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Plasticity based on compensatory effector use in the association but not primary sensorimotor cortex of people born without hands. Proc Natl Acad Sci U S A 2018; 115:7801-7806. [PMID: 29997174 PMCID: PMC6065047 DOI: 10.1073/pnas.1803926115] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
What forces direct brain organization and its plasticity? When brain regions are deprived of their input, which regions reorganize based on compensation for the disability and experience, and which regions show topographically constrained plasticity? People born without hands activate their primary sensorimotor hand region while moving body parts used to compensate for this disability (e.g., their feet). This was taken to suggest a neural organization based on functions, such as performing manual-like dexterous actions, rather than on body parts, in primary sensorimotor cortex. We tested the selectivity for the compensatory body parts in the primary and association sensorimotor cortex of people born without hands (dysplasic individuals). Despite clear compensatory foot use, the primary sensorimotor hand area in the dysplasic subjects showed preference for adjacent body parts that are not compensatorily used as effectors. This suggests that function-based organization, proposed for congenital blindness and deafness, does not apply to the primary sensorimotor cortex deprivation in dysplasia. These findings stress the roles of neuroanatomical constraints like topographical proximity and connectivity in determining the functional development of primary cortex even in extreme, congenital deprivation. In contrast, increased and selective foot movement preference was found in dysplasics' association cortex in the inferior parietal lobule. This suggests that the typical motor selectivity of this region for manual actions may correspond to high-level action representations that are effector-invariant. These findings reveal limitations to compensatory plasticity and experience in modifying brain organization of early topographical cortex compared with association cortices driven by function-based organization.
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Liao CC, Qi HX, Reed JL, Miller DJ, Kaas JH. Congenital foot deformation alters the topographic organization in the primate somatosensory system. Brain Struct Funct 2016; 221:383-406. [PMID: 25326245 PMCID: PMC4446245 DOI: 10.1007/s00429-014-0913-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 10/07/2014] [Indexed: 12/20/2022]
Abstract
Limbs may fail to grow properly during fetal development, but the extent to which such growth alters the nervous system has not been extensively explored. Here we describe the organization of the somatosensory system in a 6-year-old monkey (Macaca radiata) born with a deformed left foot in comparison to the results from a normal monkey (Macaca fascicularis). Toes 1, 3, and 5 were missing, but the proximal parts of toes 2 and 4 were present. We used anatomical tracers to characterize the patterns of peripheral input to the spinal cord and brainstem, as well as between thalamus and cortex. We also determined the somatotopic organization of primary somatosensory area 3b of both hemispheres using multiunit electrophysiological recording. Tracers were subcutaneously injected into matching locations of each foot to reveal their representations within the lumbar spinal cord, and the gracile nucleus (GrN) of the brainstem. Tracers injected into the representations of the toes and plantar pads of cortical area 3b labeled neurons in the ventroposterior lateral nucleus (VPL) of the thalamus. Contrary to the orderly arrangement of the foot representation throughout the lemniscal pathway in the normal monkey, the plantar representation of the deformed foot was significantly expanded and intruded into the expected representations of toes in the spinal cord, GrN, VPL, and area 3b. We also observed abnormal representation of the intact foot in the ipsilateral spinal cord and contralateral area 3b. Thus, congenital malformation influences the somatotopic representation of the deformed as well as the intact foot.
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Affiliation(s)
- Chia-Chi Liao
- 301 Wilson Hall, Department of Psychology, Vanderbilt University, 111 21st Avenue South, Nashville, TN, 37212, USA.
