bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dendritic reorganisation in the basal forebrain under degenerative conditions and its defects in Alzheimer's disease. I. Dendritic organisation of the normal human basal forebrain
Authors: Arendt Thomas , Marcova Lena , Bigl Volker , Brückner Martina K. 
Published: January 2005

AbstractIn the present study, the dendritic organisation of neurones in the normal human basal forebrain was analysed as a prerequisite for the evaluation of pathological changes occurring in Alzheimer's disease and related conditions (see other Arendt et al. papers in this issue).Neurones in the basal nucleus of Meynert (NbM), the nucleus of the vertical limb of the diagonal band, and the medial septal nucleus were examined after Golgi impregnation. Cells were classified according to the dendritic branching pattern and soma shape as either reticular neurones or multipolar giant neurones. The reticular type of neurones constitutes more than 90% of neurones in the NbM. Cholinergic neurones also belong to this cell type. Reticular neurones were further subdivided into four subtypes. Morphological features and arrangement of reticular basal forebrain neurones were identical to those described for “reticular formation cells” or “isodendritic” neurones. Dendritic trees of reticular neurones show a spatial orientation perpendicular to passing fibres as well as a high degree of overlap, both of which are hallmarks of “open nuclei.”The qualitative classification of Golgi‐impregnated basal forebrain neurones was substantiated by a computer‐based three‐dimensional analysis. Topologic and metric parameters of the dendritic tree were calculated for each type of neurone to characterise the degree of dendritic branching, the shape and orientation of the dendritic arborisation, the spatial extension of the dendritic tree, and soma size. The classification criteria were evaluated according to their power of discrimination between different cell types by means of a discriminant analysis. The quantitative approach applied in the present study not only provides an objective measure for the description and comparison of the structure of various types of neurones but also makes it possible to elucidate fine structural changes that might occur under pathologic conditions and that are not evident during qualitative studies alone. © 1995 Willy‐Liss, Inc.
NADPH‐diaphorase active and calbindin D‐28k‐immunoreactive neurons and fibers in the olfactory bulb of the hedgehog (Erinaceus europaeus)
Authors: Alonso J. R. , Arévalo R. , García‐Ojeda E. , Porteros A. , Briñón J. G. , Aijón J. 
Published: January 2005

AbstractThe hedgehog, a macrosomatic insectivore with an extraordinary development of the olfactory structures, has a crucial value for any phylogenetic or comparative study in mammals. The distribution pattern and morphology of NADPH‐diaphorase‐active and calbindin D‐28k‐immunoreactive neurons were studied in the main and accessory olfactory bulbs of the hedgehog. NADPH‐diaphorase (ND) staining was carried out by a direct histochemical method, and the calbindin D‐28k (CaBP) immunoreaction by using a monoclonal antibody and the avidin‐biotin‐immunoperoxidase method. The possible coexistence of both markers was determined by sequential histochemical‐immunohistochemical double labeling of the same sections. Specific neuronal populations were positive for both ND and CaBP markers. No cell colocalized both stains in the hedgehog olfactory bulb. A subpopulation of olfactory fibers, and a subpopulation of olfactory glomeruli, located on the medial side, were positive for ND. Surrounding both the ND‐positive and ND‐negative glomeruli, there were ND‐ and CaBP‐positive periglomerular cells, the latter group being much more abundant. A subpopulation of superficial short‐axon cells was CaBP positive but, contrary to what is observed in rodents, this neuronal type was always ND negative. In addition, three neuronal types were observed in the GL‐EPL border after CaBP immunostaining. These neuronal types have not been previously described either in the hedgehog or in the rodent olfactory bulb. Horizontal cells and vertical cells of Cajal were also observed after both ND and CaBP labeling. Distinct groups of ND‐ and CaBP‐positive cells, differing in size, shape, dendritic branching pattern, and staining intensity, were distinguished in the granule cell layer and in the white matter. The large and medium‐sized cells were identified as a very heterogeneous population of deep short‐axon cells, whereas a subpopulation of granule cells was ND positive. The accessory olfactory bulb showed ND staining in all vomeronasal fibers and glomeruli, and in subpopulations of periglomerular cells, granule cells, and deep short‐axon cells. The CaBP immunolabeling was more restricted and located in subpopulations of periglomerular cells and in deep short‐axon cells. These results indicate different and more complex ND and CaBP staining patterns in the hedgehog olfactory bulb than those previously described in rodents, including the presence of specific, chemically and morphologically defined new neuronal types. © 1995 Willy‐Liss, Inc.
Comparative localization of serotonin1A, 1C, and 2 receptor subtype mRNAs in rat brain
Authors: Wright D. E. , Seroogy K. B. , Lundgren K. H. , Davis B. M. , Jennes L. 
Published: January 2005

