Tag Archive | brain

Recreating the images of the mind

On “Back to the future” day, October 21st, 2015, Luís Seoane, member of the Complex Systems Lab at the IBE (UPF-CSIC) led by Ricard Solé, wrote a blog post called “Images of the mind”. In it, he discusses how much technology has advanced in the last 30 years. Our present is not quite the ‘future’ of the characters of the film directed by Robert Zemeckis, produced by Steven Spielberg and starring Michael J. Fox. But we have gone a long way.

In this post, Seoane focuses on Brain Computer Interfaces, which are bringing back motility and communication to injured patients, and on which he himself has worked prior to joining the Complex Systems Lab at the PRBB. In particular, he talks about one he came up with in 2011, which he then developed together with Stephan Gabler and Benjamin Blankertz.

carrot_strawberry

Early this morning Marty McFly has arrived to the future. It is true that cars don’t fly quite yet. Hoverboards are not available either. Households are not powered by their own nuclear reactors and clothes don’t dry and adjust automatically. Good old Marty has got reasons to be disappointed. But advances in some other directions have been astonishing during the last 30 years. Who could foresee the transformative power of the internet? Everyone is plugged to a tablet or smartphone, immediately accessing far away friends and personalized web content. Synthetic biology is taking its first, promising steps (to which we are glad to contribute) and advances in prosthetics and Brain Computer Interfaces are bringing back motility and communication to injured patients….

You can read here the whole post, published on the lab’s blog.

Interdisciplinary conference on neural engineering at the PRBB this September

Next 21-23 September 2015 an International Conference on System Level Approaches to Neural Engineering (ICSLANE) will take place at the PRBB. Organised by the Neural Engineering Transformative Technologies (NETT) Consortium, the conference presents an outstanding list of invited speakers.

Maciek Jedynak and Alessandro Barardi, both research fellows at the Jordi Garcia-Ojalvo group (CEXS-UPF), and local organisers of this exciting conference, tell us a bit more about it.

brain

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Neural Engineering is an inherently new discipline that brings together engineering, physics, neuroscience and mathematics to design and develop brain-computer interface systems, cognitive computers and neural prosthetics. Neural Engineering Transformative Technologies (NETT) is a Europe-wide consortium of 18 universities, research institutes and private companies. NETT consortium announces registration for this event is now open, and introduces a remarkable list of prominent Invited Speakers with Keynote Lecturers:

  • Eugene Izhikevich– a Co-Founder, Chairman and CEO of the cutting edge technology company Brain Corporation, located in San Diego, USA. The company’s mission is to design, produce and bring to everyday life intelligent machines equipped with the first-in-the-world operating system based on learning: BrainOS. He is also a former scientist well known for his rich contributions to the mathematical theory of dynamics of spiking neurons.
  • Nikos Logothetis– a pioneer in engaging fMRI measurements to neuronal activity studies, director of the department of Physiology of Cognitive Processes at the Max Planck Institute for Biological Cybernetics in Germany. His current research is focused on neural mechanisms of perception and object recognition. It involves a wide variety of brain imaging techniques, which allow to gather and consolidate data from different domains of neuronal activity.

The aim of this conference is to bring together theoretical and experimental neuroscientists and roboticists to discuss the state of the art in the field of Neural Engineering. This three-day long event will also provide young researchers with the opportunity to present their work.

The full list of confirmed speakers, divided into five different theme panels is:

Day 1

Brain-on-chip – engineering of neuronal circuits in-vitro with emphasis on microfluidics
Albert Folch – Department of Bioengineering, University of Washington, Seattle, WA, USA
Thibault Honegger – Laboratoire des Technologies de la Microelectronique, CNRS-CEA, Grenoble, France
Yoonkey Nam – Department for Bio and Brain Engineering, KAIST, South Korea

Optical neurotechnology Methodology – imaging and engineering techniques that allow recording of neuronal activity
Amanda Foust – Neural Coding Laboratory, Imperial College London, London, UK
Fritjof Helmchen – Brain Research Institute, University of Zürich, Zürich, Switzerland
Adam Packer – Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
Eftychios Pnevmatikakis – Department of Statistics and Center for Theoretical Neuroscience, Columbia University, New York, NY, USA

