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Jon H Kaas - One of the best experts on this subject based on the ideXlab platform.
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corticocortical projections to area 1 in squirrel monkeys saimiri sciureus
European Journal of Neuroscience, 2019Co-Authors: Christina M Cerkevich, Jon H KaasAbstract:Cortical area 1 is a non-primary somatosensory area in the primate anterior parietal cortex that is critical to tactile discrimination. The corticocortical projections to area 1 in squirrel monkeys were determined by placing multiple injections of anatomical tracers into separate body part representations defined by multiunit microelectrode mapping in area 1. The pattern of labeled cells in the cortex indicated that area 1 has strong intrinsic connections within each body part representation and has inputs from somatotopically matched regions of areas 3b, 3a, 2 and 5. Somatosensory areas in the Lateral Sulcus, including the second somatosensory area (S2), the parietal ventral area (PV), and the presumptive parietal rostral (PR) and ventral somatosensory (VS) areas, also project to area 1. Topographically organized projections to area 1 also came from the primary motor cortex (M1), the dorsal and ventral premotor areas (PMd and PMv), and the supplementary motor area (SMA). Labeled cells were also found in cingulate motor and sensory areas on the medial wall of the hemisphere. Previous studies revealed a similar pattern of projections to area 1 in Old World macaque monkeys, suggesting a pattern of cortical inputs to area 1 that is common across anthropoid primates.
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thalamocortical connections of functional zones in posterior parietal cortex and frontal cortex motor regions in new world monkeys
Cerebral Cortex, 2010Co-Authors: Omar A Gharbawie, Iwona Stepniewska, Mark J Burish, Jon H KaasAbstract:Posterior parietal cortex (PPC) links primate visual and motor systems and is central to visually guided action. Relating the anatomical connections of PPC to its neurophysiological functions may elucidate the organization of the parietal–frontal network. In owl and squirrel monkeys, long-duration electrical stimulation distinguished several functional zones within the PPC and motor/premotor cortex (M1/PM). Multijoint forelimb movements reminiscent of reach, defense, and grasp behaviors characterized each functional zone. In PPC, functional zones were organized parallel to the Lateral Sulcus. Thalamocortical connections of PPC and M1/PM zones were investigated with retrograde tracers. After several days of tracer transport, brains were processed, and labeled cells in thalamic nuclei were plotted. All PPC zones received dense inputs from the Lateral posterior nucleus and the anterior pulvinar. PPC zones received additional projections from ventral Lateral (VL) divisions of motor thalamus, which were also the primary source of input to M1/PM. Projections to PPC from rostral motor thalamus were sparse. Dense projections from ventral posterior (VP) nucleus of somatosensory thalamus distinguished the rostroLateral grasp zone from the other PPC zones. PPC connections with VL and VP provide links to cerebellar nuclei and the somatosensory system, respectively, that may integrate PPC functions with M1/PM.
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organization of the posterior parietal cortex in galagos ii ipsiLateral cortical connections of physiologically identified zones within anterior sensorimotor region
The Journal of Comparative Neurology, 2009Co-Authors: Iwona Stepniewska, Christina M Cerkevich, Peichun Y Fang, Jon H KaasAbstract:We studied cortical connections of functionally distinct movement zones of the posterior parietal cortex (PPC) in galagos identified by intracortical microstimulation with long stimulus trains (~500 msec). All these zones were in the anterior half of PPC, and each of them had a different pattern of connections with premotor (PM) and motor (M1) areas of the frontal lobe and with other areas of parietal and occipital cortex. The most rostral PPC zone has major connections with motor and visuomotor areas of frontal cortex as well as with somatosensory areas 3a and 1-2 and higher order somatosensory areas in the Lateral Sulcus. The dorsal part of anterior PPC region representing hand-to-mouth movements is connected mostly to the forelimb representation in PM, M1, 3a, 1-2, and somatosensory areas in the Lateral Sulcus and on the medial wall. The more posterior defensive and reaching zones have additional connections with nonprimary visual areas (V2, V3, DL, DM, MST). Ventral aggressive and defensive face zones have reciprocal connections with each other as well as connections with mostly face, but also forelimb representations of premotor areas and M1 as well as prefrontal cortex, FEF, and somatosensory areas in the Lateral Sulcus and areas on the medial surface of the hemisphere. Whereas the defensive face zone is additionally connected to nonprimary visual cortical areas, the aggressive face zone is not. These differences in connections are consistent with our functional parcellation of PPC based on intracortical long-train microstimulation, and they identify parts of cortical networks that mediate different motor behaviors.
