title: Diversity of GABAergic interneurons in layer VIa and VIb of mouse barrel cortex.
abstract: Neocortical layer VI modulates the thalamocortical transfer of information and has a significant impact on sensory processing. This function implicates local γ-aminobutyric acidergic (GABAergic) interneurons that have only been partly described at the present time. Here, we characterized 85 layer VI GABAergic interneurons in acute slices of mouse somatosensory barrel cortex, using whole-cell current-clamp recordings, single-cell reverse transcription-polymerase chain reaction, and biocytin labeling followed by Neurolucida reconstructions. Unsupervised clustering based on electrophysiological molecular and morphological properties disclosed 4 types of interneurons. The 2 major classes were fast-spiking cells transcribing parvalbumin (PV) (51%) and adapting interneurons transcribing somatostatin (SOM) (26%). The third population (18%) transcribed neuropeptide Y (NPY) and appeared very similar to neurogliaform cells. The last class (5%) was constituted by well-segregated GABAergic interneurons transcribing vasoactive intestinal peptide (VIP). Using transgenic mice expressing GFP under the control of the glutamic acid decarboxylase 67k (GAD67) promoter, we investigated the densities of GABAergic cells immunolabeled against PV, SOM, VIP, and NPY through the depth of layer VI. This analysis revealed that PV and NPY translating interneurons concentrate in the upper and lower parts of layer VI, respectively. This study provides an extensive characterization of the properties of layer VI interneurons.
authors.affiliation: Laboratoire de Neurobiologie et Diversité Cellulaire, CNRS UMR7637, Ecole Supérieure de Physique et de Chimie Industrielles, 75005 Paris, France.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Perrenoud
authors.forename: Jean
authors.initials: J
authors.lastname: Rossier
authors.forename: Hélène
authors.initials: H
authors.lastname: Geoffroy
authors.forename: Tania
authors.initials: T
authors.lastname: Vitalis
authors.forename: Thierry
authors.initials: T
authors.lastname: Gallopin
mesh_terms: D000818:Animals; D005455:Fluorescent Antibody Technique; D007395:Interneurons / Q000166:cytology* / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018408:Patch-Clamp Techniques; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013003:Somatosensory Cortex / Q000166:cytology* / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D005680:gamma-Aminobutyric Acid