Saturday, 29 November 2014

An interview with Professor Bruce Hood, School of Experimental Psychology, 11/11/2014 - by Melissa Levy

Professor Bruce Hood is a Professor of Developmental Psychology in Society. He is specifically interested in cognitive development from a neuroscience perspective, but also works on face and gaze processing, inhibitory control of thoughts and actions, spatial representation and action, na├»ve theories and the origin of adult magical reasoning from children’s natural intuitions. If you want any more information about what he and his group then follow this link:

Where did you go to university and what did you study?

“My first university was the University of Dundee in Scotland where I did an arts degree. In Scotland you can do a four year degree and take lots of different topics, I didn’t know anything about psychology and I was doing things like economics, accountancy and finance but I had to take another subject and so I took psychology and fell in love with it! This made me decide that I wanted to be a psychologist! So I went to Cambridge and did my PHD there, so I’ve been in Scotland and Cambridge.”

How did you get from there to where you are now in Bristol?

“How long have you got?!
After Cambridge I had a position at UCL and then I got a MRC (medical research council) travelling fellowship which enabled me to go anywhere in the world and I went to MIT. So I did my post-doctorate at MIT and then I applied for a position at Harvard and I was an associate professor there for five years. Then I came to Bristol.”

How would you describe your area of research to someone who’s not in the field?

“Well I have very diverse interests but I suppose they all deal with aspects of development of mind - in the childhood origins of how we think as adults. I’m interested in children not because they’re kids but because I think they give a great insight into the complexity of adult behaviour and the human mind and also some indication as to how we’ve evolved complexity.”

How would you describe your typical day and your typical research? It’s obviously different to that of a chemist let’s say…

“Well unfortunately I don’t have the luxury of doing the research myself directly, although occasionally I will help out. I really love conducting research and collecting data but because I’ve got so many projects running simultaneously I can’t actually collect data myself. So usually it’s working with my post-docs and my grad-students to devise and design experiments, piloting them here in the centre and then very often taking them out into the community.
We do research at the @Bristol Science Museum, but we also collect data in the schools, so it’s a lot of what you would regard as field work. But if we were using a technology which doesn’t transport like eye-movement recordings or ERP (Event Related Potentials –brain signals) then we would do that in the lab.”

If you could go back to conducting the field work yourself would you do that or are you happy with where you are now?

“Yeah I am happy where I am now, but I’ve not lost touch with the sheer joy of data collecting. For me, experimentation is just wondrous and the fact that I can be paid for something that I enjoy so thoroughly is fantastic and I love to share that! I mean there are so many questions that I’d like to answer and I couldn’t answer them myself so I need to have people doing it for me and that’s why we have research students doing that all. I mean I would be delighted if I was just doing research.”

What advice would you give to someone looking for a career in science?

“Passion! That’s what gets you out of bed in the morning!
You have to have a sense of wonder and joy and curiosity, and if this is what you want then this should be enough to drive you forward, and if you have the confidence to do so then you should be fine.”

What has been your proudest achievement to date?

“Well I suppose it has to be giving the royal institute Christmas lectures on the BBC. I’m very passionate about what I do and I really want to take science out into the community and that is the pinnacle of public engagements so that gave me, for a very short time, a platform and a spotlight, which was really quite exceptional. I got to meet so many amazing people, I got to inspire people and I’ve had email correspondence from parents of young children – they still contact me three years later keeping me up to date with their achievements in science and I find that extraordinarily valuable to realise that what you do actually changes people’s lives and makes a difference.
 I’ve always felt that we (psychologists) have a bit of an identity problem that people don’t see us as a real science and that really annoys me. So that’s my other agenda, to make sure people understand how complex the mind can be and that it’s not common sense at all. There are some extraordinary things that we are yet to discover. So yeah I’m passionate about science communication.”

If you could do science with anyone, dead or alive, who would it be?

“Gosh, so many to choose from!
One of my greatest mentors was Richard Gregory. You may not know, but Richard Gregory was and still is a great influence on many of us. Richard effectively started the first science museum, the Exploratorium here in Bristol, and he was a great and passionate science communicator. He did some really brilliant work on vision and perception, has illusions named after him – everyone who works in my field of perception will know of Richard Gregory. He was of a genre with a connection to the past, he knew Wittgenstein, he was taught by some of the great names, so he made this connection for me with the past. But he was just so enthusiastic and so passionate – it was infectious, he was like a little child at times when he was talking about things! And really that’s what’s so important to me about science.