Day 2

Neural Dynamics – mathematical description of neuronal activity
Viktor Jirsa – Institut de Neurosciences des Systèmes, Marseille, France
David Liley – Swinburne University of Technology, Melbourne, Australia
Benjamin Lindner – Bernstein Center for Computational Neuroscience, Berlin, Germany
John Terry – College of Engineering, Mathematics and Physical Sciences, University of Exeter, UK

Neural learning and control – motion planning, controlling and learning neuro-inspired techniques for robotics
Dario Farina – Bernstein Center for Computational Neuroscience, Göttingen, Germany
Sami Haddadin – Institute of Automatic Control, Hannover, Germany
Alexandre Pouget – CMU, Geneva, Switzerland
Gregor Schöner – Institut für Neuroinformatik, Ruhr-Universität Bochum, Germany
Reza Shadmehr – John Hopkins University, Baltimore, MD, USA
Patrick van der Smagt – BRML labs, TUM, Germany

Day 3

Neural Coding – investigation of neuronal strategies for encoding information
Andre Bastos – The Picower Institute for Learning & Memory at MIT, Boston, MA, USA
Romain Brette – Institut de la Vision, Paris, France
Sophie Deneve – Laboratoire de Neurosciences Cognitives, LNC, Paris, France
Kenneth Harris – Institute of Neurology and the Department of Physiology, Pharmacology and Neuroscience, UCL, London, UK
Stefano Panzeri – Neural Computation Lab, IIT, Rovereto, Italy
Jan Schnupp – Auditory Neuroscience Group, Oxford, UK

 

REGISTRATION

We invite you to submit poster abstracts and apply for contributed talks. We introduced a one-day participation option: now you can attend one day of the conference for 80 Euros. The cost of participation in the whole event is 200 Euros (plus 50 Euros for optional conference dinner).

There is a 50% fee reduction for students who will present posters. Registration is available on the event’s on the registration form and all necessary information is on the event’s website. The registration deadline is on June 20th, so hurry up!!

 

Changes in the brain in patients with ADHD

Attention-Deficit/Hyperactivity Disorder ADHD involves robust alterations in the cortical cerebral mantle, as shown in a recent article by Òscar Vilarroya and colleagues from the Neuroimaging Research Group at the IMIM-Hospital del Mar. These alterations are most prominent in brain regions involved in attention processing, and are more common in the childhood form of the disorder than in the adult one.

brain mara

ADHD is a psychiatric and neurobehavioral disorder characterized by either significant difficulties of inattention or hyperactivity and impulsiveness or a combination of the two. Although it was initially regarded as a disorder exclusive to childhood – affecting about 3 to 5 percent of children globally -, nowadays its prevalence in adulthood is well established.

Previous research on children with ADHD has shown a general reduction of brain volume, but with a proportionally greater reduction in the volume of the left-sided prefrontal cortex.  The researchers at the IMIM have now used  anatomical brain MRI scans to analyse cortical thickness in 41 normal children and 43 children with ADHD, as well as three groups of adult individuals: 31 normal, 31 ADHD patients treated with stimulants and 24 medication-naïve ADHD patients.

The results, published in PLoS One, show several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network.

Reference:

Hoekzema E, Carmona S, Ramos-Quiroga JA, Fernández VR, Picado M, Bosch R, Soliva JC, Rovira M, Vives Y, Bulbena A, Tobeña A, Casas M, Vilarroya O. Laminar thickness alterations in the fronto-parietal cortical mantle of patients with attention-deficit/hyperactivity disorder. PLoS One. 2012;7(12):e48286

“Memory is built on concept neurones”

So, here’s the interview to Rodrigo Quian Quiroga, who came recently to give a talk at the PRBB. The title “The Jenifer Anniston neurone” was interesting… the content was much more so!

This interview was published in the PRBB monthly newspaper, Ellipse.

You can also read an earlier post about his talk here.

