title: Coexistence of glutamatergic spine synapses and shaft synapses in substantia nigra dopamine neurons.
abstract: Dopamine neurons of the substantia nigra have long been believed to have multiple aspiny dendrites which receive many glutamatergic synaptic inputs from several regions of the brain. But, here, using high-resolution two-photon confocal microscopy in the mouse brain slices, we found a substantial number of common dendritic spines in the nigral dopamine neurons including thin, mushroom, and stubby types of spines. However, the number of dendritic spines of the dopamine neurons was approximately five times lower than that of CA1 pyramidal neurons. Immunostaining and morphological analysis revealed that glutamatergic shaft synapses were present two times more than spine synapses. Using local two-photon glutamate uncaging techniques, we confirmed that shaft synapses and spine synapses had both AMPA and NMDA receptors, but the AMPA/NMDA current ratios differed. The evoked postsynaptic potentials of spine synapses showed lower amplitudes but longer half-widths than those of shaft synapses. Therefore, we provide the first evidence that the midbrain dopamine neurons have two morphologically and functionally distinct types of glutamatergic synapses, spine synapses and shaft synapses, on the same dendrite. This peculiar organization could be a new basis for unraveling many physiological and pathological functions of the midbrain dopamine neurons.
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.|Center For Molecular Medicine, Samsung Biomedical Research Institute, 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.
authors.forename: Miae
authors.initials: M
authors.lastname: Jang
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.
authors.forename: Ki Bum
authors.initials: KB
authors.lastname: Um
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.|Center For Molecular Medicine, Samsung Biomedical Research Institute, 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.
authors.forename: Jinyoung
authors.initials: J
authors.lastname: Jang
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.|Center For Molecular Medicine, Samsung Biomedical Research Institute, 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.|Center For Molecular Medicine, Samsung Biomedical Research Institute, 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.
authors.forename: Hana
authors.initials: H
authors.lastname: Cho
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.|Center For Molecular Medicine, Samsung Biomedical Research Institute, 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.
authors.forename: Sungkwon
authors.initials: S
authors.lastname: Chung
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.|Center For Molecular Medicine, Samsung Biomedical Research Institute, 300 Chunchun-dong, Jangan-ku, Suwon, 440-746, Korea.
authors.forename: Myoung Kyu
authors.initials: MK
authors.lastname: Park
mesh_terms: D000818:Animals; D056547:CA1 Region, Hippocampal / Q000166:cytology; D049229:Dendritic Spines / Q000378:metabolism / Q000648:ultrastructure; D059290:Dopaminergic Neurons / Q000502:physiology / Q000648:ultrastructure*; D008822:Mice, Transgenic; D017966:Pyramidal Cells / Q000378:metabolism / Q000648:ultrastructure; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013378:Substantia Nigra / Q000166:cytology*; D013569:Synapses / Q000502:physiology / Q000648:ultrastructure; D009435:Synaptic Transmission
chemical_list: D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate