51
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Peuser J, Belhaj-Saif A, Hamadjida A, Schmidlin E, Gindrat AD, Völker AC, Zakharov P, Hoogewoud HM, Rouiller EM, Scheffold F. Follow-up of cortical activity and structure after lesion with laser speckle imaging and magnetic resonance imaging in nonhuman primates. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:096011. [PMID: 21950925 DOI: 10.1117/1.3625287] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The nonhuman primate model is suitable to study mechanisms of functional recovery following lesion of the cerebral cortex (motor cortex), on which therapeutic strategies can be tested. To interpret behavioral data (time course and extent of functional recovery), it is crucial to monitor the properties of the experimental cortical lesion, induced by infusion of the excitotoxin ibotenic acid. In two adult macaque monkeys, ibotenic acid infusions produced a restricted, permanent lesion of the motor cortex. In one monkey, the lesion was monitored over 3.5 weeks, combining laser speckle imaging (LSI) as metabolic readout (cerebral blood flow) and anatomical assessment with magnetic resonance imaging (T2-weighted MRI). The cerebral blood flow, measured online during subsequent injections of the ibotenic acid in the motor cortex, exhibited a dramatic increase, still present after one week, in parallel to a MRI hypersignal. After 3.5 weeks, the cerebral blood flow was strongly reduced (below reference level) and the hypersignal disappeared from the MRI scan, although the lesion was permanent as histologically assessed post-mortem. The MRI data were similar in the second monkey. Our experiments suggest that LSI and MRI, although they reflect different features, vary in parallel during a few weeks following an excitotoxic cortical lesion.
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Affiliation(s)
- Jörn Peuser
- University of Fribourg, Department of Physics, Ch. du Musée 3, CH-1700 Fribourg, Switzerland
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52
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Jones TA, Jefferson SC. Reflections of experience-expectant development in repair of the adult damaged brain. Dev Psychobiol 2011; 53:466-75. [PMID: 21678394 PMCID: PMC6645382 DOI: 10.1002/dev.20557] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Behavioral experience has long been known to influence functional outcome after brain injury, but only recently has its pervasive role in the reorganization of the adult brain after damage become appreciated. We briefly review findings from animal models on the role of experience in shaping neuronal events after stroke-like injury. Experience-dependent neural plasticity can be enhanced or impaired by brain damage, depending upon injury parameters and timing. The neuronal growth response to some experiences is heightened due to interactions with denervation-induced plasticity. This includes compensatory behavioral strategies developed in response to functional impairments. Early behavioral experiences can constrain later experience-dependent plasticity, leading to suboptimal functional outcome. Time dependencies and facets of neural growth patterns are reminiscent of experience-expectant processes that shape brain development. As with sensitive periods in brain development, this process may establish behavioral patterns early after brain injury which are relatively resistant to later change.
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Affiliation(s)
- Theresa A Jones
- Psychology Department and Neuroscience Institute, University of Texas at Austin, USA.
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53
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Kaeser M, Brunet JF, Wyss A, Belhaj-Saif A, Liu Y, Hamadjida A, Rouiller EM, Bloch J. Autologous Adult Cortical Cell Transplantation Enhances Functional Recovery Following Unilateral Lesion of Motor Cortex in Primates: A Pilot Study. Neurosurgery 2011; 68:1405-16; discussion 1416-7. [DOI: 10.1227/neu.0b013e31820c02c0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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54
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Najib U, Bashir S, Edwards D, Rotenberg A, Pascual-Leone A. Transcranial brain stimulation: clinical applications and future directions. Neurosurg Clin N Am 2011; 22:233-51, ix. [PMID: 21435574 PMCID: PMC3547606 DOI: 10.1016/j.nec.2011.01.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Noninvasive brain stimulation is a valuable investigative tool and has potential therapeutic applications in cognitive neuroscience, neurophysiology, psychiatry, and neurology. Transcranial magnetic stimulation (TMS) is particularly useful to establish and map causal brain-behavior relations in motor and nonmotor cortical areas. Neuronavigated TMS is able to provide precise information related to the individual's functional anatomy that can be visualized and used during surgical interventions and critically aid in presurgical planning, reducing the need for riskier and more cumbersome intraoperative or invasive mapping procedures. This article reviews methodological aspects, clinical applications, and future directions of TMS-based mapping.
