as hobbits, and despite having smaller brains researchers have still found evidence that this species also used tools. Homo sapiens may have existed as long as 200,000 years ago originating from Africa and by 30,000 years ago they replaced Neanderthals in Europe.

Did humans evolve to run? ILLUSTRATION BY PHIL DISLEY

Noakes and Spedding (2012) have now suggested that it is our ability to run and to dissipate heat which aided our evolution. As forests disappeared and large open savannahs appeared, our ancestors had to adapt and evolve from a skeleton developed for tree climbing to a structure required for walking and even running. A lack of body hair and the ability to sweat as much as 3 litres in an hour meant we could lose heat more easily and enabled us to chase after four legged prey which require panting as a mechanism to dissipate heat. The prey would not be able to pant and run at the same time and eventually would be driven to heat stroke. The development of longer legs, shorter toes, a stronger gluteus maximus, larger weight bearing joints and broader shoulders is suggested to have aided our ability to run long distances. We have also been able to develop an aerobic capacity capable of supporting such long distance runs unlike any other ape species. Therefore as you celebrate how extraordinarily well our athletes have done for London 2012, remember how remarkable evolution can really be.

Fun point: Australopithecus anamensis, Australopithecus afarensis, Australopithecus africanus – try saying this over and over again it is definitely a tongue twister. 

The evolution of human stance

More information:

Fossil record of early humans - http://www.becominghuman.org/node/human-lineage-through-time

New fossil discoveries - http://www.newscientist.com/article/dn22151-fossils-confirm-three-early-humans-roamed-africa.html

Noakes and Spedding (2012) paper - http://www.nature.com/nature/journal/v487/n7407/full/487295a.html?WT.ec_id=NATURE-20120719

The Animal Olympics

Tom Stubbs

We are over halfway through the Summer Olympic Games of 2012. Over the last week we have witnessed some incredible feats of speed and strength and multiple world records have been broken. But how do us hairless bipeds compare to other members of the animal kingdom?

Speed kings
Usain Bolt won the 100m sprint gold medal with a time of 9.63 seconds and in the 2008 Beijing Games he ran 9.69 seconds to win gold. More impressively, in the 2009 World Championships Bolt set two world records, running 100m in 9.58 seconds and 200m in a time of 19.19 seconds. This consistency has established him as the fastest human athlete ever. However, compared to some members of the animal kingdom Bolt looks like a bit of a slouch. The cheetah could complete the 100m sprint in 5.8 seconds and it is around twice as fast as the world's top sprinters, reaching speeds of 64mph. Bolt’s 200m record would be smashed by a cheetah that would complete it in just 6.9 seconds. The pronghorn antelope is another speedy competitor with running speeds of around 55 mph. If the pronghorn entered the 800m it could complete it in an incredible 33 seconds. To put this into context, the Kenyan 800m world record holder, runner David Rushida, ran that distance in 1 minute, 41 seconds.

Stamina, strength and swimming
How do our athletes compare in other Olympic events? Well this year’s Olympic gold long jump was won by Greg Rutherford with a leap of 8.31m. The world record long jump is a whopping 8.95 meters, currently held by Mike Powell. This distance approaches the leap of the red kangaroo (12.8 m) but falls short of the snow leopard that can jump up to 15 metres. Behdad Salimikordasiabi is considered the strongest man in the world after winning gold in the men's +105kg weightlifting category, lifting 247kg in the final. An elephant can lift 300kg with its trunk alone and the Gorilla, one of our closest relatives, can lift an unbelievable 900kg! It would be hard to argue that Michael Phelps is not the greatest swimmer of all time. In a 200m freestyle race Phelps swims around 4mph, a sailfish can travel at speeds of 67mph!


Although these comparisons may seem rather strange because the various animals mentioned are adapted to a specific mode of life, it does serve to highlight the incredible athletics abilities evolved through natural selection. Equally, these comparisons highlight the exceptional versatility of the human body. With training, athletes are able to tune their bodies to specific tasks. Can you image finding individuals within any other species that have such variation in speed and strength? This is what the Olympics places in the spotlight.

Check out the videos below!

