Probing Parkinson's

20 January 2013
Presented by Hannah Critchlow.

Why are researchers punching into people's skin if they are on a quest for knowledge about the brain? What does the birth of new brain cells do for memory? Plus can a 'tumour paint' be developed to help beat brain cancer? And can we shed those post Christmas extra inches by doing difficult maths problems, instead of hitting the treadmill?

In this episode

01:03 - What is Parkinson's?

Kick-starting the programme, I went in search of answers about Parkinson's disease. First up, I wanted to get some idea of how many people it affects and how.

What is Parkinson's?
with Dr James Rowe, Cambridge University

Kick-starting the programme, I went in search of answers about Parkinson's disease.  First up, I wanted to get some idea of how many people it affects and how.

James -   Yes, hello.  I'm James Rowe.  I'm a Consultant Neurologist at Addenbrooke's Hospital and I work with the Cambridge University on some of the research studies in Parkinson's disease and related disorders.  

Well, Parkinson's is diverse and challenging.  It's not just because it affects up to 100,000 people in the UK, but because of the range of problems it can cause.  Many people will be familiar with the idea that it causes a tremor and slowness and stiffness, but not everyone will be aware it causes many other problems - what we call non-motor symptoms.  These include sleep problems, affecting mood - of anxiety and depression, pain even, and many other problems.  Even constipation is remarkably common too so, a wide range of symptoms.  

Many people, even quite early than others have difficulty PET scanwith thinking flexibly or planning ahead and multitasking in their mind.  This is distinct to what can happen later on in the others which is, some patients can go on to get a dementia.  So, two very different sorts of thinking on memory problems, but both very challenging.

Hannah -   And do we know much about what's going on in the brain in order to give rise to these very complex and wide ranging symptoms associated with Parkinson's?

James -   Well, it's been known for many years that a key chemical in the brain called dopamine is lacking.  The cells that make dopamine appear to die back early in Parkinson's disease.  In fact, by the time that somebody presents to their doctor with Parkinson's disease, you may already have lost 78 or even 90% of the dopamine cells.  So, the mainstay of treatment for the last 45 years has been dopamine drugs - either to mimic dopamine or help your body boost the amount of dopamine it can make.

Hannah -   So, this highly prevalent disorder, most famously now affecting Michael J. Fox is known to have a biological cause, this dying off of the dopamine nerve cells.  We can treat it by giving patients L-Dopa or similar to replace some of the lacking chemical messenger dopamine and alleviating some of the symptoms.  But in the main, this only helps mask the symptoms for short amount of time.  Researchers are hoping to improve available treatments by coming up with clever new techniques to gain a much better understanding of the disorder.  

15:53 - Newborn neurones and newborn babies

Switching on the birth of brain cells and boosting memory formation, brain size at birth and behaviour decades down the line, and treating Alzheimer's Disease with a drug designed...

Newborn neurones and newborn babies

It's time to take a look at the top stories from this month, I join PhD student David Weston from Cambridge University. He's been busy shifting through neuroscience research and comes up with his three favourite papers from the month....

David - So the first paper I would like to talk about has to do with memory. Now scientists have long thought that the birth of new brain cells within an area of the brain called the hippocampus, is really important for memory function. But exactly how these new brain cells work and how they integrate into the brain is something that researchers having been working hard over. Now a group of scientists based at the State University of New York in the USA have used a combination of viral and optogenetic techniques to find out just how important the growth of new brain cells within the hippocampus really is.

Hannah - So these scientists want to find out why these Nerve Cellnew-born cells are so important. How did they go about finding more about these cells?

David - Well they used a virus to deliver light-sensitive genes into new-born cells within the hippocampi of adult mice. Now this virus infects only the new-born cells and gives them these genes that produce proteins sensitive to light. The researchers were then able to control these cells by shining lights of different colours onto the cells to activate or deactivate them.

Hannah - So just by shining different coloured lights they could control whether these new-born cells were activated or deactivated. What did they do next?

David - Well what they wanted to do was see how important new cells within the hippocampus are for memory function. So first they showed that if they activated these new-born cells they could enhance synaptic plasticity, which is widely believed to correlate with better memory function. They then tried deactivating these cells and they found that the mice performed much worse is some tests of memory function.

Hannah - So the new-born cells definitely had something to do with memory formation.

David - Yes, but interestingly the effects of manipulating the new-born cells were only seen when the cells were 4 weeks of age, not when they were older or younger. These results hint at the idea that new cells within the hippocampus are able to exert their memory-enhancing effects only at early stages of their development.

Hannah - So this means that the timing of when new cells are born could play an important role in memory function and behaviour. Fascinating! What's your next paper?

