bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitric oxide synthase in tiger salamander retina
Authors: Kurenni Dmitri E. , Thurlow Genevieve A. , Turner Ray W. , Moroz Leonid L. , Sharkey Keith A. , Barnes Steven 
Published: January 2005

AbstractPrevious studies have indicated that nitric oxide, a labile freely diffusible biological messenger synthesized by nitric oxide synthase, may modulate light transduction and signal transmission in the retina. In the present work, the large size of retinal cells in tiger salamander (Ambystoma tigrinum) allowed the utilization of nicotinamide adenine dinucleotide phosphate (NADPH)‐diaphorase histochemistry and nitric oxide synthase immunocytochemistry to delineate the cell‐specific intracellular localization of nitric oxide synthase. NADPH‐diaphorase activity was highly concentrated in the outer retina, in rod and cone inner segment ellipsoids, and between and adjacent to the photoreceptor cell bodies in the outer nuclear layer. Examination of enzymatically isolated retinal cells indicated that outer nuclear layer NADPHdiaphorase activity was localized to the distal processes of the retinal glial (Müller) cells and to putative bipolar cell Landolt clubs. Less intense NADPH‐diaphorase activity was seen in the photoreceptor inner segment myoid region, in a small number of inner nuclear layer cells, in cap‐like configurations at the distal poles of cells in the ganglion cell layer and surrounding ganglion cell layer somata, and in punctate form within both plexiform layers, the pigment epithelium, and the optic nerve. Nitric oxide synthase–like immunoreactivity was similarly localized, but was also concentrated along a thin sublamina centered within the inner plexiform layer. The potential for nitric oxide generation at multiple retinal sites suggests that this molecule may play a number of roles in the processing of visual information in the retina. © 1995 Wiley‐Liss, Inc.
Centrifugal projections upon the retina: An anterograde tracing study in the pigeon (Columba livia)
Authors: Woodson Walter , Shimizu Toru , Wild J. Martin , Schimke Jan , Cox Kevin , Karten Harvey J. 
Published: January 2005

AbstractPrevious work has shown that the avian retina receives two types of centrifugal fibers from the brain. These types can be distinguished based on the size and the morphology of their terminal endings and have been termed convergent and divergent. The centrifugal fibers arise from the isthmooptic nucleus (ION) and the surrounding ectopic cell region (ECR). We used injections of anterograde tracers either to the ION/ECR or to the ECR only to determine the morphology, depth of termination, and regional distribution of the centrifugal fibers arising from each.We found that the ECR gives rise only to the divergent type of the centrifugal fiber, whereas the ION gives rise mainly to the convergent type but may also send some fibers of the divergent type. Most of the fibers project contralaterally, although a few from the ECR project ipsilaterally. The terminals of either type are not uniformly distributed throughout the retina; instead, they are found mainly in the inferior, midtemporal, to nasal portion of the retina and appear to avoid the fovea and most of the red field. By comparison, the ION receives a major projection from portions of the tectum that receive input from the fovea and the red field in a type of neural loop. The neural loop does not project to the same point (homotopic), but projects from the red field to the inferior retina (heterotopic), as was recently proposed by Holden (1990; Vis. Neurosci. 4:493–497).The distribution of centrifugal axons corresponds to displaced ganglion cells that selectively innervate the nuclei of the accessory optic system (AOS), including the nucleus of the basal optic root (dorsal, ventral, and lateral) and the nucleus lentiformis mesencephali, pars magnocellularis. We suggest that the centrifugal axons act by increasing the gain on the AOS, thereby enhancing retinal stabilization of gaze with improved accuracy of pecking of small objects. © 1995 Wiley‐Liss Inc.
Postnatal development of periodontal ruffini endings in rat incisors: An immunoelectron microscopic study using protein gene product 9.5 (PGP 9.5) antibody
Authors: Nakakura‐Ohshima Kuniko , Maeda Takeyasu , Ohshima Hayato , Noda Tadashi , Takano Yoshiro 
Published: January 2005

