ICMS

Apr 11, 2011 - Apr 13, 2011

ICMS, 15 South College Street, Edinburgh, EH8 9AA

Organisers

Name	Institution
Coombes, Stephen	University of Nottingham
Timofeeva, Yulia	University of Warwick

Training Workshop Organiser:
Dr Mark van Rossum, University of Edinburgh

 

This three-day conference will provide an overview of the current state of research in mathematical approaches to neuroscience, bringing together both physical and life scientists.  Drawing together the field in this way will allow for a critical discussion of the relevant experimental facts and of various mathematical methods and techniques that have been successfully applied to date.  Importantly, it will draw attention to, and help develop, those pieces of mathematical theory which are likely to be relevant to future studies of the brain.

The meeting will consist of invited speakers and registered participants, though will be limited to 100 people. The schedule will allow for a number of poster presentations.

This event is sponsored by the EPSRC via the UK Mathematical Neuroscience Network

Arrangements

Please note that the workshop will begin with registration from 09.00-10.30 on Monday 11 April (first talk at 10.45) and will close at 16.00 on Wednesday 13 April.   Please take these timings into account when booking your travel. 

Participation
THIS WORKSHOP IS NOW FULL AND THE APPLICATION PERIOD IS CLOSED. 

Training Workshop - Informatics Forum, Edinburgh (please note that this training workshop has a different venue from the main conference)
Click here for full details and the Programme for the Training Course.   Map showing Informatics Forum. 
This one-day training workshop for PhD students and post-docs entitled "An introduction to Mathematical Neuroscience" will take place prior to the meeting (on Sunday 10 April).  This will be organised by Mark van Rossum and will comprise a series of 'primer' lectures designed to introduce the concepts that will be covered in the main conference. 

Venue for main conference (15 South College Street, Edinburgh)
The workshop will be held at ICMS, 15 South College Street, Edinburgh, EH8 9AA. All lectures will be held in the Newhaven Lecture Theatre. To view this room and a list of the visual equipment available click here. In addition, two blackboards have recently been installed. Follow this link for a map showing the location of 15 South College Street, or this map may also prove useful. Invited speakers can either bring their talk on a usb stick or laptop.

Travel
Information about travel to the UK and Edinburgh is available here.  Please note that it is your responsibility to have adequate travel insurance to cover medical and other emergencies that may occur on your trip.

A taxi directly from the airport will cost approximately 15.00 to 20.00 GBP to the city centre for a one-way journey.     There is also a bus service direct from the airport to the city centre which will cost 3.50 single or 6.00 GBP return - the Airlink 100.  This is a frequent service (every 10 minutes during peak times) and will bring you close to Waverley Railway Station and the workshop venue. 

Lothian buses charge £1.30 for a single, £3.20 for a day ticket. Please note that the exact fare is required and no change is given.

If travelling by train, please note that Edinburgh has two railway stations - Waverley Railway Station being the main station and closest to the workshop venue at 15 South College Street. If you alight at Edinburgh Waverley, the workshop venue is an easy 10 minute walk over North and South Bridge. The second railway station is called Haymarket and is at the West End of the city centre.

UK Visas
If you are travelling from overseas you may require an entry visa. A European visa does not guarantee entry to the UK. Please use this link to the UK Visas site to find out if you need a visa and if so how to apply for one.

Accommodation
Participants are asked to make their own accommodation arrangements. A list of Edinburgh accommodation of various sorts and prices is available here.  Invited Speakers will be contacted separately by email regarding accommodation.

Poster Sessions
There will 2 Poster Sessions, with A-K presenting on Monday, and L-Z presenting on Tuesday.  Please note that only A1 Portrait size posters will be accepted.

On Monday 11 April, 17.30-19.00, participants with last-name initials A-K will present their posters in the Atrium on Level 3.  There will be wine and nibbles provided outside the Cramond Room on Level 2.

The second Poster Session will be on Tuesday 12 April for those with last names L-Z.  Lunch will be available from 12.45-14.00.  The Poster Session will be run during this lunch and for the next hour until 15.00.  In order to accommodate the large number of posters at the same time as serving lunch, this second Poster Session will be split between the Atrium on Level 3 and Chapterhouse on Level 1.  There will be 2 lunch ‘stations’, one on Level 2 outside the Cramond Room for those wishing to view posters in the Atrium, and the other in Chapterhouse on Level 1 for those wishing to view posters there.  Please choose which posters you wish to view and take lunch from the nearest lunch ‘station’. 

