title: Thalamocortical and intracortical connections of monkey cingulate motor areas.
abstract: Although there has been an increasing interest in motor functions of the cingulate motor areas, data concerning their input organization are still limited. To address this issue, the patterns of thalamic and cortical inputs to the rostral (CMAr), dorsal (CMAd), and ventral (CMAv) cingulate motor areas were investigated in the macaque monkey. Tracer injections were made into identified forelimb representations of these areas, and the distributions of retrogradely labeled neurons were analyzed in the thalamus and the frontal cortex. The cells of origin of thalamocortical projections to the CMAr were located mainly in the parvicellular division of the ventroanterior nucleus and the oral division of the ventrolateral nucleus (VLo). On the other hand, the thalamocortical neurons to the CMAd/CMAv were distributed predominantly in the VLo and the oral division of the ventroposterolateral nucleus-the caudal division of the ventrolateral nucleus. Additionally, many neurons in the intralaminar nuclear group were seen to project to the cingulate motor areas. Except for their well-developed interconnections, the corticocortical projections to the CMAr and CMAd/CMAv were also distinctively preferential. Major inputs to the CMAr arose from the presupplementary motor area and the dorsal premotor cortex, whereas inputs to the CMAd/CMAv originated not only from these areas but also from the supplementary motor area and the primary motor cortex. The present results indicate that the CMAr and the caudal cingulate motor area (involving both the CMAd and the CMAv) are characterized by distinct patterns of thalamocortical and intracortical connections, reflecting their functional differences.
authors.affiliation: Tokyo Metropolitan Institute for Neuroscience, Tokyo Metropolitan Organization for Medical Research, Fuchu, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Hatanaka
authors.forename: Hironobu
authors.initials: H
authors.lastname: Tokuno
authors.forename: Ikuma
authors.initials: I
authors.lastname: Hamada
authors.forename: Masahiko
authors.initials: M
authors.lastname: Inase
authors.forename: Yumi
authors.initials: Y
authors.lastname: Ito
authors.forename: Michiko
authors.initials: M
authors.lastname: Imanishi
authors.forename: Naomi
authors.initials: N
authors.lastname: Hasegawa
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Akazawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nambu
authors.forename: Masahiko
authors.initials: M
authors.lastname: Takada
mesh_terms: D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives*; D001931:Brain Mapping; D003911:Dextrans; D004558:Electric Stimulation; D006179:Gyrus Cinguli / Q000166:cytology* / Q000502:physiology; D020646:Intralaminar Thalamic Nuclei / Q000166:cytology / Q000502:physiology; D008251:Macaca / Q000033:anatomy & histology* / Q000502:physiology; D009044:Motor Cortex / Q000166:cytology* / Q000502:physiology; D009415:Nerve Net / Q000166:cytology* / Q000502:physiology; D009434:Neural Pathways / Q000166:cytology* / Q000502:physiology; D017729:Presynaptic Terminals / Q000502:physiology / Q000648:ultrastructure; D017966:Pyramidal Cells / Q000166:cytology / Q000502:physiology; D013788:Thalamus / Q000166:cytology* / Q000502:physiology; D020651:Ventral Thalamic Nuclei / Q000166:cytology / Q000502:physiology; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate
chemical_list: D003911:Dextrans; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; C076397:biotinylated dextran amine; D001710:Biotin