bluuebunny/crossref_metadata_2025_split huggingface dataset:
A type of aspiny neuron in the rat neostriatum accumulates [3H]γ‐aminobutyric acid: Combination of golgi‐staining, autoradiography, and electron microscopy
Authors: Bolam J. P. , Clarke D. J. , Smith A. D. , Somogyi P. 
Published: December 2004

AbstractLight microscopic autoradiography was used to identify cells in the neostriatum that became labelled after the local injection of [3H]γ‐amino‐butyrate (GABA). The GABA‐accumulating cells comprised up to 15% of the total population of neurons. Thirty‐seven of these cells were examined in the electron microscope and it was found that they all had similar cytological characteristics, i.e., prominent nuclear indentations, a moderate volume of cytoplasm, rich in organelles, and sparse synaptic input to the perikaryon. Nine of the cells that had accumulated GABA were also impregnated following Golgi staining. These Golgi‐impregnated neurons were of medium size and all had dendrites that were aspiny, often varicose, and that occasionally followed a recurving path. After gold toning, the Golgi‐impregnated, GABA‐accumulating neurons were examined in the electron microscope and were found to receive boutons forming symmetrical or asymmetrical synaptic contacts on their somata and dendrites; the symmetrical synapses were most common on the cell body and proximal dendrites, while the distal dendrites mainly received boutons forming asymmetrical contacts.We conclude that one type of GABAergic neuron in the neostriatum is a type of medium‐sized aspiny neuron and that this neuron is likely to receive synaptic input both from neurons within the striatum and from neurons in distant brain regions. We suggest that this neuron is a local circuit neuron in the neostriatum since its morphological features are quite distinct from those of identified projecting neurons.
Topological analysis of the brainstem of the reedfish, Erpetoichthys calabaricus
Authors: Nieuwenhuys Rudolf , Oey P. Liam 
Published: December 2004

AbstractThe ventricular sulcal pattern and the cellular structure of the brainstem of the reedfish Erpetoichthys calabaricus were studied in transversely cut Nissl‐, Klüver‐Barrera‐, and Bodian‐stained serial sections. Six longitudinal sulci, the sulcus medianus inferior, the sulcus intermedius ventralis, the sulcus limitans, the sulcus intermedius dorsalis, the sulcus medianus superior, and the sulcus lateralis mesencephali could be distinguished. A seventh groove, the sulcus isthmi, clearly deviates from the overall longitudinal pattern of the other sulci. Although in Erpetoichthys most neuronal perikarya are contained within a diffuse periventricular gray, 32 cell masses could be delineated; six of these are primary efferent or motor nuclei, seven are primary afferent or sensory centers, nine are considered to be components of the reticular formation, and the remaining ten may be interpreted as “relay” nuclei.In order to study the zonal pattern of the brainstem, this structure was subjected to a topological analysis (cf. Nieuwenhuys, '74 and Fig. 15) which yielded the following result. In the rhombencephalon the gray matter is arranged in four longitudinal columns or areas termed area ventralis, area intermedioventralis, area intermediodorsalis, and area dorsalis. In many places the sulcus intermedius ventralis, the sulcus limitans, and the sulcus intermedius dorsalis mark the boundaries between these morphological entities. These longitudinal areas coincide largely, but not entirely, with the so‐called functional columns of Herrick and Johnston. The most obvious incongruity is that the area intermediodorsalis contains, in addition to the nucleus of the solitary tract, three nonviscerosensory cell masses, namely, the nucleus vestibularis magnocellularis and parvocellularis and the nucleus of the tractus descendens of V. The four longitudinal zones cannot be distinguished in the mesencephalon nor can the sulcus limitans be recognized here. Functionally, however, the medial part of the tegmentum mesencephali may be considered the rostral extreme of the somatomotor column, whereas the remainder of the midbrain contains a number of somatosensory centers.
Anterograde transneuronal degeneration in the ectomamillary nucleus and ventral lateral geniculate nucleus of the chick
Authors: Peduzzi J. D. , Crossland W. J. 
Published: December 2004