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somatosensory cortex of prosimian galagos physiological recording cytoarchitecture and corticocortical connections of anterior parietal cortex and cortex of the Lateral Sulcus
The Journal of Comparative Neurology, 2003Co-Authors: Jon H KaasAbstract:Compared with our growing understanding of the organization of somatosensory cortex in monkeys, little is known about prosimian primates, a major branch of primate evolution that diverged from anthropoid primates some 60 million years ago. Here we describe extensive results obtained from an African prosimian, Galago garnetti. Microelectrodes were used to record from large numbers of cortical sites in order to reveal regions of responsiveness to cutaneous stimuli and patterns of somatotopic organization. Injections of one to several distinguishable tracers were placed at physiologically identified sites in four different cortical areas to label corticortical connections. Both types of results were related to cortical architecture. Three systematic representations of cutaneous receptors were revealed by the microelectrode recordings, S1 proper or area 3b, S2, and the parietal ventral area (PV), as described in monkeys. Strips of cortex rostral (presumptive area 3a) and caudal (presumptive area 1‐2) to area 3b responded poorly to tactile stimuli in anesthetized galagos, but connection patterns with area 3b indicated that parallel somatosensory representations exist in both of these regions. Area 3b also interconnected somatotopically with areas S2 and PV. Areas S2 and PV had connections with areas 3a, 3b, 1‐2, each other, other regions of the Lateral Sulcus, motor cortex (M1), cingulate cortex, frontal cortex, orbital cortex, and inferior parietal cortex. Connection patterns and recordings provided evidence for several additional fields in the Lateral Sulcus, including a retroinsular area (Ri), a parietal rostral area (PR), and a ventral somatosensory area (VS). Galagos appear to have retained an ancestoral preprimate arrangement of five basic areas (S1 proper, 3a, 1‐2, S2, and PV). Some of the additional areas suggested for Lateral parietal cortex may be primate specializations. J. Comp. Neurol. 457:263‐292, 2003. © 2003 Wiley-Liss, Inc. Indexing terms: primates; neocortex; motor cortex
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cortical and thalamic connections of the parietal ventral somatosensory area in marmoset monkeys callithrix jacchus
The Journal of Comparative Neurology, 2002Co-Authors: David C Lyon, Jon H KaasAbstract:Microelectrode mapping methods were used to define the parietal ventral somatosensory area (PV) on the upper bank of the Lateral Sulcus in five marmosets (Callithrix jacchus). In the same animals, neuroanatomical tracers were placed into electrophysiologically identified sites in PV and/or the second somatosensory area (S2). Foci of anterograde and retrograde label were related to electrophysiological maps of cortical areas and cortical and thalamic architecture. The results lead to the following conclusions: (1) Multiunit recordings from cortex on the upper bank of the Lateral Sulcus demonstrate that PV is somatotopically organized, with the face representation adjoining area 3b and the hindlimb and tail representations away from this border in cortex deep on the upper bank of the Lateral Sulcus. The forelimb representation is caudal in PV adjacent to the S2 forelimb representation. The body surface representation in PV approximates a mirror image of that in S2; (2) Areas PV and S2 are less myelinated and have less cytochrome oxidase enzyme activity than area 3b; (3) The ventroposterior inferior nucleus (VPI) of the thalamus provides the major somatosensory projections to PV. PV is reciprocally connected with VPI and anterior pulvinar; (4) PV has ipsiLateral cortical connections with areas 3a, 3b, 1, and M1 and higher order somatosensory fields, and at least most of these connections are somatotopically matched; and (5) Callosal connections of PV are with S2 and PV of the other cerebral hemisphere. These results further establish PV as one of at least four somatosensory areas of the Lateral Sulcus of primates.
Leah Krubitzer - One of the best experts on this subject based on the ideXlab platform.
