bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cortical organization after treatment of a peripheral nerve with ricin: An evaluation of the relationship between sensory neuron death and cortical adjustments after nerve injury
Authors: Wall J. T. , Cusick C. G. , Migani‐Wall S. A. , Wiley R. G. 
Published: January 2005

AbstractThe present study was designed to assess whether cortical changes after peripheral nerve damage are related to the degree of death of primary sensory neurons in the damaged nerve. The cytotoxin ricin was injected into the sciatic nerves of adult rats to kill primary sensory neurons with axons through the injection site. Following periods of 6–101 days, the S‐I hindpaw map was evaluated with neurophysiological techniques and compared with the hindpaw maps of previously studied normal adult rats and adult rats that had undergone adult or neonatal sciatic section at a comparable level of the nerve. These comparisons allowed evaluation of cortical functional organization following different degrees of sensory neuron loss after sciatic nerve injury.There were three main results. 1) The comparison of ricin‐treated and normal adult rats indicated that ricin treatment interrupted inputs from the sciatic skin territory on the hindpaw and caused a limited increase in the size of the cortical area that was activated by stimulation of hindpaw skin innervated by the remaining saphenous nerve. 2) The cortical maps of rats that had undergone adult ricin treatment (relatively large primary neuron loss) or section during adulthood (small to moderate primary neuron loss) were similar. In both groups, only the saphenous hindpaw skin was represented in cortex, and the cortical area that was activated by stimulation of the saphenous hindpaw skin had undergone a comparable limited enlargement. 3) The comparison of ricin‐treated adult rats (relatively large primary neuron loss) and adult rats that had undergone neonatal section (relatively large primary neuron loss) indicated that cortical organization differed after these treatments. In particular, after ricin treatment the cortical area that was activated by stimulation of the saphenous hindpaw skin was larger than the comparable area in neonatal denervates, and the topographical progressions between the hindpaw and adjacent body representations were not as variable as after neonatal section.These findings indicate that cortical maps are altered after injection of ricin into a nerve. The similarity in cortical organization after ricin treatment (relatively large sensory neuron loss) and nerve section in adults (relatively small sensory neuron loss) and the differences in cortical organization after ricin treatment and nerve section in neonates (both relatively large sensory neuron loss) indicate cortical changes do not covary as a simple function of the degree of peripheral neuron death.
Organization of the association cortical afferent connections of area 5: A retrograde tracer study in the cat
Authors: Avendaño C. , Rausell E. , Perez‐Aguilar D. , Isorna S. 
Published: January 2005

AbstractThe association (intrahemispheric) cortico‐cortical afferent connections of area 5 were studied in the cat by means of retrograde tracing techniques involving horseradish peroxidase (HRP) free or wheat germ agglutininconjugated (WGA‐HRP) or fluorochrome injections. Single or multiple injections were placed in different parts of areas 5a and 5b, the medial division of area 5 (5m), or in the anterior suprasylvian area (SsA). Labeled cells were plotted on projection drawings of the coronal sections and on two‐dimensional “maps” of the cerebral cortex, which were produced according to an accurate and consistent procedure.The major findings of this study are:

All divisions of the anterior parietal cortex (areas 3a, 3b, 1, and 2) project to area 5 and to SsA. These projections, however, show marked differences in amount and topographical distribution, depending on the mediolateral and rostrocaudal location of the injections.
The motor cortex (areas 4 and 6) also projects heavily to area 5 and to SsA in a well‐organized topographic fashion: Area 4 projects mainly upon areas 5a, 5m, SsA, and the medial part of 5b; area 6 projects mainly upon the lateral part of 5b and SsA. Moreover, the upper bank of the cruciate sulcus (areas 4 and 4aα) projects to medial parts of area 5, and the lower bank (areas 4&6aδ, and 6aß) projects to lateral parts of area 5.
The somatosensory areas in the anterior ectosylvian gyrus and surrounding cortices (SIIm, SII, and SIV) are connected primarily with medial parts of area 5 (particularly 5a), and SsA.
Areas 7 and 7m and a number of visual areas (19, SVA, AmLS, PmLS, 21, 20, 18, ALS, and PLS) project in varying degrees to lateral parts of area 5b. Some of these areas also send weak to moderate projections to the medial part of 5b and the lateral part of 5a.
Sparse projections arising from the dorsolateral prefrontal, cingular, retrosplenial, granular insular, and suprasylvian fringe cortices were found to distribute in area 5 and SsA, particularly in lateral portions of 5b.
Quite abundant intrinsic connections also were found, which were loosely organized according to a complex topographic pattern.
On the basis of these and previous results (Avendaño et al., 1985), the identity of area 5 in the cat is discussed, and comparisons are made between this area and sectors of adjoining cortex of cat and primates.
Intrinsic connections within and between cochlear nucleus subdivisions in cat
Authors: Snyder Russell L. , Leake Patricia A. 
Published: January 2005

AbstractThe cat cochlear nuclear complex (CNC) is divided into three major subdivisions: the anteroventral, the posteroventral, and the dorsal cochlear nuclei (AVCN, PVCN, and DCN, respectively). Each of these subdivisions receives a topographic projection from the cochlea and each consists of a number of different cell types. The interconnections between these subdivisions and the cell types which give rise to them were studied by means of small injections of horseradish peroxidase (HRP) made at physiologically identified locations. DCN injections resulted in few labeled cells in the DCN, suggesting that its internal connections are very limited. In contrast, these same DCN injections resulted in numerous labeled cells in the PVCN and AVCN. Labeled PVCN cells, consisting of multipolar, octopus, and small spindle‐shaped cells, were located in spatially restricted laminae stretching the entire rostrocaudal length of the nucleus, while labeled AVCN cells consisting of multipolar, globular, small spindle‐shaped and small spherical cells were broadly distributed over the posterior half of the nucleus. Similar injections placed in the PVCN resulted in numerous labeled cells in all three subdivisions. The PVCN and AVCN cells labeled after PVCN injections were widely distributed across the isofrequency representations in both nuclei, while the labeled DCN cells were restricted to locations over the injection sites. Injections placed in the posterior half of the AVCN resulted in only very few labeled cells in the DCN. No cells were labeled following injections in the rostral AVCN.
Plasticity in the developing chick visual system: Topography and maintenance of experimentally induced ipsilateral projections
Authors: Thanos Solon , Düutting Dieter 
Published: January 2005

AbstractThe present work examines the topography of the contra‐ and ipsilateral centrifugal projections from the isthmooptic nuclei (IONs) to the remaining retina in monocular chick embryos. After removal of the left eyecup at embryonic day (E)1.5, the IONs were investigated at various embryonic stages by the retrograde transport of fluorescent dyes and horseradish perioxidase (HRP) injected into the remaining eye. The projection of the ipsilateral ION was consistently found at E13 and frequently disappeared by E18 to E19. Selective regional labeling of the remaining retina in monocular embryos with DiI (1,1′‐dioctadecyl‐3,3,3′,3′‐tetramethyl‐indocarbocyanine perchlorate) revealed that the retinotopic order of the enhanced projection from the ipsilateral ION corresponded precisely to the normal one from the contralateral ION.The formation of the projection from the retina to the ipsilateral tectum was also investigated at E18 to E19 by means of intravitreally injected HRP or rhodamine‐B‐isothiocyanate (RITC) in monocular embryos after early eyecup removal. In cases with persistent ION, the eye enucleations resulted in ipsilateral retinotectal projections consisting of varying numbers of retinofugal fibers.The data are consistent with the view that there is a certain degree of plasticity in the embryonic development of the chick visual system. If an ION projection to the ipsilateral retina is strongly developed, it is retinotopically organized and probably influences the maintenance of the ipsilateral retinotectal projection. The stabilization of the otherwise transiently formed ipsilateral retinotectal projection may be influenced by the tectal neurons which receive retinal input and are efferently connected with persisting ION neurons.
New high‐resolution 2‐deoxyglucose method featuring double labeling and automated data collection
Authors: McCasland James S. , Woolsey Thomas A. 
Published: January 2005