AbstractThe effects of anterograde transneuronal atrophy were studied in two visual nuclei of the chick—the ectomamillary nucleus (EMN), which shows marked degenerative changes following enucleation, and the ventral lateral geniculate nucleus (GLv), which shows less severe changes following enucleation. The chicks were enucleated on the day of hatching and killed between 2 and 81 days later.Reconstructions of the EMN and GLv revealed that enucleation retarded the growth of these two nuclei. The volume of the control EMN and GLv, ipsilateral to the removed eye, continued to increase after eye removal. The experimental EMN did not increase in volume during this time while the experimental GLv increased in volume but at a slower rate than the control GLv. The volume of the experimental GLv remained smaller than the control volume.In order to determine whether the volumetric changes were due to arrest of cellular growth or to atrophy of the neurons, a morphometric study was carried out in the two nuclei. Measurements of the cross‐sectional area of EMN neurons revealed a 20% decrease in soma area in the experimental EMN in comparison with those in the control EMN. Since neurons in the control EMN did not increase in area after hatching, it was concluded that the changes were due to atrophy rather than arrest of neuron growth. Furthermore, there was a 35% neuron loss in the EMN. The GLv, which is composed of two laminae, consistently showed a greater decrease in soma cross‐sectional area and neuron loss in its neuropil lamina (comparable to the transneuronal effects in the EMN) than in its lamina interna. Thus, in both nuclei, eye removal led to neuron loss and a decrease in soma cross‐sectional area when compared with the contralateral (control) nucleus.
Developmental relationships between trigeminal ganglia and trigeminal motoneurons in chick embryos. I. Ganglion development is necessary for motoneuron migration
Authors: Moody Sally A. , Heaton Marieta B. 
Published: December 2004

AbstractThe migration and early development of trigeminal (V) motoneurons were studied in chick embryos in which two different populations of primary trigeminal sensory neurons had been removed prior to the birthdate of the V motoneurons. Ablation of mesencephalic neural crest cells, which eliminates monosynaptic sensory input, did not affect the migration, early development, or later differentiation of the V motoneurons. However, when the anlagen of the V ganglion were removed, the V motor root did not exit from the brainstem and the V motor nucleus did not develop. Although the neurons of the V ganglion do not innervate adult V motoneurons, these populations are related developmentally. In those embryos in which the V ganglion did not develop, medial column cells, which are midline, postmitotic, premigratory V motoneurons, and a few medial, elongated cells (possibly migratory) were present until days 5–6, but these cells did not complete their lateral migration to form the lateral nucleus of V. In cases where the ganglion anlagen were not completely removed, the number of postmigratory V motoneurons was positively correlated to the size of the ganglion remnant. There also was a correlation between the axial position of the postmigratory V motoneurons and the ganglion remnants. If a caudal remnant developed, only caudal V motoneurons, whose axons reached the ganglion, migrated; if a rostral remnant developed, only rostral V motoneurons, with axons reaching this remnant, migrated. Additionally, if the central axons of the ganglion remnant entered the metencephalon in either dorsal or ventral ectopic positions, the V motor nucleus was located in a corresponding aberrant position. Thus, some characteristic of the V ganglion cells appears to guide the motor axons and somas to their final brainstem position.
Supramedullary afferents of the nucleus raphe magnus in the rat: A study using the transcannula HRP gel and autoradiographic techniques
Authors: Carlton Susan M. , Leichnetz George R. , Young Eric G. , Mayer David J. 
Published: December 2004

AbstractAfferents of the nucleus raphe magnus (NRM) were retrogradely la‐belled by using a transcannula HRP gel technique in conjunction with tetramethylbenzidine nuerohistochemistry to determine the sources of in‐puts to the nucleus which could potentially influence the descending antio‐ciceptive raphe‐spinal system. Large numbers of HRP‐labelled neurons were seen in the frontal cortex, dorsomedial nucleus of the hypothalamus, zona incerta, nucleus parafascicularis prerubralis (NPfPr), pretectum, dorsal and lateral periaqueductal gray, nucleus cuneiformis (NC), deep superior col‐liculus (dSC), a paraoculomotor cell group which may be the medial acces‐sory nucleus of Bechterew, dorsal column nuclei, and spinal trigeminal nucleus. Smaller numbers of labelled cells were also observed in the preoptic area, nucleus of Darkschewitsch, ventral peri(third)ventricular gray, nu‐cleus reticularis pontis oralis and caudalis, medial and lateral vestibular nuclei, and a subdivision of the hypoglossal nucleus. Confirmational an‐terograde autoradiographic studies were performed by injecting tritiated leucine into two of the principal sources of afferents to NRM: NPfPr, and dSC/NC.The results are compared with control HRP gel implants in the inferior olive, spinal cord, nucleus reticularis paragigantocellularis, and medial fa‐cial nucleus. Comments are also made concerning the parcellation of the ventromedial medulla and the possible role of both NRM and its afferents in central analgesic mechanisms.
Brainstem projections to the normal and noradrenergically hyperinnervated trigeminal motor nucleus
Authors: Vornov James J. , Sutin Jerome 
Published: December 2004

