title: Vesicular glutamate transporter 3-immunoreactive pericellular baskets ensheath a distinct population of neurons in the lateral septum.
abstract: The lateral septum (LS) plays a role in the adjustment of behavioral responses according to environmental demands. This is a complex integrative process wherein a variety of modulatory systems, i.e. cholinergic, dopaminergic and serotonergic projections forming pericellular baskets around LS neurons, are involved. Recently, vesicular glutamate transporter 3 (VGLUT3)-immunoreactive (-ir) structures outlining unlabeled somata and their proximal dendrites were described in the LS. However, the vesicular transporters for acetylcholine and GABA were not or only rarely co-expressed with VGLUT3. In this study, the morphology and distribution of these VGLUT3-ir structures were systematically analyzed revealing that (1) they form distinct pericellular baskets (PBs) displaying variable shapes, (2) they are arranged in a layer-like pattern similar to the terminals of other modulatory systems, (3) beside a few exceptions (e.g., choline acetyltransferase), they are generally not or very sparsely co-localized with other neurochemical markers characterizing major neuron populations or afferent systems of the LS, i.e. calcium-binding proteins, tyrosine hydroxylase, tryptophan hydroxylase, vesicular glutamate transporters 1 (VGLUT1) and 2 (VGLUT2) and the vesicular GABA transporter. Thus, in the LS, a separate population of neurons is covered by VGLUT3-ir PBs. The distribution pattern and the lack of co-localization indicate that the VGLUT3-expressing cells of origin are located in the brainstem and that they could be pure glutamatergic projection neurons-different from the well-defined canonical VGLUT1- and VGLUT2-expressing neurons. Alternatively, they could simultaneously express VGLUT3 and second transmitter, but use different release sites inside the LS for both.
authors.affiliation: Department of Zoology/Developmental Neurobiology, Otto von Guericke University, Magdeburg, Institute of Biology, Leipziger Str. 44, Haus 91, D-39120 Magdeburg, Germany. anett.riedel@ovgu.de
authors.forename: Anett
authors.initials: A
authors.lastname: Riedel
authors.forename: Sören
authors.initials: S
authors.lastname: Westerholz
authors.forename: Katharina
authors.initials: K
authors.lastname: Braun
authors.forename: Robert H
authors.initials: RH
authors.lastname: Edwards
authors.forename: Thomas
authors.initials: T
authors.lastname: Arendt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Härtig
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D005260:Female; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D008297:Male; D008856:Microscopy, Fluorescence; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D020665:Septum of Brain / Q000502:physiology* / Q000648:ultrastructure; D050496:Vesicular Glutamate Transport Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*
chemical_list: D000906:Antibodies; C482103:Slc17a8 protein, rat; D050496:Vesicular Glutamate Transport Proteins