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the organization and connections of anterior and posterior parietal cortex in titi monkeys do new world monkeys have an area 2
Cerebral Cortex, 2005Co-Authors: Jeffrey Padberg, Elizabeth A. Disbrow, Leah KrubitzerAbstract:We used multiunit electrophysiological recording techniques to examine the topographic organization of somatosensory area 3b and cortex posterior to area 3b, including area 1 and the presumptive area 5, in the New World titi monkey, Callicebus moloch. We also examined the ipsiLateral and contraLateral connections of these fields, as well as those in a region of cortex that appeared to be similar to both area 7b and the anterior intraparietal area (7b/AIP) described in macaque monkeys. All data were combined with architectonic analysis to generate comprehensive reconstructions. These studies led to several observations. First, area 1 in titi monkeys is not as precisely organized in terms of topographic order and receptive field size as is area 1 in macaque monkeys and a few New World monkeys. Second, cortex caudal to area 1 in titi monkeys is dominated by the representation of the hand and forelimb, and contains neurons that are often responsive to visual stimulation as well as somatic stimulation. This organization is more like area 5 described in macaque monkeys than like area 2. Third, ipsiLateral and contraLateral cortical connections become more broadly distributed away from area 3b towards the posterior parietal cortex. Specifically, area 3b has a relatively restricted pattern of connectivity with adjacent somatosensory fields 3a, 1, S2 and PV; area 1 has more broadly distributed connections than area 3b; and the presumptive areas 5 and 7b/AIP have highly diverse connections, including connections with motor and premotor cortex, extrastriate visual areas, auditory areas and somatosensory areas of the Lateral Sulcus. Fourth, the hand representation of the presumptive area 5 has dense callosal connections. Our results, together with previous studies in other primates, suggest that anterior parietal cortex has expanded in some primate lineages, perhaps in relation to manual abilities, and that the region of cortex we term area 5 is involved in integrating somatic inputs with the motor system and across hemispheres. Such connections could form the substrate for intentional reaching, grasping and intermanual transfer of information necessary for biLateral coordination of the hands.
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cortical connections of the second somatosensory area and the parietal ventral area in macaque monkeys
The Journal of Comparative Neurology, 2003Co-Authors: Evangelos Litinas, Elizabeth A. Disbrow, Gregg H. Recanzone, Jeffrey Padberg, Leah KrubitzerAbstract:To gain insight into how cortical fields process somatic inputs and ultimately contribute to complex abilities such as tactile object perception, we examined the pattern of connections of two areas in the Lateral Sulcus of macaque monkeys: the second somatosensory area (S2), and the parietal ventral area (PV). Neuroanatomical tracers were injected into electrophysiologically and/or architectonically defined locations, and labeled cell bodies were identified in cortex ipsiLateral and contraLateral to the injection site. Transported tracer was related to architectonically defined boundaries so that the full complement of connections of S2 and PV could be appreciated. Our results indicate that S2 is densely interconnected with the primary somatosensory area (3b), PV, and area 7b of the ipsiLateral hemisphere, and with S2, 7b, and 3b in the opposite hemisphere. PV is interconnected with areas 3b and 7b, with the parietal rostroventral area, premotor cortex, posterior parietal cortex, and with the medial auditory belt areas. ContraLateral connections were restricted to PV in the opposite hemisphere. These data indicate that S2 and PV have unique and overlapping patterns of connections, and that they comprise part of a network that processes both cutaneous and proprioceptive inputs necessary for tactile discrimination and recognition. Although more data are needed, these patterns of interconnections of cortical fields and thalamic nuclei suggest that the somatosensory system may not be segregated into two separate streams of information processing, as has been hypothesized for the visual system. Rather, some fields may be involved in a variety of functions that require motor and sensory integration.
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Thalamocortical connections of the parietal ventral area (PV) and the second somatosensory area (S2) in macaque monkeys
Thalamus and Related Systems, 2002Co-Authors: Elizabeth A. Disbrow, Daniel A. Slutsky, Evangelos Litinas, Gregg H. Recanzone, Leah KrubitzerAbstract:Neuroanatomical tracers were injected into two functionally distinct areas in the Lateral Sulcus of macaque monkeys, the parietal ventral area (PV) and the second somatosensory area (S2). Three of the four injection sites were electrophysiologically determined by defining the receptive fields of neurons at the injection site prior to the placement of the anatomical tracers. Additionally, all locations were confirmed myeloarchitectonically. Labeled cell bodies and axon terminals were identified in the ipsiLateral dorsal thalamus and related to nuclear boundaries in tissue stained for cytochrome oxidase (CO) and Nissl substance. Our results indicate that PV receives substantial input from the inferior division of the ventral posterior nucleus (VPi), the anterior pulvinar (Pla), and from the ventral portion of the magnocellular division of the mediodorsal nucleus (MDm), which also is interconnected with prefrontal cortex, the entorhinal cortex and the amygdala. S2 receives input predominantly from VPi, the ventral posterior superior nucleus (VPs), and Pla. These results indicate that PV and S2 are involved in processing inputs from deep receptors in the muscles and joints. Because PV and S2 receive little if any cutaneous input from the thalamus, cutaneous input to these fields must arise mainly through cortical connections. Connectional data supports the proposition that PV and S2 integrate motor and somatic information necessary for proprioception, goal directed reaching and grasping and tactile object identification. Further, PV may play a role in tactile learning and memory.