AbstractThe noradrenergic innervation of the trigeminal motor nucleus of the rat can be increased severalfold by neonatal treatment with the neurotoxin, 6‐hydroxydopamine. The brainstem projections to the nucleus were studied by injecting HRP into the nucleus of normal and noradrenergically hyper‐innervated rats. In order to identify the source of the noradrenergic inner‐vation, the fluorescent dye, True Blue, was used as a retrograde tracer in combination with the glyoxylic acid histofluorescence method for catechol‐amines.In both control and neonatally treated rats, the noradrenergic inner‐vation of the motor nucleus' was shown to arise from an ipsilate group of cells located among the fibers of the lateral lemniscusjust rostral to the motor nucleus. Our results confirmed the high degree of specificity of nor‐adrenergic innervation, which arises exclusively from this lateral tegmental noradrenergic cell group. During the process of sprouting, this specificity is maintained since only those noradrenergic cells normally innervating the nucleus were retrogradely labeled in neonatally treated animals. Other noradrenergic projections which are also increased in these animals, such as the nearby locus ceruleus innervation of the main sensory trigeminal nucleus, do not spread to the motor trigeminal nucleus.HRP‐labeled nonadrenergic cells were concentrated dorsally, with scat‐tered cells surrounding the nucleus. A similar distribution was observed contralateral to the injection site. The mesencephalic trigeminal nucleus was labeled only ipsilateral to the injection. The motor nucleus also receives an extensive bilateral input from the pontine and medullary reticular for‐mation. The medial reticular formation nuclei, including nucleus pontis caudalis, nucleus gigantocellularis, and nucleus reticularis ventralis con‐tained large labeled cells, which were especially numerous in the retrotri‐geminal area. Smaller, lateral reticular formation neurons were concen‐trated rostrally and ipsilaterally in the nucleus pontis lateralis. HRP retrograde labeling revealed no obvious change in the overall pattern of cells innervating the trigeminal motor nucleus following noradrenergic hy‐perinncrvation.
Direct projections from the centre median‐parafascicular complex to the subthalamic nucleus in the cat and rat
Authors: Sugimoto Tetsuo , Hattori Toshiaki , Mizuno Noboru , Itoh Kazuo , Sato Manabu 
Published: December 2004

AbstractSingle injections of a mixture of [3H] leucine and L‐[3H] made into the centre median‐parafascicular complex (CM‐Pf) of the cat. The ipsilateral subthalamic nucleus (STN) was most heavily labeled at its ros‐tral pole and moderately in the ventral and ventromedial portions of its rostral third, At middle subthalamic levels, label was more sparse and disappeared over the caudal third of the nucleus. Labeled fibers appeared to outline the borders of the STN throughout its rostral half. Control in‐jections of isotope into several other thalamic andmesodiencephalic regions produced no terminal labeling in the cat STN. After horseradish peroxidase (HRP) injections into the cat STN, a small number of the CM‐Pf neurons were labeled retrogradely. The labeled neurons were scattered diffusely in the CM‐Pf and were not obviously distinguishable from other unlabeled neurons in the nucleus. Single injections of L‐[3H] leucine were made into the CM‐Pf of the rat. Anterograde labeling was seen in the rostral half of the ipsilateral STN. Heavy labeling was present throughout the most rostral STN, became less prominent more caudally, and was absent from the caudal half of the STN. HRP injections in the rat CM‐Pf produced a distribution of anterograde labeling in the STN similar to the isotope injections. It was concluded that a small number of scattered CM‐Pf neurons project primarily to rostral region of the STN. Thus, the CM‐Pf is in a unique position to regulate the basal ganglia by way of a newly established thalamosubthal‐amic pathway as well as a widespread, conspicuous thalamostriate pathway in those two mammalian species.
Neurons at the origin of the medical component of the bulbopontine spinoreticular tract in the rat: An anatomical study using horseradish peroxidase retrograde transport
Authors: Chaouch A. , Menetrey D. , Binder D. , Besson J. M. 
Published: December 2004