AbstractPostnatal development of Ruffini endings was ultrastructuraally investigated in the upper incisors of the rat from 1 day to 60 days after birth by means of protein gene product 9. 5 (PGP 9. 5) immunocytochemistry. The immunostaining with PGP 9. 5 antibody clearly demonstrated chronological alterations of the distribution and ultrastructure of the Ruffini endings during postnatal development. At 1 day after birth, the PGP 9. 5 positive nerve terminals contained a few mitochondria and vesicles immunonegative for PGP 9. 5. Dendritic terminals appeared at 4 days after birth, with a small number of expanded or bulbous portions. These expanded portions possessed morphological features similar to those of the growth cone: several mitochondria and various kinds of vesicles. Typical Ruffini endings with dendritic ramification and expanded portions appeared 7–11 days after birth. At this stage, parts of the axon terminals extended through the slits of Schwann cell covering and formed finger‐like projections called axonal spines. These Ruffini endings increased dramatically in number after 24–26 days and were identical in density and morphology to those seen in adult rats. After the commencement of the occlusion between the incisors, the number of large mitochondria increased, in contrast to the decrease of the vesicles in the axon terminals. Moreover, the axonal spines increased both in number and in length. Thus, the periodontal nerve endings showed stage‐specific morphological features intimately related in timing to tooth eruption and occlusion. Functional stimuli possibly contribute to the final differentiation and maturation of the periodontal Ruffini endings. © 1995 Wiley‐Liss Inc.
An immunochemical, ultrastructural, and developmental characterization of the horizontal basal cells of rat olfactory epithelium
Authors: Holbrook Eric H. , Szumowski Karen E. Mieleszko , Schwob James E. 
Published: January 2005

AbstractThe olfactory epithelium, which retains a capacity for neurogenesis throughout life, contains two categories of basal cells, dark/horizontal and light/globose, neither of which is fully characterized with respect to their function during the processes of neurogenesis and epithelial reconstitution after injury. The aim of this study was to define the potential biological role(s) of dark/horizontal basal cells (D/HBCs) in the epithelium by performing immunochemical, electron microscopic, and developmental analyses of this cell population. The D/HBCs express several specific immunochemical characteristics, which include the rat homologues of human cytokeratins 5 and 14, which were identified on the basis of staining with subunit‐ specific monoclonal antibodies and two‐dimensional immunoblot analysis of the immunoreactive proteins. Indeed, the D/HBCs are the only cells in the olfactory mucosa that express these specific cytokeratins. The D/HBCs also express an α‐galactose or α‐N galactosamine moiety to which the Iß4 isolectin from Bandeiraea simplicifolia binds. Moreover, the D/HBCs are heavily labeled by two different antibodies against the EGF receptor and by a monoclonal antibody that binds to phosphotyrosine. These characteristics are also common to the basal cells of respiratory epithelium. The electron microscopic analysis of the basal region of the olfactory epithelium and the light microscopic immunofluorescence observations demonstrate that the D/HBCs provide a bridge between the basal processes of some sustentacular cells and the basal lamina. The most striking ultrastructural feature of the D/HBCa is their enfolding of virtually all bundles of olfactory axons within tunnels formed where D/HBCs arch over the basal lamina. The intimacy of the arrangement between D/HBCs and olfactory axons suggests that signals may pass from axons to D/HBCs or vice‐versa. With respect to the development of D/HBCs, cells that express cytokeratins 5 and 14 and the EGF receptor first appear near the boundary with respiratory epithelium late in development, but do not extend throughout the olfactory epithelium until the middle of the first postnatal week. Taken together, the present findings and previously published data suggest that D/HBCs help to maintain the structural integrity of the olfactory epithelium, participate in its recovery from injury, and may also function to signal the status of the neuronal population of the epithelium. © 1995 Wiley‐Liss, Inc.
Cytoskeleton gradients in three dimensions during neurulation in the rabbit
Authors: Viebahn Christoph , Lane E. Birgitte , Ramaekers Frans C. S. 
Published: January 2005