People think that science is dull and boring and of course it isn’t! You and I know that it’s actually very fulfilling, and  communicating that passion in a way which is sensible to the general public is what my agenda is.”

Thursday, 20 November 2014

Jaws: the impact of media on shark declines by Rachel Baxter

One of Hollywood’s favourite villains, sharks have always been dubbed as horrifying man-eaters. However, this is more fictional creation than fact, and as shark populations rapidly decline, are creations like ‘Jaws’ partly to blame?  

In 1975 when ‘Jaws’ hit our screens, sharks swam into the spotlight as malevolent killers lurking in the deep. Following the film’s release, shark fishing increased rapidly, especially in the USA, as many wanted to emulate the heroic protagonists, whilst others wanted to cull sharks to make the seas safer. This reduced shark populations and 40 years later they are still deteriorating, due to overfishing for sport and meat, particularly for use in shark fin soup, a traditional Asian delicacy.

Scientists estimate that shark finning kills up to 100 million sharks a year. Finning involves catching any shark, regardless of species or size, and removing its fin and discarding the body back into the water. This is often carried out whilst the shark is still alive and subsequently leaves the animal to die a slow and painful death. The heightened demand for shark fins is due to increasing prosperity in Asian countries such as China. This has resulted in a higher demand for expensive delicacies like shark fin soup, which costs up to $100 a bowl. Consequently, the value of shark fins has soared, meaning that thousands of sharks are killed for their fins daily. As a result, many shark species such as tiger sharks and hammerheads have experienced population decreases of over 90% in recent years.

Sharks are an apex predator throughout the world’s oceans. This means that they are at the top of the food chain and significant decline in their numbers has the potential to impact nearly every organism living in our seas. One issue is that in the absence of shark predation prey species populations will proliferate, thus decimating populations of their own prey. An example of this is already occurring in the eastern Pacific Ocean, spanning from California to Tierra del Fuego, at the southern tip of South America. The decline of sharks here has led to a huge increase in Humboldt squid, a predatory species of squid whose populations were historically controlled by sharks. However, due to the reduction in their natural predators, their populations have expanded rapidly and this is having an impact on fish stocks, as the squid will consume nearly any fish that they come across. The true impact of shark declines is still unknown but it is likely to change population numbers of a vast variety of different species and seriously upset the balance of marine ecosystems, all over the world.

Therefore, the conservation of sharks is key. Current conservation efforts include discouragement of shark consumption, especially in shark fin soup through methods such as petitions. Also, more and more sharks are becoming protected. In 1991 South Africa became the first country to protect great white sharks. Furthermore, many countries, including the UK, have now implemented restrictions on shark fishing and finning. Therefore there is hope for sharks, but attitudes need to be changed in order to increase support of conservation efforts.

To change attitudes, it is essential that people understand that sharks pose very little danger to humans; in fact we pose much more danger to them. Whilst an average of 4.2 humans may be killed by sharks each year, humans kill an estimated 100 million sharks annually. There are over 400 species of shark, whilst only 4 of these species have ever been involved in attacks on humans (great white, tiger, bull and oceanic whitetip), yet almost all shark species are affected by fishing. In fact, the chance of a shark attack is minute. Millions of people swim in the sea every year whilst only about 4 fatalities occur annually. In contrast, every year 150 people die due to falling coconuts, 10,000 die by lightning strike, and 24 are killed by flying champagne corks!

What’s more, many shark attacks on humans are thought to be accidental. Shark attacks often occur on surfers. This is because from below, a surfboard with four legs resembles the shape of a seal. In fact, sharks are never out to get humans, as we are not their natural prey. Humans are much larger and bonier than prey organisms such as fish and seals, and wetsuits are not part of a shark’s ideal diet! Also, the vast majority of shark attacks on humans involve only one bite. This is interesting as hunting sharks use an initial bite to weaken their prey, and then use further bites to kill. This indicates that most sharks that attack humans immediately realise that they have made an error, and consequently back away. So, is the revengeful, human-hunting shark from ‘Jaws’ simply an entertaining invention?

It is true that ‘Jaws’ is based on real events; the Jersey Shore attacks of 1916. These attacks involved four fatalities and one injury during the summer of 1916 off the Jersey Coast in North America. However, scientists concur that these attacks were a freak incident, and the same scenario has never been repeated. Ironically, Peter Benchley, the author of ‘Jaws’, became a keen shark conservationist, regretting his portrayal of sharks as monsters as it had such a significant impact on the world’s perception of them.