| | - Hui-Xin Qi
- 301 Wilson Hall, Department of Psychology, Vanderbilt University, 111 21st Avenue South, Nashville, TN, 37212, USA
| | - Jamie L Reed
- 301 Wilson Hall, Department of Psychology, Vanderbilt University, 111 21st Avenue South, Nashville, TN, 37212, USA
| | - Daniel J Miller
- 301 Wilson Hall, Department of Psychology, Vanderbilt University, 111 21st Avenue South, Nashville, TN, 37212, USA
| | - Jon H Kaas
- 301 Wilson Hall, Department of Psychology, Vanderbilt University, 111 21st Avenue South, Nashville, TN, 37212, USA
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Stoeckel MC, Morgenroth F, Buetefisch CM, Seitz RJ. Differential grey matter changes in sensorimotor cortex related to exceptional fine motor skills. PLoS One 2012; 7:e51900. [PMID: 23300575 PMCID: PMC3530578 DOI: 10.1371/journal.pone.0051900] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 11/13/2012] [Indexed: 11/19/2022] Open
Abstract
Functional changes in sensorimotor representation occur in response to use and lesion throughout life. Emerging evidence suggests that functional changes are paralleled by respective macroscopic structural changes. In the present study we used voxel-based morphometry to investigate sensorimotor cortex in subjects with congenitally malformed upper extremities. We expected increased or decreased grey matter to parallel the enlarged or reduced functional representations we reported previously. More specifically, we expected decreased grey matter values in lateral sensorimotor cortex related to compromised hand function and increased grey matter values in medial sensorimotor cortex due to compensatory foot use. We found a medial cluster of grey matter increase in subjects with frequent, hand-like compensatory foot use. This increase was predominantly seen for lateral premotor, supplementary motor, and motor areas and only marginally involved somatosensory cortex. Contrary to our expectation, subjects with a reduced number of fingers, who had shown shrinkage of the functional hand representation previously, did not show decreased grey matter values within lateral sensorimotor cortex. Our data suggest that functional plastic changes in sensorimotor cortex can be associated with increases in grey matter but may also occur in otherwise macroscopically normal appearing grey matter volumes. Furthermore, macroscopic structural changes in motor and premotor areas may be observed without respective changes in somatosensory cortex.
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Affiliation(s)
- M Cornelia Stoeckel
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Incarnation and animation: physical versus representational deficits of body integrity. Exp Brain Res 2009; 204:315-26. [DOI: 10.1007/s00221-009-2043-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Accepted: 10/02/2009] [Indexed: 11/26/2022]
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Funk M, Lutz K, Hotz-Boendermaker S, Roos M, Summers P, Brugger P, Hepp-Reymond MC, Kollias SS. Sensorimotor tongue representation in individuals with unilateral upper limb amelia. Neuroimage 2008; 43:121-7. [DOI: 10.1016/j.neuroimage.2008.06.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 05/30/2008] [Accepted: 06/04/2008] [Indexed: 11/28/2022] Open
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Gazarian A, Abrahamyan DO. Allogreffe de main chez le nouveau-né agénésique: étude de faisabilité. ANN CHIR PLAST ESTH 2007; 52:451-8. [PMID: 17688993 DOI: 10.1016/j.anplas.2007.05.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2007] [Accepted: 05/22/2007] [Indexed: 11/22/2022]
Abstract
Would a newborn with a single hand benefit from hand allograft? Transantebrachial aplasia is the chosen clinical form of agenesia in our interrogation. The feasibility study presents several aspects: 1) ethical and psychological aspects. Is this a desired surgery for agenesic population? Which are the functional, psychological and social situations of agenesic patient? Is the hand transplantation in newborn ethically acceptable? What is the parents' attitude toward agenesia? Can we envisage organ donation in neonatal period? 2) immunological aspects. The non-vital character of this condition and its' good functional tolerance cannot make accepting the risk of adverse effects of hand allotransplantation. Hence, one may consider this surgery only without immunosuppression. Can the peculiarities of the neonate "immature" immune system represent an opportunity of easier tolerance obtaining, avoiding immunosuppression? 3) anatomical and technical aspects. The proximal tissues at the level of amputation are all hypoplastic in agenesic patients. Can we efficaciously suture those structures with donor eutrophic tissues? 4) cognitive aspects. Is a neonate born with only one hand is able to use two? A feasibility study on such a subject needs to take into account all these aspects. This research is useful because, even if hand allograft in agenesic newborn will never be done, the provided information will allow to progress in the vaster domain of composite tissue allotransplantation in perinatology.
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Affiliation(s)
- A Gazarian
- Chirurgie de la main et du membre supérieur, clinique du Parc, hôpital Debrousse, pavillons Tbis (orthopédie pédiatrique) et V (transplantation), hôpital Edouard-Herriot, 86, boulevard des Belges, 69006 Lyon, France.