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somatotopic organization of cortical fields in the Lateral Sulcus of homo sapiens evidence for sii and pv
The Journal of Comparative Neurology, 2000Co-Authors: Timothy P L Roberts, Elizabeth A. Disbrow, Leah KrubitzerAbstract:The human somatosensory cortex in the Sylvian fissure was examined using functional magnetic resonance imaging to describe the number and internal organization of cortical fields present. Somatic stimuli were applied to the lips, face, hand, trunk, and foot of 18 human subjects. Activity patterns were transposed onto three-dimensional magnetic resonance images of the brain so that the location of activity associated with the different stimuli could be related to specific regions of the cortex. There were several consistent findings. First, there were three regions of activity in the Lateral Sulcus associated with stimulation of the contraLateral body. The most consistent locus of activation was on the upper bank of the Lateral Sulcus, continuing onto the operculum. The other two areas, one rostral and one caudal to this large central area, were smaller and were activated less consistently. Second, when activity patterns in the large central area resulting from stimulation of all body parts were considered, this region appeared to contain two fields that corresponded in location and somatotopic organization to the second somatosensory area (SII) and the parietal ventral area (PV). Finally, patterns of activation within SII and PV were somewhat variable across subjects. Repeated within-subject stimulus presentation indicated that differences across subjects were not due to inconsistent stimulus presentation. Comparisons with other mammals suggest that some features of organization are found only in primates. It is hypothesized that these features may be associated with manual dexterity and coordination of the hands, a characteristic generally restricted to the primate lineage. J. Comp. Neurol. 418:1–21, 2000. © 2000 Wiley-Liss, Inc.
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a redefinition of somatosensory areas in the Lateral Sulcus of macaque monkeys
The Journal of Neuroscience, 1995Co-Authors: Leah Krubitzer, Janine C Clarey, Rowan Tweedale, Guy N Elston, M B CalfordAbstract:The present investigation was designed to determine the organization of somatosensory fields in the Lateral Sulcus of macaque monkeys using standard microelectrode recording techniques. Our results provide evidence for two complete representations of the body surface. We term these fields the second somatosensory area (SII) and the parietal ventral area (PV) because of their similarities in position, internal organization, and relationship to anterior parietal fields, as described for SII and PV in other mammals. Areas SII and PV are mirror-symmetrical representations of the body surface, sharing a common boundary at the representations of the digits of the hand and foot, lips, and mouth. These fields are located adjacent to the face representations of anterior parietal fields (areas 3b, 1, and 2), and are bounded ventrally and caudally by other regions of cortex in which neurons are responsive to somatic or multimodal stimulation. The finding of a double representation of the body surface in the region of cortex traditionally designated as SII may explain conflicting descriptions of SII organization in macaque monkeys. In addition, the present study raises some questions regarding the designation of serial processing pathways in Old World monkeys, by suggesting that fields may have been confused in studies demonstrating such pathways. We propose that SII and PV are components of a common plan of organization, and are present in many eutherian mammals.
Elizabeth A. Disbrow - One of the best experts on this subject based on the ideXlab platform.