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Affiliation(s)
- Umer Najib
- Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Shahid Bashir
- Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
| | - Dylan Edwards
- Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
- Non-Invasive Brain Stimulation and the Human Motor Control Laboratory, Burke Medical Research Institute, Inc, 785 Mamaroneck Avenue, White Plains, NY 10605, USA
| | - Alexander Rotenberg
- Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Alvaro Pascual-Leone
- Department of Neurology, Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, USA
- Institut Guttman de Neurorehabilitació, Institut Universitari, Universitat Autonoma de Barcelona, Camí de Can Ruti s/n, 08916 Badalona, Spain
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55
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Abstract
The past decade of neuroscience research has provided considerable evidence that the adult brain can undergo substantial reorganization following injury. For example, following an ischemic lesion, such as occurs following a stroke, there is a cascade of molecular, genetic, physiological and anatomical events that allows the remaining structures in the brain to reorganize. Often, these events are associated with recovery, suggesting that they contribute to it. Indeed, the term plasticity in stroke research has had a positive connotation historically. But more recently, efforts have been made to differentiate beneficial from detrimental changes. These notions are timely now that neurorehabilitative research is developing novel treatments to modulate, increase, or inhibit plasticity in targeted brain regions. We will review basic principles of plasticity and some of the new and exciting approaches that are currently being investigated to shape plasticity following injury in the central nervous system.
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Affiliation(s)
- Numa Dancause
- Département de Physiologie, Université de Montréal, Montréal, Québec, Canada.
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56
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Nishibe M, Barbay S, Guggenmos D, Nudo RJ. Reorganization of motor cortex after controlled cortical impact in rats and implications for functional recovery. J Neurotrauma 2010; 27:2221-32. [PMID: 20873958 DOI: 10.1089/neu.2010.1456] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We report the results of controlled cortical impact (CCI) centered on the caudal forelimb area (CFA) of rat motor cortex to determine the feasibility of examining cortical plasticity in a spared cortical motor area (rostral forelimb area, RFA). We compared the effects of three CCI parameter sets (groups CCI-1, CCI-2, and CCI-3) that differed in impactor surface shape, size, and location, on behavioral recovery and RFA structural and functional integrity. Forelimb deficits in the limb contralateral to the injury were evident in all three CCI groups assessed by skilled reach and footfault tasks that persisted throughout the 35-day post-CCI assessment period. Nissl-stained coronal sections revealed that the RFA was structurally intact. Intracortical microstimulation experiments conducted at 7 weeks post-CCI demonstrated that RFA was functionally viable. However, the size of the forelimb representation decreased significantly in CCI-1 compared to the control group. Subdivided into component movement categories, there was a significant group effect for proximal forelimb movements. The RFA area reduction and reorganization are discussed in relation to possible diaschisis, and to compensatory functional behavior, respectively. Also, an inverse correlation between the anterior extent of the lesion and the size of the RFA was identified and is discussed in relation to corticocortical connectivity. The results suggest that CCI can be applied to rat CFA while sparing RFA. This CCI model can contribute to our understanding of neural plasticity in premotor cortex as a substrate for functional motor recovery.
