SEARCH · Search PubMed

Results for “Red Nucleus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

PubMed1995

Connections to cerebellar cortex (Larsell's HVI) in the rabbit: a WGA-HRP study with implications for classical eyeblink conditioning.

Conditioned eyeblink responses are presumably learned in the cerebellum and relayed to motoneurons by way of the red nucleus. Projections from the red nucleus to cerebellar cortex (Larsell's lobule HVI) could be important for shaping temporally adaptive features of the conditioned response. Rabbits that had pipettes containing wheat germ agglutinated horseradish peroxidase (WGA-HRP) implanted unilaterally into HVI showed retrograde labeling of neurons within subregions of the contralateral red nucleus implicated in eyeblink conditioning by lesioning and recording studies. Retrogradely labeled neurons were also observed in the pontine nuclei, inferior olive, and spinal trigeminal nucleus pars oralis. Projections to HVI provide a possible neural substrate for implementing time-derivative computational models of learning in the cerebellum. Time-derivative models are capable of describing the timing and topography of conditioned responses.

Animals↗

PubMed1993

Anatomy of the turtle cerebellorubral circuit studied in vitro using neurobiotin and biocytin.

We have combined the rapid anterograde and retrograde transport of neurobiotin and biocytin with the extended viability of the isolated turtle brainstem-cerebellum to conduct in vitro studies of the chelonian cerebellorubral circuit. Tracers were pressure injected in 15-25 nl quantities and the optimal transport time was 16 h. Tissue sections were incubated with avidin-biotin-HRP complex and reacted with DAB. Retrogradely labeled soma, dendrites and axons, and anterogradely labeled axons and to a lesser extent terminals were visible with both tracers. Red nucleus injections resulted in dense retrograde label in the contralateral lateral cerebellar nucleus and a heavily labeled contralateral rubrospinal tract. Cerebellar nucleus injections revealed light retrograde and dense terminal label in the contralateral red nucleus, together with retrograde label in a cell cluster in the ipsilateral ventrolateral medullary reticular formation, an area we identify as the lateral reticular nucleus. Injections into this medullary region resulted in heavy mossy fiber input to the ipsilateral cerebellum and moderate retrograde label in the contralateral red nucleus. These results identify prominent recurrent projections between the lateral cerebellar nucleus, red nucleus and lateral reticular nucleus, in addition to revealing other features of the cerebellorubral circuit.

Animals↗

PubMed1975

Degenerative processes after punctate intracerebral administration of 6-hydroxydopamine.

Various doses of the neurotoxin 6-hydroxydopamine (6-OHDA) were infused into the substantia nigra-ventromedial tegmental area, caudateputamen nucleus, and red nucleus. A maximum of four successively occurring zones of neuropathology could by detected at all injection sites: (1) A zone of complete absence of neural, glial, and vascular elements due to tissue displacement by the cannula, (2) an area of glial cells, developing over time, which surrounded the cannula tract, (3) a region exhibiting virtually complete loss of neuronal elements, and (4) a zone of selective neuropathological reaction or cellular loss in which some neurons were affected and others were not. All investigators who have histochemically and/or histologically evaluated the effects of intracerebrally administered 6-OHDA agree on the existence and genesis, some non-selective process, of the first three zones. Although some scientists maintain that the fourth zone is where 6-OHDA operates selectively, data are presented in this report that other, well-established processes can account for neuropathology beyond zone 3. Prominent among these are retrograde and anterograde degeneration, ischemia as a function of interruption of blood supply, and nonselective traumatization. In addition, the topography of the injected site (e.g., morphology of affected neurons, degree of myelination) was found to be as important a determinant of the locus of tissue damage as the presumed selectivity of 6-OHDA's action. Furthermore, monoamine oxidase inhibition by nialamide did not appear to increase the neurotoxicity of 6-OHDA. Similarly, 1-(2,5-dihydroxy-4-methylphenyl)-2-aminopropane was not a more potent cytotoxin than 6-OHDA even though this new neurotoxin has a propane side chain which renders it immune to monoamine oxidase. These observations, taken together, suggest that considerable cautioon should be exercised in interpreting data from experiments in which 6-OHDA, or related neurotoxins, are used to uncover catecholaminergic mechanisms of behavior and other functional processes.