Meals and Refreshments
Refreshments will be provided during the breaks in the Programme.  On Tuesday 12 April there will be a light buffet lunch provided.  During this time and for the next hour, the second of the two Poster Sessions will take place.  The Conference Dinner will take place on Tuesday 12 April at 19.00 at Howie's Restaurant, 29 Waterloo Place, Edinburgh, EH1 3BQ (see map).

Wireless Access
The workshop venue, 15 South College Street, has wireless access throughout. On arrival you will be given instructions and a code for accessing the wireless network.

Registration Fee and Financial Matters
Many thanks to all who paid their registration fee so promptly.   If you have yet to pay, this can be paid by completing the details on this credit/debit card payment form.   As email is not secure, please print the form and return it by fax using the fax number at the top of the form.   ICMS will take your payment and a receipt will be given to you at Registration.  Alternatively, we can accept sterling cheques, made payable to Heriot-Watt University but sent to Audrey Brown, ICMS, 15 South College Street, Edinburgh, EH8 9AA.  If you have any difficulty in paying in advance, please email Audrey Brown (email address below).     For Speakers only - no registration fee is required - you will be given a claim form for travel expenses when you arrive at Registration.

All enquiries about arrangements for this workshop should be addressed to audrey.brown at icms.org.uk   

 

Programme

Monday 11 April 2011

09.00 - 10.30	Registration - ground floor, 15 South College Street
10.30 - 10.45	Welcome and introductions
10.45 - 11.30	John White (University of Utah) Dynamic-clamp studies of neuronal synchronization
11.30 - 12.15	Ernest Barreto (George Mason University) Ion concentration dynamics and neuronal excitability
12.15 - 14.00	Lunch break
14.00 - 14.45	Romain Brette (École Normale Supérieure ) Neural computation with synchrony
14.45 - 15.30	Paul Tiesinga (Radboud University Nijmegen ) Phase and synchrony dynamics of gamma oscillations in cortical networks
15.30 - 16.15	Coffee
16.15 - 17.00	Bard Ermentrout (University of Pittsburgh) A role for oscillations in working memory
17.30 - 19.00	Poster session and wine reception - 15 South College Street

Tuesday 12 April 2011

09.00 - 09.45	Eric Shea-Brown (University of Washington) Cooperative dynamics in simple neural circuits
09.45 - 10.30	Alex Roxin (Institut d'Investigacions Biomèdiques August Pi i Sunyer) The effect of degree distribution on the dynamics of sparsely connected neuronal networks
10.30 - 11.15	Coffee
11.15 - 12.00	Axel Hutt (INRIA) Linear and non-linear effects of stochastic fluctuations on the spatio- temporal activity of neural populations
12.00 - 12.45	Jack Cowan (University of Chicago) A new approach to the modelling of large-scale brain activity
12.45 - 14.00	Lunch provided in the Chapterhouse, ground floor. Please note that lunch overlaps with the second Poster Session.
12.45 - 15.00	Poster session - 15 South College Street
19.00	Conference Dinner - Howies, Waterloo Place

Wednesday 13 April 2011

09.00 - 09.45	Arjen van Ooyen ( (Vrije Universiteit Amsterdam) Homeostatic structural plasticity in neuronal network formation and maintenance
09.45 - 10.30	Máté Lengyel (University of Cambridge) Information bottlenecks and their remedies in neural computation
10.30 - 11.15	Coffee
11.15 - 12.00	Kenneth Harris (Imperial College London) The neural marketplace
12.00 - 12.45	Louis Tao (Peking University) Dimension reduction of a visual cortical network model
12.45 - 14.30	Lunch break
14.30 - 15.15	Yixin Guo (Drexel University ) Deep brain stimulation diminishes thalamocortical relay errors in computational models
15.15 - 16.00	Si Wu (Chinese Academy of Sciences) Neural information processing with dynamical synapses

Presentations:

