title: Somatotopically arranged inputs from putamen and subthalamic nucleus to primary motor cortex.
abstract: Employing retrograde transsynaptic transport of rabies virus, we investigated the organization of basal ganglia inputs to hindlimb, proximal and distal forelimb, and orofacial representations of the macaque primary motor cortex (MI). Four days after rabies injections into these MI regions, neuronal labeling occurred in the striatum and the subthalamic nucleus (STN) through the cortico-basal ganglia loop circuits. In the striatum, two distinct sets of the labeling were observed: one in the dorsal putamen, and the other in the ventral striatum (ventromedial putamen and nucleus accumbens). The dorsal striatal labeling was somatotopically arranged and its distribution pattern was in good accordance with that of the corticostriatal inputs, such that the hindlimb, orofacial, or forelimb area was located in the dorsal, ventral, or intermediate zone of the putamen, respectively. The distribution pattern of the ventral striatal labeling was essentially the same in all cases. In the STN, the somatotopic arrangement of labeled neurons was in register with that of corticosubthalamic inputs. The present results suggest that the cortico-basal ganglia motor circuits involving the dorsal putamen and the STN may constitute separate closed loops based on the somatotopy, while the ventral striatum provides common multisynaptic projections to all body-part representations in the MI.
authors.affiliation: Department of System Neuroscience, Tokyo Metropolitan Institute for Neuroscience, Tokyo Metropolitan Organization for Medical Research, Fuchu, Tokyo 183-8526, Japan. miyachi@pri.kyoto-u.ac.jp <miyachi@pri.kyoto-u.ac.jp>
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Miyachi
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lu
authors.forename: Michiko
authors.initials: M
authors.lastname: Imanishi
authors.forename: Kaori
authors.initials: K
authors.lastname: Sawada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nambu
authors.forename: Masahiko
authors.initials: M
authors.lastname: Takada
mesh_terms: D000344:Afferent Pathways / Q000033:anatomy & histology / Q000502:physiology*; D000818:Animals; D001931:Brain Mapping; D064026:Calbindins; D002452:Cell Count / Q000379:methods; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004558:Electric Stimulation / Q000379:methods; D005145:Face / Q000294:innervation; D005260:Female; D005552:Forelimb / Q000294:innervation; D006614:Hindlimb / Q000294:innervation; D007150:Immunohistochemistry / Q000379:methods; D008251:Macaca; D008297:Male; D008959:Models, Neurological; D009044:Motor Cortex / Q000166:cytology* / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D010320:Parvalbumins / Q000378:metabolism; D011699:Putamen / Q000033:anatomy & histology / Q000502:physiology*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D020531:Subthalamic Nucleus / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D064026:Calbindins; D010320:Parvalbumins; D064030:S100 Calcium Binding Protein G; D002795:Choline O-Acetyltransferase