Perhaps, one day, films will undo what they have done and depict sharks in a new light. Swimmers will no longer be haunted by ‘ba-dum ba-dum’ and more people will be concerned by shark declines. This could reduce shark fishing and improve attitudes towards conservation, so that shark populations are saved before it is too late and the balance of our oceans changes forever.

Monday, 17 November 2014

The IgNobel awards

The ‘stinker’. Official mascot of the IgNobel awards

“For work that first makes people laugh and then think”

by Felix Kennedy

September 18th saw the 24th annual IgNobel awards ceremony take place. Now, almost as famous as the Nobel Prize awards they aim to mimic, prizes are given for research that ‘first makes you laugh, and then makes you think’. The prizes are intended to celebrate the unusual, honour the imaginative and spur people's interest in science, medicine, and technology.

Past notable winners have included University of Bristol professor, Sir Michael Berry, who won the prize along with Sir Andre Geim, for floating a frog in a strong magnetic field. This is possible as almost all material displays a very weak type of magnetism called diamagnetism. Even material that would never usually be regarded as magnetic, such as water, contains electrons. Under a strong enough magnetic influence, the electrons within a material align and develop a magnetic field of their own that opposes the magnetic field they are in. This causes the material to be repelled from the magnet and if the repulsion is strong enough, the material will simply float, in this case the frog. Although the feeling of weightlessness was probably rather disconcerting to the frog, I would like to point out that no animals were hurt in the undertaking of this experiment-the frog was completely fine afterwards!
A weightless frog, floating in a magnetic field

Historically, IgNobel prizes have been awarded for rather obscure work, but real world applications have been found for discoveries that may seem merely interesting at first glance. A good example is a study that won the IgNobel prize in Biology showing that malaria mosquitoes (Anophelese gambiae) are equally attracted by the smell of Limburger cheese and human feet. Since then traps have been baited with Limburger cheese across Africa to help combat the epidemic of malaria. Another such example was in the field of Chemistry when the 2011 Chemistry IgNobel prize went to researchers who determined the ideal density of airborne wasabi to wake people up. The research has now been incorporated into some alarm systems to help wake deaf people in the case of an emergency.

On the other hand, some winners have produced work where it hard to find an application in the real world. This rather extensive list includes the 2008 IgNobel prize in Biology that was award to researches for discovering that fleas on dogs jump higher than fleas on cats. In another case a prize was awarded researchers from Scotland’s Rural College for their work on bovine behaviour. They found that cows that have been lying down longer are more likely to stand up soon, however once a cow has stood up it is much harder to predict when it will lie down again. Other cow related IgNobel prizes include one given to Newcastle University researchers who found that cows with names produced more milk than those without names, and one given to researchers who developed a method to extract vanilla flavour from cow dung. In this instance vanillin was extracted in a more cost efficient method than taking it from vanilla pods. This means if you want cheaper vanilla extract for your cakes, then look no further a field of cows!

With other winning pieces, if you really try, you might just be able to find some useful information. For example, unless you have rather stubborn sheep and are looking for the easiest floor to pull them across, I can’t see why a paper written by Australian scientists entitled "An analysis of the forces required to drag sheep over various surfaces” would be of any interest to you. Despite this, the paper still won the IgNobel prize in Physics in 2003.

Some prizes are award in jest to people you may not think deserve recognition for their work. One that falls into this category is the 2005 IgNobel award for literature, given to the ‘internet entrepreneurs of Nigeria’. You may know these people as the ‘lost relative’ scam artists, where an email will pop into your inbox from some distance relative explaining that they are in line to inherit a large sum of money. The catch is they need a small amount of cash to pay some legal fees and, if you are able to pay the fees, then you would be rewarded handsomely once they receive their money. Unfortunately the story is a fable, but the less savvy amongst us have sent money abroad in a hope of receiving part of the fortune anyway. The organisers of the IgNobel awards found that this fraud showed ingenuity and imagination, awarding the prize for literature to these con artists. Another controversial winner was the president of Belarus, Alexander Lukashenko, who won the IgNobel peace prize rather ironically, in 2013. He received the Ig Nobel award for decreeing that it would now be illegal to applaud in a public area and he shared the award with the Belarus state police department for arresting a one armed man for clapping in public.
Sloping, slatted, wooden platforms are preferable for sheep dragging.
Sheep pulling over the preferred surface

The breadth of work that the prizes cover and the weirdness of some of the academic work complied here, I believe, is outstanding. I think it is also interesting how the IgNobel awards are also used to highlight questionable work, such as the distant relative scam and the odd laws that have been introduced in Belarus. If you have enjoyed this article I suggest you have a look at the rather extensive IgNobel award Wikipedia page. There are many more interesting winners that I have not been able to list here and I am certain many will ‘First making you laugh and then making you think’

All that is left to say is that I hope you are looking forward to the 2015 IgNobel prizes as eagerly as I am!