AbstractAn anatomical technique based on the retrograde transport of horseradish perodidase (HRP) was used to investigate the progections of sponal cord neurions to the reticular formations in the rat. Both large and restricted injections were staggered all along the bulbar and pontine levels, involving the nucleus gigantocellularis, the nuclei reticularis pontis, pars oralis and cauladis and in some cases the nucleus raphé magnus.Labeled cells we constantly encountered in the reticular part of the neck of the dorsal horn throughout the whole length of the cord, mainly contralateral to the central core of the injection iste. This area was taken as the equivalent of lamina V in the cat. Other labeled cells were observed in the medial arts of the intermediate and ventral horns, in areas considered similar to laminae VII and VIII in the cat. The two most rostral cervical nating form the dorsolateral part of ventral horns.Thus, this study is a clear confirmation that the bulbopontine reticular formations constitute a target for various somatosensory inputs originating in spinal cord. It demonstrates that the medial spinoreticular tract (mSRT) differs from the other main ascending tracts by the absence of projections from (1) superficial layers and nucleus of the dorsolateral funiculus contrary to the spinomesencephalic tract; (2)ventromedial zone of the lumber dorsal horn unlike the spinothalamic tact; (3) the neck of the doral hor in its medial portuion contrary to the spinoreticular component reaching the lateral reticular nucleus; and (4) central cervical nucleus and Clarke's columns, unlike the spinocerebellar tracts. The difficulty in demonstrating retrograde labeling from discrete injections coulde result from the fact that mSRT neu‐rons have sparsely ramified collaterals on their terminal zones.
Centrifugal innervation of goldfish retina from ganglion cells of the nervus terminalis
Authors: Springer Alan D. 
Published: December 2004

AbstractCobaltous‐lysine was applied to one optic nerve of normal goldfish in order to determine the source of the centrifugal innervation of the retina. Cobalt‐filled cells were not observed in the optic tectum, pretectum, thal‐amus, or hypothalamus. However, filled cells were observed outside the central nervous system either interspersed between the olfactory nerve fibers orrostrally along the ventromedial aspect of the olfactory bulbs. These cells appear to correspond to the ganglion cells of the nervus terminalis. The cells were located bilaterally and had dendrites that branched in close proximity to the cell body and axons that coursed caudally through the medial olfactory tract. The axons traveled in the ventral forebrain and entered the optic tracts. The axons also gave off fine branches that appeared to terminate in the vicinity of the anterior commissure and in the preoptic region. Application of cobaltous‐lysine to a cut olfactory tract resulted in cobalt‐filled fibers in the optic tracts, retinal optic fiber layer, and retinal ganglion cell layer. However, the precise terminations of these fibers within the retina could not be readily established. The results are discussed with respect to the plethora of sources of retinopetal cells observed by others in fish and with respect to the innervation of the retina by luteinizing hormone‐releasing hormone axons.
Distribution patterns of individual medial lemniscal axons in the ventrobasal complex of the monkey thalamus
Authors: Jones E. G. 
Published: December 2004