Bolt vs. Cheetah 

  

The 10 Fastest Creatures on Earth

The controversy of immortal cells

Louisa Cockbill

Did you know that it is possible for human cells to be removed from the body and survive, even multiply in number? Growing cells outside the body is known as ‘cell culture’. Cells grown in culture are often taken from tumours because tumour cells have the ability to grow infinitely when supplied with nutrients.These immortal cells are incredibly important in medical research, as they allow researchers to study and experiment on cells humanely; that is outside the body.

HeLa cells

But where do these cells originate from? I mentioned that many cells in culture are originally taken from human tumours, from biopsies or from a surgically removed tumour. Nowadays ethical permission is received from the patient to study the tumour; however medical permission forms didn’t always exist and neither did cell culture, so where did the practice of growing cells come from?

The first cells ever to be immortalised in culture were from a biopsy of a cervical mass (a tumour) from an African American woman called Henrietta Lacks from Baltimore in 1951. They were called HeLa cells and their immortalisation in culture changed the face of medical research. HeLa cells were exposed to all forms of bacteria and viruses to study the method of infection, replication etc. in order to block these processes with antibiotics, vaccines etc. Indeed Polio vaccine neutralisation tests were some of the first vaccine trials that used HeLa cells. Today HeLa cells can still be found cultured in every lab and it is estimated that 50 million tons of HeLa cells could have been grown.

I’ve always viewed cell culture from a purely scientific perspective, but since reading ‘The immortal life of Henrietta Lacks’ by Rebecca Skloot I’ve started to look at cell culture from an entirely new perspective. Henrietta Lacks’ family didn’t find out about her immortal cells until 1973; 22 years after HeLa cells were first cultured. Why had no one told the family? Why is it that the Lacks family can’t afford health insurance, when their mother’s cells have driven forward frontiers in understanding disease?

The truth is that Henrietta’s cells were cultured without her knowledge or consent at a time before regulations were set in place to safeguard patient’s rights. Regulations now ensure that informed consent must be received and the patient informed of any commercial benefit that can be made from their medical donation.

Henrietta Lacks

I think what particularly struck me on reading ‘The immortal life of Henrietta Lacks’ is how strange it must have been for Henrietta Lacks’ children to find that cells from their mother were alive! It has made me wonder how I would feel if cells had been taken from my Grandmother’s colorectal tumours and grown; who knows, she died in 1965 before law ensured patient consent, maybe her cells are out there. It’s a disconcerting thought.

On the other hand how amazing would it be if the cells from the cancer that killed my grandmother were used to cure the disease? Especially handy as the cancer appears to be hereditary. Indeed although the Lacks’ family are indignant at not being informed about the culture of HeLa cells for two decades and the lack of explanation given them, they are marvelled by the medical breakthroughs made possible by the cells cultured from their mother.

The story of Henrietta Lacks may have made me question certain scientific precepts but has certainly opened my eyes to better appreciate the invention of cell culture and the lives behind the cells. To read more about Rebecca Skloot’s discovery of the world of Henrietta Lacks and cell culture I’d advise you to read ‘The Immortal life of Henrietta Lacks’ which is available for loan from the University of Bristol Medical Library.

More information:

http://henriettalacksfoundation.org/

http://www.youtube.com/watch?v=_FaQ9Utx--E

Why do our fingers wrinkle when wet?

Gemma Hallam

Look familiar?

Now you’re home from student accommodation you may have re-established access to a bathtub! And there’s nothing better than a steamy, relaxing wallow to cheer us up from this ghastly downpour, which is invading our ‘summer’ break. But upon finally emerging, you look down at your hands and feet and wonder at what point your appendages were replaced with those of an old lady!

Layers of the skin

What happens is the outer layer of skin (the epidermis) absorbs a little bit of water and expands. The layer underneath (the dermis) doesn't do this and so the skin on top buckles – folding in places – leading to the wrinkly digits we’re all so familiar with. The skin on our hands and feet is thicker than on the rest of the body and so the changes here are noticeable whereas the rest of our braised bods appear to have remained less than 80 years old!

'Wrinkle drainage'

Another idea was recently forwarded that suggested ‘pruney’ fingers are an adaptation to help humans and other primates grip in wet conditions. In this theory the wrinkles act like rain treads on tyres allowing water to drain through channels when we press our fingertips on a wet surface.

Functional or unintentional it is certainly a relief when our hands dry and return to normal!

For more information on the current theories check out this link - Are Wet-Induced Wrinkled Fingers Primate Rain Treads?