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the organization and connections of anterior and posterior parietal cortex in titi monkeys do new world monkeys have an area 2
Cerebral Cortex, 2005Co-Authors: Jeffrey Padberg, Elizabeth A. Disbrow, Leah KrubitzerAbstract:We used multiunit electrophysiological recording techniques to examine the topographic organization of somatosensory area 3b and cortex posterior to area 3b, including area 1 and the presumptive area 5, in the New World titi monkey, Callicebus moloch. We also examined the ipsiLateral and contraLateral connections of these fields, as well as those in a region of cortex that appeared to be similar to both area 7b and the anterior intraparietal area (7b/AIP) described in macaque monkeys. All data were combined with architectonic analysis to generate comprehensive reconstructions. These studies led to several observations. First, area 1 in titi monkeys is not as precisely organized in terms of topographic order and receptive field size as is area 1 in macaque monkeys and a few New World monkeys. Second, cortex caudal to area 1 in titi monkeys is dominated by the representation of the hand and forelimb, and contains neurons that are often responsive to visual stimulation as well as somatic stimulation. This organization is more like area 5 described in macaque monkeys than like area 2. Third, ipsiLateral and contraLateral cortical connections become more broadly distributed away from area 3b towards the posterior parietal cortex. Specifically, area 3b has a relatively restricted pattern of connectivity with adjacent somatosensory fields 3a, 1, S2 and PV; area 1 has more broadly distributed connections than area 3b; and the presumptive areas 5 and 7b/AIP have highly diverse connections, including connections with motor and premotor cortex, extrastriate visual areas, auditory areas and somatosensory areas of the Lateral Sulcus. Fourth, the hand representation of the presumptive area 5 has dense callosal connections. Our results, together with previous studies in other primates, suggest that anterior parietal cortex has expanded in some primate lineages, perhaps in relation to manual abilities, and that the region of cortex we term area 5 is involved in integrating somatic inputs with the motor system and across hemispheres. Such connections could form the substrate for intentional reaching, grasping and intermanual transfer of information necessary for biLateral coordination of the hands.
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cortical connections of the second somatosensory area and the parietal ventral area in macaque monkeys
The Journal of Comparative Neurology, 2003Co-Authors: Evangelos Litinas, Elizabeth A. Disbrow, Gregg H. Recanzone, Jeffrey Padberg, Leah KrubitzerAbstract:To gain insight into how cortical fields process somatic inputs and ultimately contribute to complex abilities such as tactile object perception, we examined the pattern of connections of two areas in the Lateral Sulcus of macaque monkeys: the second somatosensory area (S2), and the parietal ventral area (PV). Neuroanatomical tracers were injected into electrophysiologically and/or architectonically defined locations, and labeled cell bodies were identified in cortex ipsiLateral and contraLateral to the injection site. Transported tracer was related to architectonically defined boundaries so that the full complement of connections of S2 and PV could be appreciated. Our results indicate that S2 is densely interconnected with the primary somatosensory area (3b), PV, and area 7b of the ipsiLateral hemisphere, and with S2, 7b, and 3b in the opposite hemisphere. PV is interconnected with areas 3b and 7b, with the parietal rostroventral area, premotor cortex, posterior parietal cortex, and with the medial auditory belt areas. ContraLateral connections were restricted to PV in the opposite hemisphere. These data indicate that S2 and PV have unique and overlapping patterns of connections, and that they comprise part of a network that processes both cutaneous and proprioceptive inputs necessary for tactile discrimination and recognition. Although more data are needed, these patterns of interconnections of cortical fields and thalamic nuclei suggest that the somatosensory system may not be segregated into two separate streams of information processing, as has been hypothesized for the visual system. Rather, some fields may be involved in a variety of functions that require motor and sensory integration.
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Thalamocortical connections of the parietal ventral area (PV) and the second somatosensory area (S2) in macaque monkeys
Thalamus and Related Systems, 2002Co-Authors: Elizabeth A. Disbrow, Daniel A. Slutsky, Evangelos Litinas, Gregg H. Recanzone, Leah KrubitzerAbstract:Neuroanatomical tracers were injected into two functionally distinct areas in the Lateral Sulcus of macaque monkeys, the parietal ventral area (PV) and the second somatosensory area (S2). Three of the four injection sites were electrophysiologically determined by defining the receptive fields of neurons at the injection site prior to the placement of the anatomical tracers. Additionally, all locations were confirmed myeloarchitectonically. Labeled cell bodies and axon terminals were identified in the ipsiLateral dorsal thalamus and related to nuclear boundaries in tissue stained for cytochrome oxidase (CO) and Nissl substance. Our results indicate that PV receives substantial input from the inferior division of the ventral posterior nucleus (VPi), the anterior pulvinar (Pla), and from the ventral portion of the magnocellular division of the mediodorsal nucleus (MDm), which also is interconnected with prefrontal cortex, the entorhinal cortex and the amygdala. S2 receives input predominantly from VPi, the ventral posterior superior nucleus (VPs), and Pla. These results indicate that PV and S2 are involved in processing inputs from deep receptors in the muscles and joints. Because PV and S2 receive little if any cutaneous input from the thalamus, cutaneous input to these fields must arise mainly through cortical connections. Connectional data supports the proposition that PV and S2 integrate motor and somatic information necessary for proprioception, goal directed reaching and grasping and tactile object identification. Further, PV may play a role in tactile learning and memory.
