Red nucleus

The preparations, stained according to the Nissl and Klüver-Barrera methods, were used to describe the topography and morphology of the red nucleus (RN) as well as the structure of the rubral perikarya in newborn (P0) guinea pigs. The Golgi impregnated preparations were used to distinguish types of neurons. RN is a uniform cell group and has the length from 740 to 860 microm. The Nissl stained perikarya were classified into three categories: big, medium-sized and small (A, B, C, respectively). The big perikarya, which contain a lot of tigroidal substance, were mainly observed at the caudal and ventral portions of RN. The small perikarya often have multiple nucleoli. The impregnated neurons were classified into 5 types: 1--large, aspiny, rich-arborised multipolar cells, 2--large and medium sized, spiny, rich-arborised fusiform or pear-shaped cells, 3--medium-sized, spiny, rich-arborised rounded cells, 4--medium-sized, spiny, rich-arborised bipolar cells, 5--small and single medium-si...

Object The localization of any given target in the brain has become a challenging issue because of the increased use of deep brain stimulation to treat Parkinson disease, dystonia, and nonmotor diseases (for example, Tourette syndrome, obsessive compulsive disorders, and depression). The aim of this study was to develop an automated method of adapting an atlas of the human basal ganglia to the brains of individual patients. Methods Magnetic resonance images of the brain specimen were obtained before extraction from the skull and histological processing. Adaptation of the atlas to individual patient anatomy was performed by reshaping the atlas MR images to the images obtained in the individual patient using a hierarchical registration applied to a region of interest centered on the basal ganglia, and then applying the reshaping matrix to the atlas surfaces. Results Results were evaluated by direct visual inspection of the structures visible on MR images and atlas anatomy, by comparis...

The electrical activity of single units located in the parvicellular part of the red nucleus (pRP) was recorded extracellularly in nitrous oxide anesthetized and C1-transected adult cats. In this area, neurons were found to respond to electrical stimulation applied to intermediate and deep layers of the right superior colliculus (SC). Forty neurons located in the pRN of both sides were studied. Three neurons out of 18 (16.6%) located in the contralateral pRN and six neurons out of 22 (27.3%) located in the ipsilateral pRN were driven by the right SC stimulation. The pRN neurons were separated into four groups according to the latency response to the SC stimulation: 1) 0.6-1.9 ms, 2) 2-4 ms, 3) 4-6 ms, 4) variable latency responses. Each of these four groups of neurons showed a particular pattern of discharge, even though their discharge frequency showed a strong consistency. Four pRN neurons, which responded to SC stimulation, showed a significant correlation with spontaneous horizo...

Introduction. Aqueductus mesencephali is the biggest part of the ventricular system and that is why it is the most common place of intraventricular obstruction of cerebrospinal fluid. This study was done in order to study topographic characteristics of aqueduct more thoroughly. Materials and methods. Transversal sections of mesencephalon were made in three levels. The first section was made caudally immediately from the posterior commissure. The second section was made in the middle part of the superior colliculi, and the third section was made in the rostral parts of the caudal sections of the superior colliculi. Distances of the aqueduct from structures of mesencephalon, obtained on the second section, are: 1. The distance of the aqueduct from the superior colliculi - 6.96 mm; 2. The distance of the aqueduct from the red nucleus - 6.02 mm; 3. The distance of the aqueduct from the substantia nigra - 12.29 mm; 4. The distance of the aqueduct from the interpeduncular fossa - 10.22 mm...

Neurotransmitter abnormalities in the basal ganglia of individual "choreic" patients (9 cases of Huntington's disease-HD and 3 cases of dentatorubropallidoluysian atrophy-DRPLA) and 14 normal controls were investigated. Choline acetyltransferase activity in the striatum was decreased in approximately half the "choreic" patients. GABA concentration in the substantia nigra or in the globus pallidus was decreased in all "choreic" cases except one case of DRPLA. Substance P concentration was also reduced in the same nuclei as GABA except in one case of HD. These findings imply: cholinergic, GABAergic or substance P-related markers found in the basal ganglia of HD are not disease-specific but also found in the other "choreic" disorder, i.e. DRPLA; most prominent biochemical changes in HD would be a decrease of GABA in the basal ganglia. Correlation analysis of the markers in the basal ganglia and the striatal neurone densities of "choreic" patients (5 cases of HD and 3 cases of DRPLA) and 7 normal controls yielded positive correlation between GABA concentration in the substantia nigra and the globus pallidus, and the neuronal cell density in "small" cells in the striatum of normal control and HD. Positive correlation between substance P concentration and the striatal neurone density was only found in the substantia nigra. Choline acetyltransferase activity in the striatum was found to be positively correlated with the density of "large" cells in the striatum rather than that of "small" cells. In DRPLA there was no direct correlation between the values of the markers in the basal ganglia and the striatal neurone density. The decrease of transmitter markers without striatal cell loss in this particular choreic disorder could be regarded as a sequence of "biochemical degeneration" of striatal neurones. Based on these findings, the underlying mechanisms of choreic involuntary movements were briefly discussed.

