laboratoire de physique statistique
 
 
laboratoire de physique statistique

Publications

Rechercher
NEURON 


3
P U B L I C A T I O N S

S E L E C T I O N N E R
P A R M I :



 
2016
Structures of Neural Correlation and How They Favor Coding - Franke, Felix and Fiscella, Michele and Sevelev, Maksim and Roska, Botond and Hierlemann, Andreas and da Silveira, Rava Azeredo
NEURON 89409-422 (2016)

Abstract : The neural representation of information suffers from ``noise''-the trial-to-trial variability in the response of neurons. The impact of correlated noise upon population coding has been debated, but a direct connection between theory and experiment remains tenuous. Here, we substantiate this connection and propose a refined theoretical picture. Using simultaneous recordings from a population of direction-selective retinal ganglion cells, we demonstrate that coding benefits from noise correlations. The effect is appreciable already in small populations, yet it is a collective phenomenon. Furthermore, the stimulus-dependent structure of correlation is key. We develop simple functional models that capture the stimulus-dependent statistics. We then use them to quantify the performance of population coding, which depends upon interplays of feature sensitivities and noise correlations in the population. Because favorable structures of correlation emerge robustly in circuits with noisy, nonlinear elements, they will arise and benefit coding beyond the confines of retina.
 
2009
Electrical Coupling Mediates Tunable Low-Frequency Oscillations and Resonance in the Cerebellar Golgi Cell Network - Dugue, Guillaume P. and Brunel, Nicolas and Hakim, Vincent and Schwartz, Eric and Chat, Mireille and Levesque, Maxime and Courtemanche, Richard and Lena, Clement and Dieudonne, Stephane
NEURON 61126-139 (2009)

Abstract : Tonic motor control involves oscillatory synchronization of activity at low frequency (5-30 Hz) throughout the sensorimotor system, including cerebellar areas. We investigated the mechanisms underpinning cerebellar oscillations. We found that Golgi interneurons, which gate information transfer in the cerebellar cortex input layer, are extensively coupled through electrical synapses. When depolarized in vitro, these neurons displayed low-frequency oscillatory synchronization, imposing rhythmic inhibition onto granule cells. Combining experiments and modeling, we show that electrical transmission of the spike afterhyperpolarization is the essential component for oscillatory population synchronization. Rhythmic firing arises in spite of strong heterogeneities, is frequency tuned by the mean excitatory input to Golgi cells, and displays pronounced resonance when the modeled network is driven by oscillating inputs. In vivo, unitary Golgi cell activity was found to synchronize with low-frequency LFP oscillations occurring during quiet waking. These results suggest a major role for Golgi cells in coordinating cerebellar sensorimotor integration during oscillatory interactions.
 
2008
High-frequency organization and synchrony of activity in the Purkinje cell layer of the cerebellum - de Solages, Camille and Szapiro, German and Brunel, Nicolas and Hakim, Vincent and Isope, Philippe and Buisseret, Pierre and Rousseau, Charly and Barbour, Boris and Lena, Clement
NEURON 58775-788 (2008)

Abstract : The cerebellum controls complex, coordinated, and rapid movements, a function requiring precise timing abilities. However, the network mechanisms that underlie the temporal organization of activity in the cerebellum are largely unexplored, because in vivo recordings have usually targeted single units. Here, we use tetrode and multisite recordings to demonstrate that Purkinje cell activity is synchronized by a high-frequency (similar to 200 Hz) population oscillation. We combine pharmacological experiments and modeling to show how the recurrent inhibitory connections between Purkinje cells are sufficient to generate these oscillations. A key feature of these oscillations is a fixed population frequency that is independent of the firing rates of the individual cells. Convergence in the deep cerebellar nuclei of Purkinje cell activity, synchronized by these oscillations, likely organizes temporally the cerebellar output.