Title
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The dynamical response properties of neocortical neurons to temporally modulated noisy inputs in vitro
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Author
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Abstract
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Cortical neurons are often classified by currentfrequency relationship. Such a static description is inadequate to interpret neuronal responses to time-varying stimuli. Theoretical studies suggested that single-cell dynamical response properties are necessary to interpret ensemble responses to fast input transients. Further, it was shown that input-noise linearizes and boosts the response bandwidth, and that the interplay between the barrage of noisy synaptic currents and the spike-initiation mechanisms determine the dynamical properties of the firing rate. To test these model predictions, we estimated the linear response properties of layer 5 pyramidal cells by injecting a superposition of a small-amplitude sinusoidal wave and a background noise. We characterized the evoked firing probability across many stimulation trials and a range of oscillation frequencies (11000 Hz), quantifying response amplitude and phase-shift while changing noise statistics. We found that neurons track unexpectedly fast transients, as their response amplitude has no attenuation up to 200 Hz. This cut-off frequency is higher than the limits set by passive membrane properties (∼50 Hz) and average firing rate (∼20 Hz) and is not affected by the rate of change of the input. Finally, above 200 Hz, the response amplitude decays as a power-law with an exponent that is independent of voltage fluctuations induced by the background noise. |
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Language
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English
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Source (journal)
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Cerebral cortex. - New York
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Publication
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New York
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2008
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ISSN
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1047-3211
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Volume/pages
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18
:9
(2008)
, p. 2086-2097
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ISI
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000259144800012
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Full text (Publisher's DOI)
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Full text (publisher's version - intranet only)
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