title: Characterizing VIP Neurons in the Barrel Cortex of VIPcre/tdTomato Mice Reveals Layer-Specific Differences.
abstract: Neocortical GABAergic interneurons have a profound impact on cortical circuitry and its information processing capacity. Distinct subgroups of inhibitory interneurons can be distinguished by molecular markers, such as parvalbumin, somatostatin, and vasoactive intestinal polypeptide (VIP). Among these, VIP-expressing interneurons sparked a substantial interest since these neurons seem to operate disinhibitory circuit motifs found in all major neocortical areas. Several of these recent studies used transgenic Vip-ires-cre mice to specifically target the population of VIP-expressing interneurons. This makes it necessary to elucidate in detail the sensitivity and specificity of Cre expression for VIP neurons in these animals. Thus, we quantitatively compared endogenous tdTomato with Vip fluorescence in situ hybridization and αVIP immunohistochemistry in the barrel cortex of VIPcre/tdTomato mice in a layer-specific manner. We show that VIPcre/tdTomato mice are highly sensitive and specific for the entire population of VIP-expressing neurons. In the barrel cortex, approximately 13% of all GABAergic neurons are VIP expressing. Most VIP neurons are found in layer II/III (∼60%), whereas approximately 40% are found in the other layers of the barrel cortex. Layer II/III VIP neurons are significantly different from VIP neurons in layers IV-VI in several morphological and membrane properties, which suggest layer-dependent differences in functionality.
authors.affiliation: Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, Göttingen D-37075, Germany.
authors.forename: Alvar
authors.initials: A
authors.lastname: Prönneke
authors.affiliation: Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, Göttingen D-37075, Germany.
authors.forename: Bianca
authors.initials: B
authors.lastname: Scheuer
authors.affiliation: Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, Göttingen D-37075, Germany.
authors.forename: Robin J
authors.initials: RJ
authors.lastname: Wagener
authors.affiliation: Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, Göttingen D-37075, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Möck
authors.affiliation: Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, Göttingen D-37075, Germany.
authors.forename: Mirko
authors.initials: M
authors.lastname: Witte
authors.affiliation: Institute for Neuroanatomy, Universitätsmedizin Göttingen, Georg-August-Universität, Göttingen D-37075, Germany.
authors.forename: Jochen F
authors.initials: JF
authors.lastname: Staiger
mesh_terms: D000200:Action Potentials; D000818:Animals; D001369:Axons; D003712:Dendrites; D059330:GABAergic Neurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007395:Interneurons / Q000166:cytology* / Q000378:metabolism* / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D010320:Parvalbumins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013003:Somatosensory Cortex / Q000166:cytology* / Q000378:metabolism* / Q000502:physiology*; D013004:Somatostatin / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
chemical_list: D010320:Parvalbumins; D012333:RNA, Messenger; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin
keywords: GABA; Vip-ires-cre; barrel cortex; cortical interneurons; vasoactive intestinal polypeptide