Acetylcholinesterase↗

PubMed1999

Can secondary degeneration accelerate the formation of neurofibrillary tangles? A case of hemispheric infarction showing asymmetric degeneration of the substantia nigra, red nuclei, inferior olivary nuclei and dentate nuclei with concomitant changes of progressive supranuclear palsy.

A case of hemispheric infarction involving the territory of the right middle cerebral artery and the thalamus showed conspicuous asymmetric degeneration in the substantia nigra, red nuclei, inferior olivary nuclei and dentate nuclei with concomitant changes of progressive supranuclear palsy (PSP). The right substantia nigra and red nucleus showed loss of neurons and proliferation of astrocytes. The right olivary nucleus was hypertrophic, while the neuronal loss and astrocytosis in the dentate nucleus were predominant on the contralateral side. Modified Gallyas-Braak staining revealed the extensive distribution of neurofibrillary tangles (NFTs), threads and intraglial argyrophilic structures in the globus pallidus, subthalamic nuclei, cerebral cortex and dentate nuclei, as well as in the affected brain stem nuclei, with a distinct predominance on the affected side. In this case, the one-sided predominance of the extended degeneration in these brain stem and cerebellar areas is considered, in addition to the PSP changes, to be due to secondary retrograde degeneration via the nigrostriatal and dentato-rubro-thalamic pathways following the hemispheric infarction, and to also be the result of disruption of the dentato-olivary fiber connections. In addition, because of the predominant distribution of NFTs on the more degenerated side, it is surmised that the formation of NFTs may be accelerated by secondary degeneration.

Aged↗

PubMed2002

Fluoxetine-induced tremor: clinical features in 21 patients.

We report a cohort of 21 patients (12 females and nine males), with a mean age of 42.4 years, who developed tremor after receiving fluoxetine at a mean dose of 25.7 mg per day. The mean latency period for tremor appearance was 54.3 days. Severity was found to be mild. In all patients, tremor was postural, with P<0.0005, compared to patients with rest tremor and P<0.05 compared to action/intention-tremor patients. The frequency range was 6-12 Hz/s. After fluoxetine was discontinued, tremor disappeared in 10 patients after a mean latency period of 35.5 days. In the remaining 11 patients, tremor persisted up to the end of the observation period (a mean of 449 days). We believe that this tremor phenomenon is due to the involvement of the red nucleus and the inferior olivary nucleus through their projections to the thalamus and the spinal cord.

Adult↗

PubMed1984

Topographic specificity of aberrant cerebellorubral projections following neonatal hemicerebellectomy in the rat.

Anterograde transport of horseradish peroxidase-wheat germ agglutinin (HRP-WGA) was used to examine the topographic specificity of ascending cerebellar efferent projections in adult rats which were hemicerebellectomized at birth. The results were compared to similar cerebellar projections in unlesioned adults. HRP-WGA placement in the nucleus interpositus of control rats resulted in a dense projection of labeled fibers which decussated in the midbrain, caudal to the red nucleus. In the red nucleus, dense terminal labeling was confined to the magnocellular region, while retrogradely labeled rubrocerebellar neurons were present throughout both parvo- and magnocellular areas. Similar HRP-WGA placements in the nucleus lateralis gave rise to fewer labeled fibers which terminated in the parvocellular red nucleus. In addition to the cerebellorubral projection, other areas of terminal labeling included the mid-brain reticular formation, nucleus parafascicularis prerubralis, zona incerta, fields of Forel and ventral thalamus. In neonatally lesioned adults, aberrant cerebellorubral and cerebellothalamic projections were observed deflecting ipsilaterally at the decussation of the normal contralateral projection. Topographic specificity of the aberrant ipsilateral cerebellorubral projection mirrored that of the normal contralateral fibers. In addition, an ipsilateral projection from the cerebellum could be followed rostral to the red nucleus, to terminate in the ipsilateral ventral thalamus. Lesioned animals also demonstrated marked cell loss in the red nucleus contralateral to the hemicerebellectomy.

