bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmentally regulated expression of α‐ and β‐calcitonin gene‐related peptide mRNA and calcitonin gene‐related peptide immunoreactivity in the rat inferior olive
Authors: Morara Stefano , Sternini Catia , Provini Luciano , Rosina Anna 
Published: January 2005

AbstractImmunohistochemical methods have revealed the transient neonatal expression of calcitonin gene‐related peptide (CGRP) in olivocerebellar compartments, and it has been hypothesized that this peptide plays a role in the development of olivocerebellar connectivity. Furthermore, the distribution of the CGRP binding sites in the cerebellar cortex also favors this hypothesis. In this study, the pattern of postnatal expression of α‐ and β‐CGRP mRNAs in the inferior olive (IO) complex was analyzed using in situ hybridization histochemistry with RNA probes complementary to specific sequences of α‐ and β‐CGRP mRNAs, and the results were compared with the pattern of CGRP immunoreactivity. High levels of α‐CGRP mRNA expression were found in specific subnuclei of the IO complex, i. e., the medial part of the dorsal fold of the dorsal accessory olive, the β nucleus, the dorsal cap, the caudal third of the medial accessory olive, and the rostral part of the dorso‐medial cell column; in the same subnuclei β‐CGRP mRNA was detected. The olivary distribution of the two CGRP mRNAs coincided with that of CGRP immunoreactivity. The expressions of α‐CGRP mRNA and CGRP immunoreactivity were restricted to the first 2 postnatal weeks, the peak being reached at the end of the first week; β‐CGRP mRNA was transiently expressed in the same olivary compartments, but only from postnatal day 6 to 9. In general, the α‐CGRP signal was also more intense than the β‐CGRP signal. The present findings indicate that the α‐ and β‐CGRP mRNA expression in the olivary complex is under developmental control and restricted to specific olivocerebellar compartments. The data provide a basis for the transient expression of a CGRP olivocerebellar compartment and further support the hypothesis of a role for CGRP in the complex postnatal cerebellar phenomena of connectivity reshaping and synapse stabilization. © 1995 Wiley‐Liss, Inc.
Organization of the avian “corticostriatal” projection system: A retrograde and anterograde pathway tracing study in pigeons
Authors: Veenman C. Leo , Wild J. Martin , Reiner Anton 
Published: January 2005

AbstractBirds have well‐developed basal ganglia within the telencephalon, including a striatum consisting of the medially located lobus parolfactorius (LPO) and the laterally located paleostriatum augmentatum (PA), Relatively little is known, however, about the extent and organization of the telencephalic “cortical” input to the avian basal ganglia (i. e., the avian “corticostriatal” projection system). Using retrograde and anterograde neuroanatomical pathway tracers to address this issue, we found that a large continuous expanse of the outer pallium projects to the striatum of the basal ganglia in pigeons. This expanse includes the Wulst and archistriatum as well as the entire outer rind of the pallium intervening between Wulst and archistriatum, termed by us the pallium externum (PE). In addition, the caudolateral neostriatum (NCL), pyriform cortex, and hippocampal complex also give rise to striatal projections in pigeon. A restricted number of these pallial regions (such as the “limbic” NCL, pyriform cortex, and ventral/caudal parts of the archistriatum) project to such ventral striatal structures as the olfactory tubercle (TO), nucleus accumbens (Ac), and bed nucleus of the stria terminalis (BNST). Such “limbic” pallial areas also project to medialmost LPO and lateralmost PA, while the hyperstriatum accessorium portion of the Wulst, the PE, and the dorsal parts of the archistriatum were found to project primarily to the remainder of LPO (the lateral two‐thirds) and PA (the medial four‐fifths).The available evidence indicates that the diverse pallial regions projecting to the striatum in birds, as in mammals, are parts of higher order sensory or motor systems. The extensive corticostriatal system in both birds and mammals appears to include two types of pallial neurons: (1) those that project to both striatum and brainstem (i. e., those in the Wulst and the archistriatum) and (2) those that project to striatum but not to brainstem (i. e., those in the PE). The lack of extensive corticostriatal projections from either type of neuron in anamniotes suggests that the anamniote‐amniote evolutionary transition was marked by the emergence of the corticostriatal projection system as a prominent source of sensory and motor information for the striatum, possibly facilitating the role of the basal ganglia in movement control. © 1995 Wiley‐Liss, Inc.
Origin of microglia in the quail retina: Central‐to‐peripheral and vitreal‐to‐scleral migration of microglial precursors during development
Authors: Navascués Julio , Moujahid Amale , Almendros Antonio , Marin‐Teva José L. , Cuadros Miguel A. 
Published: January 2005