Presentation Details
Barreto, Ernest
Ion concentration dynamics and neuronal excitability
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We develop models of individual neurons and of networks that include intra- and extra-cellular ion concentration dynamics. A reduction of the single neuron model is used to identify the bifurcation structure, leading to the identification of a novel mechanism for bursting and seizure-like events that are similar to that seen in experiments. In addition, we examine the stability of persistent states of activity and excitatory-inhibitory interplay. A possible role of cation-chloride co-transporters is also discussed.
Brette, Romain
Neural computation with synchrony
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Neuronal synchronization is ubiquitous in the nervous system, but it is not clear what computational role it might play, if any. I show that structure in stimuli, for example sound periodicity or correlations in binaural signals, results in specific patterns of synchrony in spiking models, which produce increased firing in specific assemblies of postsynaptic neurons. Such elementary neural circuits extract structural properties of stimuli with natural invariances.
Cowan, Jack
A new approach to the modelling of large-scale brain activity
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We have recently found a way to describe large-scale neural activity in terms of non-equilibrium statistical mechanics. This allows us to calculate the effects of fluctuations and correlations on neural activity. Major results of this formulation include a role for critical branching, and the demonstration that there exists a non-equilibrium phase transition in neocortical activity which is in the same universality class as directed percolation. Here we show how the population dynamics of interacting excitatory and inhibitory neural populations can be described in similar terms, and how such a theory can be used to explain the origins and properties of random bursts of synchronous activity (avalanches), population oscillations (quasi-cycles), and fluctuation-driven spatial patterns (quasi-patterns).
Ermentrout, Bard
A role for oscillations in working memory
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In this talk, we discuss the relationship between inhibition, synchrony, and rhythmicity and various dynamical pathologies of the central nervous system. We first describe a new role for gamma frequency oscillations in working memory. We then show how disruption of inhibition affects the oscillations as well as how it affects the ability of the network to maintain memories and switch between them. Reduction of the spiking model to a firing rate model provides intuition about the effects.
Guo, Yixin
Deep brain stimulation diminishes thalamocortical relay errors in computational models
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I will first introduce how thalamocortical (TC) relay errors result from pathological data recorded in both nonhuman primates and parkinsonian patients in a data-driven computational model. Then I will discuss several protocols of deep brain stimulation that can restore TC relay fidelity through different mechanisms using a biophysical network model.
Harris, Kenneth
The neural marketplace
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Classically, neurons communicate by anterograde conduction of action potentials. However, information can also pass backward along axons, a process that is well characterized during nervous system development. Here we suggest that competition for such retroaxonal factors causes neurons to form functional networks, through processes akin to those of a free-market economy. We hypothesize that strengthening of a neuron’s output synapses stabilizes recent changes in the same neuron’s inputs. During learning, the input synapses of many neurons undergo transient changes, resulting in representation of a wide variety of new sensory features. Only a few of these features are useful to behaviour, however, and it is these neurons that strengthen output connections onto downstream cells. These neurons will receive a retroaxonal signal, and stabilize their recently changed inputs, causing the new features to be retained; neurons that did not strengthen their outputs will not, and the corresponding features will be lost. Successful neurons in turn have more “capital” to pass on to their own inputs, allowing complex “supply chains” to build up across large neuronal networks. We describe experimental evidence in support of this hypothesis, and simulations in which networks constructed along similar principles are applied to information-processing tasks.
Hutt, Axel
Linear and non-linear effects of stochastic fluctuations on the spatio-temporal activity of neural populations
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The talk will show recent results on the linear response of neural fields to additive stochastic forces motivated by the physiological structure of the primary sensory system in weakly electric fish. To learn more about the response of neural populations to stochastic stimuli, we consider nonlinear effects and find a noise-induced shift of the stability threshold. Finally, the work presents first numerical results on the stochastic effects in two-dimensional neural fields involving finite axonal transmission speeds.