 

Figuring out how the brain works is the obsession of Rodrigo Quian, professor at the University of Leicester (UK). This challenge led him to apply his physics training and a PhD in maths to neuroscience. With the discovery of the “Jennifer Aniston neurone”, or concept cells, it seems we have taken a step towards the understanding of memory.

 

 

How can we “see” neurones?

We work on patients with epilepsy requiring hippocampus surgery. As part of this they have electrodes attached to the brain for several hours. This allows us to talk to them and detect how the neurones respond to stimuli we present them with.

Why the Jennifer Aniston neurone?

We did experiments where we showed patients people close to them like relatives and celebrities. The first neurone I found responded to pictures of Jennifer Aniston. It was a shock to discover that somewhere in the brain are neurones that respond in such a specific way to abstract concepts.

Did it only respond to photos?

It responded to various photos of Aniston, images as different in colour and format as we were able to find. The same with her name when written or spoken. Specifically, to the ‘concept’ of Jennifer Aniston. We found neurones that responded to different famous people depending on the person. The only neurones that did not respond were in an autistic patient.

One neurone per concept?

If I could find one neurone that responded to Jennifer Aniston, there must be more because if it was the only one, the probability of me finding it among the thousands of neurones in that area is practically zero. There has to be a network of neurones that encode a concept. These concept cells can quickly generate associations, so there are neurones that respond to two concepts, but they are always related to one another. This is a key mechanism for generating memories. I think they are the building blocks of memory and the link between perception and memory. This is a radically different idea to what was believed until now, that the basis of memory was distributed networks of millions of neurones.

Can you locate complex thoughts like phobias?

Often a complex thought is an association of simple thoughts. My old mentor at Caltech, Christof Koch, said it was necessary to break down the difficult problem of consciousness into related problems that are simpler and easier to attack. The consciousness of self is a very complex thing. One must first understand how the flow of consciousness works. That is, that one thing makes me think about another thing and that about another and so on. This can be studied in the neurones generating associations between two concepts and, from the moment we have made this association, we can see if the neurone also responds to the association and encodes it. In a few tests we have found that these concept cells begin to respond to the association we have created.

What other experiments are you working on?

We want to know if neurone response changes according to the presentation of the stimulus, for example the exposure time to the photos. The results demonstrate that neural response is closely related to the conscious perception of the patient. That is, if the patient believes that he has seen something, then the neurone is activated. In fact, it is even possible to predict beforehand when neurones will be activated and know what image a patient is looking at only from the neurone records.

 

Effects of chemical exposure and social environment on the developing brain

The developing brain is exceptionally sensitive to environmental influences, and two recent papers lead by scientists at the CREAL have analysed the effect of several variables – chemical exposure and social environment – in neurodevelopment of infants. In the specific cases studied, the effect didn’t seem to be very substantial.

One of the articles was published in the American Journal of Epidemiology, and it focuses on the potential effect of prenatal exposure to mercury, since it is known that vulnerability of the central nervous system to this metal is increased during early development. The scientists examined 1,683 children who are part of the INMA (Environment and Childhood) Project from 4 regions of Spain between 2003 and 2010. The mercury levels at the cord blood were analyzed by atomic absorption spectrometry, and infant neurodevelopment was assessed around age 14 months by the Bayley Scales of Infant Development – a standard series of measurements originally developed by psychologist Nancy Bayley and which are used to assess the motor, language, and cognitive development of children aged 0-3.

Although the maternal-birth cohort studied comes from moderate-high fish consumption areas, and mercury is found primarily in fish, even a doubling in total mercury levels did not show an association with mental or psychomotor developmental delay. When findings where stratified by sex, there was a slight negative association between prenatal exposure to total mercury and psychomotor development among female infants, but the researchers admit that follow-up is required to confirm these results.

The second paper, published in Gaceta Sanitaria, wanted to examine the effect of maternal intelligence and mental health, taking into account also maternal occupational social class and education, on the neuropsychological development of their children. The subjects studied were also from the INMA project and the children were, again, analysed at 14 months. The mothers’ intelligence and mental health were assessed by professional psychologists and standard tests and questionnaires.

