Project Description

The project SENSOPAC: Sensorimotor structuring of Perception and Action is funded under the EU Framework 6 IST Cognitive Systems initiative for a period of 48 months. The project involves a total of 11 partners across Europe including research groups from Cambridge (D. Wolpert), DLR Germany (P. van der Smagt), SONY France (O. Coenen), Erasmus MC (C. De Zeeuw), Edinburgh (S. Vijayakumar), UMEA-Sweden (R.Johansson), LUND-Sweden (Jorntell, Ekerot), Bar-Ilan (Cohen), UGR-Spain (Ros), Altjira (Arnold) besides Pavia.

The overall aims of the SENSOPAC project are to: (i) Understand the sensorimotor foundation of perception and cognition, (ii) Improve our understanding of the neurobiological substrate for action-perception systems, (iii) Build a physical system for haptic cognition, (iv) Use probabilistic techniques to investigate cognition in the brain, (v) Develop real-time neuromorphic and computing platforms for cognitive robotics. The project will deal with multiple sensory modalities like haptic, proprioceptive, position and force feedback.

Pavia's Principal Role

The Pavia group will be responsible for single cell neurophysiology and modelling in the cerebellum and for the analysis of circuit functions in vitro and in vivo. The main targets concern the development of learning rules for granular layer synapses, models of information transfer at the main cerebellum input-stage, and cerebellar microcomplex activation and plasticity during whisking,, a form of haptic control in the rat. PAVIA is collaborating with other groups of the consortium to implement biologically inspired network simulations of sensory-motor control systems to be interfaced with robots.

SENSOPAC related publications

PAVIA is especially concerned with the experimental and modelling investigation of the input stage of the cerebellar cortex, the granular layer, in which timing and learning fundamental for cerebellar signal processing take place. During the 1st year PAVIA has progressed in the experimental and modeling investigation of micorcomplex functional properties. The work converges toward the construction of a microcomplex model and its theoretical investigation and application for bio-inspired control systems for haptics. The works have been developed in part through collaborations with ERASMUS, UGR, and SONY and their extension is in progress.

GROUP 1: Spatio-temporal organisation of activity and plasticity in the microcomplex.

1. E.D’Angelo, C De Zeeuw (2008). Timing and plasticity in the cerebellum: focus on the granular layer. TINS

2. E. D’Angelo. The critical role of Golgi cells in regulating spatio-temporal integration and plasticity at the cerebellum input stage. Frontiers in Cellular Neuroscience.

3. Roggeri L, Rivieccio B, Rossi P, D’Angelo E (2008) Tactile stimulation evokes long-term synaptic plasticity in the granular layer of cerebellum”. J Neuroscience.

4. Shyam Diwakar, Jacopo Magistretti, Mitchell Goldfarb, Giovanni Naldi, Egidio D’Angelo.  Axonal Na+ channels ensure fast spike activation and back-propagation in cerebellar granule cells. J Neurophysiology, in press.
   

These works have been fully supported by and are relevant to SENSOPAC. The convergence toward SENSOPAC main target is in act through the following actions, which are being actively pursued and at remarkable stage of advancement:

• development of algorithms to reconstruct functional microcomplex connectivity.

• determination of a general learning rule for the granular layer

These works are continuing through the application of VSD imaging to achieve higher spatio-temporal resolution of activity and plasticity in the microcomplex. A detailed network simulation in NEURON is already running and under testing. Moreover, through collaboration with UGR, the network is now being translated in EDLUT for real-time simulations.

GROUP 2: Detailed analysis of the inhibitory circuit of the microcomplex.

1. Sergio Solinas, Lia Forti, Elisabetta Cesana, Jonathan Mapelli, Erik De Schutter, Egidio D’Angelo. (2007) Fast-reset of pacemaking and theta-frequency resonance patterns in cerebellar Golgi cells. Frontiers in Cellular Neuroscience 1-4:1-9 .

2. Sergio Solinas, Lia Forti, Elisabetta Cesana, Jonathan Mapelli, Erik De Schutter, Egidio D’Angelo. (2007) Computational reconstruction of pacemaking and intrinsic electroresponsiveness in cerebellar Golgi cells. Frontiers in Cellular Neuroscience 1-2:1-12.