AbstractA new approach to high‐resolution 2‐deoxy‐D‐glucose (2DG) emulsion‐autoradiography which combines improved retention of 2DG labeling, staining with immunohistochemical and other specific markers, and automated data collection and analysis of local silver grain and stain densities is described. The Durham et al. (J. Neurosci. 1:519–526, '81) procedure for fixation of 2DG with periodate‐lysine‐paraformaldehyde (PLP, McLean and Nakane: J. Histochem. Cytochem. 22:1077–1083, '74) was adapted to increase retained label roughly tenfold. Phenobarbital anesthesia is induced 45 minutes after 2DG injection. Barbiturate anesthesia increases brain glycogen (Nelson et al.: J. Neurochem. 15:1271–1279, '68) and presumably increases the incorporation of intracellular 2DG from 2DG‐6P into brain glycogen and other molecules (Nelson et al.: J. Neurochem. 43:949–956, '84; Pentreath et al.: Neuroscience 7:759–767, '82). Iodoacetate is added to cold fixative to prevent glycogen breakdown (Cammermeyer and Fenton: Histochemistry 76:339–356, '82).This high‐resolution 2DG protocol is directly compatible with many other neuroanatomical techniques. We demonstrate 2DG emulsion autoradiography combined with cytochrome oxidase (CO) histochemistry, markers for axonal pathway tracing, plastic embedding for semithin sections, and immunohistochemical staining for glutamate decarboxylase (GAD). The method should be compatible with antibodies for other antigens and with other neuroanatomical stains.To collect the data directly from microscope slides, a computer‐controlled microscope was integrated with image‐processing software to eliminate the need for manual counting and scoring of autoradiograms. Regions of interest are scanned automatically at high resolution to map regional labeling and/or stain density. There is excellent correspondence between computer‐enhanced two‐dimensional maps of the data and the original autoradiograms. Automated counts for five specimens were compared to counts of labeled cells by trained observer. The correlation between the two sets of measurements is high (r =. 93).Automated data collection has been generalized to measure regional stain densities on the autoradiographed sections for direct comparison with silver grain density. The method is extremely flexible, especially since new image‐processing strategies can be developed in software to extract the desired information from materials labeled by other methods (e.g., HRP).The combination of experimental and data collection strategies generates two‐ or three‐dimensional “maps” of 2DG labeling, histochemical stain, etc., over a brain area of interest and allows direct comparison of these different maps. To our knowledge this is the first report of quantitative reconstructions of 2DG labeling patterns on the basis of large and systematically scanned data samples from emulsion autoradiograms.
Morphology of fungiform papillae in canine lingual epithelium: Location of intercellular junctions in the epithelium
Authors: Holland V. F. , Zampighi G. A. , Simon S. A. 
Published: January 2005

AbstractThe localization and structure of intercellular junctions and barriers in the extragemmal epithelium of canine fungiform papillae were determined by using both morphological and electrophysiological methods. Gap junctions were located in all epithelial strata with the exception of the stratum corneum, suggesting that the epithelium functions as a syncytium. The extracellular space of the stratum corneum was composed of a discontinuous, three‐dimensional network of tight junctions, modified desmosomes, and lamellar bodies. A zonula occludens, which stops the penetration of lanthanum, is present in the uppermost layer of the stratum granulosum. In freeze‐fracture replicas, tight junctions appear as extended networks of ridges of variable thickness on the PF fracture face and complementary grooves on the EF fracture face. The relatively high resistance pathway resulting from the layers of corneocytes and networks of tight junctions and lamellar bodies in the stratum corneum is bypassed by the low‐resistance pathway provided by the taste pore.
Immunohistochemical distribution of serotonin in spinal autonomic nuclei: I. Fiber patterns in the adult rat
Authors: Newton Bruce W. , Hamill Robert W. 
Published: January 2005