AbstractSerotonin (5‐HT) mediates its effects on neurons in the central nervous system through a number of different receptor types. To gain better insight as to the localization of 5‐HT responsive cells, the distribution of cells expressing mRNAs encoding the three 5‐HT receptor subtypes 1A,1C, and 2 was examined in rat brain with in situ hybridization using cRNA probes. 5‐HT1A receptor mRNA labeling was most pronounced in the olfactory bulb, anterior hippocampal rudiment, septum, hippocampus (dentate gyrus and layers CAI‐3), entorhinal cortex, interpeduncular nucleus, and medullary raphe nuclei. 5‐HT 1C receptor mRNA labeling was the most abundant and widespread of the three 5‐HT receptor subtypes examined. Hybridization signal was denset in the choroid plexus, anterior olfactory nucleus, olfactory tubercle piriform cortex, septum, subiculum, entorhinal cortex, claustrum, accumbens nuclues, striatum, lateral amygdala, paratenial and paracentral thalamic nuclei, subthalamic nucleus, substantia nigra, and reticular cell groups. 5‐HT2 receptor mRNA was localized to the olfactory bulb, anteriorhippocampal rudiment, frontal cortex, piriform cortex, entorhinal cortex, claustrum, pontine nuclei, and cranial nerve motor nuclei including the oculomotor, trigeminal motor, facial, dorsal motor nucleus of the vagus, and hypoglossal nuclei. The distributions of mRNAs for the three different 5‐HT receptor subtypes overlap with regions that bind various 5‐HT receptor‐selective ligands and are present in nearly all areas known to receive serotonergic innervation. The results of this study demonstrate that nervous which express these 5‐HT receptor subtypes are very widespread in the central nervous system, yet possess unique distributions with in the rat brain. Moreover, previously unreported regions of 5‐HT receptor subtype expression were observed, particulary with the 5‐HT receptor riboprobe in the brainstem. Finally, several brain areas contain multiple 5‐HT receptor subtype mRNAs, which leads to the possibility that individual cells may express more than one 5‐HT receptor subtype. © 1995 Willy‐Liss, Inc.
Quantitative analysis of the columnar arrangement of neurons in the human cingulate cortex
Authors: Schlaug Gottfried , Schleicher Axel , Zilles Karl 
Published: January 2005

AbstractThe spatial organization of human cingulate (areas 24b, 23b, and 31) and pericingulate (areas 7 and 19) cortex was examined by using an image analyzer to measure characteristics of vertically oriented, translaminar columns of neurons in the cerebral cortex. Columns of 30–50 μm in diameter are hypothesized to be a general feature of cortical organization, but no quantitative analysis of different human cortical areas has been performed. Our results prove for the first time that a columnar organization was detectable in every area examined. The average width of cell columns was approximately 40 μm separated by a neuropil‐rich fascile of the same dimension. Because differences in the expression of a columnar organization were seen, the degree of columnization was subsequently expressed by a verticality index (VI) revealing specific changes in its dimension depending on the architectonic area. The VI was calculated by a linear combination of three variables derived from the measurement of cell density profiles in Nissl‐stained sections at right angles to vertically oriented cell columns. Variables included the amplitude of profile peaks, the standard deviation of the width of those profile peaks, and the standard deviation of the distances between profile peaks. The index of verticality describes the deviation of a distinct area and layer from the mean degree of vertical organization of all cortical areas and layers examined. Thus, different degrees of columnar organization can be quantitatively described by the verticality index and can be used as criteria to characterize architectonic areas. © 1995 Willy‐Liss, Inc.
Colocalization of somatostatin, neuropeptide Y, and NADPH‐diaphorase in the caudate‐putamen of the rat
Authors: Rushlow W. , Flumerfelt B. A. , Naus C. C. G. 
Published: January 2005