AbstractMorphogenetic movements leading to the formation of the neural tube and cellular differentiation leading to neuronal and glial cell lineages are both part of early development of the vertebrate nervous system. In order to analyze the degree of overlap between these processes, cellular differentiation during the shaping of the neural plate is investigated immunohistochemically by using monoclonal intermediate filament protein antibodies and the 7.5–8.0‐day‐old rabbit embryo as a model. Western blotting is used to confirm the specificity of the antibodies, which include a new monoclonal vimentin antibody suitable for double‐labeling in combination with monoclonal cytokeratin (and fibronectin) antibodies. Starting in the early somite embryo and concomitant with neural plate folding, a gradual loss of cytokeratin 8 (and 18) expression in the neuroepithelium is mirrored by a gain in virnentin expression with partial coexpression of both proteins. At the prospective rhombencephalic and spinocaudal levels, vimentin expression, in particular, changes (i. e., increases) along gradients in three dimensions: along the longitudinal axis of each neuroepithelial cell from bssal to apical, in the transverse plane of the embryo from dorsolateral to veritromedial and along the craniocaudal axis from prospective rhombencephalic toward spinocaudal levels of the neural plate. At the prospective mes‐ and prosencephalic levels, the expression change also proceeds from basal to apical within each neuroepithelial cell, but along the other axes described here, the progress in expression change is more complex. Although the functional meaning of these highly ordered expression changes is at present unclear, the gradients suggest a novel pattern of neuroepithelial differentiation which may be functionally related to the process of interkinetic nuclear migration (Sauer [1935] J. Comp. Neurol. 62:377–402) and which partially coincides with the morphogenetic movements involved in the shaping of the neural plate. © 1995 Wiley‐Liss, Inc.
Dependence of developing group Ia afferents on neurotrophin‐3
Authors: Kucera Jan , Fan Guoping , Jaenisch Rudolf , Linnarsson Sten , Ernfors Patrik 
Published: January 2005

AbstractAt birth, group Ia proprioceptive afferents and muscle spindles, whose formation is Ia afferent‐dependent, are absent in mice carrying a deletion in the gene for neurotrophin‐3 (NT‐3 –/–). Whether Ia afferents contact myotubes, resulting in the formation of spindles which subsequently degenerate, or whether Ia afferents and spindles never form was examined in NT‐3 –/– mice at embryonic days (E) 10.5–18.5 by light and electron microscopy. Three sets of data indicate that Ia neurons do not develop and spindles do not form in NT‐3‐deflcient mice. First, peripheral projections of Ia afferents did not innervate hindlimbs of NT‐3 –/– mice, as reflected by a deficiency of nerve fibers in limb peripheral nerves and an absence of afferent nerve‐muscle contacts and spindles in the soleus muscle at E13.5–E18.5. Second, central projections of Ia afferents did not innervate the spinal cord in the absence of NT‐3, as shown by an atrophy of the dorsal spinal roots and absence of afferent projections from limb musculature to spinal motor neurons at E13.5 or E15.5. Lastly, the lumbar dorsal root ganglia (DRGs) at E10.5–E 14.5, the stages of development that precede or coincide with the innervation of the spinal cord and hindlimbs by Ia afferents, were 20–64% smaller in mutant than in wild‐type mice, presumably because the cell bodies of Ia neurons were absent in embryos lacking NT‐3.The failure of Ia neurons to differentiate and/or survive and Ia afferent projections to form in early fetal mice lacking NT‐3 suggests that NT‐3 may regulate neuronal numbers by mechanisms operating prior to neurite outgrowth to target innervation fields. Thus, developing Ia neurons may be dependent on NT‐3 intrinsic to the DRGs before they reach a stage of potential dependence on NT‐3 retrogradely derived from skeletal muscles or spinal motor neurons. © 1995 Wiley‐Liss, Inc.
Anatomy of the antennal motoneurons in the brain of the honeybee (Apis mellifera)
Authors: Kloppenburg Peter 
Published: January 2005

AbstractThis paper describes the morphology and location of the cerebral motoneurons that control the movement of the antennae in the honeybee. The position of each antenna is controlled by two muscle systems; the basal segment (scape) is moved by four muscles within the head capsule, and two muscles within the scape control the distal segments (flagellum) of the antenna. The motor system of the scape is controlled by nine motoneurons, and that of the flagellum by six motoneurons. All of these motoneurons share the dorsal lobe as a common projection area where their dendritic fields overlap extensively. These motoneurons do not have contralateral projections. The cell bodies of the antennal motoneurons are located in the soma layer lateral to the dorsal lobe. The somata for each muscle system are arranged in three clusters; two clusters are located in a region of the cortex dorsal to the dorsal lobe and one cluster is located in the cortex ventral to the dorsal lobe. In the cortex dorsal to the dorsal lobe, one cluster of each muscle system shares the same region. Altogether five groups of cell bodies can be distinguished. Double labeling of the motoneurons and presumptive mechanosensory primary antennal afferents with fluorescent dyes has shown that there is an extensive overlap of axonal projection of antennal mechanosensory afferents with dendritic fields of antennal motoneurons. © 1995 Wiley‐Liss, Inc.
Genesis of the retinal pigment epithelium in the macaque monkey
Authors: Rapaport David H. , Rakic Pasko , Yasamura Douglas , LaVail Matthew M. 
Published: January 2005