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Affiliation(s)
- Mariko Nishibe
- Department of Physical Therapy and Rehabilitation Science, University of Kansas Medical Center, Kansas City, Kansas, USA
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57
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Lesions in posterior parietal area 5 in monkeys result in rapid behavioral and cortical plasticity. J Neurosci 2010; 30:12918-35. [PMID: 20881111 DOI: 10.1523/jneurosci.1806-10.2010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We examined the effects of focal lesions of posterior parietal area 5 in macaque monkeys on bimanual behavior performed with and without visual guidance. The animals were trained on two reaching tasks and one tactile texture discrimination task. Task 1 simply involved reaching toward and grasping a reward from one of five well positions. Task 2 required the monkey to use both hands simultaneously to obtain a reward. The tactile texture discrimination task required the monkey to signal the roughness of a passively delivered texture using its jaw. After lesions to area 5, the monkeys showed a decrease in hand use for tasks 1 and 2 and an inability to perform task 2 in specific locations in visual space. These deficits recovered within several days. No deficits were observed in the tactile texture discrimination task or in an analgesic control monkey. Electrophysiological recordings made just before the lesion, immediately after the lesion, and 2 months after the lesion demonstrated that cortical areas just rostral to the lesioned area 5, and areas 1 and 2, were topographically reorganized and that receptive fields for neurons in these fields changed location on the body surface. These cortical map changes are correlative and may, in part, contribute to the rapid behavioral recovery observed. The mechanism for such rapid changes may be the unmasking of existing divergent and convergent thalamocortical connections that are part of the normal cortical circuitry.
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58
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Zörner B, Schwab ME. Anti-Nogo on the go: from animal models to a clinical trial. Ann N Y Acad Sci 2010; 1198 Suppl 1:E22-34. [DOI: 10.1111/j.1749-6632.2010.05566.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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59
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McNeal DW, Darling WG, Ge J, Stilwell-Morecraft KS, Solon KM, Hynes SM, Pizzimenti MA, Rotella DL, Vanadurongvan T, Morecraft RJ. Selective long-term reorganization of the corticospinal projection from the supplementary motor cortex following recovery from lateral motor cortex injury. J Comp Neurol 2010; 518:586-621. [PMID: 20034062 DOI: 10.1002/cne.22218] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Brain injury affecting the frontal motor cortex or its descending axons often causes contralateral upper extremity paresis. Although recovery is variable, the underlying mechanisms supporting favorable motor recovery remain unclear. Because the medial wall of the cerebral hemisphere is often spared following brain injury and recent functional neuroimaging studies in patients indicate a potential role for this brain region in the recovery process, we investigated the long-term effects of isolated lateral frontal motor cortical injury on the corticospinal projection (CSP) from intact, ipsilesional supplementary motor cortex (M2). After injury to the arm region of the primary motor (M1) and lateral premotor (LPMC) cortices, upper extremity recovery is accompanied by terminal axon plasticity in the contralateral CSP but not the ipsilateral CSP from M2. Furthermore, significant contralateral plasticity occurs only in lamina VII and dorsally within lamina IX. Thus, selective intraspinal sprouting transpires in regions containing interneurons, flexor-related motor neurons, and motor neurons supplying intrinsic hand muscles, which all play important roles in mediating reaching and digit movements. After recovery, subsequent injury of M2 leads to reemergence of hand motor deficits. Considering the importance of the CSP in humans and the common occurrence of lateral frontal cortex injury, these findings suggest that spared supplementary motor cortex may serve as an important therapeutic target that should be considered when designing acute and long-term postinjury patient intervention strategies aimed to enhance the motor recovery process following lateral cortical trauma.
