title: Characteristics of fast-spiking neurons in the striatum of behaving monkeys.
abstract: Inhibitory interneurons are the fundamental constituents of neural circuits that organize network outputs. The striatum as part of the basal ganglia is involved in reward-directed behaviors. However, the role of the inhibitory interneurons in this process remains unclear, especially in behaving monkeys. We recorded the striatal single neuron activity while monkeys performed reward-directed hand or eye movements. Presumed parvalbumin-containing GABAergic interneurons (fast-spiking neurons, FSNs) were identified based on narrow spike shapes in three independent experiments, though they were a small population (4.2%, 42/997). We found that FSNs are characterized by high-frequency and less-bursty discharges, which are distinct from the basic firing properties of the presumed projection neurons (phasically active neurons, PANs). Besides, the encoded information regarding actions and outcomes was similar between FSNs and PANs in terms of proportion of neurons, but the discharge selectivity was higher in PANs than that of FSNs. The coding of actions and outcomes in FSNs and PANs was consistently observed under various behavioral contexts in distinct parts of the striatum (caudate nucleus, putamen, and anterior striatum). Our results suggest that FSNs may enhance the discharge selectivity of postsynaptic output neurons (PANs) in encoding crucial variables for a reward-directed behavior.
authors.affiliation: Department of Physiology, Kyoto Prefectural University of Medicine Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan; National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8502, Japan; Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan; Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan. Electronic address: h-yamada@md.tsukuba.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
authors.affiliation: Department of Physiology, Kyoto Prefectural University of Medicine Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Inokawa
authors.affiliation: Department of Physiology, Kyoto Prefectural University of Medicine Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan; Department of Molecular Neuroimaging, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hori
authors.affiliation: Brain Science Institute, Tamagawa University, 6-1-1, Tamagawa-Gakuen, Machida, Tokyo 194-8610, Japan; Institute for Cognitive Neurodynamics, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Physiology, Kansai Medical University, Shin-machi, Hirakata city, Osaka 570-1010, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Matsuzaki
authors.affiliation: Department of Physiology, Kansai Medical University, Shin-machi, Hirakata city, Osaka 570-1010, Japan; Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Kae
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Brain Science Institute, Tamagawa University, 6-1-1, Tamagawa-Gakuen, Machida, Tokyo 194-8610, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Samejima
authors.affiliation: Division of Biomedical Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan; Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Munetaka
authors.initials: M
authors.lastname: Shidara
authors.affiliation: Department of Physiology, Kyoto Prefectural University of Medicine Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan; Brain Science Institute, Tamagawa University, 6-1-1, Tamagawa-Gakuen, Machida, Tokyo 194-8610, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Brain Science Institute, Tamagawa University, 6-1-1, Tamagawa-Gakuen, Machida, Tokyo 194-8610, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Sakagami
authors.affiliation: Department of Physiology, Kyoto Prefectural University of Medicine Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan; Department of Molecular Neuroimaging, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba 263-8555, Japan; Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Minamimoto
mesh_terms: D000200:Action Potentials; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003342:Corpus Striatum / Q000166:cytology / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology; D059330:GABAergic Neurons / Q000502:physiology*; D000882:Haplorhini; D007395:Interneurons / Q000502:physiology*; D010320:Parvalbumins / Q000378:metabolism; D012201:Reward
chemical_list: D010320:Parvalbumins
keywords: Basal ganglia; Inhibitory interneuron; Monkey; Reward