Lengyel, Máté
Information bottlenecks and their remedies in neural computation
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Neural computation is plagued by various forms of information bottlenecks. I will discuss three such bottlenecks implied by 1) the conversion of analogue membrane potentials into digital spike trains, 2) the conversion of distributed patterns of neural activity into synaptic efficacies, and 3) the conversion of features of the environment into distributed patterns of neural activity. I will show how various aspects of neural circuit dynamics can be seen as adaptations to resolve these bottlenecks by 1) short-term synaptic plasticity, 2) the way long-term synaptic plasticity is matched to the statistics and dynamics of neural activities, 3) controlled forms of variability in cortical responses.
Roxin, Alex
The role of degree distribution in shaping the dynamics in networks of sparsely connected spiking neurons
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Neuronal network models often assume a fixed probability of connection between neurons. This leads to a ''standard'' random network in which the number of presynaptic inputs (in-degree) and postsynaptic targets (out-degree) for each cell is narrowly distributed. However, recent multiple intracellular recordings in visual cortex of mouse revealed that certain connectivity motifs between pairs and triplets of neurons, occurred with either a higher or lower frequency than what one would expect from a standard random network (Song et al. 2005). Here, I explore the consequences of allowing for ''non-standard'' random connectivity on network dynamics. Specifically, I interpolate between standard and broad, power-law distributions in the in-degree and out-degree of the network. A broad in-degree distribution results in a large amount of heterogeneity in the number of inputs across neurons, while a broad out-degree distribution leads to an increased fraction of common inputs to pairs of neurons. Equivalently, they lead to an increase in the number of convergence- and divergence-related connectivity motifs, respectively. Through numerical simulation of networks of spiking neurons and analytical work with a reduced rate equation, it is shown that the in-degree affects the global dynamical state of the network, e.g. whether asynchronous or oscillatory, while the out-degree affects pairwise correlations in synaptic currents.
Shea-Brown, Eric
Cooperative dynamics in simple neural circuits
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The brain's networks contain numerous mechanisms that could lead to synchronized -- or correlated -- dynamics among cells. Moreover, information-theoretic calculations tell us that precisely what pattern of correlations emerges can have major impact on the fidelity with which a network encodes incoming signals. We'll explore simplified circuit models in which the link between single-cell dynamics, coupling architecture, and correlation can be understood, and discuss the consequences for neural coding.
Tao, Louis
Dimension reduction of a visual cortical network model
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Systems-level neurophysiological data reveal coherent activity that is distributed across large regions of cortex. This activity is often thought of as an emergent property of recurrently connected networks. The fact that this activity is coherent means that populations of neurons may be thought of as the carriers of information, not individual neurons. Therefore, systems-level descriptions of functional activity in the network often find their simplest form as combinations of the underlying neuronal variables. In this talk, we provide a general framework for constructing low-dimensional dynamical systems that capture the essential systems-level information contained in large-scale networks of neurons. We demonstrate that these dimensionally-reduced models are capable of predicting the response to previously un-encountered input and that the coupling between systems-level variables can be used to reconstruct cellular-level functional connectivities. Furthermore, we show that the effect of the neglected modes can be modelled as stochastic processes.
Tiesinga, Paul
Phase and synchrony dynamics of gamma oscillations in cortical networks
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Recent experiments demonstrate that in prefrontal cortex spikes at a specific gamma (30-80 Hz) phase relative to the local field potential are most informative about stimulus identity, where the specific value of the phase depends on the order of the stimulus within the stimulus sequence. Within the context of a model cortical circuit this corresponds to changes in the relative phase between excitatory (E) and inhibitory (I) cells. We study using mathematical analysis and simulations how phase and synchrony can be modulated in the cortical circuit for gamma oscillations generated by the pyramidal interneuron gamma (PING) mechanism. We compare the effect of neuromodulators such as acetylcholine, which can be modeled as a depolarizing current, to that of short current pulses representing optical activation of channelrhodopsin-2 (ChR2) channels. From a functional point of view, our model results predict that targeting I cells by neuromodulators will change the gain local to the circuit, that is, of those neurons receiving local E and I inputs (Buia & Tiesinga, J. Computational Neuroscience 2006), whereas light pulses will modulate the effective strength of connectivity between circuits in different cortical areas according to the Communication through Coherence principle (Fries, Trends in Cognitive Sciences 2005). In the PING mechanism, gamma oscillations emerge when the E cells are sufficiently depolarized and when a synchronized E cell volley recruits a synchronous I cell volley, which inhibits the E cells for approximately a gamma cycle. When the E cells have recovered, the oscillation cycle starts over. We find that hyperpolarizing the I cells will delay the I cell volley, thus increasing the phase of the I cells relative to the E cells. By contrast, when the depolarization of the E cells is increased, they recover faster from inhibition, which increases the oscillation frequency, but does not strongly alter the delay between I and E cells. When I cells (or E cells) expressing ChR2 are targeted by a light pulse, the relative E-I phase does not change, instead the overall phase relative to local circuits in other cortical areas changes.
van Ooyen, Arjen
Homeostatic structural plasticity in neuronal network formation and maintenance
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Most studies, experimental and theoretical, focus on synaptic strength plasticity, whereby the connectivity structure among neurons is considered fixed. Over the past years, however, it has become clear that the adult brain is not as hard-wired as traditionally thought. Neurons establish new synapses and break existing ones, whereby previously unconnected neurons become connected and vice versa (structural plasticity). Formation and deletion of dendritic spines, as well as outgrowth and retraction of axons and dendrites, still take place in adulthood. In current neuronal network models, network structure is fixed, with plasticity only arising from changes in the strength of existing synapses. Here, I introduce novel models that incorporate structural plasticity. I use these models to study the development of connectivity and the restructuring of cortical circuits that is induced by lesions in adulthood. In these models, the need of neurons to maintain their average level of electrical activity at a particular level (homeostatic regulation) drives structural plasticity. I explore what the implications of this homeostatic structural plasticity are for the development and restructuring of cortical connectivity.
White, John
Dynamic-clamp studies of neuronal synchronization
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Dynamic-clamp technology allows one to immerse neurons in virtual realities that can be manipulated with fine quantitative precision. In dynamic-clamp recordings from cortical and hippocampal neurons, we studied the problem of neuronal synchronization. Among our conclusions: (1) Ongoing conductance-based inputs can change neuronal resonance, bifurcation structures, and frequency-vs.-current relationships dramatically; (2) neurons that show no resonance to broadband stimuli can still respond preferentially to stimuli including sinusoidal modulation of input rates; (3) recordings and associated modelling studies suggest that incoherent inputs to pyramidal cells and fast-spiking interneurons have disparate effects on synchrony.
Wu, Si
Neural information processing with dynamical synapses
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Neuronal interaction efficacy exhibits two types of short-term plasticity, called short-term depression (STD) and short-term facilitation (STF). They have time scales residing between fast neural signalling and slow learning, and hence can serve as substrates for neural systems manipulating temporal information in the relevant time orders. The present study investigates the impacts of STD and STF on the dynamics of continuous attractor neural networks (CANNs) and their potential roles in neural information processing. We find that the network with STD can generate both static and travelling bumps, and STD enhances the performance of the network in tracking external inputs. In particular, we find that STD endows the network with slow-decaying plateau behaviours, namely, the network being initially stimulated to an active state will decay to silence very slowly in the time scale of STD rather than that of neural signalling. This provides a mechanism for neural systems to hold short-term memory easily and shut off persistent activities naturally. With STF, we find that the network can hold a memory trace of external inputs in the facilitated neuronal interactions, which provides a way to stabilize the network response to noisy inputs, leading to improved population decoding results. We also show that STD and STP tend to have opposite effects on network dynamics and varied computational advantages, suggesting that the brain may employ a strategy of weighting them differentially for serving different computational purposes.