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60
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Kaeser M, Wyss AF, Bashir S, Hamadjida A, Liu Y, Bloch J, Brunet JF, Belhaj-Saif A, Rouiller EM. Effects of Unilateral Motor Cortex Lesion on Ipsilesional Hand's Reach and Grasp Performance in Monkeys: Relationship With Recovery in the Contralesional Hand. J Neurophysiol 2010; 103:1630-45. [DOI: 10.1152/jn.00459.2009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Manual dexterity, a prerogative of primates, is under the control of the corticospinal (CS) tract. Because 90–95% of CS axons decussate, it is assumed that this control is exerted essentially on the contralateral hand. Consistently, unilateral lesion of the hand representation in the motor cortex is followed by a complete loss of dexterity of the contralesional hand. During the months following lesion, spontaneous recovery of manual dexterity takes place to a highly variable extent across subjects, although largely incomplete. In the present study, we tested the hypothesis that after a significant postlesion period, manual performance in the ipsilesional hand is correlated with the extent of functional recovery in the contralesional hand. To this aim, ten adult macaque monkeys were subjected to permanent unilateral motor cortex lesion. Monkeys' manual performance was assessed for each hand during several months postlesion, using our standard behavioral test (modified Brinkman board task) that provides a quantitative measure of reach and grasp ability. The ipsilesional hand's performance was found to be significantly enhanced over the long term (100–300 days postlesion) in six of ten monkeys, with the six exhibiting the best, though incomplete, recovery of the contralesional hand. There was a statistically significant correlation ( r = 0.932; P < 0.001) between performance in the ipsilesional hand after significant postlesion period and the extent of recovery of the contralesional hand. This observation is interpreted in terms of different possible mechanisms of recovery, dependent on the recruitment of motor areas in the lesioned and/or intact hemispheres.
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Affiliation(s)
- Mélanie Kaeser
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Fribourg; and
- Department of Neurosurgery, Neurosurgery Clinic, University Hospital of Lausanne, Lausanne, Switzerland
| | - Alexander F. Wyss
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Fribourg; and
| | - Shahid Bashir
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Fribourg; and
| | - Adjia Hamadjida
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Fribourg; and
| | - Yu Liu
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Fribourg; and
| | - Jocelyne Bloch
- Department of Neurosurgery, Neurosurgery Clinic, University Hospital of Lausanne, Lausanne, Switzerland
| | - Jean-François Brunet
- Department of Neurosurgery, Neurosurgery Clinic, University Hospital of Lausanne, Lausanne, Switzerland
| | - Abderaouf Belhaj-Saif
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Fribourg; and
| | - Eric M. Rouiller
- Unit of Physiology and Program in Neurosciences, Department of Medicine, Faculty of Sciences, University of Fribourg, Fribourg; and
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61
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Jablonka J, Burnat K, Witte O, Kossut M. Remapping of the somatosensory cortex after a photothrombotic stroke: dynamics of the compensatory reorganization. Neuroscience 2010; 165:90-100. [DOI: 10.1016/j.neuroscience.2009.09.074] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 09/25/2009] [Accepted: 09/26/2009] [Indexed: 10/20/2022]
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62
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Imaging rapid redistribution of sensory-evoked depolarization through existing cortical pathways after targeted stroke in mice. Proc Natl Acad Sci U S A 2009; 106:11759-64. [PMID: 19571005 DOI: 10.1073/pnas.0812695106] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Evidence suggests that recovery from stroke damage results from the production of new synaptic pathways within surviving brain regions over weeks. To address whether brain function might redistribute more rapidly through preexisting pathways, we examined patterns of sensory-evoked depolarization in mouse somatosensory cortex within hours after targeted stroke to a subset of the forelimb sensory map. Brain activity was mapped with voltage-sensitive dye imaging allowing millisecond time resolution over 9 mm(2) of brain. Before targeted stroke, we report rapid activation of the forelimb area within 10 ms of contralateral forelimb stimulation and more delayed activation of related areas of cortex such as the hindlimb sensory and motor cortices. After stroke to a subset of the forelimb somatosensory cortex map, function was lost in ischemic areas within the forelimb map center, but maintained in regions 200-500 microm blood flow deficits indicating the size of a perfused, but nonfunctional, penumbra. In many cases, stroke led to only partial loss of the forelimb map, indicating that a subset of a somatosensory domain can function on its own. Within the forelimb map spared by stroke, forelimb-stimulated responses became delayed in kinetics, and their center of activity shifted into adjacent hindlimb and posterior-lateral sensory areas. We conclude that the focus of forelimb-specific somatosensory cortex activity can be rapidly redistributed after ischemic damage. Given that redistribution occurs within an hour, the effect is likely to involve surviving accessory pathways and could potentially contribute to rapid behavioral compensation or direct future circuit rewiring.
