title: Thalamocortical connections of parietal somatosensory cortical fields in macaque monkeys are highly divergent and convergent.
abstract: We examined the organization and cortical projections of the somatosensory thalamus using multiunit microelectrode recording techniques in anesthetized monkeys combined with neuroanatomical tracings techniques and architectonic analysis. Different portions of the hand representation in area 3b were injected with different anatomical tracers in the same animal, or matched body part representations in parietal areas 3a, 3b, 1, 2, and areas 2 and 5 were injected with different anatomical tracers in the same animal to directly compare their thalamocortical connections. We found that the somatosensory thalamus is composed of several representations of cutaneous and deep receptors of the contralateral body. These nuclei include the ventral posterior nucleus, the ventral posterior superior nucleus, the ventral posterior inferior nucleus, and the ventral lateral nucleus. Each nucleus projects to several different cortical fields, and each cortical field receives projections from multiple thalamic nuclei. In contrast to other sensory systems, each of these somatosensory cortical fields is uniquely innervated by multiple thalamic nuclei. These data indicate that multiple inputs are processed simultaneously within and across several, "hierarchically connected" cortical fields.
authors.affiliation: Center for Neuroscience, University of California, Davis, Davis, CA, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Padberg
authors.forename: Christina
authors.initials: C
authors.lastname: Cerkevich
authors.forename: James
authors.initials: J
authors.lastname: Engle
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Rajan
authors.forename: Gregg
authors.initials: G
authors.lastname: Recanzone
authors.forename: Jon
authors.initials: J
authors.lastname: Kaas
authors.forename: Leah
authors.initials: L
authors.lastname: Krubitzer
mesh_terms: D000344:Afferent Pathways / Q000166:cytology*; D000818:Animals; D008252:Macaca fascicularis; D008253:Macaca mulatta; D008953:Models, Anatomic; D008959:Models, Neurological; D010296:Parietal Lobe / Q000166:cytology*; D013003:Somatosensory Cortex / Q000166:cytology*