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'Spinal Cord Topographical and Functional Anatomy' (46)


Dec
2015

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.

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Jan
2016

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.

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Jun
2015

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.

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Jan
2015

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.

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Aug
2014

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.

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Oct
2013

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.

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Aug
2013

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.
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).

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Dec
1969

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.

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Dec
2012

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.

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Sep
2012

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.
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.

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Oct
2010

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.

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Mar
2010

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.

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Feb
2009

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).

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May
2007

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.

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Jun
2007

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.

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Sep
2006

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.

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Jul
2003

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.

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Nov
2002

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.

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May
2001

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.

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Dec
1969

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.

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Nov
2000

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.

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Sep
2000

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.

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Feb
2000

The neuromotor pattern (i.e. the onset/offset of muscle contraction within the locomotor cycle) is conserved for some homologous muscles of the tetrapod shoulder but not others in the transition from terrestrial locomotion to flight.

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Jul
1999

To better understand the functional role of EphA5 in the adult human central nervous system (CNS), we performed an immunohistochemical mapping study. EphA5, like other members of the Elk/Eph family of receptor tyrosine kinases, was widely distributed in CNS neurons. However, the distribution of the neuronal staining was not uniform.

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Oct
1998

The aim of the present study was to establish whether gracile afferents to the inferior olive are topographically organized and whether such inputs coincide with the location of cells that output to the hindlimb C1 zone in the cerebellar posterior lobe. Small injections (n=15) of the anterograde tracers Fluoro-Ruby or biotinylated dextran amine were made into gracile, resulting in anterograde labelling often distributed in partially separate, rostrocaudally directed columns within the lateral half of the contralateral rostral dorsal accessory olive (rDAO). In 12 cases, anterograde labelling was also located within the caudolateral medial accessory olive.

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Mar
1997

Glycinergic synapses play a major role in shaping the activity of spinal cord neurons. The spatial organization of postsynaptic receptors is likely to determine many functional parameters at these synapses and is probably related to the integrative capabilities of different neurons. In the present study, we have investigated the organization of gephyrin expression along the dendritic membranes of alpha- and gamma-motoneurons, Ia inhibitory interneurons, and Renshaw cells.

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Apr
1996

Transient topographical amnesia (TTA) is the temporary inability to find one's way in familiar or unfamiliar surroundings due to the inability to use well known environmental landmarks for route finding. The syndrome has not been described as having any obvious aetiology and has been thought to be caused by a vascular deficit in right hemispheric structures which are crucial for topographic recognition, i.e.

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Feb
1996

With the anterograde tracers Phaseolus vulgaris-leucoagglutinin (PHA-L) and biotinylated dextranamine (BD), direct spinal connections from the upper cervical spinal cord (UC; C1 and C2) and the cervical enlargement (CE; C5-T1) were demonstrated in various striatal and limbic nuclei in both squirrel monkey and rat. Within each species and from each spinal level, the total number of terminals seen in the limbic and striatal areas was approximately 50-80% of the number seen within the thalamus. Labeled terminal structures were seen in the hypothalamic nuclei, ventral striatum, globus pallidus, amygdala, preoptic area, and septal nuclei.

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Jul
1995

Although the cerebrospinal fluid-contacting neurons of the avian paraventricular organ exhibit considerable amounts of catecholamines, they show no tyrosine hydroxylase immunoreactivity. In the quail embryo, the development of these neurons has been studied using the paraformaldeyde-glutaraldeyde method for the fluorescence-histochemical localization of catecholamines. The timing of the appearance of catecholamine fluorescence in cerebrospinal fluid-contacting neurons and that in catecholamine-containing neurons of the brainstem have been compared.

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Dec
1969

Animals studies have shown that peripheral nerve lesions can induce secondary changes in the dorsal horn of the spinal cord. Histological changes include degeneration of both primary afferent terminals (transganglionic degeneration) and second order neurones (transsynaptic degeneration). Secondary regeneration phenomena associated with changes in the topographical organization of central terminals of primary afferents have also been described.

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Dec
1969

The postnatal appearance of diaminobenzidine (DAB)-staining glial cells was studied in certain regions of the rat central nervous system. DAB-positive cells appeared in the hypothalamus, the nucleus of the solitary tract and the most superficial laminae of the spinal dorsal horn on the 7th, 8th and 14th postnatal day, respectively. The number and staining intensity of these DAB-positive cells progressively increased and reached the adult levels at the end of the third postnatal week.

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Dec
1969

Multi-unit spike triggered averaging was used to determine functional connectivity between spindle afferent fibers from the medial gastrocnemius muscle and the motoneurons innervating the medial (homonymous connections) and the lateral gastrocnemius-soleus muscle (heteronymous connections). As many as 288 possible connections between 24 motoneurons and 12 afferent fibers were studied in single, acute experiments. The influences of morphological and topographical factors, as well as of motoneuron species on functional connectivity were analysed.