Saturday, 15 November 2014

Meet the cells that keep neurons running

by Jonathan Smith

When watching a Formula 1 race, it’s easy to forget that the racing drivers, skilled as they are, don’t work alone. When the car pulls into a pit stop, however, you see a bustling team of mechanics and other experts eagerly rush out to keep the car and driver in top condition. Meanwhile, security staff stand by, blocking public access and keeping a watchful eye on any danger that may present itself. Similarly too, the F1 drivers of the nervous system, neurons, get a lot of attention due to their unique information-processing properties. However, there’s a diverse team of specialised cells that beaver away in the background of the nervous system, carrying out essential tasks analogous to the F1 driver’s pit stop team. Without these plucky little cells, neurons wouldn’t propagate information properly and the nervous system would cease to function. With that in mind then, let’s give some of the most important overlooked cells the limelight for a change, starting with the ‘security guards’ of the mammalian nervous system.

Endothelial cells form the Great Wall of the Brain
As we eat, sleep and move about, our blood ion and sugar levels are constantly in fluctuation. For our neurons that require tightly controlled conditions, exposure to this would be highly detrimental. Thankfully, we can look to endothelial cells, which line the interface between brain tissue and the bloodstream, forming a shield against peripheral influence known as the Blood-Brain Barrier (BBB). By surrounding blood vessels and plugging gaps in the line with protein complexes called Tight Junctions, these endothelial cells and their buddies the pericytes not only cushion brain tissue from fluctuating ion and glucose concentrations but also block passage to many complex molecules, including foreign pathogens.

Figure 1: The endothelial Blood-Brain Barrier around a capillary (red chamber) combines with glial cells such as microglia and astrocytes to form a safe nutrient delivery system to neurons. Pericytes and tight junctions help the endothelial cells to seal the boundary and astrocytes use an end foot process to suck up the nutrients passed along by the barrier. Microglia wait on the side, checking for hazards. Source: SR Yusof and NJ Abbott, from Abbot, 2013, doi: 10.1007/s10545-013-9608-0

Not content to simply act as a wall, these cells also tirelessly shuttle essential ions, sugars and other chemicals into the brain and remove toxins through their own cytoplasm, ensuring that neurons are both protected from the outside world and aptly supplied with the nutrients they require. Furthermore, white blood cells of the immune system - the body’s police force - regularly squeeze through the barrier in order to check for danger. However, this also works against the brain in conditions such as strokes in which the BBB becomes leaky and can’t limit the passage of white blood cells, thus increasing inflammation and exacerbating the problem.

You won’t like microglia when they’re angry
Inside the BBB we encounter the glial cell population. Glial cells - named after the Greek word for ‘glue’ - share many characteristics with neurons but lack the unique structures and functions that specialise neurons for information transmission. Instead, glial cells play a diverse set of roles maintaining the nervous system. Numbering at around 15% of all glial cells, security guard microglia are the subject of intense research because of their incredible versatility. These cells spend the majority of their time simply sitting in the brain tissue, waving their dainty branch-like processes around in a constant search for signs of danger. When they pick up a scent of damage or invasion, however, microglia turn ugly. These sentinels kick off tissue inflammation and undergo an Incredible Hulk-esque transformation into a blob that engulfs and digests the offending party before innocently reverting back to its original state. 

Figure 2: Microglia (green) detects a tissue injury and springs to action. Its extended processes detect signs of damage and trigger the cell’s transformation into a big blob that engulfs the debris. Source: adapted from Nayak et al, 2014, doi: 10.1146/annurev-immunol-032713-120240

With this astounding response to hazards, microglia make impressive enforcers. However, mountains of research have revealed that they can do much more than this. They communicate with cells of the immune system that pop in every so often. In addition, microglia have been found to nurture the growth of neurons in embryonic development and help to prune unwanted cells from the nervous system in developing juveniles. They could even play an important role in synaptic function, making them crucial for normal information processing. However, these eager cells may also work against us in neurodegenerative diseases such as Alzheimer’s Disease and Parkinson’s Disease, believed to involve high inflammation that proves to be neurotoxic in the long run. By better understanding the role these cells play in the pathology, we might able to devise new strategies for treating these conditions.