AbstractThe origin, migration, and differentiation of microglial precursors in the avascular quail retina during embryonic and posthatching development were examined in this study. Microglial precursors and developing microglia were immunocytochemically labeled with QH1 antibody in retinal whole mounts and sections. The retina was free of QH1+ macrophages at embryonic day 5 (E5). Ameboid QH1+ macrophages from the pecten entered the retina from E7 on. These macrophages spread from central to peripheral areas in the retina by migrating on the endfeet of the Müller cells and reached the periphery of the retina at E12. While earlier macrophages were migrating along the inner limiting membrane, other macrophages continued to enter the retina from the pecten until hatching (E16). From E9 on, macrophages were seen to colonize progressively more scleral retinal layers as development advanced. Macrophages first appeared in the ganglion cell layer at E9, in the inner plexiform layer at E12, and in the outer plexiform layer at E 14. Therefore, it seems that macrophages first migrated tangentially along the inner retinal surface and then migrated from vitreal to scleral levels to gain access to the plexiform layers, where they differentiated into ramified microglia. Macrophages appeared to differentiate shortly after arrival in the plexiform layers, as poorly ramified QH1+ cells were seen as early as E12 in the inner plexiform layer and at E14 in the outer plexiform layer. Radial migration of macrophages toward the outer plexiform layer continued until posthatching day 3, after which retinal microglia showed an adult distribution pattern. We also observed numerous vitreal macrophages intimately adhered to the surface of the pecten during embryonic development, when macrophages migrated into the retina. These vitreal macrophages were not seen from hatching onwards, when no further macrophages entered the retina. © 1995 Wiley‐Liss, Inc.
Distribution and effects of tachykinin‐like peptides in the stomatogastric nervous system of the crab, Cancer borealis
Authors: Blitz Dawn M. , Christie Andrew E. , Marder Eve , Nusbaum Michael P. 
Published: January 2005

AbstractThe rhythmically active pyloric and gastric mill motor patterns in the stomatogastric ganglion of the crab, Cancer borealis, are influenced by modulatory projection neurons whose somata are located primarily in the other ganglia of the stomatogastric nervous system. One of these projection neurons exhibits substance P‐like immunolabeling. However, bath application of substance P does not influence these motor patterns. To determine whether a different peptide is responsible for the substance P‐like immunolabeling, we studied the presence and physiological effects of the locustatachykinins and the leucokinins, two families of tachykininlike peptides originally identified in insect nervous systems. Locustatachykinin‐hke immunolabeling has the same distribution in the stomatogastric nervous system as substance P‐like immunolabeling and colocalizes with it in the majority of immunopositive structures. Preincubation of locustatachykinin antibody with substance P, and preincubation of substance P antibody with locustatachykinin, blocks subsequent immunolabeling in the stomatogastric nervous system. In contrast, we found no leucokinin‐like immunolabeling in this system. Bath application to the stomatogastric ganglion of individual locustatachykinins or leucokinins excited the pyloric rhythm in a state‐dependent manner. Each peptide family had distinct effects on the pyloric rhythm. Thus, both of these tachykinin‐like peptide families are likely related to native neuropeptides that influence the pyloric rhythm. Furthermore, a member of the locustatachykinin family is likely to be the source of the previously identified substance P‐like immunoreactivity in the stomatogastric nervous system. © 1995 Wiley‐Liss, Inc.
Macrophages, microglia, and astrocytes are rapidly activated after crush injury of the goldfish optic nerve: A light electron microscopic analysis
Authors: Battisti W. P. , Wang J. , Bozek K. , Murray M. 
Published: January 2005

AbstractSeveral matrix and adhesion molecules in fish optic nerve, which are constitutively expressed, are increased during axonal regeneration and are primarily associated with nonneuronal cells (W. P. Battisti, Y. Shinar, M. Schwartz, P. Levitt, and M. Murray [1992] J. Neurocytol. 21:557–573). The current study examines the reactions of specific cell types to optic nerve crush and axonal regeneration.The goldfish optic nerve contains macroglia and microglia as well as a population of monocyte‐derived cells (granular macrophages) unique to goldfish. Two cell types were OX‐42 positive (granular macrophages and microglia), indicating monocyte lineage, each with a distinct morphology and distribution within the nerve. Within hours of the optic nerve crush, the number of OX‐42‐labeled cell profiles increased near the crush site, remained elevated during the time axons were elongating, and then declined. Microglia, but not granular macrophages, were phagocytically active. Astrocytes are readily identified in the normal optic nerve, but they exhibited marked morphologic changes within hours of injury, which is consistent with the contribution these cells make to the altered environment. Oligodendroglia could not be reliably identified in regenerating optic nerves until myelin was formed.A comparison of the distribution of OX‐42‐labeled cells with that of transforming growth factor β‐1 (TGF‐β1) and tenascin suggests that these molecules are expressed by granular macrophages. Tenascin staining may be additionally associated with astrocytes and/or microglia. The rapid response of these nonneuronal cells to injury, their rapid phagocytic activity, and the secretion of growth‐promoting factors by these cells likely contributes to the environment that supports robust regeneration by optic axons in the goldfish. © 1995 Wiley‐Liss, Inc.
Early development of efferent projections from the chick tectum
Authors: Shepherd I. T. , Taylor J. S. H. 
Published: January 2005

