Michele Bezzi

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Multielectrode arrays allow recording of the activity of many single neurons, from which correlations can be calculated. The functional roles of correlations can be revealed by measures of the information conveyed by neuronal activity; a simple formula has been shown to discriminate the information transmitted by individual spikes from the positive or(More)
A nerve cell receives multiple inputs from upstream neurons by way of its synapses. Neuron processing functions are thus influenced by changes in the biophysical properties of the synapse, such as long-term potentiation (LTP) or depression (LTD). This observation has opened new perspectives on the biophysical basis of learning and memory, but its(More)
In this paper we extend the Celada-Seiden (CS) model of the humoral immune response to include infectious virus and cytotoxic T lymphocytes (cellular response). The response of the system to virus involves a competition between the ability of the virus to kill the host cells and the host's ability to eliminate the virus. We find two basins of attraction in(More)
We investigate the problem of speciation and coexistence in simple ecosystems when the competition among individuals is included in the Eigen model for quasispecies. By suggesting an analogy between the competition among strains and the diffusion of a chemical inhibitor in a reaction-diffusion system, the speciation phenomenon is considered the analogous of(More)
We present a simple spiking model that extends the classical integrate-and-ÿre neuron to reproduce the diierent dynamical behaviors observed in cerebellar granule cells. The model is two dimensional: in addition to the membrane potential V , we consider a gating variable that models a slow K + current. This current plays a major role in generating the(More)
Neurons communicate through spikes; their arrangement in different sequences generates the neural code. Spikes are transmitted between neurons via synapses; the mechanism underlying synaptic transmission involves numerous processes including neurotransmitter release and diffusion, postsynaptic receptor activation, and intrinsic electrore-sponsiveness. Based(More)
A novel definition of the stimulus-specific information is presented, which is particularly useful when the stimuli constitute a continuous and metric set, as, for example, position in space. The approach allows one to build the spatial information distribution of a given neural response. The method is applied to the investigation of putative differences in(More)