Animals↗

PubMed2000

The role of some brain structures in the switching of the descending influences in operantly conditioned rats.

A hypothesis was proposed according to which the switching of descending influences by the corticospinal and corticorubrospinal systems was associated with rubro-olivary projection involvement depending on the context of movement [Kennedy P. R. (1990) Trends Neurosci. 13, 474-479]. Our results confirmed and extended this hypothesis. It was shown that a preliminary transection of the dorsolateral funiculus (containing the rubrospinal tract) accelerated the compensatory rehabilitation process following lesions of the red nucleus and the ventrolateral thalamic nucleus in albino rats with learned instrumental reflexes on equilibrium. A preliminary lesion of the ventrolateral thalamic nucleus considerably hampered the switching process; nevertheless, performance of the reflexes suggested that the switching of cerebellar ascending influences to the cerebral cortex could be completed through other cerebellocortical pathways as well. Comparison of the results of electrolytic and chemical lesions of the red nucleus suggested a similar conclusion. It was established that the conditioning and recovery of already learned instrumental reflexes were impossible after complete neurotoxic destruction of the inferior olive. The data obtained emphasize the role of the inferior olive, ventrolateral thalamic nucleus and red nucleus in the switching of descending influences in operantly motor conditioned rats. Motor deficit and the compensatory rehabilitation process depended on the severity of inferior olive destruction combined with a high transection of the dorsolateral funiculus and a destroyed red nucleus. Long-lasting training improved compensation of motor deficit and stabilized instrumental reflexes to some extent in rats with incomplete destruction of the inferior olive. It has been suggested that these modifications occur because of collateral sprouting in the olivocerebellar system.

Animals↗

PubMed1988

[Rubro-caudate projections in the cat].

A few neurons projecting to the caudate nucleus were found in the cat red nucleus by the horse-radish peroxidase (HRP) method. Rubro-caudate neurons were observed both in the magnocellular and parvocellular parts of the red nucleus. Organization of the reciprocal connections of red nucleus and striopallidal system is discussed.

Animals↗

PubMed1994

Distribution of manganese-dependent superoxide dismutase in the human brain.

The distribution of manganese-dependent superoxide dismutase, an enzyme that transforms superoxide radicals into hydrogen peroxide, was studied in the human brain post mortem using a sheep polyclonal antiserum raised against the enzyme from liver mitochondria. One band, corresponding to a protein of 22,000 mol. wt was detected in the human brain by western blot analysis. At the light-microscopy level, a punctate immunostaining was observed in the neuropil and in some but not all, glial and neuronal cell bodies. Electron-microscopy revealed that the staining was exclusively confined to the inner mitochondrial membrane. A heterogeneous distribution of manganese-dependent superoxide dismutase was observed in the human brain. In the forebrain, numerous immunostained neurons were detected in the striatum, thalamus, pallidal complex and the nucleus basalis of Meynert. In the cerebellum, only granular and Purkinje cells were immunostained. Various nuclei from the brainstem displayed superoxide dismutase immunoreactivity, including the cranial nerve nuclei, the nucleus supratrochlearis, the red nucleus, the substantia nigra, the nucleus cuneiformis and subcuneiformis, the nucleus parabigeminal, the nucleus centralis superior, the nucleus supraspinalis, the nucleus of the medullae oblongata and the gigantocellularis nucleus. Large pyramidal neurons containing superoxide dismutase were detected in the CA subsectors, the hilus of the hippocampus and the cerebral cortex. Smaller immunostained neurons were also observed in layers I, IV and VI of all cortical regions studied. The distribution of immunostained glial cells was more limited, and restricted to the internal and external capsules, the hypothalamus, the red nucleus, the pyramidal white matter and surrounding areas, the cerebral cortex and the sub-ependymal layer, the alveus and the stratum oriens of the hippocampus. This heterogeneous but not ubiquitous distribution of cells expressing manganese-dependent superoxide dismutase suggests that not all cells in the human brain are protected to the same extent against the deleterious effects of superoxide.

Aged↗

PubMed2004

Properties of primary motor cortex output to forelimb muscles in rhesus macaques.

