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Statut |
Confirmé |
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Série |
LPS/ENS |
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Domaines |
physics |
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Date |
Mercredi 29 Septembre 2010 |
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Heure |
14:00 |
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Institut |
LPS/ENS |
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Salle |
Conf. IV |
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Nom de l'orateur |
Stepanyants |
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Prenom de l'orateur |
Armen |
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Addresse email de l'orateur |
a [dot] stepanyants [at] neu [dot] edu |
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Institution de l'orateur |
Center for Interdisciplinary Research on Complex Systems Northeastern University |
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Titre |
Statistical traces of long-term memories stored in strengths and patterns of synaptic connections |
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Résumé |
Learning and long-term memory rely on plasticity of neural circuits. In adult cerebral cortex plasticity can be mediated by modulation of existing synapses and structural reorganization of circuits through growth and retraction of dendritic spines. By analyzing 166 distributions of spine head volumes and spine lengths from mouse, rat, monkey, and human brains, we deduce the “generalized cost” of dendritic spines. This cost universally depends on spine shape, i.e. the dependence is the same in all the considered systems. We show that in adult the modulatory and structural plasticity mechanisms are in statistical equilibrium, the numbers of dendritic spines in different cortical areas are nearly optimally chosen for memory storage, and the distribution of spine shapes is governed by a single parameter – the effective temperature. Our results suggest that the effective temperature of a cortical area may be viewed as a measure of longevity of stored memories. |
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Numéro de preprint arXiv |
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Commentaires |
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Fichiers attachés |
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