title: VTA Projection Neurons Releasing GABA and Glutamate in the Dentate Gyrus.
abstract: Both dopamine and nondopamine neurons from the ventral tegmental area (VTA) project to a variety of brain regions. Here we examine nondopaminergic neurons in the mouse VTA that send long-range projections to the hippocampus. Using a combination of retrograde tracers, optogenetic tools, and electrophysiological recordings, we show that VTA GABAergic axons make synaptic contacts in the granule cell layer of the dentate gyrus, where we can elicit small postsynaptic currents. Surprisingly, the currents displayed a partial sensitivity to both bicuculline and NBQX, suggesting that these mesohippocampal neurons corelease both GABA and glutamate. Finally, we show that this projection is functional in vivo and its stimulation reduces granule cell-firing rates under anesthesia. Altogether, the present results describe a novel connection between GABA and glutamate coreleasing of cells of the VTA and the dentate gyrus. This connection could be relevant for a variety of functions, including reward-related memory and neurogenesis.
authors.affiliation: Department of Basic Neurosciences, Medical Faculty, University of Geneva , CH-1211 Geneva, Switzerland.
authors.forename: Niels R
authors.identifier: 0000-0001-6573-0467
authors.initials: NR
authors.lastname: Ntamati
authors.affiliation: Department of Basic Neurosciences, Medical Faculty, University of Geneva, CH-1211 Geneva, Switzerland; Department of Clinical Neurosciences, Geneva University Hospital, CH-1211 Geneva, Switzerland.
authors.forename: Christian
authors.identifier: 0000-0001-7917-4596
authors.initials: C
authors.lastname: Lüscher
mesh_terms: D000200:Action Potentials; D000818:Animals; D018891:Dentate Gyrus / Q000166:cytology / Q000378:metabolism*; D005260:Female; D005968:Glutamate Decarboxylase / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D008297:Male; D008822:Mice, Transgenic; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism; D056347:Neuroanatomical Tract-Tracing Techniques; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D062308:Optogenetics; D018408:Patch-Clamp Techniques; D046509:Tissue Culture Techniques; D017557:Ventral Tegmental Area / Q000166:cytology / Q000378:metabolism*; D050599:Vesicular Glutamate Transport Protein 2 / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: C493477:Slc17a6 protein, mouse; D050599:Vesicular Glutamate Transport Protein 2; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; C401141:glutamate decarboxylase 2
keywords: GABA; VTA; corelease; dentate gyrus; glutamate