Stimulus-triggered averaging (StTA) of electromyographic (EMG) activity from 24 simultaneously recorded forelimb muscles was used to investigate properties of primary motor cortex (M1) output in the macaque monkey. Two monkeys were trained to perform a reach-to-grasp task requiring multijoint coordination of the forelimb. EMG activity was recorded from 24 forelimb muscles including 5 shoulder, 7 elbow, 5 wrist, 5 digit, and 2 intrinsic hand muscles. Microstimulation (15 microA at 15 Hz) was delivered throughout the movement task. From 297 stimulation sites in M1, a total of 2,079 poststimulus effects (PStE) were obtained including 1,398 poststimulus facilitation (PStF) effects and 681 poststimulus suppression (PStS) effects. Of the PStF effects, 60% were in distal and 40% in proximal muscles; 43% were of extensors and 47% flexors. For PStS, the corresponding numbers were 55 and 45% and 36 and 55%, respectively. M1 output effects showed extensive cofacilitation of proximal and distal muscles (96 sites, 42%) including 47 sites that facilitated at least one shoulder, elbow, and distal muscle, 45 sites that facilitated an elbow muscle and a distal muscle, and 22 sites that facilitated at least one muscle at all joints. The muscle synergies represented by outputs from these sites may serve an important role in the production of coordinated, multijoint movements. M1 output effects showed many similarities with red nucleus output although red nucleus effects were generally weaker and showed a strong bias toward facilitation of extensor muscles and a greater tendency to facilitate synergies involving muscles at noncontiguous joints.

Animals↗

PubMed1993

The dentatorubral projection in the rabbit with emphasis on distinction from the interpositorubral connectivity: an HRP retrograde tracer study.

The projection from the lateral (dentate) cerebellar nucleus (NL) to the red nucleus in the rabbit was investigated using free horseradish peroxidase (HRP). Following injections of this tracer into the red nucleus (RN), the distribution patterns of retrogradely labeled cells were checked in the NL. The projection from the NL was found to extend rostrocaudally throughout the contralateral RN except for the predominant part of the rostral one-quarter and the caudalmost part of the RN, i.e. the regions described to receive projections exclusively from the interpositus nuclear complex (NI). On the other hand, the only region of the RN receiving projection exclusively from the NL appeared to be rostralmost parvocellular region of the RN (RN-PA). This study suggested that, in contrast to other species, the projection from the NL is not confined to the most rostrally localized RN-PA but is distributed throughout predominant part of the nucleus and to a great extent overlapped with projection from the NI. This overlapping projection pattern parallels the absence of clear differentiation between parvo- and magnocellular parts of the rabbit RN.

Afferent Pathways↗

PubMed1987

Experimental hemiplegia in the monkey: basal ganglia glucose activity during recovery.

Unilateral ablation of cerebral cortical areas 4 and 6 of Brodmann in the macaque monkey results in a dense contralateral hemiplegia that recovers partially with time. During the phase of dense hemiplegia, the local cerebral metabolic rate for glucose (lCMRGlc) is decreased significantly in the caudate nucleus, putamen, globus pallidus, subthalamic nucleus, substantia nigra, and red nucleus of the hemisphere ipsilateral to the lesion. In the present study, lCMRGlc in the basal ganglia was studied during the phase of partial recovery of motor activity. lCMRGlc was partially restored, and the greatest degree of restoration occurred in structures with direct connections to the cerebral cortex (caudate nucleus, putamen, subthalamic nucleus, substantia nigra, and red nucleus). Restoration was least in structures that do not receive direct connections from the cerebral cortex (the internal and external segments of the globus pallidus). The findings support the hypothesis that corticofugal activity accounts for a substantial degree of functional recovery.

Animals↗

PubMed1983

[Experimental tremor induced by VMT lesion in monkeys--neuroanatomical study].