AbstractThe development of the retinal pigment epithelium (RPE) was studied in rhesus monkey (Macaca mulatta) fetuses, neonates, and juveniles exposed to a pulse of (3H‐TdR) between embryonic day (E) 25 and postnatal day (P) 204 and examined at short and long intervals after the injection of the isotope.The RPE develops from the outer layer of the optic cup which by E45 consists of a multistratified epithelium. The outer layer appears immature near the retina's edge and gradually becomes monostratified and more mature centrally. Even at this early stage, all cells contain pigmented melanosomes, although peripherally the pigment is limited to the apical portion of the cells. Examination of autoradiograms from animals allowed to survive for several postnatal months shows that monkey RPE cell genesis begins just after E27, increasing to a peak frequency of 0. 38 cells/mm at E43. Between E30 and E85 the density of radiolabelled cells varies within a restricted range of from 0.2 to 0.4 cells/mm (mean = 0.25 ± 0.09). From the density of radiolabelled cells, and data on the overall density of RPE cells in the juvenile retina, we determined the labelling index. During the first half of gestation, between 0. 38% and 0. 99% (mean = 0. 65 ± 0. 22) of RPE cells are generated during the short interval of isotope availability after pulse injection. Approximately 5% of RPE cells were generated by E33, and 50% by E71. After E85, RPE cytogenesis begins gradually to decrease, and 95% of the cells have been generated by the time of birth. Continued, very low density (0. 01 cells/mm) cytogenesis in the RPE is seen at P17, and persists at least until seven months postnatally.RPE cell genesis begin near the fovea, and proceeds towards the periphery. Cell division largely ceases in both foveal and perifoveal regions by E56, at which time labelled cells first begin to appear peripheral to the equator. Besides the timing differences, RPE genesis in the central retina differs from that in the peripheral retina in that it proceeds at a higher rate, and lasts for a shorter time period. A prolonged postnatal period of low density RPE cell genesis persists in both central and peripheral retina. Comparison of the pattern of expansion of the area containing radiolabelled cells in the RPE and neuroretina demonstrates a remarkable spatial and temporal correspondence. Close analysis suggests that at any point on the retina, the last cells are generated in the neuroretina slightly before the last cells in the RPE. © 1995 Wiley‐Liss, Inc.
Evidence for corticotropin‐releasing hormone projections from Barrington's nucleus to the periaqueductal gray and dorsal motor nucleus of the vagus in the rat
Authors: Valentino Rita J. , Pavcovich Luis A. , Hirata Harumitsu 
Published: January 2005

AbstractThe present study used anterograde and retrograde tract tracing and immunohistochemistry to determine the efferent projections of corticotropin‐releasing hormone (CRH) neurons of Barrington's nucleus in the rat. Injections of Phaseolus vulgaris‐leucoagglutinin into Barrington's nucleus resulted in anterograde labeling in the dorsal motor nucleus of the vagus, periaqueductal gray, medial thalamic nuclei, lateral hypothalamus, paraventricular nucleus of the hypothalamus, lateral preoptic area, and lateral septum. The retrograde tract tracer, fluorogold, injected into the lumbosacral spinal cord labeled many, but not all, CRH‐immunoreactive neurons in Barrington's nucleus. Moreover, some Barrington's neurons that were retrogradely labeled from the spinal cord were not CRH‐immunoreactive. Several CRH‐immunoreactive Barrington's neurons were retrogradely labeled by fluorogold injections into the periaqueductal gray, and these were located predominantly in the dorsal part of the nucleus. Additionally, some CRH‐immunoreactive Barrington's neurons were retrogradely labeled from fluorogold injections into the dorsal motor nucleus of the vagus. In contrast, fluorogold injections into the lateral hypothalamus, lateral preoptic area, or lateral septum did not result in double labeling of CRH‐immunoreactive neurons in Barrington's nucleus. These results suggest that many, but not all, CRH‐containing neurons of Barrington's nucleus project to the lumbosacral spinal cord. In addition to their previously documented projections to the spinal cord, these neurons may be a source of CRH in the periaqueductal gray and dorsal motor nucleus of the vagus. CRH projections of Barrington's nucleus may play a role in behavioral or autonomic aspects of stress responses, in addition to their proposed role in micturition. © 1995 Wiley‐Liss, Inc.
Monosynaptic projections from the medullary gigantocellular reticular formation to sympathetic preganglionic neurons in the thoracic spinal cord
Authors: Aicher Sue A. , Reis Donald J. , Nicolae Raluca , Milner Teresa A. 
Published: January 2005

