On March 11th, Venkatesh Murthy from the Department of Molecular and Cellular Biology of Harvard University, US, gave a conference at the PRBB invited by the CRG. He explained his study “An olfactory cocktail party: figure-ground segregation of odorants in rodents”, which was the cover of Nature Neuroscience in September 2014. After a brief introduction to the anatomy of the olfactory system of rodents, he explained that many odours are complex mixtures: different chemicals combine and then we can smell a particular object. His main question was: how well can a mouse pick out an individual odorant from a mixture?
They wanted the mice to pick a single ingredient within an odour cocktail. In order to do that, mice were trained to recognize target odorants embedded in unpredictable and variable background mixtures. They used 14 different chemicals, so there were more than 16.000 possible mixtures. It was impossible for the mice to memorize the combination; they had to recognize the single odorant. The test used was the go/no go, in which stimuli, in this case smell, are presented in a continuous stream and mice perform a binary decision on each stimulus. One of the outcomes (the correct smell) requires mice to make a motor response (go) in order to receive the reward, whereas the other requires mice to withhold a response (no-go). Accuracy and reaction time are measured for each event.
Mice could learn this task in a few days, they performed it well, but performance dropped with increasing number of background odours. To understand why, the researchers first had to overcome a problem particular to olfaction.
While the relationship among different visual stimuli is relatively simple – differences in colour can be described as differences in wavelength of light – there is not a simple explanation for describing how odours relate to each other. Instead, the researchers tried to describe scents according to how they activate neurons in the brain. They used optical imaging and computational models to relate behavioural performance to the combinatorial neural representation of odorants in odour receptors.
Using fluorescent proteins, they created images that showed how each of 14 different odours stimulated neurons in the olfactory bulb. Each odour gave rise to a particular spatial pattern of neural responses. When the spatial pattern of the background odours overlapped with the target odour, the ability of mice to identify the target was diminished. Therefore, the difficulty of picking out a particular smell among a cocktail of other odours depends on how much the background interferes with the target smell.
All in all, it was a very interactive session, with the public discussing several issues all through the talk, especially about methodology, so both the speaker and the public got new ideas!
A report by Mari Carmen Cebrián
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.
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:
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
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
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
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!!
The March 2012 edition of the PRBB newspaper, El.lipse, a monthly bilingual newspaper, is now available.
Her Majesty the Queen of Spain has visited the FPM at the PRBB this February. Also, find out about the core facilities coalition that supports research at the park. Matthieu Louis, from the Centre for Genomic regulation (CRG), tells us about his research into Drosophila neuroscience, and Anna Bigas (IMIM-Hospital del Mar Research Institute) explains her life as a scientist. Other news include the repositioning of drugs for rare diseases; improving the value of preleukaemia prognosis, the health cost of swine flu; the recent origin of North Africans; or understanding resistance to colorectal cancer treatment; or new pathways involved in bladder cancer. Finally, should ‘dangerous’ data be published? Find out our researchers’ views on this!