Features

Are there spiders in the store room? How about woodlice in the hall? And did anyone see beetles in the headteacher's office?

Pupils around Oxfordshire are looking into these and other questions as part of Bug Quest 2009, a six-month research project to survey invertebrate biodiversity across the county.

It's the the third time that the Oxford University Museum of Natural History (OUMNH) has staged a Bug Quest event and this time the emphasis is on pupils doing more of the research themselves: placing insect traps in locations around their schools, uploading data on the types of insects captured to the Bug Quest website as well as photos of any puzzling or unusual invertebrates.

The project began in January and at the latest count around half of the 42 schools taking part have entered their first batch of results with Sunningwell Cof E Primary School and Checkendon Cof E Primary School achieving the coveted accolade of buggiest schools in January!

Those taking part receive regular updates from Colin A Cricket with information on the Bug of the Month: March is officially Beetle Month [Colin tell us that the UK's largest insect is the Stag Beetle].

Bug Quest runs until June with bug identication sessions for teachers and a special morning reception on 14 July where pupils can bring along homemade bug models and the prize for this year's buggiest school will be awarded.

Next month Oxford engineers will start investigating what kind of composite materials would make for stronger, stealthier and more durable submarines.

Composites are already being used in warships because they can be made stronger and lighter than metal parts and are less susceptible to corrosion. They have also been shown to resist the forces unleashed in an explosion better than metal.

The Oxford team will begin their EPSRC-funded project by testing how composites submerged in water respond to a shockwave generated by a metal projectile. High-speed cameras will capture how the materials deform under the pressure.

Testing and modelling is vital to determine what the best structure for a submarine composite would be – many composites, for instance, are made out of a ‘sandwich’ of different materials – as well as how composites fare after being submerged in water for a long time.

Vito Tagarielli, one of the Oxford team led by Nik Petrinic, told The Engineer: ‘We hope to reduce the weight of the submarine so there is less inertia and it can have higher acceleration and easier manoeuvrability.’

‘[Also] If a submarine is made of composite it makes it invisible to modern sea mines that detonate when they recognise a specific magnetic or acoustic signature.’

The project runs for five years and involves a host of industrial partners alongside the Ministry of Defence.

When is a hole not just a hole? When it’s a nanopore: a hole 10,000 times smaller than the diameter of a human hair.

Oxford spinout Oxford Nanopore recently announced how such tiny holes can work as part of a DNA sequencing system.

As Mark Henderson reported in The Times DNA sequencing, which is used to build-up an individual’s genetic profile, is currently very expensive and without a cheaper way to do it the era of personalised medicine – when treatments can be tailored to a person’s unique genetic make-up – will have to wait.

Enter Oxford chemist Hagan Bayley and colleagues who, working with Oxford Nanopore (which Hagan founded in 2005), have found a way to detect the four DNA bases using nanopores.

Current sequencing techniques require DNA samples to be amplified (which can introduce errors), cut to the right length, attached to a bead or surface and given a fluorescent tag which has to be read with expensive imaging equipment.

The beauty of the new approach is that it does away with the tagging and enables the DNA bases to be snipped off a strand one by one and then fired through a nanopore. Each base disrupts an electric current passed across the nanopore by a different amount so the DNA base ‘letter’ (A, C, G or T) can be read.

At present the order in which the bases are detected is not necessarily the same as the actual sequence in the intact DNA strand, but the researchers are now working on streamlining the process so that as each base is cut it is fed into the nanopore in sequence – effectively ‘reading’ the strand like one long sentence.

This technology could be a big step towards a $1000 human genome – regarded by many as a key cost target that would make personalised medicine based on an individual’s DNA sequence truly affordable.

No surprise perhaps then that earlier this year leading biotech firm Illumina invested $18m in Oxford Nanopore towards developing the technology as part of a wider commercialisation agreement.

Read a report of this research in Nature Nanotechnology.

Professor Hagan Bayley is based at Oxford’s Department of Chemistry.

Congratulations to Oxford's Mark Roberts who was runner-up in the latest I'm a Scientist: Get me out of Here!

The online competition enables school pupils to quiz six scientists about their work and life as a researcher. Pupils vote off a scientist one-by-one until the group is whittled down to the last two and then vote for a winner.

Mark's specialist subject was bacteria: in particular the soil bacterium R. sphaeroides [it forms the orange writing in the petri dish above]. This bacterium is ideal for studying bacteria signalling as it's non-pathogenic, so its DNA is safe to chop and change.

Mark told me: 'The event was great fun and I got lots of different questions: everything from what my favourite and worst parts of my job are, how much I get paid, to questions about my science - so how bacteria sense and live.'

'I had one really interesting question about how viruses can jump species (like avian flu!) and then completely random questions like what music do I like or what is your favourite cheese!'

'My favourite question was - what would you rather cure AIDS or cancer? - which was a tough one to answer. I went for AIDS as, given there is one target, that should be easier.'

Although Mark didn't win the £500 first prize (to be spent on science communication) he is still looking to get involved in more work with schools as well as develop a website for pupils with information on how bacteria live.

Mark Roberts is a postdoctoral researcher in Oxford's Department of Biochemistry and a tutor at Lincoln College.

‘Pleasure is fundamental to us,’ says Morten Kringelbach who holds a dual appointment as senior research fellow at the Department of Psychiatry at Oxford University and professor at Aarhus University, Denmark. He should know – he’s been studying the basis of pleasure and how the emotion is generated by the brain. ‘It’s what gets us up in the morning, or guides us in choosing whether we want coffee or tea.’