AbstractMicroinjection of L‐glutamate into a restricted area of the medullary gigantocellular reticular formation, the gigantocellular depressor area (GiDA), lowers arterial pressure. Unlike the nuclei tractus solitarii and the caudal ventrolateral medulla, the two principle medullary vasodepressor areas, the GiDA projects directly to the spinal cord and not to the rostral ventrolateral medulla (Aicher et al. [1994] Neuroscience 60:761–779). We investigated whether neurons within GiDA directly innervate autonomic areas of the thoracic spinal cord. FluroGold injected into the thoracic spinal cord labeled neurons within functionally defined vasodepressor sites in the GiDA in the same animal.To examine the morphology of GiDA efferents to the spinal cord, the anterograde tracer Phaseolus vulgaris‐leucoagglutinin was iontophoresed into the GiDA, and efferent processes in the intermediolateral cell column and nucleus intercalatus spinalis were examined by electron microscopy. Labeling was confined to axons and axon terminals (n = 144) that usually contained primarily small clear vesicles, contacted large and small dendrites, and formed symmetric (inhibitory) synapses.To determine whether some of the postsynaptic targets of GiDA efferent terminals in the thoracic spinal cord were sympathoadrenal preganglionic neurons, these neurons were retrogradely labeled from the adrenal gland with Fluoro‐Gold in rats that had deposits of the anterograde tracer, biotinylated dextran amine (BDA), in the GiDA. Some BDA‐containing terminals formed symmetric synapses with dendrites containing Fluoro‐Gold. We conclude that a population of neurons in the GiDA monosynaptically innervates some sympathetic preganglionic neurons. The findings suggest the presence of a novel reticulospinal sympathoinhibitory projection originating in the GiDA. © 1995 Wiley‐Liss, Inc.
The physicochemical approach to drug design and discovery (QSAR)
Authors: Hansch Corwin 
Published: January 2005

AbstractThe study of physicochemical parameters to correlate mathematically chemical structure with biological activity induced by sets of congeneric drugs is now generally referred to as QSAR (quantitative structure‐activity relationships). The ways in which the QSAR paradigm are developing are becoming more varied and complex. Many kinds of parameters are under study in many different groups; various types of mathematical models have been proposed and are being evaluated. Drug researchers are turning more to enzyme modulation to control various biological processes. It is the study of enzyme‐ligand reactions of enzymes whose x‐ray crystallographic structure is known that affords us the means for developing a deeper understanding of QSAR and, at the same time, enhancing our ability to make drugs more selective for various forms of a given enzyme. The union of x‐ray crystallography, moleculargraphics, and QSAR is one of the most exciting new areas of drug development. This report is an introduction to how QSAR is being used to gain insight into the interaction of drugs with macromolecules and macromolecular systems.
450088‐S, a ring‐opened prodrug of a 1,4‐benzodiazepine, inhibited [3H]flunitrazepam labeling of rat cerebral cortex in vivo
Authors: Wong David T. , Bymaster Frank P. 
Published: January 2005

AbstractWe report here that a peptidoaminobenzophenone (450088‐S), a ring‐opened prodrug of a 1,4‐benzodiazepine, effectively inhibited the labeling of receptors for 1,4‐benzodiazepines by [3H]flunitrazepam in vivo despite the lack of receptor affinity for 450088‐S in vitro. Labeling of cerebral cortex after an intravenous injection of [3H]flunitrazepam was inhibited by about 80% after an intraperitoneal injection of 450088‐S or diazepam. 450088‐S was found to be four times more potent than diazepam. The inhibition occurred within 5 and 10 min of administration of diazepam and 450088‐S, respectively. These findings demonstrate the occupancy of 1,4‐benzodiazepine receptors in brain upon administration of the prodrug 450088‐S in rats.