3. Mapelli L, Rossi P, Nieus T, D’Angelo E . Tonic activation of GABA-B receptors reduces release probability at inhibitory connections in the cerebellar glomerulus. J Neuroscie., submitted.

4. R. Carrillo, E. Ros, S. Tolu, T. Nieus, E. D’Angelo. (2007) Event-driven simulation of cerebellar granule cells. Information Processing in Cells and Tissue. In preparation

5. Jesús A. Garridoa, Eduardo Ros a, Richard R. Carrilloa, Egidio D'Angelo (2007) Noise reduction and time slicing facilitated by local network topologies in the cerebellum granular layer network. Information Processing in Cells and Tissue. In preparation

6. Michele Bezzi, Angelo Arleo, Thierry Nieus, Olivier Coenen, Egidio D’Angelo. Quantitaive characterization of information transmission in a single neuron.  In preparation.

These works, supported by and relevant to SENSOPAC, allow the reconstruction of functional principles of the inhibitory circuit, which governs the spatio-temporal organization of activity in the microcomplex. The convergence toward SENSOPAC main target is in act through

• inclusion of these mechanisms in microcomplex simulations.

• extraction of rules for spatio-temporal signal processing through inhibition

GROUP 3: Analysis of mutations to understand the functional relevance of network mechanisms.

1. Goldfarb M, Schoorlemmer J, Williams A, Mukundanunny SD, Huang X,  Giza J, Tchetchik D,  Kelley K, Vega A, Matthews G, Rossi P,  Ornitz D, and D’Angelo E (2007) Fibroblast growth factor homologous factors control neuronal excitability through modulation of voltage-gated sodium channels. Neuron,55:449-463

2. Francesca Prestori, Paola Rossi, Bertrand Bearzatto, Jeanne Lainé, Daniela Necchi,  Shyam Diwakar, Serge N. Schiffmann, Herbert Axelrad, Egidio D’Angelo (2008) Altered neuron excitability and synaptic plasticity in the cerebellar granular layer of juvenile prion protein knock-out mice with impaired motor control. J Neuroscience.
   

These works have been largely supported by external funding but are also converging toward SENSOPAC main target. The aim, besides understanding certain pathological states, is to understand the functional relevance of microcomplex mechanisms for sensori-motor control. This sector of research is under expansion and is going to become more integral part of SENSOPAC through an intensive collaboration with ERASMUS. This will make use of cell-specific genetic constructs (NMDA receptor, calcium channels and GABA receptor KO) aimed at identifying:

• the role of plasticity in the microcomplex through gene-specific KO

• the role of inhibition in the microcomplex through gene-specific cell-specific KO.

Work in progress and extended convergence to the main SENSOPAC target.

GROUP 4: Techniques.

1. L. Sacconi, J. Mapelli, D. Gandolfi, J. Lotti, R. P. O’Connor, E. D’Angelo and F. S. Pavone (2008). Optical recording of electrical activity in intact neuronal networks with random access second-harmonic generation microscopy.
   

The integration with the main SENSOPAC target requires that current low-level (cellular-molecular) knowledge is projected at the circuit level and translated into sensori-motor control models. To this aim, during the first year, we have developed three benchmark techniques.

• Field recordings in vivo. The technique has been fully developed and tested during the first year. A paper is in preparation. The extension toward sensori-motor integration will consist in a detailed analysis of activity and learning when the microcomplex interacts with the sensory system and the motor cortex during whisking, a form of haptic control in the rat. This is expected to provide critical constraints for the implementation of the large-scale model and the controller of the haptic robotic system.

• Imaging recordings in vivo. The technique has been fully characterized in vitro and the equipment for the in vivo set-up has been installed. Testing in vivo is now beginning. It will extend the spatial analysis of the microcomplex during sensory-motor interactions.

• Detailed network simulation in NEURON. Far from real-time, incorporates and elaborates biological details. It is the preliminary step toward real-time spiking networks and large-scale networks for robotic control. Developed and tested, the granular layer network is currently under implementation.

Click on the SENSOPAC logo to go to the SENSOPAC official site.

A detailed list of recent publications related to SENSOPAC can be also found at the publications page of the sensopac project.