Ventromedial portion of the mesencephalic tegmentum in a monkey is known as one of the major target to produce experimental tremor. By Ohye's method, we made lesions at the above mentioned target in 18 monkeys. Out of them, 5 showed hemiparesis and cubital joint flexion on the contralateral side which are known as precursors of experimental tremor of this kind. In these 5 monkeys, we made neuroanatomical studies on various relating nuclei and neural pathways by Nissl and silver impregnation methods. Results are as follows: 1. The lesion involved at the parvocellular part of red nucleus and the area located ventromedial to the red nucleus. 2. Silver impregnation revealed degenerated nerve fibers and terminals in the ipsilateral globus pallidus, putamen, nucleus olivaris inferior (major accessorius medialis), thalamus (VA, VPL, Cn. Md, Pcn, Cl major VL, X, VI) and bilateral substantia nigra. In conclusion, blocking of projecting fibers to VI, VL and X seems to elicit an experimental tremor.

Animals↗

PubMed1979

An autoradiographic study of the rubroolivary tract in the rhesus monkey.

Autoradiographic tracing methods were employed to study the course and distribution of the rubroolivary tract following unilateral injections of tritiated leucine into the rostral red nucleus of seven rhesus monkeys. A topographic organization of projections to the ipsilateral principal nucleus of the inferior olivary complex was demonstrated. Lateral and medial portions of the rostral red nucleus projected to medial parts of the dorsal and ventral laminae of the principal inferior olive respectively; neurons in intermediate lateralities emitted fibers which terminated in lateral parts of the principal olive. Injections involving the oral end of the rostral red nucleus elicited label overlying the medial accessory olive in addition to the principal nucleus. Projections to the medial accessory olive may have arisen from the rostral end of the red nucleus and/or the immediately adjacent tegmentum. There were no projections to the dorsal accessory olive. Fibers of rubral origin also were distributed ipsilaterally to several reticular nuclei including the pedunculopontine, pontis oralis, caudalis, and gigantocellularis.

Animals↗

PubMed1984

Mesencephalic projections to the facial nucleus in the cat. An autoradiographical tracing study.

In 33 cats the projections of different parts of the mesencephalon to the facial nucleus were studied with the aid of the autoradiographical tracing method. The results indicate the existence of many different mesencephalo-facial pathways. The dorsomedial facial subnucleus, containing motoneurons innervating ear muscles, receives afferents from 4 different mesencephalic areas: a, the most rostral mesencephalic reticular formation; b, the nucleus of Darkschewitsch and/or the ventral part of the rostral PAG; c, the interstitial nucleus of Cajal and/or the mesencephalic tegmentum dorsomedial to the red nucleus. These areas project bilaterally by way of an ipsilateral medial tegmental pathway. The medial part of the deep tectum. This area projects bilaterally by way of the tecto-spinal tract. The lateral mesencephalic tegmentum close to the parabigeminal nucleus. This area projects mainly contralaterally by way of a separate contralateral lateral tegmental fiber bundle. The mesencephalic tegmentum just dorsolateral to the red nucleus and perhaps from the dorsolateral red nucleus itself. This area projects contralaterally by way of the rubrospinal tract. The intermediate facial subnucleus containing motoneurons innervating the muscle around the eye, receives afferents from two different mesencephalic areas: The dorsal part of the rostral as well as caudal red nucleus (but not from its caudal pole) and from the dorsally adjoining mesencephalic tegmentum including the area of the nucleus of Darkschewitsch and the interstitial nucleus of Cajal. These areas project contralaterally by way of the contralateral rubrospinal tract. The nucleus of the optic tract and/or the olivary pretectal nucleus. This area projects contralaterally by way of a contralateral medial tegmental pathway. The lateral and ventrolateral facial subnuclei containing motoneurons innervating the muscles around the mouth receive afferents from two different mesencephalic areas: The lateral part of the deep tectal layers. This area projects contralaterally by way of the tecto-spinal tract. The nucleus raphe dorsalis and perhaps the nucleus centralis superior. This area projects by way of the lateral tegmentum of caudal pons and medulla.

Animals↗

PubMed2002

Grafts of BDNF-producing fibroblasts rescue axotomized rubrospinal neurons and prevent their atrophy.