The authors found that maternal IQ plays an important role in the first stages of cognitive development in children in the more disadvantaged occupational social classes. For the other groups, the effects of maternal IQ on cognitive development were mostly explained by maternal education. As per maternal mental health, it had no effect on the childrens’ neurodevelopment, although the authors say this might be because the study was performed in a non-clinical population in which mothers were not suffering from any other serious depressive or psychiatric disorders.

References:
Llop S, Guxens M, Murcia M, Lertxundi A, Ramon R, Riaño I, Rebagliato M, Ibarluzea J, Tardon A, Sunyer J, Ballester F, on Behalf of the INMA Project. Prenatal Exposure to Mercury and Infant Neurodevelopment in a Multicenter Cohort in Spain: Study of Potential Modifiers. Am J Epidemiol. 2012 Jan 27;

Forns J, Julvez J, García-Esteban R, Guxens M, Ferrer M, Grellier J, Vrijheid M, Sunyer J. Maternal intelligence-mental health and child neuropsychological development at age 14 months. Gac Sanit. 2012 Jan 26;

“Alzheimer’s is the price we pay for a life of thinking” – Ageing brain research group of the CEXS-UPF

All four of the PhD students in the ageing brain research group of the CEXS-UPF studied biology at the UPF. “It is our direct source of students!”, says Paco Muñoz López, head of the group and professor at that university. A postdoctoral researcher completes the group, which focuses on nitro-oxidative stress and its link to Alzheimer’s disease.

“The most important risk factor in Alzheimer’s disease is age –says Muñoz–. About 10% of the population over 65 suffer Alzheimer’s, but the percentage goes up to 50% in over 80 year-olds. I think it’s just the price to pay for a life of thinking, a consequence of the overuse of our neurones”. There are also genetic factors, but less than 3% of the cases are familial, mostly due to mutations in APP (amyloid precursor protein) and presenilins.

An aggregation problem

At a molecular level, Alzheimer’s is triggered by the accumulation of amyloid ß-peptide (Aß) aggregates in the brain, in particular in the hippocampus and the cortex. The Aß is a subproduct of the processing of APP, a ubiquitous protein of unknown function. Muñoz’s group suggests that it is a key protein in memory and learning processes.

In other parts of the body, the soluble Aß is eliminated through the liver, but in the case of the brain it cannot pass the bloodbrain barrier and therefore it accumulates. “Once it aggregates the problem starts”, says Muñoz. The group tries to understand how and when APP is processed by BACE1, the enzyme that generates Aß from APP, as well as the role of nitroxidative stress in BACE1 activation and Aß neurotoxicity. When the Aß aggregates it produces free radicals which react with the neuronal nitric oxide, generating peroxynitrite, a very reactive anion that harms proteins.

On the other hand, Aß oligomers bind different membrane proteins, in particular NMDA, a huge receptor for glutamate that, when opened, lets Ca2+ into the cell. When Aß amyloid binds NMDA, it forces the receptor to be half open all the time. This allows a constant flux of Ca2+ into the neurone which, slowly, kills it. The inhibition of the NMDA receptor has been proposed as a specific treatment to slow down Alzheimer’s. But there are other proteins that could pave the way to new therapeutic targets.

One of these was pinpointed by Muñoz’s group in a study that took them four years. “We added Aß to cell cultures and then did some proteomic analyses to determine which proteins had been nitrated. One of them was TPI, a key glycolytic enzyme. Interestingly, glucose consumption in the neurones of people with Alzheimer’s is lower than normal, and it wasn’t known why”, explains the biologist. They looked in APP and presenilin transgenic mice and in brains of Alzheimer’s patients. In both cases they saw that TPI was nitrated. The biochemical studies that followed and some computational studies done by colleagues at the GRIB (UPF-IMIM) confirmed that, when nitrated, TPI was less active. A three-month stay in Japan followed, where Muñoz cloned the TPI enzyme. Finally, they were able to show by electron microscopy that the nitrated TPI aggregated within the cell.

“So far we have focused on the pathological role of APP. But in the near future I want to understand the physiological role of APP in memory, something that remains a mystery”, concludes Muñoz.

This article was published in the El·lipse publication

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