AbstractSomatostatin, neuropeptide Y, and nicotinamide adenine dinucleotide phosphatediaphorase are colocalized within a small population of medium aspiny neurons in the caudate‐putamen of the rat. The extent of colocalization, however, appears to be in dispute. In order to examine the question of colocalization between these three neuroactive substances, a series of double‐labelling experiments was performed. This was accomplished by combining immunocytochemistry for somatostatin or neuropeptide Y or enzyme histochemistry for nicotinamide adenine dinucleotide phosphate‐diaphorase with in situ hybridization for somatostatin and/or neuropeptide Y mRNA. The results of such analysis indicate that nicotinamide adenine dinucleotide phosphate‐diaphorase and somatostatin mRNA are 100% colocalized throughout the caudate‐putamen, except for the area bordering the globus pallidus. All neurons that contain neuropeptide Y contain somatostatin message. Only 84% of the neurons that contain somatostatin mRNA, however, also contain neuropeptide Y. Neurons that contain somatostatin 28 but not neuropeptide Y are found throughout the caudate‐putamen. These results indicate that the somatostatin neuron population in the rat caudate‐putamen is not homogeneous. Instead, the medium aspiny neuron population is actually composed of several subpopulations based on the content of neuroactive substances. © 1995 Willy‐Liss, Inc.
Development of the catecholamine neurons in human embryos and fetuses, with special emphasis on the innervaton of the cerebral cortex
Authors: Zecevic Nada , Verney Catherine 
Published: January 2005

AbstractThe cathecholaminergic (CA) systems have been described as appearing early in the development of the mammalian central nervous system (CNS), but their exact distribution in humans has been studied only following gestational week (g.w.) 13. Furthermore, it is not known when CA fibers initially penetrate the developing cerebral cortex. In this study, the CA cells groups and fibers are described in the human central nervous system from 6 to 13 g.w. as revealed with immunocytochemical techniques, with antibodies raised against three synthetic enzymes of the catecholamine (CA) pathway: tyrosine hydroxylase (TH), dopamine‐β‐hydroxylase (DBH), and phenylethanolamine‐N‐methyltransferase (PNMT). At 6 g.w., TH‐like immunoreactive (TH‐IR) cell groups were widespread through the caudorostral extension of the CNS corresponding to the different dopaminergic mesencephalic and hypothalamic groups. Noradrenergic groups also were labeled in the medulla oblongata and in the locus coeruleus as well as in other areas in the pons. Additional TH‐IR cell groups might represent a transient developmental expression of TH similar to that observed in the rat. DBH immunoreactivity labeled primarily the noradrenergic pontic cell groups and, to a lesser extent, groups located in the medulla oblongata. Rare PNMT‐IR neurons were detected in the medulla oblongata only at 13 g.w. The main CA bundles described in the adult were also observed in human embryos and fetuses. At 6 g.w., TH‐IR pathways extended caudorostrally within the central tegmental tract and the dorsal tegmental bundle, the latter merging with the dopaminergic mesotelencephalic pathway giving rise to the medial forebrain bundle in the basal forebrain. At 7–8 g.w., TH‐IR fibers extended to the basal ganglia and the telencephalic wall. The first TH‐IR and, to a much lesser extent, DBH‐IR fibers penetrated the frontal lateral cortical anlage through the intermediate zone and sparsely through the marginal zone but not through the thin cortical plate. A second stream entered the telencephalic anlage frontomedially, ventral to the septal area. At 11 g.w., numerous TH‐IR fibers invaded the subplate layer, but they penetrated the cortical plate only at 13 g.w. At that time, TH‐IR and DBH‐IR fibers had reached the occipital cortex in a rostrocaudal gradient. The appearance of well‐organized CA system already in embryonic stages in humans could be of great importance for normal shaping of the nervous system as well as for development of cortical circuitry. © 1995 Willy‐Liss, Inc.
Organization of the somatosensory cortex of the star‐nosed mole
Authors: Catania Kenneth C. , Kaas Jon H. 
Published: January 2005