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Stoeckel MC, Pollok B, Schnitzler A, Seitz RJ. Studying the human somatosensory hand area: A new way to compare fMRI and MEG. J Neurosci Methods 2007; 164:280-91. [PMID: 17597225 DOI: 10.1016/j.jneumeth.2007.05.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 04/03/2007] [Accepted: 05/13/2007] [Indexed: 10/23/2022]
Abstract
Valid localization is a prerequisite to study plasticity of the somatosensory cortex in humans. We compared the localizations of left and right thumb and little finger in the primary somatosensory cortex obtained with fMRI and MEG. Representations were investigated in 11 healthy right-handed subjects using echoplanar fMRI and 122-channel MEG together with electric finger stimulation. Activation observed with fMRI was based on an increase in the BOLD signal. Most of the activation clusters (71.1%) were located on the lateral surface of the postcentral gyrus. Representations of thumb and little finger were 17mm apart on average and consistently showed a somatotopic arrangement with the thumb representation inferior, lateral, and anterior to the representation of the little finger. Activation observed with MEG was modelled by equivalent current dipoles. Dipole localization was compatible with an assumed origin of activation within the posterior wall of the central sulcus. The Euclidian distance between corresponding dipoles was 11.5mm on average with deviations from the expected spatial arrangement of 35, 30, and 20% in the x-, y- und z-direction, respectively. Our study demonstrates how relative localization of somatosensory activations can serve as an indicator for localization validity when comparing different methods or studying somatosensory plasticity.
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Affiliation(s)
- Maria Cornelia Stoeckel
- Department of Neurology, University Hospital Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
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Borsook D, Becerra L, Hargreaves R. A role for fMRI in optimizing CNS drug development. Nat Rev Drug Discov 2006; 5:411-24. [PMID: 16604100 DOI: 10.1038/nrd2027] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Drug development today needs to balance agility, speed and risk in defining the probability of success for molecules, mechanisms and therapeutic concepts. New techniques in functional magnetic resonance imaging (fMRI) promise to be part of a sequence that could transform drug development for disorders of the central nervous system (CNS) by examining brain systems and their functional activation dynamically. The brain is complex and multiple transmitters and intersecting brain circuits are implicated in many CNS disorders. CNS therapeutics are designed against specific CNS targets, many of which are unprecedented. The challenge is to reveal the functional consequences of these interactions to assess therapeutic potential. fMRI can help optimize CNS drug discovery by providing a key metric that can increase confidence in early decision-making, thereby improving success rates and reducing risk, development times and costs of drug development.
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Affiliation(s)
- David Borsook
- Imaging Center for Drug Development (ICD), Mclean Hospital, Department of Psychiatry, USA.
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Funk M, Shiffrar M, Brugger P. Hand movement observation by individuals born without hands: phantom limb experience constrains visual limb perception. Exp Brain Res 2005; 164:341-6. [PMID: 15818499 DOI: 10.1007/s00221-005-2255-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2004] [Accepted: 12/04/2004] [Indexed: 10/25/2022]
Abstract
Increasing evidence suggests that the visual analysis of other people's actions depends upon the observer's own body representation or schema. This raises the question of how differences in observers' body structure and schema impact their perception of human movement. We investigated the visual experiences of two persons born without arms, one with and the other without phantom sensations. These participants, plus six normally-limbed control observers, viewed depictions of upper limb movement under conditions of apparent motion. Consistent with previous results (Shiffrar M, Freyd JJ (1990) Psychol Sci 1:257), normally-limbed observers perceived rate-dependent paths of apparent human movement. Specifically, biologically impossible motion trajectories were reported at rapid display rates while biologically possible trajectories were reported at slow display rates. The aplasic individual with phantom experiences showed the same perceptual pattern as control participants, while the aplasic individual without phantom sensations did not. These preliminary results suggest that phantom experiences may constrain the visual analysis of the human body. These results further suggest that it may be time to move beyond the question of whether aplasic phantoms exist and instead focus on the question of why some people with limb aplasia experience phantom sensations while others do not. In this light, the current results suggest that somesthetic representations are not sufficient to define body schema. Instead, neural systems matching action observation, action execution and motor imagery likely contribute to the definition of body schema in profound ways. Additional research with aplasic individuals, having and lacking phantom sensations, is needed to resolve this issue.
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Affiliation(s)
- Marion Funk
- Department of Neurology, University Hospital Zürich, 8091, Zürich, Switzerland
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