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somatotopic organization of cortical fields in the Lateral Sulcus of homo sapiens evidence for sii and pv
The Journal of Comparative Neurology, 2000Co-Authors: Timothy P L Roberts, Elizabeth A. Disbrow, Leah KrubitzerAbstract:The human somatosensory cortex in the Sylvian fissure was examined using functional magnetic resonance imaging to describe the number and internal organization of cortical fields present. Somatic stimuli were applied to the lips, face, hand, trunk, and foot of 18 human subjects. Activity patterns were transposed onto three-dimensional magnetic resonance images of the brain so that the location of activity associated with the different stimuli could be related to specific regions of the cortex. There were several consistent findings. First, there were three regions of activity in the Lateral Sulcus associated with stimulation of the contraLateral body. The most consistent locus of activation was on the upper bank of the Lateral Sulcus, continuing onto the operculum. The other two areas, one rostral and one caudal to this large central area, were smaller and were activated less consistently. Second, when activity patterns in the large central area resulting from stimulation of all body parts were considered, this region appeared to contain two fields that corresponded in location and somatotopic organization to the second somatosensory area (SII) and the parietal ventral area (PV). Finally, patterns of activation within SII and PV were somewhat variable across subjects. Repeated within-subject stimulus presentation indicated that differences across subjects were not due to inconsistent stimulus presentation. Comparisons with other mammals suggest that some features of organization are found only in primates. It is hypothesized that these features may be associated with manual dexterity and coordination of the hands, a characteristic generally restricted to the primate lineage. J. Comp. Neurol. 418:1–21, 2000. © 2000 Wiley-Liss, Inc.
Sebastian M. Frank - One of the best experts on this subject based on the ideXlab platform.
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white matter connectivity of the visual vestibular cortex examined by diffusion weighted imaging
Brain, 2018Co-Authors: Anna M. Wirth, Sebastian M. Frank, Mark W. Greenlee, Anton L. BeerAbstract:The parieto-insular vestibular cortex (PIVC) and the posterior insular cortex (PIC) are key regions of the cortical vestibular network, both located in the midposterior section of the Lateral Sulcus. Little is known about the structural connectivity pattern of these areas. We used probabilistic fiber tracking based on diffusion-weighted magnetic resonance imaging (MRI) and compared the ipsiLateral connectivity of PIVC and PIC. Seed areas for the tracking algorithm were identified in each brain by functional MRI activity during caloric and visual motion stimulation, respectively. Cortical track terminations were investigated by a surface-based approach. Both PIVC and PIC shared ipsiLateral connections to the insular/Lateral Sulcus, superior temporal cortex, and inferior frontal gyrus. However, PIVC showed significantly more connections than PIC with the anterior insula and Heschl's gyrus in both hemispheres and with the precuneus, intraparietal Sulcus, and posterior callosum of the right hemisphere. In contrast, PIC connectivity was more pronounced with the supramarginal gyrus and superior temporal Sulcus. Subcortical tracks were examined by a region-of-interest-based approach, which was validated on cortico-thalamic motor tracts. Both PIVC and PIC were connected with Lateral nuclei of the thalamus and the basal ganglia (primarily putamen). PIVC tracks but not PIC tracks showed a right-hemispheric Lateralization in cortical and subcortical connectivity. Overall, these results suggest that human PIVC and PIC share cortical and even subcortical connections. Nevertheless, they also differ in their primary connectivity pattern: PIVC is linked with posterior parietal and inferior frontal cortex, whereas PIC is linked with superior temporal and inferior parietal cortex.