AbstractThe nose of thestar‐nosed mole consists of a star‐like array of 22 fleshy appendages that radiate from the nostrils and are moved about to explore the environment. The surface of each appendage, or ray, is densely packed with bulbous receptor organs (Eimer's organs) that are highly responsive to tactile stimulation. Here, we report that these rays have corresponding morphological specializations in somatosensory cortex. Using a stain for the metabolic enzyme, cytochrome oxidase (CO), to reveal subdivisions of cortex, we disclosed a complex pattern of CO‐dense stripes or bands separated by sharp lines or septa of low CO staining. Multiunit microelectrode recordings of neural activity evoked by light tactile stimuli in somatosensory cortex of anesthetized moles allowed us to mark some of the bands and other CO‐dark regions with small electrolytic lesions and later relate recording results to the CO pattern. The results suggest that the primary somatosensory cortex, S1, has an unusual ventrolateral location and orientation with representations of mouth, nose rays, facial vibrissae, forepaw, and trunk in a rostrocaudal sequence. Within this presumptive S1, the 11 rays of the contralateral nose are represented as a rostral‐to‐caudal cortical pinwheel of 11 stripes. Cortex ventral to the primary set of stripes contains a second rostrocaudal representation of the rays as a mirror image of the first. This second set of stripes may be part of the second somatosensory area, S2. A third pattern of CO stripes appears to merge partially with caudal stripes of the first two patterns, so that a full pattern of 11 stripes is not obvious. This representation may correspond to the ventral somatosensory area, VS, of other mammals. An extensive area of cortex separated from the nose by a large septum was responsive to stimulation of the forelimb. Auditory cortex is unusually caudal in this mole, and the presumptive primary visual area is relatively small. These specializations of somatosensory cortex in star‐nosed moles may be more patent examples of the consequences of more general factors in brain development. The observations are consistent with the general rule that the terminations of sensory projections with discorrelated activity segregate. © 1995 Willy‐Liss, Inc.
Development of the hippocamposeptal projection in the rat
Authors: Linke Rüdiger , Pabst Thomas , Frotscher Michael 
Published: January 2005

AbstractWe analyzed the development of the hippocamposeptal projection and the morphology of the neurons giving rise to this projection. The fluorescent tracer Dil was injected into the septal region or the hippocampus in fixed brains of embryonic and early postnatal rats. Anterogradely labeled hippocampal axons first reached the septal region at E16. They ran along the midline of the brain, thereby approaching the medial septum. Axons to the lateral septum were first observed around E18/19. The lateral septum is partly innervated by collaterals of axons that travel to the medial septum. The projection to the lateral septal nuclei becomes more massive during early postnatal stages, whereas that to the medial septum becomes smaller. Cells in the medial septum retrogradely labeled by injection into the hippocampus were first observed at E18. Thus, the hippocamposeptal projection is established earlier than the septohippocampal projection.The first hippocampal projection neurons are nonpyramidal neurons that appear to pioneer the pathway to the septum. Pyramidal cell axons follow this first cohort of axons into the medial septum. Pyramidal cells could be retrogadely labeled from the medial septum during the perinatal period but then diminished in number. At P10, only nonpyramidal cells were labeled by medial septal injections. This indicates that the pyramidal component of this projection is transient and is removed shortly after birth. However, as is known from ther studies, hippocampal pyramidal cells give rise to a powerful projection to the lateral septum in adult animals. Our results show that there is a considerable remodeling of the projection from the hippocampus to the septum during ontogenetic development. © 1995 Willy‐Liss, Inc.
Distribution and development of β‐adrenergic receptors in the rat olfactory bulb
Authors: Woo Cynthia C. , Leon Michael 
Published: January 2005

AbstractBeta‐adrenergic stimulation appears to be involved in the establishment of both learned olfactory preferences and functional changes in the olfactory bulb of young rats. We examined the postnatal development of beta‐adrenergic receptors within the main olfactory bulb to determine the density and distribution of these receptors. To quantify beta‐adrenergic receptor density, olfactory bulb homogenates from postnatal day (PND) 1, 6, 12, and 19 rats were assessed for receptor binding with 125I‐iodopindolol. In addition, receptor autoradiography was performed with the selective P, antagonist ICI 89,406 and selective β2 antagonist ICI 118,551 on tissue sections from PND 1–30 rats to examine the distribution of the beta‐adrenergic receptor subtypes. We observed both an increase in receptor density with increasing age and the formation of distinct spatial distributions of the two beta receptor subtypes within the bulbar lamina. Beta‐adrenergic receptors were located in both deep and superficial layers of the bulb. Specifically, β1 receptors were present in the granule cell, internal plexiform and glomerular layers. β2 receptors were present in the granule cell, internal plexiform, external plexiform, and glomerular layers. High levels Of β2 receptors also were visible in the meningeal layers between the two bulbs. High densities of β1 and β2 adrenergic receptors were present within different sets of individual glomeruli by PND 12–19, and the number of these foci increased with age. The knowledge of beta‐noradrenergic receptor localization in the bulb may provide the basis for understanding the action of norepinephrine on neural processes in the developing olfactory bulb. © 1995 Wiley‐Liss, Inc.
Transient subcortical connections of inferior temporal areas TE and TEO in infant macaque monkeys
Authors: Webster Maree J. , Bachevalier Jocelyne , Ungerleider Leslie G. 
Published: January 2005