David - The second paper I want to talk about also has something to do with timing. It's about how much of your life is affected by your time as a foetus. There is an increasing amount of evidence suggesting that many aspects of your adult health can be traced back to your aspects of your foetal environment and importantly your birth weight.

Hannah - So your weight at the time of you birth might be linked to things to do with your brain? How did the scientists in the study work that out?

BrainsDavid - So this group of scientists working across both Norway and the USA collected data from 628 adults, adolescents and children, measuring things like the thickness of their cerebral cortex, their brain volume and the surface area of their brain using scans taken in an MRI machine. They found that as birth weight increased the total brain size as an adult was much larger.

Hannah - So birth weight influences brain size, but why is this important?

David - Well low birth weight can influence your likelihood of getting some cognitive disorder such as autism, where you are five times more likely to get the disease. And while this study doesn't make any specific links between birth weight and disease it does show that brain development is heavily influenced by factors surrounding your birth.

Hannah - What's your final paper?

David - So the final paper this time is about a new drug that could help fight the effects of Alzheimer's disease. A collaboration between groups in Japan and Canada have taken an anti-diabetes drug and tested its ability to reverse some of the deleterious effects of the disease.

Hannah - How can a drug designed for diabetes treatment help with Alzheimer's Disease?

David - Well this drug, AC253, was originally part of a drug trial looking for potential targets for diabetes.  One of these targets is the amylin protein, which is similar to the toxic amyloid protein, that builds up in the brain and is a key target for Alzheimer's Disease.  This team had already shown that AC253 could block the formation of toxic amyloid protein and in this paper they showed that treating brain cells with this drug could reverse some of the effects of Alzheimer's.

Hannah - So these experiments were performed on cells in petri dishes, but how close could this be to a treatment for Alzheimer's disease in humans?

David - Well the authors themselves seemed quite optimistic about the prospect for a drug treatment. These results are encouraging because they show a reversal of Alzheimer's effects, which might mean things like being able to reverse a loss of memory!

21:12 - All ears, brown eyes and glowing cancer

Restoring hearing, brown eyed people perceived as more trustworthy, and scorpion venom paves the way for brain tumour treatment

All ears, brown eyes and glowing cancer

Listen Up, Restoring hearing!

Repetitively listening to loud music, getting old, and even certain drugs can cause the hair cells in your inner ear to stop working. This can result in irreversible hearing problems. But Edge and colleagues at Harvard Medical School have used a drug to trick existing cells in the ear to follow a different path and become new hair cells, resulting in the partial recovery of hearing. 

This study, published in Neuron was conducted on mice but may pave the way for a new treatment for hearing problems in humans.

Brown eyed people more trustworthy than blue

Kleisner and colleagues from Charles University, Czech Republic wanted to know what makes for a most trustworthy face!So, the researchers presented 250 volunteers with 80 photos of different men and women, asking them to rate trustworthiness. Results were analysed. And the brown eyes have it! This scorpion is black when viewed under normal lighting. Here it is seen illuminated by an ultra violet light.

Both men and women with brown eyes were perceived as more trustworthy than those with blue.  They followed the study with a bit of photo shopping, altering the eye colours, and found that it was not the eye colour per say that affected trustworthiness but more the eye shape and features associated with brown eyes. That study published in PLoS One.

Scorpion venom paves the way for better brain tumour treatment 

A compound inspired by scorpion venom could help neurosurgeons tell apart cancerous from healthy brain tissue.

Traditionally surgeons have just felt their way around the brain when trying to remove just the cancerous tissue, which when it goes wrong, can lead to mental disability.

But a scorpion toxin has somehow evolved to that bind specifically to cancerous brain cells. Now Jim Olson at Seattle Children's Hospital working with the Company Blaze Bioscience, have linked the toxin to a molecule so that it glows, forming a "tumor paint". Clinical trials start this year.

Maths to lose weight?

We tackle some of your neuroscience questions. I joined Professor Simon Laughlin from Cambridge University who's been flexing his brain power to answer your questions about the brain.

Sean Hoskins got in touch via Facebook asking: "Can you burn off a hot fudge sundae by doing a difficult math problem instead of hitting the treadmill?"

Simon - The answer is definitely no. So, scientists wanted to measure oxygen consumption of the human brain, and test whether the brain was like a muscle - that if you worked it harder, it had to use more energy. And so, they got people to sit down and solve difficult math problems and measured their energy consumption of the brain. And what they found was that there was no detectable change.

So, doing difficult math problems will certainly not enable you to lose weight. The best thing you can use your brain for, is to design a good exercise regime and a diet.

Hannah - Thank you, Simon. I suppose I should be hitting the treadmill then in order to shed those Christmas pounds.

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