Two hundred and forty-eight patients from 116 Italian families with dominant ataxia were studied for CAG expansion within SCA1, 2, 3, 6, 7 (spinocerebellar ataxia) and DRPLA (dentatorubropallidoluysian atrophy) genes. Fifty-six percent of the families originated from Southern, 19% from Central and 25% from Northern Italy. SCA2 was the commonest mutation, accounting for 47% of the families, followed by SCA1 (24%), SCA6 (2%), SCA7 (2%) and DRPLA (1%). No SCA3 family was found. Twenty-four percent of the families carried a still unidentified mutation. When occurrence of mutations was evaluated according to the geographic origin, SCA1 was the commonest in Northern (72%), whereas SCA2 was prevalent (63%) in Southern Italy. The number of CAG repeats in SCA1 normal alleles was higher in Northern than in Central-Southern Italy.

We measured the effective synaptic currents (IN) produced by stimulating the contralateral pyramidal tract (PT) in triceps surae motoneurons of the cat. This is an oligosynaptic pathway in the cat that generates both excitation and inhibition in hindlimb motoneurons. We also determined the effect of the PT synaptic input on the discharge rate of some of the motoneurons by inducing repetitive firing with long, injected current pulses during which the PT stimulation was repeated. At resting potential, all but one triceps motoneuron received a net depolarizing effective synaptic current from the PT stimulation. The effective synaptic currents (IN) were much larger in putative type F motoneurons than in putative type S motoneurons [+4.6 +/- 2.9 (SD) nA for type F vs. 0.9 +/- 2.4 nA for putative type S]. When the values of IN at the threshold for repetitive firing were estimated, the distribution was markedly altered. More than 60% of the putative type S motoneurons received a net hyperp...

Copyright © 2008 The American Society of Neurorehabilitation ... Lateral Funiculus Injury in the Adult Rat ... Y. Cao, MD, JS Shumsky, PhD, MA Sabol, RA Kushner, S. Strittmatter, PhD, FPT Hamers, PhD, DHS Lee, PhD, SA Rabacchi, PhD, and M. Murray, PhD

Magnocellular red nucleus (RNm) is involved in controlling goal-directed limb movements such as reaching to grasp. We tested two hypotheses related to RNm's role in controlling reach-to-grasp movements. One hypothesis is that forelimb RNm neurons are grasp specific, and the other is that they specify the timing of metacarpi-phalangeal (MCP) extension to preshape the hand during the appropriate phase of the reach. We recorded single-unit discharge while monkeys performed two behavioral tasks that elicited similar reaches but differed in grasp. One task consisted of a reach with a precision grasp that elicited independent use of thumb and forefinger; the other included a whole-hand grasp that elicited concerted use of the four fingers. Most RNm neurons tested were engaged strongly during both the whole-hand and precision tasks, and the magnitude of discharge modulation did not differ between tasks. Thus most RNm neurons are not grasp specific but, instead, may contribute to behavi...

In this study, we aimed to determine the presence as well as the diverse distribution of N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptor subunits in the rat red nucleus. Using adult Sprague-Dawley rats as the experimental animals, immunohistochemistry was performed on 30 µm thick coronal brain sections with antibodies against α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (GluA1-4), kainate (GluK1, GluK2/3, and GluK5), and NMDA (GluN1 and GluN2A) receptor subunits. The results showed that all ionotropic glutamate receptor subunits are expressed in the red nucleus. Specific staining was localized in the neuron bodies and processes. However, the pattern of immunoreactivity and the number of labeled neurons changed depending on the type of ionotropic glutamate receptor subunits and the localization of neurons in the red nucleus. The neurons localized in the magnocellular part of the red nucleus were particularly immunopositive for GluA2, GluA4, GluK2/3, GluK5, GluN1, and GluN2A receptor proteins. In the parvocellular part of the red nucleus, ionotropic glutamate receptor subunit immunoreactivity of variable intensity (lightly to moderately stained) was detected in the neurons. These results suggest that red nucleus neurons in rat heterogeneously express ionotropic glutamate receptor subunits to form functional receptor channels. In addition, the likelihood of the coexpression of different subunits in the same subgroup of neurons suggests the formation of receptor channels with diverse structure by way of different subunit combination, and the possibility of various neuronal functions through these channels in the red nucleus.