AbstractTwenty‐seven medial lemniscal axons were traced to their terminations in the thalamic ventrobasal complex of monkeys, following injection of horseradish peroxidase into the lemniscus at midbrain levels.Most axons had terminal ramifications at one horizontal level in the ventrobasal complex. All terminations were focal, many were anteropos‐teriorly elongated, though none were sufficiently long to occupy more than one‐third to one‐half of the anteroposterior extent of the VPLc nucleus. All terminal ramifications were compressed sagittally into a slab 200–300 μm wide. There was modest overlap in the terminal territories of adjacent labelled axons and, as judged light microscopically, only a small amount of convergence onto the vicinities of single cells.Axons terminating selectively in the anterodorsal shell or central core of VPLc could be identified. In the anterodorsal shell (of neurons responding to stimulation of deep tissues) axons tended to terminate either in the part projecting to area 3a or in that projecting to areas 3a and 2 of the cortex. In the central core (of neurons responding to cutuneous stimulation and projecting to areas 3b and 1) larger ramifications were present in its center and smaller ramifications in its ventral part.A few axons had terminal ramifications at two dorsoventral levels in the cutaneous core; others had terminations in both the dorsal deep shell and the cutaneous core. In both cases, one ramification was always smaller than the other.The termination of lemniscal axons at defined foci instead of along the dorsoventral extent of the representational lamellae of the ventrobasal complex has implications for the nature of the body representation in the nuclei. Their tendency to be focal implies that not all members of an anteropos‐teriorly elongated rod of place‐and‐modality‐specific ventrobasal cells that project their axon to a single column in the somatic sensory cortex receive afferent inputs from the same lemniscal fibers.
Interneurons in the flight system of the locust: Distribution, connections, and resetting properties
Authors: Robertson R. M. , Pearson K. G. 
Published: December 2004

AbstractThe organization and functional properties of interneurons in the flight system of the locust, Locusta migratoria, were investigated by using intra‐cellular recording and staining techniques. Interneurons were found to be distributed within the three thoracic and the first three abdominal ganglia, and they could be subdivided into three organizational categories: (1) members of one of two serially homologous groups controlling either the forewing or the hindwing, (2) unique individuals with no known homologues in other ganglia, and (3) members of a set of serial homologues in the metathoracic and first three abdominal ganglia. Interneurons in the last two categories influenced both forewing and hindwing motoneurons in a similar manner. Thus interneuronal organization is not characterized by two distinct homologous groups of interneurons for the separate control of forewing and hindwing motor activity.Flight interneurons may also form two separate functional categories: (1) those making short latency connections to motoneurons (premotor interneurons), and (2) those which reset the flight rhythm when depolarized by brief current pulses (pattern generator interneurons). None of the ten premotor interneurons we identified influenced the flight rhythm when depolarized and none of the three groups of pattern generator interneurons were found to form short latency connections with motoneurons. This separation of function may allow phase‐shifts in motor output for flight control without changes in wingbeat frequency. Pattern generator interneurons influence motor output to both forewings and hindwings. Thus we conclude that the flight rhythm is generated in a distributed neuronal oscillator driving both pairs of wings.The organization of flight interneurons is considerably more complex than predicted from existing models of the flight system, or anticipated from the relative simplicity of the motor output. Our finding of homologous sets of interneurons in the abdominal ganglia supports the notion that insect flight evolved from a behavior using appendages distributed along the thorax and the abdomen. Thus the organization of flight interneurons may reflect an interneuronal system which controlled the behavior from which flight evolved.
Claustroneocortical projections studied in the cat by means of multiple retrograde fluorescent tracing
Authors: Macchi G. , Bentivoglio M. , Minciacchi D. , Molinari M. 
Published: December 2004

AbstractThe topographical interrelations of Claustroneocortical cells and their degree of divergent collateralization were investigated in cat by means of retrograde fluorescent double labeling. The tracers Fast Blue (FB) and Nuclear Yellow (NY) were injected in several combinations in two different cortical fields. FB‐labeled and NY‐labeled cells were found in all cases in the insular portion of the ipsilateral claustrum (C1I). The distributions of labeled cells confirmed the organization reported in previous studies. In some cases the two labeled cell populations were segregated in different parts of the C1I; in other cases there was more or less overlap in the two distributions. The degree of overlap was not simply related to the topographic proximity of the injected cortical territories.In all cases the vast majority of cells were single labeled. In one case both FB and NY were injected in the same cortical area in order to control that claustral axons can retrogradely transport two tracers back to the same parent cell bodies. In this control case C1I cells were double labeled. All together these data indicate that widely divergent Claustroneocortical projections take origin mainly from separate cells.