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Brain Struct Funct 2021 Jun 21;226(5):1363-1384. Epub 2021 Apr 21.

Groupe d'Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives, UMR 5293, CNRS, CEA, University of Bordeaux, Centre Broca Nouvelle-Aquitaine - 3ème étage - 146 rue Léo Saignat, CS 61292, 33076, Bordeaux Cedex, France.

The description of human white matter pathways experienced a tremendous improvement, thanks to the advancement of neuroimaging and dissection techniques. The downside of this progress is the production of redundant and conflicting literature, bound by specific studies' methods and aims. The Superior Longitudinal System (SLS), encompassing the arcuate (AF) and the superior longitudinal fasciculi (SLF), becomes an illustrative example of this fundamental issue, being one of the most studied white matter association pathways of the brain. Read More

Clin Neurophysiol 2020 05 28;131(5):1075-1086. Epub 2020 Feb 28.

University of Lyon, Lyon, France; Clinique Bretéché, Nantes, France.

Objective: Most of knowledge on muscle radicular innervation was from explorations in root/spinal cord pathologies. Direct and individual access to each of the lumbar-sacral -ventral and dorsal- nerve roots during dorsal rhizotomy for spastic diplegia allows precise study of the corresponding muscle innervation. Authors report the lumbo-sacral segmental myotomal organization obtained from recordings of muscle responses to root stimulation in a 20-children prospective series. Read More

Acta Biomater 2020 01 19;102:114-126. Epub 2019 Nov 19.

Department of Chemistry, City University of Hong Kong, Hong Kong. Electronic address:

Cells in tissues are enveloped by an instructive niche made of the extracellular matrix. These instructive niches contain three general types of information: topographical, biochemical and mechanical. While the combined effects of these three factors are widely studied, the functions of each individual one has not been systematically characterised, because it is impossible to alter a single factor in a tissue microenvironment without simultaneously affecting the other two. Read More

Neuroimage 2020 01 15;205:116237. Epub 2019 Oct 15.

Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center, 80 Avenue Augustin Fliche, Montpellier, France; National Institute for Health and Medical Research (INSERM), U1051, Team ''Plasticity of the Central Nervous System, Human Stem Cells and Glial Tumors'', Institute for Neurosciences of Montpellier, Montpellier University Medical Center, 80 Av Augustin Fliche, Montpellier, France.

Objective: The structural and functional organization of brain networks subserving basic daily activities (i.e. language, visuo-spatial cognition, movement, semantics, etc. Read More

Hum Brain Mapp 2019 09 22;40(13):3738-3752. Epub 2019 May 22.

Non-Invasive Neurostimulation Therapies (NINET) Laboratory, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada.

The hippocampus is a key brain region that participates in a range of cognitive and affective functions, and is involved in the etiopathogenesis of numerous neuropsychiatric disorders. The structural complexity and functional diversity of the hippocampus suggest the existence of structural and functional subdivisions within this structure. For the first time, we parcellated the human hippocampus with two independent data sets, each of which consisted of 198 T1-weighted structural magnetic resonance imaging (sMRI) images of healthy young subjects. Read More

Sci Rep 2019 03 11;9(1):4046. Epub 2019 Mar 11.

Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto (TN), Italy.

Diffusion MRI tractography allows in-vivo characterization of white matter architecture, including the localization and description of brain fibre bundles. However, some primary bundles are still only partially reconstructed, or not reconstructed at all. The acoustic radiation (AR) represents a primary sensory pathway that has been largely omitted in many tractography studies because its location and anatomical features make it challenging to reconstruct. Read More

Acta Biomater 2018 09 1;78:48-63. Epub 2018 Aug 1.

