Highlights from the Society for Neuroscience Meeting 2010

21 November 2010

Interview with

Smitha Mundasad

Chris -   Also this week, the annual meeting of the Society for Neuroscience took place in San Diego, California; a nice sunny place.  This is actually the largest meeting of neuroscientists from around the world who meet to discuss their latest research and the progress they're making in understanding how the brain works.  Naked Scientist Smitha Mundasad was there for all the action and she's with us now to tell us what she got up to.  Hello, Smitha.

Smitha -   Hi, Chris.

Chris -   So the weather here, decidedly worse than California then?

Smitha -   It's so much nicer in California.

Chris -   So, a shame to be back, but what did you get up to?

An animated gif of MRI images of a human head.Smitha -   Well, with over 30,000 neuroscientists in attendance, this year's Society for Neuroscience Conference in San Diego, was a hot bed of new research and exciting ideas.  One of the meeting's highlights was news that researchers have found a way for people to control computer cursors with their thoughts alone.  Using MRI machines connected to computers, scientists from the University of Pennsylvania School of Medicine had 14 participants think alternatively of two thoughts:  One, to think about playing tennis; and the other, to imagine going from room to room in a familiar place.  Analysing the brain activity from these two different scenarios, the researchers were able to show that the computers could distinguish two distinct patterns of brain activity for each thought.  While still in the MRI scanner, the participants were asked to use these thoughts to control the movement of a computer cursor on a screen.  This means that they had near instant feedback of how well they could control their own thoughts.  Lead author, Dr. Anna Rose Childress explains that how new approach could have major therapeutic implications, for example, in the treatment of addiction...

Anna -   Control of the screen cursor is a really good measure of how well a person can alternate their thoughts, between tennis and room by room.  The thoughts, of course, are completely arbitrary, but the act of controlling them and shifting them does require considerable attention and cognitive control.  For our patients, when they are in the real world and maintaining cognitive control while they're driving their car down the street in a cocaine neighbourhood, what they describe is that they will be intruded on by a brief vision of something cocaine related and they become derailed.  So we're going to be able to model that with this task.  We'll have people performing this task and be blipping in very brief cocaine images and be able to actually see the brain struggling to maintain control.  So it's a very sensitive probe for disrupted cognitive control in pathological conditions such as addiction for example.

Smitha -   Anna Rose Childress from the University of Pennsylvania. 

In other news from the conference, again combining the disciplines of computing and neuroscience, researchers have found a novel way to make blind mice see.  There's over 25 million people worldwide who suffer from degenerative diseases of the retina, often resulting in partial sight and blindness.  Photoreceptors on the retina normally receive light and then, with the help of retinal ganglion cells, this is converted into electrical impulses that can be understood by the brain.  But with many retinal diseases, these photoreceptors stop working.

Visual Cortex (in red)Existing retinal prosthesis offer very limited hope.  Implanting electrodes into the retinal cells can allow people to make out spots of light or edges of objects, but very little in the way of real vision.  

But now, researchers at Weill Cornell Medical College in New York have taken a new approach.  By analysing the light input and then the corresponding neural output of the healthy mice retinal cells, they were actually able to mimic the way the retina converts light into electrical signals.  They've actually essentially cracked the neural code used by the brain.  This code can then be used to produce a much sharper, clearer image in mouse models.  The team hope to work with primates next and then humans very soon.  Lead author, Sheila Nirenberg, explains how her research differs from other approaches...

Sheila -   Our common analogy is that the patient's eye is like a digital camera with damaged pixels.  So the more of the pixels you replace, the better the picture you're going to get.  What our research shows is that there's another factor that's just as critical.  Not only do you need to stimulate large numbers of cells, but you also have to stimulate them with the code that the eye is sending to the brain.  This is because the camera analogy really only holds in part.  The eye does essentially take a picture, but then it goes much further.  It processes the picture.  It extracts information from it and then it converts that information into a code that the brain can read.  So, to make an effective prosthetic device, you've really got to have both these functions:  acquiring the picture and then converting the picture into a code that the brain can make use of, and I think we really have this now.  We have both of these components.

Smitha -   Sheila Nirenberg from Weill Cornell Medical College, New York.  

There was also good news for musicians at the Society for Neuroscience Conference.  Benjamin Zendel of the University of Toronto presented research that suggests that musicians may actually be protected from some of the age-related changes in the auditory cortex of the brain.  The researchers presented participants with complex sounds under two conditions:  One, where they were distracted by another activity and the other, where they were focused on the sounds.  During these experiments, the participant's brain activity was measured using EEG.  The brain activity patterns of older people with musical training were very similar to that of young people during the attentive listening task, but older non-musicians showed typical age-related changes.  Lead author, Benjamin Zendel...

Benjamin -   A lot of research has shown that musicians do better on many hearing tasks.  They have more acute hearing, they're better at making fine distinctions between sounds, and also the exact same things that change with age.  So as you get older, it's harder to make these fine distinctions between sound and that contributes to difficulty understanding speech in noisy environments like at a noisy restaurant or a noisy coffee shop, and so, the really exciting part of this research is that older musicians seem to maintain some of those abilities and it's reflected in changes in the auditory cortex.  That there are changes in the functional components of the auditory cortex in older musicians that make their brains effectively look like that of the younger adults.

Smitha -   So those piano lessons might have been a bit more valuable than I thought!  That was Benjamin Zendel from the University of Toronto.

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