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63
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Levin MF, Kleim JA, Wolf SL. What Do Motor “Recovery” and “Compensation” Mean in Patients Following Stroke? Neurorehabil Neural Repair 2008; 23:313-9. [DOI: 10.1177/1545968308328727] [Citation(s) in RCA: 581] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is a lack of consistency among researchers and clinicians in the use of terminology that describes changes in motor ability following neurological injury. Specifically, the terms and definitions of motor compensation and motor recovery have been used in different ways, which is a potential barrier to interdisciplinary communication. This Point of View describes the problem and offers a solution in the form of definitions of compensation and recovery at the neuronal, motor performance, and functional levels within the framework of the International Classification of Functioning model.
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Affiliation(s)
- Mindy F. Levin
- School of Physical and Occupational Therapy, McGill University and Center for Interdisciplinary Research in Rehabilitation, Jewish Rehabilitation Hospital, Montreal, Quebec, Canada,
| | - Jeffrey A. Kleim
- McKnight Brain Institute, University of Florida, and Brain Rehabilitation Research Center, Malcom Randall VA Hospital, Gainesville, Florida
| | - Steven L. Wolf
- Departments of Rehabilitation Medicine, Medicine and Cell Biology, Emory University School of Medicine, and Atlanta VA Rehabilitation R&D Center, Atlanta, Georgia
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64
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Till C, Colella B, Verwegen J, Green RE. Postrecovery Cognitive Decline in Adults With Traumatic Brain Injury. Arch Phys Med Rehabil 2008; 89:S25-34. [DOI: 10.1016/j.apmr.2008.07.004] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 06/23/2008] [Accepted: 07/28/2008] [Indexed: 11/25/2022]
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65
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Hummel FC, Celnik P, Pascual-Leone A, Fregni F, Byblow WD, Buetefisch CM, Rothwell J, Cohen LG, Gerloff C. Controversy: Noninvasive and invasive cortical stimulation show efficacy in treating stroke patients. Brain Stimul 2008; 1:370-82. [DOI: 10.1016/j.brs.2008.09.003] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 09/03/2008] [Accepted: 09/05/2008] [Indexed: 11/17/2022] Open
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66
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Eisner-Janowicz I, Barbay S, Hoover E, Stowe AM, Frost SB, Plautz EJ, Nudo RJ. Early and late changes in the distal forelimb representation of the supplementary motor area after injury to frontal motor areas in the squirrel monkey. J Neurophysiol 2008; 100:1498-512. [PMID: 18596180 DOI: 10.1152/jn.90447.2008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuroimaging studies in stroke survivors have suggested that adaptive plasticity occurs following stroke. However, the complex temporal dynamics of neural reorganization after injury make the interpretation of functional imaging studies equivocal. In the present study in adult squirrel monkeys, intracortical microstimulation (ICMS) techniques were used to monitor changes in representational maps of the distal forelimb in the supplementary motor area (SMA) after a unilateral ischemic infarct of primary motor (M1) and premotor distal forelimb representations (DFLs). In each animal, ICMS maps were derived at early (3 wk) and late (13 wk) postinfarct stages. Lesions resulted in severe deficits in motor abilities on a reach and retrieval task. Limited behavioral recovery occurred and plateaued at 3 wk postinfarct. At both early and late postinfarct stages, distal forelimb movements could still be evoked by ICMS in SMA at low current levels. However, the size of the SMA DFL changed after the infarct. In particular, wrist-forearm representations enlarged significantly between early and late stages, attaining a size substantially larger than the preinfarct area. At the late postinfarct stage, the expansion in the SMA DFL area was directly proportional to the absolute size of the lesion. The motor performance scores were positively correlated to the absolute size of the SMA DFL at the late postinfarct stage. Together, these data suggest that, at least in squirrel monkeys, descending output from M1 and dorsal and ventral premotor cortices is not necessary for SMA representations to be maintained and that SMA motor output maps undergo delayed increases in representational area after damage to other motor areas. Finally, the role of SMA in recovery of function after such lesions remains unclear because behavioral recovery appears to precede neurophysiological map changes.