Department of Materials Science and Engineering, Broad Lane, Sheffield S3 7HQ, United Kingdom. Electronic address:

Entubulating devices to repair peripheral nerve injuries are limited in their effectiveness particularly for critical gap injuries. Current clinically used nerve guidance conduits are often simple tubes, far stiffer than that of the native tissue. This study assesses the use of poly(glycerol sebacate methacrylate) (PGSm), a photocurable formulation of the soft biodegradable material, PGS, for peripheral nerve repair. Read More

PLoS One 2018 27;13(7):e0201277. Epub 2018 Jul 27.

Clinic of Clinical Neurophysiology, Georg August University of Göttingen, University Medical Center, Göttingen, Germany.

Background: Most humans have the ability to activate the auricular muscles. Although (intentional) control suggests an involvement of higher cortical centers underlying posterior auricular muscle (PAM) activation, the cortical representation of the auricular muscles is still unknown.

Methods: With the purpose of identifying a possible cortical representation area we performed automated robotic and image-guided transcranial magnetic stimulation (TMS) mapping (n = 8) and functional magnetic resonance imaging (fMRI) (n = 13). Read More

Proc Natl Acad Sci U S A 2015 Dec 11;112(52):16024-9. Epub 2015 Dec 11.

Neuropsychiatry Laboratory, Department of Neurology, Hadassah Hebrew University Medical Center, Jerusalem 9112001, Israel; Department of Medical Neurobiology, Faculty of Medicine, The Hebrew University, Jerusalem 9112001, Israel;

Topographic maps and their continuity constitute a fundamental principle of brain organization. In the somatosensory system, whole-body sensory impairment may be reflected either in cortical signal reduction or disorganization of the somatotopic map, such as disturbed continuity. Here we investigated the role of continuity in pathological states. Read More

J Neurol 2016 Jan 11;263(1):157-67. Epub 2015 Nov 11.

Team "Plasticity of Central Nervous System, Stem Cells and Glial Tumors", INSERM U1051, Institute of Neurosciences of Montpellier, Montpellier, France.

The neural correlates of stuttering are to date incompletely understood. Although the possible involvement of the basal ganglia, the cerebellum and certain parts of the cerebral cortex in this speech disorder has previously been reported, there are still not many studies investigating the role of white matter fibers in stuttering. Axonal stimulation during awake surgery provides a unique opportunity to study the functional role of structural connectivity. Read More

J Appl Physiol (1985) 2015 Jun 26;118(11):1364-74. Epub 2015 Mar 26.

Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California; Pavlov Institute of Physiology, St. Petersburg, Russia; and Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia.

Transcutaneous and epidural electrical spinal cord stimulation techniques are becoming more valuable as electrophysiological and clinical tools. Recently, we observed selective activation of proximal and distal motor pools during epidural spinal stimulation. In the present study, we hypothesized that the characteristics of recruitment curves obtained from leg muscles will reflect a relative preferential activation of proximal and distal motor pools based on their arrangement along the lumbosacral enlargement. Read More

J Anat 2015 Jan 17;226(1):47-59. Epub 2014 Nov 17.

Department of Neurosciences, Division of Neurosurgery, 'S. Chiara' Hospital, Trento, Italy; Biomedical and Surgical Sciences, Section of Neurological Psychiatric and Psychological Sciences, 'S. Anna' University-Hospital, Ferrara, Italy.

Even if different dissection, tractographic and connectivity studies provided pure anatomical evidences about the optic radiations (ORs), descriptions of both the anatomical structure and the anatomo-functional relationships of the ORs with the adjacent bundles were not reported. We propose a detailed anatomical and functional study with 'post mortem' dissections and 'in vivo' direct electrical stimulation (DES) of the OR, demonstrating also the relationships with the adjacent eloquent bundles in a neurosurgical 'connectomic' perspective. Six human hemispheres (three left, three right) were dissected after a modified Klingler's preparation. Read More

J Anat 2014 Aug 30;225(2):132-51. Epub 2014 Jun 30.

Neurosurgery Unit, Department of Neuroscience and Neurorehabilitation, Bambino Gesù Children's Hospital, IRCCS, Roma, Italy.

