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Synaptic plasticity and response properties of cortical neurons: theory and experiments

Applicant Senn Walter
Number 65234
Funding scheme Project funding (Div. I-III)
Research institution Institut für Physiologie Medizinische Fakultät Universität Bern
Institution of higher education University of Berne - BE
Main discipline Neurophysiology and Brain Research
Start/End 01.10.2001 - 30.09.2004
Approved amount 352'792.00
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Keywords (5)

neuronal current-to-rate transfer functions; computational models; neuronal adaptation; pyramidal neurons; fast spiking neurons

Lay Summary (English)

Lead
Lay summary
We investigated the response properties of neocortical pyramidal neurons and fast spiking (inhibitory) neurons to in vivo-like input currents. Our combined experimental and modeling approach yields a quantitative understanding of the input-output relation of these cells. In particular, we showed that the steady-state and transient firing rates of both cell types can be accurately reproduced by a simple integrate-and-fire neuron model with adaptation. We were also showing that, in contrast to the commonly held view, fast spiking neurons exhibit a slow adaptation in the range of a few seconds. Further investigations of the layer 5 pyramidal cell firing behavior revealed that top-down input onto the distal apical tree can increase the gain of this neuron. Such a top-down gain modulation would be consistent with the modulatory effect of attentional signals observed in vivo. In a second line of research we theoretically explored functional consequences of synaptic short- and long-term plasticity in the primary visual cortex (V1). We showed that short-term synaptic depression in thalamocortical synapses may explain a variety of phenomena observed in V1 which was widely believed to be mediated by lateral inhibition. Changing the degree of synaptic depression by spike-timing dependent plasticity, moreover, is shown to explain the development of neurons in V1 which are selective to the direction of a moving stimulus.
Direct link to Lay Summary Last update: 21.02.2013

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Associated projects

Number Title Start Funding scheme
105966 Top-down gain modulation and learning across cortical areas 01.10.2004 Project funding (Div. I-III)
57076 Roles of Dynamic synapses and backpropagating action potentials in receptive field formation 01.10.1999 Project funding (Div. I-III)

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