AbstractThe differential distribution of serotonin (5HT) fibers in spinal laminae VII and X is described for the adult rat. The results indicate that descending 5HT fibers preferentially innervate those regions of lamina VII that contain sympathetic and parasympathetic neurons. In lamina X, especially the dorsal commissural nucleus, large numbers of 5HT fibers are observed throughout the spinal cord. Moreover, sympathetic nuclei are more richly innervated with 5HT than the spinal parasympathetic nuclei. Spinal cord hemisections reveal that spinal autonomic nuclei are differentially innervated: ipsilateral serotoninergic projections to the intermediolateral cell column are preferentially interrupted. In addition, a large crossed 5HT projection exists throughout the length of the spinal cord that decussates five to six spinal segments rostral to its termination. Both crossed and uncrossed 5HT fibers span many spinal segments and have large numbers of collaterals. Spinal cord transections show that the vast majority of spinal 5HT descends from the brainstem but that some 5HT fibers are of intrinsic origin.
Immunohistochemical distribution of serotonin in spinal autonomic nuclei: II. Early and late postnatal ontogeny in the rat
Authors: Newton Bruce W. , Burkhart Amy B. , Hamill Robert W. 
Published: January 2005

AbstractThese studies reveal that the postnatal ontogeny of serotonin (5HT) in the sympathetic nuclei of the rat spinal cord is protracted; the adult complement of 5HT‐immunoreactive fibers is not achieved until at least 60 days of age. As descending serotonin fibers innervate and demarcate the distribution of preganglionic sympathetic nuclei, rostral‐caudal and temporal gradients exist. Additionally, a heterogeneous segmental 5HT ontogenetic pattern is observed in sympathetic nuclei. Most serotonin fibers in laminae VII and X are unorganized at birth except for some sympathetic nuclei in high thoracic regions where the 5HT sympathetic pattern is being initiated. By postnatal day 6 the framework of the 5HT pattern is established in all sympathetic nuclei, and by postnatal day 16 a pattern is formed, which develops into the compact adult state by postnatal day 60. The protracted period of sympathetic 5HT development corresponds with the length of time it takes for the autonomic nervous system to mature. In addition, 5HT intraspinal cell bodies are observed at all time points examined, except for the day of birth, and are found in the same regions as adult 5HT neurons, i.e., dorsal or lateral to the central canal in laminae VII and X and in all spinal segments except cervical levels. Many of the 5HT neurons are pericanalicular and bipolar in appearance. Multipolar 5HT neurons are first observed on postnatal day 45.
Golgi study of the mouse striatum: Age‐related dendritic changes in different neuronal populations
Authors: Rafols José A. , Cheng Heng Wei , McNeill Thomas H. 
Published: January 2005

AbstractThe Van der Loos modification of the Golgi‐Cox method and morphometric analyses were used to study the neuronal types in the striatum of adult (3, 6, and 10 months) and aged (20, 25, and 30 months) C57BL/6N mice. In adult mice six types of striatal neurons were distinguished primarily on the basis of the morphology of their cell body and dendrites. Each of these types was compared with morphologically similar neurons from previous Golgi classifications in other species and discussed within the framework of recent immunocytochemical work.With similar methods the age‐related changes occurring on the dendrites of three of the six striatal types were also analyzed. In the mediumsized neuron with spine‐laden dendrites, various dendritic tree shapes and sizes were distinguished in all age groups studied. Qualitative observations as well as measurements of total dendritic length per cell suggested that the dendrites in this type may both grow and regress throughout the life span, although signs of dendritic atrophy and regression were observed only in the aged groups. In the other two types of neuron, one a medium aspiny cell with thin varicose dendrites and the other a large spiny neuron with many dendrites, measurements of total dendritic lengths revealed sustained growth of the tree well into advanced age, followed by moderate regression in the oldest groups. The present findings also indicate that the dendrites of each type of striatal neuron follow unique temporal patterns of growth and regression during the life span of the mouse.
Early postnatal development of the monkey globus pallidus: A Golgi and electron microscopic study
Authors: Cano Josefina , Pasik Pedro , Pasik Tauba 
Published: January 2005

