title: Basal ganglia outputs map instantaneous position coordinates during behavior.
abstract: The basal ganglia (BG) are implicated in many movement disorders, yet how they contribute to movement remains unclear. Using wireless in vivo recording, we measured BG output from the substantia nigra pars reticulata (SNr) in mice while monitoring their movements with video tracking. The firing rate of most nigral neurons reflected Cartesian coordinates (either x- or y-coordinates) of the animal's head position during movement. The firing rates of SNr neurons are either positively or negatively correlated with the coordinates. Using an egocentric reference frame, four types of neurons can be classified: each type increases firing during movement in a particular direction (left, right, up, down), and decreases firing during movement in the opposite direction. Given the high correlation between the firing rate and the x and y components of the position vector, the movement trajectory can be reconstructed from neural activity. Our results therefore demonstrate a quantitative and continuous relationship between BG output and behavior. Thus, a steady BG output signal from the SNr (i.e., constant firing rate) is associated with the lack of overt movement, when a stable posture is maintained by structures downstream of the BG. Any change in SNr firing rate is associated with a change in position (i.e., movement). We hypothesize that the SNr output quantitatively determines the direction, velocity, and amplitude of voluntary movements. By changing the reference signals to downstream position control systems, the BG can produce transitions in body configurations and initiate actions.
authors: Department of Psychology and Neuroscience, Center for Cognitive Neuroscience, Duke University, Durham, North Carolina 27708.
authors: Joseph W
authors: JW
authors: Barter
authors: Department of Psychology and Neuroscience.
authors: Suellen
authors: http://orcid.org/0000-0002-4711-5388
authors: S
authors: Li
authors: Department of Psychology and Neuroscience.
authors: Tatyana
authors: T
authors: Sukharnikova
authors: Department of Psychology and Neuroscience.
authors: Mark A
authors: MA
authors: Rossi
authors: Department of Psychology and Neuroscience.
authors: Ryan A
authors: RA
authors: Bartholomew
authors: Department of Psychology and Neuroscience, Department of Neurobiology, and Center for Cognitive Neuroscience, Duke University, Durham, North Carolina 27708 hy43@duke.edu.
authors: Henry H
authors: HH
authors: Yin
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000502:physiology*; D001522:Behavior, Animal / Q000502:physiology*; D003216:Conditioning, Operant / Q000502:physiology; D055724:Electrophysiological Phenomena; D019416:Head Movements / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D012201:Reward; D014741:Video Recording; D005680:gamma-Aminobutyric Acid / Q000502:physiology
chemical_list: D005680:gamma-Aminobutyric Acid
keywords: GABA; Parkinson's disease; basal ganglia; substantia nigra