The temporo-parieto-occipital (TPO) junction is a complex brain territory heavily involved in several high-level neurological functions, such as language, visuo-spatial recognition, writing, reading, symbol processing, calculation, self-processing, working memory, musical memory, and face and object recognition. Recent studies indicate that this area is covered by a thick network of white matter (WM) connections, which provide efficient and multimodal integration of information between both local and distant cortical nodes. It is important for neurosurgeons to have good knowledge of the three-dimensional subcortical organisation of this highly connected region to minimise post-operative permanent deficits. Read More

J Neurosci 2013 Oct;33(43):17138-49

Department of Neurosciences, University of California, San Diego, La Jolla, California 92093, Veterans Administration Medical Center, San Diego, California 92161, Spinal Cord Injury Center, Heidelberg University Hospital, D-69118 Heidelberg, Germany, Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129.

High-level spinal cord injury can lead to cardiovascular dysfunction, including disordered hemodynamics at rest and autonomic dysreflexia during noxious stimulation. To restore supraspinal control of sympathetic preganglionic neurons (SPNs), we grafted embryonic brainstem-derived neural stem cells (BS-NSCs) or spinal cord-derived neural stem cells (SC-NSCs) expressing green fluorescent protein into the T4 complete transection site of adult rats. Animals with injury alone served as controls. Read More

J Am Heart Assoc 2013 Aug 2;2(4):e000090. Epub 2013 Aug 2.

Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA.

Background: The purpose of this study was to define the incidence, imaging characteristics, natural history, and prognostic implication of corticospinal tract Wallerian degeneration (CST-WD) in spontaneous intracerebral hemorrhage (ICH) using serial MR imaging.

Methods And Results: Consecutive ICH patients with supratentorial ICH prospectively underwent serial MRIs at 2, 7, 14, and 21 days. MRIs were analyzed by independent raters for the presence and topographical distribution of CST-WD on diffusion-weighted imaging (DWI). Read More

PLoS One 2013 16;8(1):e53673. Epub 2013 Jan 16.

Wolfson Centre for Age-Related Diseases, The Wolfson Wing, King's College London, Guy's Campus, London, United Kingdom.

EphB receptors tyrosine kinases and ephrinB ligands were first identified as guidance molecules involved in the establishment of topographical mapping and connectivity in the nervous system during development. Later in development and into adulthood their primary role would switch from guidance to activity-dependent modulation of synaptic efficacy. In sensory systems, they play a role in both the onset of inflammatory and neuropathic pain, and in the establishment of central sensitisation, an NMDA-mediated form of synaptic plasticity thought to underlie most forms of chronic pain. Read More

J Neurosurg 2012 Dec 21;117(6):1053-69. Epub 2012 Sep 21.

Department of Neurosciences, Division of Neurosurgery, Bambino Gesù Children's Hospital, Roma, Italy.

Object: Recent neuroimaging and surgical results support the crucial role of white matter in mediating motor and higher-level processing within the frontal lobe, while suggesting the limited compensatory capacity after damage to subcortical structures. Consequently, an accurate knowledge of the anatomofunctional organization of the pathways running within this region is mandatory for planning safe and effective surgical approaches to different diseases. The aim of this dissection study was to improve the neurosurgeon's awareness of the subcortical anatomofunctional architecture for a lateral approach to the frontal region, to optimize both resection and postoperative outcome. Read More

Hum Brain Mapp 2012 Sep 25;33(9):2072-80. Epub 2011 Aug 25.

Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Milan, Italy.

Objective: Aim of this study was to compare tactile-associated cervical cord fMRI activity between primary progressive (PP) and secondary progressive (SP) MS patients and to investigate whether cord recruitment was associated with structural brain and cord damage.

Experimental Design: Cervical cord fMRI during a tactile stimulation of the right hand was acquired from 17 healthy controls, 18 SPMS patients, and 16 PPMS patients. Average fMRI activity and its topographical distribution in cord sectors (left vs. Read More

J Neuroimmunol 2010 Oct 21;227(1-2):144-52. Epub 2010 Aug 21.

Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, D-30559 Hannover, Germany.

Differences in the regulation of surface molecule expression and functional activity of microglia, the resident immune effector elements of the central nervous system (CNS), might give important insights into understanding the predilection sites of some diseases within the CNS. Therefore, canine microglial cells in relation to different topographical regions within the healthy CNS were evaluated ex vivo from the brain, cervical, and thoracolumbar spinal cord using density gradient centrifugation and flow cytometry in a homogenous dog population. Immunophenotypical characterization showed physiological regional differences for B7-1, CD14, CD44, CD1c, CD18, CD11b, and CD11c. Read More

Biomaterials 2010 Mar 8;31(8):2323-34. Epub 2009 Dec 8.

Institute of Pharmaceutical Sciences, ETH Zurich, 8093 Zurich, Switzerland.

Artificial nerve conduits (NC) can be used as an alternative to autologous nerve grafts to enhance the repair of small nerve gaps. Current NC lack adequate molecular and structural functionalities. Thus, we developed silk fibroin NC (SF NC) that were loaded with glial cell line-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) and topographically functionalized with aligned and non-aligned SF nanofibers. Read More

Eur J Neurosci 2009 Feb 6;29(4):845-54. Epub 2009 Feb 6.

Laboratory of Neurophysiology, Institute of Neuroscience (INES), Université catholique de Louvain, Brussels, Belgium.

When damaged perinatally, as in congenital hemiplegia (CH), the corticospinal tract usually undergoes an extensive reorganization, such as the stabilization of normally transient projections to the ipsilateral spinal cord. Whether the reorganization of the corticospinal projections occurring in CH patients is also accompanied by a topographical rearrangement of the hand representations in the primary motor cortex (M1) remains unclear. To address this issue, we mapped, for both hands, the representation of the first dorsal interosseous muscle (1DI) in 12 CH patients by using transcranial magnetic stimulation co-registered onto individual three-dimensional magnetic resonance imaging; these maps were compared with those gathered in age-matched controls (n = 11). Read More

Neuroreport 2007 May;18(7):665-8

Department of Neurology, Rakuwakai-Otowa Hospital, Kyoto, Japan.

Using functional MRI and diffusion tensor tractography, we studied the topographical relation of hand and foot fibers of the corticospinal tract within the internal capsule to verify the recent unexpected finding by Holodny et al., who reported that hand fibers are located anterolateral to foot fibers, not anteromedial as is currently believed. The location of hand fibers with respect to foot fibers was anterolateral in four participants, posterolateral in two, and anteromedial in one of seven participants examined. Read More

Exp Brain Res 2007 Jun 31;180(1):113-22. Epub 2007 Jan 31.

INSERM U 455, 31059 Toulouse, France.

It has been shown on hand muscles in normal subjects that paired associative stimulation (PAS) combining peripheral nerve stimulation and transcranial magnetic stimulation (TMS) induces lasting changes in cortical motor excitability (Stefan et al., Brain 123 (Pt3):572-584, 2000). Because the motor recovery of distal upper limb and particularly wrist extension in post-stroke patients is one of the major rehabilitation challenge, we investigate here the effect of one session of paired associative stimulation on the excitability of the corticospinal projection to extensor carpi radialis (ECR) muscle (motor evoked potential size) before and after PAS in 17 healthy subjects and in two patients 5 months after stroke. Read More

Neuroscience 2006 Sep 22;141(4):1983-94. Epub 2006 Jun 22.

Department of Biomedical Engineering, Case Western Reserve University, Wickenden Building, Room 114, 10900 Euclid Avenue, Cleveland, OH 44106-7207, USA.