Radioligand binding and behavioral studies were conducted to determine whether a relationship existed between the motor effects produced by (+)-pentazocine and its binding to sigma sites. Scatchard analyses revealed decreased [3H](+)-pentazocine binding in middle aged rats (5-6 months old) compared to young adult rats (2-3 months old). However, there was no difference between the extent of circling behavior or dystonia produced by microinjection of (+)-pentazocine into the substantia nigra or red nucleus in the older animals compared to the young adult rats. There was also a significant decrease in [3H](+)-pentazocine binding in rats chronically treated with haloperidol. Again, however, despite the reduction in [3H](+)-pentazocine binding, there was no difference between the extent of dystonia produced by unilateral intrarubral microinjection of (+)-pentazocine into animals chronically treated with haloperidol vs. saline. The postural changes produced by (+)-pentazocine could not be attenuated with coadministration of the putative sigma receptor antagonist BD1047 (N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino) ethylamine), or the opiate receptor antagonist naloxone. However, the (+)-opiate, (+)-nordihydrocodeinone, partially attenuated the postural effects of (+)-pentazocine, despite its very low affinity for sigma 1, sigma 2, or opiate receptors. Taken together with previous studies, the results suggest that [3H](+)-pentazocine is a potent and selective probe for sigma 1 binding sites, but the in vivo effects of (+)-pentazocine cannot be fully attributed to actions through these sites. Some of the in vivo effects of (+)-pentazocine appear to involve other binding sites that are not detected under the conditions normally used in in vitro assays.

The monoclonal antibody Py was previously developed as a tool for the identification of subpopulations of hippocampal neurons. Here, the differential distribution of Py immunoreactivity in the mid-brain is described showing that Py also serves as a useful marker for other populations of neurons. Medium to strong immunoreactivity was observed in the cell body and dendrites of neurons of the oculomotor nucleus, superior colliculus and substantia gelatinosa reticulata. However, particularly intense Py-immunoreactivity was identified in the magnocellular neurons in the caudal pole of the red nucleus. Unilateral transection of the rubrospinal tract at Th9-10 induced a marked reduction of Py immunoreactivity in the ventrolateral territory of the caudal pole of the axotomised red nucleus. A small but statistically significant reduction of Py-immunoreactivity was first seen at 7 days after surgery and a maximal loss of immunoreactivity (reduced to 66% of control levels) was observed by 21 d...

The red nucleus (RN) is a pair of small gray matter structures located in the midbrain and involved in muscle movement and cognitive functions. This retrospective study aimed to investigate the metabolism of human RN and its correlation to other brain regions. We developed a high-resolution semiconductor PET system to image small brain structures. Twenty patients without neurological disorders underwent whole brain scanning after injection of 400 MBq F-18 fluorodeoxyglucose (FDG). The individual brain (18)F-FDG-PET images were spatially normalized to generate a surface projection map using a 3-dimensional stereotactic surface projection (3D-SSP) technique. The correlation between the RN and each voxel on the cerebral and cerebellar cortices was estimated with Pearson's product-moment correlation analysis. Both right and left RNs were visualized with higher uptake than that in the background midbrain. The maximum standardized uptake value (SUVmax) values of RN were 7.64±1.92; the...

The corticospinal and the rubrospinal tracts are thought to synergistically contribute to the limb control during motor development. Williams et al. ( J Neurosci 34: 4432–4441, 2014) demonstrate that the postnatal maturation of red nucleus motor map and the rubrospinal tract develops earlier than the corticospinal tract, to support early forelimb control. They have two distinct phases of maturation; a “precorticospinal” phase characterized by development of the rubrospinal system, and a “cocorticospinal” phase where they overlap with corticospinal development.

Conscious, anaesthetized and decerebrate young mammals respond to acute hypoxia with an initial increase in breathing followed by a fall to, or to below, pre-hypoxic levels--the biphasic ventilatory response. The ventilatory rise is due to sustained hypoxic stimulation of the peripheral chemoreceptors. We present evidence from brain stem and peripheral chemoreflex studies supporting the concept that, in addition to the peripheral chemoreceptors, hypoxia also activates brain stem pathways that inhibit ventilation. A key part of the inhibitory pathway is an area within the red nucleus. Destruction of this area in young decerebrate rabbits abolishes the ventilatory fall during hypoxia, yet has no effect on respiratory control during normoxia and does not affect arterial blood pressure changes in hypoxia. In support of this hypothesis, we report that there are neurones within the red nucleus that increase their discharge in hypoxia. The role of higher brain stem/hypothalamic function in...