Participants

Name	Institution
Adhikari, Mohit	INSERM
Akam, Thomas	University College London
Ashwin, Peter	University of Exeter
Azad, Abul Kalam al	University of Plymouth
Bányai, Mihály	Hungarian Academy of Sciences
Baradaranshokouhi, Yashar	University of Sheffield
Barreto, Ernest	George Mason University
Bergmann, Urs	Humboldt-Universität zu Berlin
Berthouze, Luc	University of Sussex
Bhattacharya, Basabdatta Sen	University of Ulster
Blenkinsop, Alexander	University of Sheffield
Bodova, Katarina	Comenius University
Borisyuk, Roman	Plymouth University
Bos, Hannah	Technische Universität Berlin
Brette, Romain	École Normale Supérieure
Brown, Andrew	University of Southampton
Buckley, Christopher	University of Sussex
Buckwar, Evelyn	Heriot-Watt University
Castejón, Oriol	Universitat Politècnica de Catalunya
Caudron, Quentin	University of Warwick
Chiarcos, Olga	Springer-Verlag GmbH
Coombes, Stephen	University of Nottingham
Costa, Rui	University of Edinburgh
Cowan, Jack	University of Chicago
Deger, Moritz	Freiburg University
Donoso Leiva, Jose Ramon	Humboldt-Universität zu Berlin
Down, Matt	Insititue for Adaptive and Neural Computation
Ermentrout, Bard	University of Pittsburgh
Faye, Grégory	INRIA Sophia-Antipolis
Finke, Christian	Carl von Ossietzky University Oldenburg
Gekas, Nikos	University of Edinburgh
Gillespie, James B	Trinity College Dublin
Guillamon, Toni	Universitat Politècnica de Catalunya
Guo, Yixin	Drexel University
Harris, Kenneth	Imperial College London
Hennig, Matthias	University of Edinburgh
Herrmann, J Michael	University of Edinburgh
Houghton, Conor	Trinity College Dublin/University of Bristol
Hutt, Axel	LORIA-INRIA
Jaramillo, Jorge	Humboldt-Universität zu Berlin
Kirt, Toomas	University of Tartu
Kollar, Richard	Comenius University
Kuhn, Markus	University of Cambridge
Laudanski, Jonathan	École Normale Supérieure
Lengyel, Máté	University of Cambridge
Lesica, Nicholas	University College London
Linssen, Charl	Radboud University Nijmegen
Lyamzin, Dmitry	University College London
Mäki-Marttunen, Tuomo	Tampere University of Technology
Matthey, Loic	University College London
Mugruza Vassallo, Carlos	University of Dundee
Negahbani, Ehsan	University of Waikato
Neishabouri, Mohammad Ali	Imperial College London
Nowacki, Jakub	University of Bristol
Panas, Dagmara	University of Edinburgh
Pegg, Kathryn	École Polytechnique Federal de Lausanne (EPFL)
Pelko, Miha	University of Edinburgh
Penny, Will	University College London
Perez, Maria	Institut d'Investigacions Biomèdiques August Pi i Sunyer)
Pernice, Volker	Bernstein Center Freiburg
Petersen, Rasmus	University of Manchester
Petrovic, Cornelia	University of Münster
Rankin, James	INRIA Sophia-Antipolis
Reimer, Imke	Bernstein Center Freiburg
Riedler, Martin	Heriot-Watt University
Rogers, Lisa	Courant Institute of Applied Mathematics
Roxin, Alex	Institut d'Investigacions Biomèdiques August Pi i Sunyer
Rudiger, Philipp	University of Edinburgh
Schmidt, Helmut	University of Nottingham
Schroeder, Sylvia	University of Zurich and ETH
Sengor, Neslihan Serap	Istanbul Technical University
Shea-Brown, Eric	University of Washington
Smith, Ruth	University of Nottingham
Solanka, Lukas	University of Edinburgh
Steenbuck, Ines Derya	Vrije Universiteit Amsterdam
Stevens, Jean-Luc	University of Edinburgh
Svensson, Carl-Magnus	University of Nottingham
Tao, Louis	Peking University
Terry, John	University of Exeter
Thul, Ruediger	University of Nottingham
Tiesinga, Paul	Radboud University Nijmegen
Timofeeva, Yulia	University of Warwick
Tomsett, Richard	Newcastle University
Tsaneva-Atanasova, Krasimira	University of Bristol
Tully, Philip	Kungliga Tekniska högskolan & University of Edinburgh
van Ooyen, Arjen	Vrije Universiteit Amsterdam
van Rossum, Mark	University of Edinburgh
Veltz, Romain	INRIA
Walker, Jamie	University of Bristol
Wedgwood, Kyle	University of Nottingham
Weigenand, Arne	Universität zu Lübeck
White, John	University of Utah
Wu, Si	Chinese Academy of Sciences
Yarrow, Stuart	University of Edinburgh
Yim, Man Yi	University of Freiburg