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Affiliation(s)
- Ines Eisner-Janowicz
- Department of Molecular and Integrative Physiology Department and Landon Center on Aging, University of Kansas Medical Center, Kansas City, Kansas, USA
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67
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Giszter S, Davies MR, Ramakrishnan A, Udoekwere UI, Kargo WJ. Trunk sensorimotor cortex is essential for autonomous weight-supported locomotion in adult rats spinalized as P1/P2 neonates. J Neurophysiol 2008; 100:839-51. [PMID: 18509082 DOI: 10.1152/jn.00866.2007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Unlike adult spinalized rats, approximately 20% of rats spinalized as postnatal day 1 or 2 (P1/P2) neonates achieve autonomous hindlimb weight support. Cortical representations of mid/low trunk occur only in such rats with high weight support. However, the importance of hindlimb/trunk motor cortex in function of spinalized rats remains unclear. We tested the importance of trunk sensorimotor cortex in their locomotion using lesions guided by cortical microstimulation in P1/P2 weight-supporting neonatal spinalized rats and controls. In four intact control rats, lesions of hindlimb/trunk cortex caused no treadmill deficits. All spinalized rats lesioned in trunk cortex (n = 16: 4 transplant, 6 transect, 6 transect + fibrin glue) lost an average of about 40% of their weight support. Intact trunk cortex was essential to their level of function. Lesion of trunk cortex substantially increased roll of the hindquarters, which correlated to diminished weight support, but other kinematic stepping parameters showed little change. Embryonic day 14 (E14) transplants support development of the trunk motor representations in their normal location. We tested the role of novel relay circuits arising from the grafts in such cortical representations in E14 transplants using the rats that received (noncellular) fibrin glue grafting at P1/P2 (8 allografts and 32 xenografts). Fibrin-repaired rats with autonomous weight support also had trunk cortical representations similar to those of E14 transplant rats. Thus acellular repair and intrinsic plasticity were sufficient to support the observed features. Our data show that effective cortical mechanisms for trunk control are essential for autonomous weight support in P1/P2 spinalized rats and these can be achieved by intrinsic plasticity.
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Affiliation(s)
- Simon Giszter
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA.
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68
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Dancause N, Duric V, Barbay S, Frost SB, Stylianou A, Nudo RJ. An additional motor-related field in the lateral frontal cortex of squirrel monkeys. Cereb Cortex 2008; 18:2719-28. [PMID: 18424778 PMCID: PMC2583161 DOI: 10.1093/cercor/bhn050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Our earlier efforts to document the cortical connections of the ventral premotor cortex (PMv) revealed dense connections with a field rostral and lateral to PMv, an area we called the frontal rostral field (FR). Here, we present data collected in FR using electrophysiological and anatomical methods. Results show that FR contains an isolated motor representation of the forelimb that can be differentiated from PMv based on current thresholds and latencies to evoke electromyographic activity using intracortical microstimulation techniques. In addition, FR has a different pattern of cortical connections compared with PMv. Together, these data support that FR is an additional, previously undescribed motor-related area in squirrel monkeys.
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Affiliation(s)
- Numa Dancause
- Department of Neurology, University of Rochester Medical Center, 601 Elmwood Ave, Box 673, Rochester, NY 14642, USA.