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Dec
1969

A sub/supraependymal system of varicose axons in the tectal midline ridge formation of shark brains is described. Lengths of axons and their terminals are seen freestanding in the cerebrospinal fluid (CSF) as well as in close contiguity with the large CSF-contacting and supraependymal mesencephalic trigeminal neurons of the midline ridge formation. The relationship of axonal varicosities and terminals to both CSF and supraependymal somata is such as to suggest a nonsynaptic association.

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Oct
1987

The lumbar sympathetic outflow projects through the lumbar splanchnic, lumbar colonic, and hypogastric nerves (and to a lesser degree through the sacral sympathetic chain and pelvic nerves). It is thought to be involved in the regulation of the storage and evacuation functions of the following three organ systems: lower urinary tract, hindgut, and reproductive organs. In addition, it controls vascular resistance and capacitance.

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Dec
1969

The authors report a series of 53 bedridden patients having harmful spasticity in one (6) or both (47) lower limb(s) and treated with selective posterior rhizotomy (SPR) in the dorsal root entry zone (DREZ). This severe spasticity was associated with irreducible flexion contracture in 49 cases and hyperextension in 3 others. 37 of these patients also had painful manifestations.

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Dec
1985

The types of layer III neurons in cat primary auditory cortex (AI) projecting to the contralateral AI were studied with horseradish peroxidase or horseradish peroxidase conjugated to wheat germ agglutinin. Injections between the anterior and posterior ectosylvian sulci retrogradely labeled both pyramidal and non-pyramidal somata in contralateral cortical layers III, V, and VI in AI, and in the ventral nucleus of the ipsilateral medial geniculate body. Three-quarters (72%) of the retrogradely labeled cells were found in layer III and one-quarter (28%) lay in layers V and VI.

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May
1985

In the guinea pig, horseradish peroxidase (HRP) was injected in the cervical or lumbar enlargements of the spinal cord in order to examine the origin and topographical organization of corticospinal (CS) neurons. The cortex was divided into granular and agranular regions to attempt correlations with the location of labeled CS neurons. These, of all sizes, are found only in pyramidal layer V of both kinds of cortical regions and could be seen as single, grouped or organized in clusters of 3-5 or more cells.

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Jan
1985

A greatly expanded version of spike-triggered averaging (Mendell & Henneman, 1971), performed off-line on tape-recorded signals, was utilized to determine the presence or absence of functional connexions between stretch-afferent fibres and homonymous motoneurones. As many as 264 possible connexions between eleven Ia or spindle group II fibres and twenty-four motoneurones were studied in each single, acute experiment. Morphological and topographical factors influencing functional connectivity were analysed with the aid of wiring diagrams and connectivity matrices.

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Nov
1984

Extracellular field potentials in the lumbosacral dorsal horn evoked by stimulation of cutaneous C fibres in the sural nerve were explored in the halothane-anaesthetized rat. C-fibre-evoked field potentials were prominent in lamina II and lamina V of the dorsal horn. These potentials had a latency of 80-130 ms and a duration of more than 200 ms.

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Aug
1983

The sites of termination of the primate spinothalamic tract have been reinvestigated using the anterograde transport of wheatgerm agglutinin conjugated to horseradish peroxidase. Monkeys which received an injection of the conjugate at the spinal cervical level (C7-C8) displayed a "patchy" pattern of labelling in the coronal plane in the ventral posterior lateral and caudal ventrolateral nucleus. In three dimensional reconstructions this labelling appeared to be rod-like in shape.

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Jun
1982

Degeneration methods were used to study the dorsal root and descending projections after chronic partial denervation of adult cat spinal cord. Conventional mapping methods were used, supplemented in some cases by densitometric measurements of the amounts of degeneration present. The amount of shrinkage of spinal gray matter in some sections was estimated by planimetric measurement.

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Dec
1981

Pathways taken by motoneuron axons from the lumbosacral lateral motor column to individual hindlimb muscles have been characterized throughout the normal period of outgrowth and the establishment of specific functional connections in the chick embryo. Axon pathways from individual cord segments were identified after injections of horseradish peroxidase (HRP) directly into the cord. Labelled motoneuron axons were then traced through the plexus and major nerve trunks to termination sites within the limb.

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May
1980

1. The development of motoneurone projection patterns in the chick hind limb from reversed spinal cord segments was studied from the onset of axonal outgrowth (St. 24) to the establishment of mature connectivity patterns (St.

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Jul
1979

The somatotopical organization of the projection through the dorsal spino-olivocerebellar path (DF-SOCP) to the c3 zone in the cerebellar anterior lobe was studied by recording climbing fiber field potentials in the cerebellar cortex evoked on stimulation of peripheral nerves. The c3 zone was shown to contain a detailed and systematic representation of the ipsilateral body half with the follwing characteristics: 1. Single nerves project to one or two sagittal strips of cortex which extend across several folia.

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Jul
1979

There is fairly plentiful old and recemt literature on the dorsal nucleus (Clarke's nucleus), but the research reported is mainly in animals. The present study covers human material (9 spinal cords), considered mostly from the morphological-topographical aspects. In man, Clarke's column is not perfectly symmetrical, is "clublike" in shape, and reaches from the eighth cervical to the second lumbar segment.

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