There exists a spatial organization of receptive fields and a modular organization of the flexion withdrawal reflex system. However, the three dimensional location and organization of interneurons interposed in flexion reflex pathways has not been systematically examined. We determined the anatomical locations of spinal neurons involved in the hindlimb flexion withdrawal reflex using expression of the immediate early gene c-fos and the corresponding FOS protein. Read More

Cell Tissue Res 2003 Jul 27;313(1):71-80. Epub 2003 May 27.

Institute of Anatomy and Cell Biology, Justus Liebig University, Aulweg 123, 35385, Giessen, Germany.

Among recent vertebrates only birds possess a glycogen body (corpus gelatinosum), located in the rhomboidal sinus of the lumbosacral region of the spinal cord and separated from the neural tissue proper. Because of the specific topographical situation of this circumventricular organ, the structure of its vascular system is of special interest with respect to the still unsolved functional problems. The existence of a blood-brain barrier is demonstrated by the exclusion of intravascularly injected tracer (horseradish peroxidase), and immunocytochemical demonstration of glucose transporter-1 as a functional marker and of neurothelin, occludin and ZO-1 as structural markers. Read More

Brain 2002 Nov;125(Pt 11):2567-78

ParaCare, University Hospital Balgrist, Zürich, Switzerland.

Peripheral and central nervous system lesions can induce reorganization within central somatosensory and motor body representations. We report changes in brain activation patterns during movements of non-affected body parts in paraplegic patients with spinal cord injury (SCI). Nine SCI patients and 12 healthy controls underwent blood oxygen level dependent signal functional MRI during sequential finger-to-thumb opposition, flexion and extension of wrist and of elbow, and horizontal movements of the tongue. Read More

J Physiol 2001 May;533(Pt 1):31-40

Department of Physiology, Göteborg University, Box 432, 405 30 Göteborg, Sweden.

This review focuses on the flexibility of operation of spinal interneuronal networks and their multifunctional character in mammals. It concerns, in particular, two ways in which spinal interneuronal networks may be functionally reorganised, namely by modulating the synaptic actions of primary afferents by monoamines and by GABAergic presynaptic inhibition. The evidence will be reviewed for topographical and target-related differences in modulatory effects in various interneuronal networks and these will be related to differences in the intrinsic properties of different functional types of interneurones in these networks and to the role played by them. Read More

Neuroscience 2000 ;101(1):179-88

Department of Physiology, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK.

In the present study c-fos expression has been used as a marker of neuronal activation following noxious stimuli applied to one of three different sites on the forelimb in rats. In three treatment groups (n=4 animals in each group) rats were anaesthetized with barbiturate and a mechanical pinch was applied to either (i) the most medial digit, (ii) the most lateral digit, or (iii) the shoulder area of one forelimb. An additional control group (n=4) received no pinch. Read More

J Neurophysiol 2000 Nov;84(5):2651-7

National Institutes of Health, National Institute of Neurological Disorders and Stroke, Lab of Neural Control, Bethesda, Maryland 20892-4455, USA.

A number of homeodomain transcription factors have been implicated in controlling the differentiation of various types of neurons including spinal motoneurons. Some of these proteins are also expressed in spinal interneurons, but their function is unknown. Progress in understanding the role of transcription factors in interneuronal development has been slow because the synaptic connections of interneurons, which in part define their identity, are difficult to establish. Read More

Brain Res Brain Res Rev 2000 Sep;33(2-3):131-54

IRCCS S Giovanni di Dio, Istituto Sacro Cuore, Brescia, Italy.

The potential for reorganization in the adult brain has been largely underestimated in the past and we are just beginning to understand the organisational principles involved in functional recovery. A bulk of experimental evidences have been accumulated in support of the hypothesis that neuronal aggregates adjacent to a lesion in the cortical brain areas can be progressively vicarious to the function of the damaged neurones. Such a reorganisation, if occurring in the affected hemisphere of a patient with a monohemispheric lesion, should significantly modify the interhemispheric symmetry of somatotopic organisation of the sensorimotor cortices, both in terms of absolute surfaces and number of "recruited" neurons, as well as of spatial coordinates. Read More