AbstractAs part of a long‐term study designed to examine the ontogeny of visual memory in monkeys and its underlying neural circuitry, we have examined the subcortical connections of the inferior temporal cortex in infant monkeys and compared them to those previously described in adult monkeys (Webster et al. [1993] J. Comp. Neurol. 335:73–91). Inferior temporal areas TEO and TE were injected with wheat germ agglutinin conjugated to horseradish peroxidase and tritiated amino acids, respectively, or vice versa, in 1‐week‐old (N = 6) and 3–4‐year‐old (N = 6) Macaca mulatta, and the distributions of labeled cells and terminals were examined in subcortical structures. Although the connections of inferior temporal cortex with subcortical structures were found to be similar in infant and adult monkeys, several projections appear to undergo refinement during development. Quantitative analysis showed that (1) whereas the projection from TE to the superior colliculus is consistent (5 of 5 cases) and widespread in infants, it is less reliable (2 of 7 cases) and limited in areal extent in adults; (2) although the projections from TE to nucleus medialis dorsalis and the tail of the caudate are present in infants and adults, they are reduced in adults; and (3) TEO receives input from the dorsal lateral geniculate nucleus in both infants and adults, but the number of cells giving rise to this projection is lower in adults. There was also a suggestion that TE projects to nucleus paracentralis in infants (2 of 5 cases) but not in adults (0 of 7 cases). No differences between infants and adults were apparent in other subcortical connections, including those with the pulvinar, reticular nucleus, claustrum, and putamen. © 1995 Wiley‐Liss, Inc.
Distribution of calcitonin gene‐related peptide‐like immunoreactivity in the brain of the small‐spotted dogfish, scyliorhinus canicula L
Authors: Molist Pilar , Rodriguez‐Moldes Isabel , Batten Trevor F. C. , Anadon Ramon 
Published: January 2005

AbstractThe distribution of neuropeptides has been useful in comparing neuronal aggregates of elasmobranchs with those in other vertebrates. The distribution of calcitonin gene‐related peptide (CGRP)‐like immunoreactivity in the brain of the dogfish was examined with an antiserum to rat α‐CGRP. Western blot analysis confirms that our antiserum recognizes a single peptide in the dogfish brain very similar to mammalian CGRP. CGRP‐like immunoreactivity was located in discrete neuronal groups. CGRP‐like‐immunoreactive (CGRP‐ir) neurons were found in the motor nuclei III, IV, V, VI, VII, IX, and X of the brainstem motor column and in the octavolateral efferent neurons. In the isthmal region, two groups of CGRP‐ir neurons appeared in the parabrachial region and reticular substance. Three other CGRP‐ir cell groups were observed in the mesencephalon: in the ventral tegmental area, in the substantia nigra, and one widely scattered but numerous population in superficial layers of the optic tectum. In the diencephalon, CGRP‐ir cells were observed in the magnocellular preoptic nucleus and the organon vasculosum hypothalami. A population of CGRP‐ir cells was also observed in the entopeduncular nucleus in the impar telencephalon. CGRP‐ir fibers of central origin were widely distributed in the brain, but the most conspicuous areas were found in the ventral telencephalon, the hypothalamus, the mesencephalic lateral reticular area, and the dorsolateral isthmal region. The neurointermediate lobe of the hypophysis was also richly innervated by CGRP‐ir fibers. CGRP‐ir sensory fibers of cranial nerves IX and X and of dorsal spinal roots formed very conspicuous terminal fields in the lobus vagi and Cajal's nucleus commissuralis and in the dorsal region of the substantia gelatinosa, respectively. Comparison of the distribution of fibers and perikarya in dogfish and other vertebrates suggests that this CGRP‐ir system has been well conserved during evolution. © 1995 Wiley‐Liss, Inc.