title: Queuing of concurrent movement plans by basal ganglia.
abstract: How the brain converts parallel representations of movement goals into sequential movements is not known. We tested the role of basal ganglia (BG) in the temporal control of movement sequences by a convergent approach involving inactivation of the BG by muscimol injections into the caudate nucleus of monkeys and assessing behavior of Parkinson's disease patients, performing a modified double-step saccade task. We tested a critical prediction of a class of competitive queuing models that explains serial behavior as the outcome of a selection of concurrently activated goals. In congruence with these models, we found that inactivation or impairment of the BG unmasked the parallel nature of goal representations such that a significantly greater extent of averaged saccades, curved saccades, and saccade sequence errors were observed. These results suggest that the BG perform a form of competitive queuing, holding the second movement plan in abeyance while the first movement is being executed, allowing the proper temporal control of movement sequences.
authors.affiliation: National Brain Research Centre, Manesar, Gurgaon, Haryana 122050, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Bhutani
authors.forename: Ramakrishnan
authors.initials: R
authors.lastname: Sureshbabu
authors.forename: Ausaf A
authors.initials: AA
authors.lastname: Farooqui
authors.forename: Madhuri
authors.initials: M
authors.lastname: Behari
authors.forename: Vinay
authors.initials: V
authors.lastname: Goyal
authors.forename: Aditya
authors.initials: A
authors.lastname: Murthy
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects / Q000502:physiology*; D016022:Case-Control Studies; D002421:Caudate Nucleus / Q000187:drug effects / Q000502:physiology; D005260:Female; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D006801:Humans; D033182:Intention; D008253:Macaca mulatta; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000187:drug effects / Q000502:physiology*; D009118:Muscimol / Q000494:pharmacology; D010300:Parkinson Disease / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D011237:Predictive Value of Tests; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology*; D011930:Reaction Time / Q000187:drug effects; D012438:Saccades / Q000187:drug effects / Q000502:physiology*; D055815:Young Adult
chemical_list: D058785:GABA-A Receptor Agonists; D009118:Muscimol