Functional and Structural Properties of Highly Responsive Somatosensory Neurons in Mouse Barrel Cortex

C S Barz (1, 2) , Pierre-Marie Garderes (2, 3) , D A Ganea (2, 4) , S Reischauer (5, 6) , D Feldmeyer (5, 2) , Florent Haiss (2, 3)

1 Jülich Research Centre
2 RWTH - Rheinisch-Westfälische Technische Hochschule Aachen University
3 Dynamique corticale et prise de décision - Neural circuit dynamics and decision making
4 Unibas - Université de Bâle = University of Basel = Basel Universität
5 JLU - Justus-Liebig-Universität Gießen = Justus Liebig University
6 MPI-HLR - Max Planck Institute for Heart and Lung Research

Sparse population activity is a well-known feature of supragranular sensory neurons in neocortex. The mechanisms underlying sparseness are not well understood because a direct link between the neurons activated in vivo, and their cellular properties investigated in vitro has been missing. We used two-photon calcium imaging to identify a subset of neurons in layer L2/3 (L2/3) of mouse primary somatosensory cortex that are highly active following principal whisker vibrotactile stimulation. These high responders (HRs) were then tagged using photoconvertible green f luorescent protein for subsequent targeting in the brain slice using intracellular patch-clamp recordings and biocytin staining. This approach allowed us to investigate the structural and functional properties of HRs that distinguish them from less active control cells. Compared to less responsive L2/3 neurons, HRs displayed increased levels of stimulus-evoked and spontaneous activity, elevated noise and spontaneous pairwise correlations, and stronger coupling to the population response. Intrinsic excitability was reduced in HRs, while we found no evidence for differences in other electrophysiological and morphological parameters. Thus, the choice of which neurons participate in stimulus encoding may be determined largely by network connectivity rather than by cellular structure and function.

Mots clés: barrel cortex; patch clamp; somatosensory; sparse coding; two-photon imaging

Domaines: Neurosciences

C S Barz, Pierre-Marie Garderes, D A Ganea, S Reischauer, D Feldmeyer, et al.. Functional and Structural Properties of Highly Responsive Somatosensory Neurons in Mouse Barrel Cortex. Cerebral Cortex, 2021, ⟨10.1093/cercor/bhab104⟩. ⟨pasteur-03261719⟩