An increase in dendritic plateau potentials is associated with experience-dependent cortical map reorganization

Stéphane Pagès , Nicolas Chenouard (1) , Ronan Chéreau , Vladimir Kouskoff (1) , Frédéric Gambino (1) , Anthony Holtmaat

1 IINS - Interdisciplinary Institute for Neuroscience [Bordeaux]

The organization of sensory maps in the cerebral cortex depends on experience, which drives homeostatic and long-term synaptic plasticity of cortico-cortical circuits. In the mouse primary somato-sensory cortex (S1) afferents from the higher-order, posterior medial thalamic nucleus (POm) gate synaptic plasticity in layer (L) 2/3 pyramidal neurons via disinhibition and the production of dendritic plateau potentials. Here we address whether these thalamo-cortically mediated responses play a role in whisker map plasticity in S1. We find that trimming all but two whiskers causes a partial fusion of the representations of the two spared whiskers, oncomitantly with an increase in the occurrence of POm-driven N-methyl-D-aspartate receptor-dependent plateau potentials. Blocking the plateau potentials restores the archetypical organization of the sensory map. Our results reveal a mechanism for experience-dependent cortical map plasticity in which higher-order thalamocortically mediated plateau potentials facilitate the fusion of normally segregated cortical representations.

Domaines: Neurobiologie

Stéphane Pagès, Nicolas Chenouard, Ronan Chéreau, Vladimir Kouskoff, Frédéric Gambino, et al.. An increase in dendritic plateau potentials is associated with experience-dependent cortical map reorganization. Proceedings of the National Academy of Sciences of the United States of America, 2021, ⟨10.1073/pnas.2024920118⟩. ⟨hal-03429986⟩