Insulating the wiring with oligodendrocytes
Mammal neurons are small, thin cells compared to some of the whoppers found in invertebrate animals such as the giant squid. Most neurons output their information through a long process called an axon and, due to electrical resistance inside the cell, neurons with thinner axons propagate information more slowly than those with thicker axons. How then could a nervous system operate with such small neurons? The answer is myelination. This is the process by which specialised glial cells called oligodendrocytes and their peripheral cousins Schwann cells tightly wrap their own fatty membrane - the myelin sheath - around the axons, leaving little gaps of axonal membrane that allow electrical potentials to ‘jump’ significant distances along the axon. This increases possible propagation speeds up to 100 metres per second in humans - perfect for neuronal communication.

Figure 3: Oligodendrocytes (blue) ensheathe many axons (brown) in myelin to facilitate electrical transmission. Source: Wikipedia

Insulation might not be the only function for these ‘mechanics’ of the nervous system. Recent research indicates that oligodendrocytes can not only insulate axons, but may also directly support the axon’s energy requirements by supplying substrate molecules used in metabolic reactions such as lactate. Further studies indicate that oligodendrocytes promote neuronal survival and axonal growth. The importance of these cells and Schwann cells is further underscored by the fact that the disorder Multiple Sclerosis (MS) arises from demyelination of axons throughout the nervous system. For a multitude of reasons, the immune system attacks myelin and thus deprives neurons of essential support, causing neurodegeneration and, as a consequence of this, ultimately life-threatening paralysis in MS patients. However, strategies are now being trialled that may be able to divert or retrain the immune system and prevent the progression of MS.

Astrocytes - star players in the nervous system
Astrocytes are star-shaped glial cells thanks to their many fine processes, hence the name. Acclaimed as the most abundant type of cell in the human brain, these cells have the chief responsibility of transporting nutrients from blood vessels to nearby neurons by means of a long ‘foot’ process. Astrocytes also oversee chemical synapses - vital junctions at which neurons communicate using neurotransmitters - and each astrocyte can monitor up to a whopping 140,000 synapses! Taking roles analogous to trainers, medics and mechanics in the F1 team, astrocytes are absolutely essential for the survival of the nervous system and by extension, the entire organism.

As can be expected, lots of research gets devoted to unraveling the precise roles that astrocytes play in the nervous system. It’s now clear that these ubiquitous cells encourage the formation and pruning of synapses in the developing brain. In addition, they fine-tune synaptic activity by supplying necessary energy substrates, hoovering up and recycling excess neurotransmitters, prevent seizures by clearing away potassium ions and physically ensheath the synaptic space, reducing spillover of neurotransmitters to nearby cells. Unfortunately, astrocytomas are among the most common cancers in the nervous system and have a relatively high mortality rate. They damage the brain tissue by increasing pressure inside the skull, compete for nutrients and releasing toxic chemicals into the brain, resulting in varied symptoms including headaches, seizures and occasionally personality changes. Though the classic cancer treatments are available such as surgical removal, it’s hard to cut away all of the high-grade tumours due to their rapid infiltration into the brain.

Collective thinking
Aside from the heroes discussed in this piece, there are also tons more subsets of cells that deserve honourable mentions, including parenchymal cells that circulate cerebrospinal fluid around the brain and the somewhat enigmatic NG2 glia, whose precise function still eludes us. While staying mostly in the background, these other cells all have vital functions that serve to ensure that our neurons keep running smoothly. 

Neurons tend to be the main focus of neuroscientific studies. This attention is well deserved considering that they are the substrates of our very thoughts. However, after examining some non-neuronal cells, it’s clear that neurons wouldn’t last a minute without the help of their expert team on hand. By exerting modulatory influence on neuronal development and synaptic activity, it could be argued that the support cells similarly affect our thinking and learning processes, an argument particularly evidenced by complex neurodegenerative diseases involving lots of cell pathologies. With this in mind then, let’s all watch some F1 and spare a thought about the collaborative efforts involved in securing first place!