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69
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Cramer SC. Repairing the human brain after stroke: I. Mechanisms of spontaneous recovery. Ann Neurol 2008; 63:272-87. [PMID: 18383072 DOI: 10.1002/ana.21393] [Citation(s) in RCA: 538] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Stroke remains a leading cause of adult disability. Some degree of spontaneous behavioral recovery is usually seen in the weeks after stroke onset. Variability in recovery is substantial across human patients. Some principles have emerged; for example, recovery occurs slowest in those destined to have less successful outcomes. Animal studies have extended these observations, providing insight into a broad range of underlying molecular and physiological events. Brain mapping studies in human patients have provided observations at the systems level that often parallel findings in animals. In general, the best outcomes are associated with the greatest return toward the normal state of brain functional organization. Reorganization of surviving central nervous system elements supports behavioral recovery, for example, through changes in interhemispheric lateralization, activity of association cortices linked to injured zones, and organization of cortical representational maps. A number of factors influence events supporting stroke recovery, such as demographics, behavioral experience, and perhaps genetics. Such measures gain importance when viewed as covariates in therapeutic trials of restorative agents that target stroke recovery.
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Affiliation(s)
- Steven C Cramer
- Departments of Neurology and Anatomy & Neurobiology, University of California, Irvine, Irvine, CA 92868-4280, USA.
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70
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Dancause N, Barbay S, Frost SB, Mahnken JD, Nudo RJ. Interhemispheric connections of the ventral premotor cortex in a new world primate. J Comp Neurol 2008; 505:701-15. [PMID: 17948893 DOI: 10.1002/cne.21531] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study describes the pattern of interhemispheric connections of the ventral premotor cortex (PMv) distal forelimb representation (DFL) in squirrel monkeys. Our objectives were to describe qualitatively and quantitatively the connections of PMv with contralateral cortical areas. Intracortical microstimulation techniques (ICMS) guided the injection of the neuronal tract tracers biotinylated dextran amine or Fast blue into PMv DFL. We classified the interhemispheric connections of PMv into three groups. Major connections were found in the contralateral PMv and supplementary motor area (SMA). Intermediate interhemispheric connections were found in the rostral portion of the primary motor cortex, the frontal area immediately rostral and ventral to PMv (FR), cingulate motor areas (CMAs), and dorsal premotor cortex (PMd). Minor connections were found inconsistently across cases in the anterior operculum (AO), posterior operculum/inferior parietal cortex (PO/IP), and posterior parietal cortex (PP), areas that consistently show connections with PMv in the ipsilateral hemisphere. Within-case comparisons revealed that the percentage of PMv connections with contralateral SMA and PMd are higher than the percentage of PMv connections with these areas in the ipsilateral hemisphere; percentages of PMv connections with contralateral M1 rostral, FR, AO, and the primary somatosensory cortex are lower than percentages of PMv connections with these areas in the ipsilateral hemisphere. These studies increase our knowledge of the pattern of interhemispheric connection of PMv. They help to provide an anatomical foundation for understanding PMv's role in motor control of the hand and interhemispheric interactions that may underlie the coordination of bimanual movements.
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Affiliation(s)
- Numa Dancause
- Department of Neurology, University of Rochester Medical Center, Rochester, New York 14642, USA.
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71
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Murata Y, Higo N, Oishi T, Yamashita A, Matsuda K, Hayashi M, Yamane S. Effects of motor training on the recovery of manual dexterity after primary motor cortex lesion in macaque monkeys. J Neurophysiol 2007; 99:773-86. [PMID: 18094104 DOI: 10.1152/jn.01001.2007] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To investigate the effects of postlesion training on motor recovery, we compared the motor recovery of macaque monkeys that had received intensive motor training with those that received no training after a lesion of the primary motor cortex (M1). An ibotenic acid lesion in the M1 digit area resulted in impairment of hand function, with complete loss of digit movement. In the monkeys that had undergone intensive daily training (1 h/day, 5 days/wk) after the lesion, behavioral indexes used to evaluate manual dexterity recovered to the same level as in the prelesion period after 1 or 2 mo of postlesion training period. Relatively independent digit movements, including precision grip (prehension of a small object with finger-to-thumb opposition), were restored in the trained monkeys. Although the behavioral indexes of manual dexterity recovered to some extent in the monkeys without the postlesion training, they remained lower than those in the prelesion period until several months after M1 lesion. The untrained monkeys frequently used alternate grip strategies to grasp a small object with the affected hand, holding food pellets between the tip of the index finger and the dorsum of the thumb. These results suggest that the recovery after M1 lesion includes both use-dependent and use-independent processes and that the recovery of precision grip can be promoted by intensive use of the affected hand in postlesion training.