AbstractThe globus pallidus of 20 monkeys ranging in age from newborn to 4 months was examined in Golgi‐impregnated material and ultrastructurally. There was no discernible difference between the lateral and medial segments of the structure. At the light microscope level, all neuronal types described in the adult are found at birth. The most common, the large fusifom cell, shows initial signs of immaturity such as blunt protrusions and dendritic dilations at bifurcation points, as well as growth cones, filopodia, and filiform processes. These features become more rare with age, and by 4 months, the neurons appear fully mature save for the terminal dendritic arborizations which are still underdeveloped. From the earliest ages examined, the large globular cells and the interneurons are more mature than the previous type. The afferent radial fibers of striatal origin are observed from birth, but they are grouped in bundles only after 8 weeks. The density of their climbing branches increases over time, reaching a mature appearance by 16 weeks. Afferents entering from the ventral surface do not yet show clusters of varicosities at 2 weeks. At the latter age, plexuses of fine beaded fibers are already seen covering large extensions of the nucleus.The fine structure correlates well with the Golgi material. The basic features of the neuropil are present at birth, albeit with immature characteristics such as the incomplete covering of the dendrites with axonal boutons and the low level of myelination of the radial fibers. Growth cones and profiles with signs of degeneration are observed during the first month. In the early ages examined, most dendrites show large varicosities and protrusions, some of which are spinelike and can be postsynaptic to multiple terminals. The other dendritic type, with only an occasional axodendritic synapse, is also seen from birth and increases in size as a function of time. The type I axonal boutons, of probable striatal origin, are quite immature at birth, and their characteristic interdigitations are seen only after the first week. The type II, III, IV, and V boutons appear mature at all ages examined but crest synapses formed by the type III terminals are observed in the later stages of the study. Finally, postsynaptic vesicle‐containing profiles are present at 4 weeks, but triadic synaptic arrangements are formed only by 16 weeks.Results indicate the occurrence of progressive changes in neuronal and neuropil morphology of both segments of the primate globus pallidus in the first 4 postnatal months and suggest that this structure matures earlier than the neostriatum, probably as a reflection of its diencephalic origin.
Connections of the olfactory bulb and nucleus olfactorius anterior in the hedgehog (Erinaceus europaeus): Fluorescent tracers and HRP study
Authors: De Carlos Juan A. , López‐Mascaraque Laura , Valverde Facundo 
Published: January 2005

AbstractThe projections of the main olfactory bulbs (MOBs) and the dorsal part of the anterior olfactory nucleus (NOA) in the hedgehog (Erinaceus europaeus) have been studied by fluorescent tracers and the horseradish peroxidase method (HRP), respectively, to reveal the pattern of labeling from these structures.After different dye injections in both MOBs, labeled cells were present in the following structures: tenia tecta, vertical limb of the diagonal band of Broca, and medial septal nucleus in the ipsilateral injection site; and the NOA, piriform cortex, nucleus of the lateral olfactory tract, horizontal limb of the diagonal band of Broca, posterolateral cortical amygdaloid nucleus, anterior amygdaloid area, and dorsal raphe nucleus in both hemispheres. Structures showing double‐labeled cells were the NOA, horizontal limb of the diagonal band of Broca, nucleus of the lateral olfactory tract, anterior amygdaloid area, and posterolateral cortical amygdaloid nucleus.After HRP injections in the dorsal part of the NOA, labeled cells were distributed in the NOA, nucleus of the lateral olfactory tract, posterolateral cortical amygdaloid nucleus, piriform cortex, horizontal and vertical limbs of the diagonal band of Broca, mitral cell layer of the MOB, tenia tecta, anterior amygdaloid area, and the contralateral NOA. We suggest that the contralateral projection nuclei to the MOB of the hedgehog, unusual in other mammals, and the large number of cells with axonal collaterals projecting to both hemispheres, may be a strategy in these animals to bilaterally integrate brain functions at the expense of its reduced corpus callosum.