We have reported that intraspinal transplants of fibroblasts genetically modified to express brain-derived neurotrophic factor (BDNF) promote rubrospinal axon regeneration and functional recovery following subtotal cervical hemisection that completely ablated the rubrospinal tract. In the present study we examined whether these transplants could prevent cell loss and/or atrophy of axotomized Red nucleus neurons. Adult rats received a subtotal spinal cord cervical hemisection followed by a graft of unmodified fibroblasts or fibroblasts producing BDNF into the lesion cavity. One or 2 months later, fluorogold was injected several segments caudal to the lesion-transplant site to retrogradely label those Red nucleus neurons whose axons have regenerated. Unmodified fibroblasts failed to protect against either cell loss or atrophy. Neuron counts and soma-size measurements in Nissl-stained preparations showed a 45% loss of recognizable neurons and 40% atrophy of the surviving neurons in the injured Red nucleus. Grafts of BDNF-producing fibroblasts reduced neuron loss to less than 15% and surviving neurons showed only a 20% decrease in mean soma size. Soma size analysis of fluorogold-labeled Red nucleus neurons indicated that the Red nucleus neurons whose axons regenerated caudal to the graft did not atrophy. We conclude that fibroblasts engineered ex vivo to secrete BDNF and grafted into a partial cervical hemisection promote axon regeneration while reducing cell loss and atrophy of neurons in the Red nucleus. These results suggest that transplants of genetically engineered cells could be an important tool for delivery of therapeutic factors that contribute to the repair of spinal cord injury.

Animals↗

PubMed1993

Distribution of rubrospinal synaptic input to cat triceps surae motoneurons.

1. We evoked steady-state synaptic potentials in triceps surae motoneurons of the cat by stimulating the hindlimb projection area of the contralateral magnocellular red nucleus at 200 Hz. We measured the effective synaptic currents (IN) underlying the synaptic potentials using a modified voltage-clamp technique. We also determined the effect of the rubrospinal input on the discharge rate of some of the motoneurons by inducing repetitive discharge with long injected current pulses during which the red nucleus stimulation was repeated. 2. At motoneuron resting potential, the distribution of IN from the red nucleus within the triceps surae pools was qualitatively similar to the distribution of synaptic potentials: 86% of the putative type F motoneurons received a net depolarizing IN from the red nucleus stimulation, whereas only 38% of the putative type S units did so. The mean values of IN were significantly different in the two groups [+4.1 +/- 5.0 nA (SD) for putative type F and -1.6 +/- 3.1 nA for putative type S]. 3. However, when the values of IN at threshold for repetitive firing were estimated, the distribution of IN from the red nucleus was quite different. At threshold, all of the putative type S units received hyperpolarizing IN but so did nearly half of the putative type F units. 4. As would be expected from the wide range of IN at threshold (-20 to +12 nA), the red nucleus input produced dramatically different effects on the discharge of different motoneurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

PubMed2004

Effect of region of interest on interobserver variance in apparent diffusion coefficient measures.

BACKGROUND AND PURPOSE: Apparent diffusion coefficient (ADC) values derived from diffusion-weighted MR imaging are useful measurements for assessment of cellular alterations in pathologic conditions of the brain. In this study, two radiologists independently quantitated ADCs and region-of interest sizes in prespecified locations of human brain to test interobserver ADC variance and the effect of varying ROI sizes on ADC differences. METHODS: Twenty-seven patients with normal MR findings underwent diffusion-weighted imaging (b value = 1000 s/mm(2)) on a 1.5-T system. Two radiologists independently placed two ROI areas of 22 +/- 5 mm(2) and 62 +/- 6 mm(2) (former area inside the latter area) at different sites of the brain (centrum semiovale, frontal white matter, nucleus caudatus, putamen, thalamus, substantia nigra, red nucleus, and pons) from trace images. Differences in ADC measurement obtained from each region of the brain for each radiologist and the size of each ROI were compared statistically. RESULTS: Mean ADC of prespecified areas of brain ranged between 0.673 and 0.818 mm(2)/s x10(-3). Interobserver variance was significant in some of the specified areas (centrum semiovale, frontal white matter, pons, substantia nigra, and red nucleus). Varying ROI sizes at the pons, substantia nigra, and red nucleus yielded statistically different ADC values. CONCLUSION: ADC values are found to be unreliable for use in assessing brain disease in some specified areas of the brain owing to interobserver variance and different ROI sizes.

Adolescent↗