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Affiliation(s)
- Yumi Murata
- Neuroscience Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki 305-8568, Japan
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72
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Structural damage to the corticospinal tract correlates with bilateral sensorimotor cortex reorganization in stroke patients. Neuroimage 2007; 39:1370-82. [PMID: 18024157 DOI: 10.1016/j.neuroimage.2007.09.071] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 09/26/2007] [Accepted: 09/28/2007] [Indexed: 12/13/2022] Open
Abstract
Damage to the corticospinal tract (CST) in stroke patients has been associated with functional reorganization in the ipsilesional and contralesional sensorimotor cortices. However, it is unknown whether a quantitative relationship exists between the extent of structural damage to the CST and functional reorganization in stroke patients. The purpose of the current study was to examine the relationship between structural CST damage and motor task-related cortical activity in chronic hemiparetic stroke patients. In 10 chronic hemiparetic stroke patients with heterogeneous lesions, CST damage was quantified using conventional structural magnetic resonance imaging and tractography based on diffusion tensor imaging. Cortical activity was measured using functional magnetic resonance imaging during repetitive flexion/extension movements of the digits. We found that the two measures of CST damage were strongly correlated. Moreover, greater CST damage was significantly and linearly correlated with increased activation during affected hand movement in the hand area of the contralesional primary sensorimotor cortex (M1/S1) and in the ipsilesional M1/S1 ventral to the hand area. To our knowledge, this is the first demonstration of a quantitative relationship between the extent of structural damage to the CST and functional reorganization in stroke patients. This relationship was observed in stroke patients with heterogeneous lesions, suggesting that CST damage is a factor relevant to the variation in functional reorganization in the clinical population.
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73
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Abstract
Evidence supporting the plastic capacity of the adult cortex is abundant. Changes have been associated with exposure to enriched environments, learning, peripheral lesions and central lesions. The initial loss of function caused by a lesion is generally followed by a certain amount of recovery that is believed to be due, at least in part, to adaptive plasticity. In particular, the reorganization of cortical representational maps has been associated with improvement of performance. Therefore, areas undergoing such reorganization following lesions are generally assumed to participate in the recovery. We review evidence demonstrating the remodeling of representational maps of the forelimb in adult cortex and the structural plasticity that has been coupled with it. A particular emphasis is paid to non-human primate studies and stroke.
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Affiliation(s)
- Numa Dancause
- Department of Neurology, University of Rochester Medical Center, 601 Elmwood Ave, Box 673, Rochester, NY 14642, USA.
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74
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Abstract
Plasticity phenomena in the cerebral cortex after ischemic injury have been documented repeatedly over the past 2 decades both in animal models and in human stroke survivors. This review highlights many of the major neuroanatomic and neurophysiological changes that characterize poststroke plasticity in experimental animals. Spared regions adjacent to the infarct and far removed from the infarct undergo functional alterations that are modified by behavioral experience. Recent evidence is also reviewed, demonstrating that long-range intracortical pathways can be rerouted to completely novel territories. The implications of this new finding for understanding the brain's capacity for recovery are discussed.
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Affiliation(s)
- Randolph J Nudo
- KU Medical Center, Landon Center on Aging, Kansas City, KS 66160, USA
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