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vestibular and visual responses in human posterior insular cortex
Journal of Neurophysiology, 2014Co-Authors: Sebastian M. Frank, Oliver Baumann, Jason B Mattingley, Mark W. GreenleeAbstract:The central hub of the cortical vestibular network in humans is likely localized in the region of posterior Lateral Sulcus. An area characterized by responsiveness to visual motion has previously been described at a similar location and named posterior insular cortex (PIC). Currently it is not known whether PIC processes vestibular information as well. We localized PIC using visual motion stimulation in functional magnetic resonance imaging (fMRI) and investigated whether PIC also responds to vestibular stimuli. To this end, we designed an MRI-compatible caloric stimulation device that allowed us to stimulate bithermally with hot temperature in one ear and simultaneously cold temperature in the other or with warm temperatures in both ears for baseline. During each trial, participants indicated the presence or absence of self-motion sensations. We found activation in PIC during periods of self motion when vestibular stimulation was carried out with minimal visual input. In combined visual-vestibular stimulation area PIC was activated in a similar fashion during congruent and incongruent stimulation conditions. Our results show that PIC not only responds to visual motion but also to vestibular stimuli related to the sensation of self motion. We suggest that PIC is part of the cortical vestibular network and plays a role in the integration of visual and vestibular stimuli for the perception of self motion.
David C Lyon - One of the best experts on this subject based on the ideXlab platform.
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cortical and thalamic connections of the parietal ventral somatosensory area in marmoset monkeys callithrix jacchus
The Journal of Comparative Neurology, 2002Co-Authors: David C Lyon, Jon H KaasAbstract:Microelectrode mapping methods were used to define the parietal ventral somatosensory area (PV) on the upper bank of the Lateral Sulcus in five marmosets (Callithrix jacchus). In the same animals, neuroanatomical tracers were placed into electrophysiologically identified sites in PV and/or the second somatosensory area (S2). Foci of anterograde and retrograde label were related to electrophysiological maps of cortical areas and cortical and thalamic architecture. The results lead to the following conclusions: (1) Multiunit recordings from cortex on the upper bank of the Lateral Sulcus demonstrate that PV is somatotopically organized, with the face representation adjoining area 3b and the hindlimb and tail representations away from this border in cortex deep on the upper bank of the Lateral Sulcus. The forelimb representation is caudal in PV adjacent to the S2 forelimb representation. The body surface representation in PV approximates a mirror image of that in S2; (2) Areas PV and S2 are less myelinated and have less cytochrome oxidase enzyme activity than area 3b; (3) The ventroposterior inferior nucleus (VPI) of the thalamus provides the major somatosensory projections to PV. PV is reciprocally connected with VPI and anterior pulvinar; (4) PV has ipsiLateral cortical connections with areas 3a, 3b, 1, and M1 and higher order somatosensory fields, and at least most of these connections are somatotopically matched; and (5) Callosal connections of PV are with S2 and PV of the other cerebral hemisphere. These results further establish PV as one of at least four somatosensory areas of the Lateral Sulcus of primates.
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cortical and thalamic connections of the parietal ventral somatosensory area in marmoset monkeys callithrix jacchus
The Journal of Comparative Neurology, 2002Co-Authors: David C Lyon, Jon H KaasAbstract:Microelectrode mapping methods were used to define the parietal ventral somatosensory area (PV) on the upper bank of the Lateral Sulcus in five marmosets (Callithrix jacchus). In the same animals, neuroanatomical tracers were placed into electrophysiologically identified sites in PV and/or the second somatosensory area (S2). Foci of anterograde and retrograde label were related to electrophysiological maps of cortical areas and cortical and thalamic architecture. The results lead to the following conclusions: (1) Multiunit recordings from cortex on the upper bank of the Lateral Sulcus demonstrate that PV is somatotopically organized, with the face representation adjoining area 3b and the hindlimb and tail representations away from this border in cortex deep on the upper bank of the Lateral Sulcus. The forelimb representation is caudal in PV adjacent to the S2 forelimb representation. The body surface representation in PV approximates a mirror image of that in S2; (2) Areas PV and S2 are less myelinated and have less cytochrome oxidase enzyme activity than area 3b; (3) The ventroposterior inferior nucleus (VPI) of the thalamus provides the major somatosensory projections to PV. PV is reciprocally connected with VPI and anterior pulvinar; (4) PV has ipsiLateral cortical connections with areas 3a, 3b, 1, and M1 and higher order somatosensory fields, and at least most of these connections are somatotopically matched; and (5) Callosal connections of PV are with S2 and PV of the other cerebral hemisphere. These results further establish PV as one of at least four somatosensory areas of the Lateral Sulcus of primates. J. Comp. Neurol. 443:168–182, 2002. © 2002 Wiley-Liss, Inc.