‘It’s no accident,’ he points out, ‘that food and sex are our primary sources of pleasure. They are critical for our survival, so having dedicated pleasure networks in the brain that tend to make us seek them out makes absolute sense.’

Being around other people is also pleasurable, he says. Social interactions are part of what sustains us as humans, and pleasure plays a key role in this. ‘It’s one reason why food is more enjoyable with other people, for example.’

On top of the basic pleasure-inducing elements of food, sex, and other people which have helped our survival, there are the higher-order sources of enjoyment such as music, art and beauty, or monetary rewards. But these are processed in the brain in similar ways. ‘Brain scanning experiments have shown that music hits the same parts as food or sex,’ says Professor Kringelbach.

His work can also tell us about when this impulse goes wrong. This is very important in depression, which can be associated with less engagement with other people and a lack of normal feelings of pleasure in situations where it might be expected. But, to understand that, the layers of systems and brain processes involved in experiencing pleasure, both conscious and unconscious, must be stripped back.

One set of experiments by Kringelbach and colleagues used functional magnetic resonance imaging [fMRI] and neatly identified the regions of the human brain involved in experiencing pleasure.

Hungry volunteers were placed in the MRI scanner and were asked to rate their enjoyment of small aliquots of tomato juice or chocolate milk on a subjective pleasantness scale from -2 to +2. Both foods were on average rated around +1.5 by the participants. They were then taken out of the scanner and fed as much as they wanted of either tomato juice or chocolate milk. The now-full volunteers went back into the scanner and the experiment of feeding them both liquid foods was repeated exactly as before. Except that the participants now strongly disliked the food that they had just been fed and rated their subjective experience as negative at -1.5. In contrast, the other food was still experienced as very positive (on average +1.5 or better).

In this way the changes in brain activity in both parts of the experiment could be compared, separating those parts of the brain involved purely in taste and sensory perceptions from those higher systems involved in the subsequent subjective experience of pleasure. The result was that the subjective experience of pleasure appeared to be linked to activity in a particular region of the brain just behind the eyebrows (see figure below). ‘Activity in the mid-anterior orbitofrontal cortex correlates very strongly with how much we like something,’ says Professor Kringelbach.

Other results have similarly found that the rush caused by drugs, music and other pleasures are all linked to the same network of pleasure centres of which the orbitofrontal cortex appears to be the most important in humans. Of course, it was Dutch researchers that confirming the same was true of sex, finding that the difference between real and fake orgasms in women is experienced in the orbitofrontal cortex.

Work elsewhere has also given an insight into the chemical basis of pleasure. US research from Kringelbach’s close collaborator Professor Kent Berridge has shown that pleasure can be studied in other animals such as rats who lick their lips in proportion to the amount of sugar in their water, giving a behavioural measure of pleasure.

Dopamine, a chemical involved in neural processes in the brain, was for many years thought to be the brain’s pleasure chemical. But rodents with more dopamine in their brains didn’t lick their lips any more than normal. Instead they went to the sugar water more quickly. So there seems to be a difference in the brain processes of ‘liking’ (licking lips) and ‘wanting’ (going to get the food reward). This is of interest in understanding addiction, which is associated with a lot of ‘wanting’ or at least an imbalance between liking and wanting. Conversely, opioid drugs such as morphine (which are used to reduce pain), are found to increase ‘liking’ processes.

‘The question is can we use the picture we are building up of pleasure, its causes and its purpose, to be able to restore it. Can we find out what is wrong in treatment-resistant disorders including depression?’ asks Professor Kringelbach. ‘Will it be possible to change the baseline of pleasure in people, possibly even from early childhood?’

To answer these questions, Professor Kringelbach is using both MRI and a technique called magnetoencephalography [MEG], which allows much greater time resolution, to begin to see more of what neurons are actually doing rather than just look at the much slower changes in oxygenation of blood flow in the brain measured with MRI. In this way, it may be possible to monitor real changes in the brain that may result from cognitive behaviour therapies, he suggests. His transnational research group, Hedonia: TrygFonden Research Group [http://kringelbach.org] is using these techniques in collaboration with Professor Alan Stein at Department of Psychiatry to understand the pleasures of the parent-infant relationship. They have recently discovered a potential neural signature for parental instinct in the adult brain, which could potentially help with post-natal depression.

He is also working closely with Professor Tipu Aziz of Oxford University to understand the mechanisms of deep brain stimulation [DBS], which can help in otherwise treatment-resistant cases. DBS, described by Kringelbach as a ‘pacemaker for the brain’, involves implanting electrodes very carefully in specific areas of the brain and applying an electric stimulus at the right frequency to override or correct aberrant brain impulses. It has been used to great effect in a number of patients with movement disorders, such as Parkinson’s and in patients with very severe chronic pain, where nothing else has been successful. Many of these patients are suffering from an acute lack of pleasure in their lives and they describe the pain relief from DBS as deeply pleasurable.

‘DBS is a radical solution and it’s not for everyone,’ says Professor Kringelbach. ‘However, there are people in which this surgery have led to a remarkable change in their quality of life.’

Morten Kringelbach has a new book out called The Pleasure Center (Oxford University Press). Read more about Kringelbach’s pleasure research.