AbstractThe early development of the uncrossed tectobulbar and the crossed tectospinal tracts was studied. These two projections arise from the same structure, the mesencephalon, and develop during the same time period, but follow divergent courses. We have traced the pathways followed by these projections and identified the positions at which axon guidance decisions are made. The first neurons differentiate either side of the entire rostrocaudal extent of the dorsal midline and initiate axons that extend dorsoventrally across the surface of the tectum. At the ventral edge of the tectum these axons turn abruptly and fasciculate to form a caudal descending projection to the hindbrain. These axons extend to the caudal hindbrain and do not project to the periphery along cranial nerve roots. We therefore consider this tract to be the teetobulbar, rather than the mesencephalic division of the trigeminal. While the tectobulbar projection is still developing, a second wave of axons is initiated, which arises from only the rostral part of the tectum. These axons grow beyond the tectobulbar turn point and continue toward the ventral midline, where they cross the floor plate, before turning caudally at the lateral edge of the main descending hindbrain tract, the ventrolateral tract. We discuss the development of these tracts with reference to possible guidance cues mediating their course. © 1995 Wiley‐Liss, Inc.
Projections of the lateral terminal accessory optic nucleus of the common marmoset (Callithrix jacchus)
Authors: Blanks Robert H. I. , Clarke Robert J. , Lui Fausta , Giolli Roland A. , Van Pham Sang , Torigoe Yasuhiro 
Published: January 2005

AbstractThe connections of the lateral terminal nucleus (LTN) of the accessory optic system (AOS) of the marmoset monkey were studied with anterograde 3H‐amino acid light autoradiography and horseradish peroxidase retrograde labeling techniques. Results show a first and largest LTN projection to the pretectal and AOS nuclei including the ipsilateral nucleus of the optic tract, dorsal terminal nucleus, and interstitial nucleus of the superior fasciculus (posterior fibers); smaller contralateral projections are to the olivary pretectal nucleus, dorsal terminal nucleus, and LTN. A second, mejor bundle produces moderate‐to‐heavy labeling in all ipsilateral, accessory oculornotor nuclei (nucleus of posterior commissure, interstitial nucleus of Cajal, nucleus of Darkschewitsch) and nucleus of Bechterew; some of the fibers are distributed above the caudal oculomotor complex within the supraoculornotor periaqueductal gray. A third projection is ipsilateral to the pontine and mesencephalic reticular formations, nucleus reticularis tegmenti pontis and basilar pontine complex (dorsolateral nucleus only), dorsal parts of the medial terminal accessory optic nucleus, ventral tegmental area of Tsai, and rostral interstitial nucleus of the medial longitudinal fasciculus. Lastly, there are two long descending bundles: (1) one travels within the medial longitudinal fasciculus to terminate in the dorsal cap (ipsilateral > > contralateral) and medial accessory olive (ipsilateral only) of the inferior olivary complex. (2) The second soon splits, sending axons within the ipsilateral and contralateral brachium conjunctivum and is distributed to the superior and medial vestibular nuclei.The present findings are in general agreement with the documented connections of LTN with brainstem oculomotor centers in other species. In addition, there are unique connections in marmoset monkey that may have developed to serve the more complex oculomotor behavior of nonhuman primates. © 1995 Wiley‐Liss, Inc.
Effects of unilateral cochlea ablation on the distribution of calretinin mRNA and immunoreactivity in the guinea pig ventral cochlear nucleus
Authors: Winsky Lois , Jacobowitz David M. 
Published: January 2005

AbstractThe predominantly neuronal, calcium‐binding protein calretinin is highly expressed in the guinea pig auditory system. Within the ventral cochlear nucleus (VCN), calretinin‐positive auditory nerve fibers terminate on many calretinin‐containing bushy, octopus, and multipolar cells. The abundance of calretinin in the cochlear nucleus provides an ideal system for examining the effects of altered neuronal input on the expression of this calcium‐binding protein.The present experiments examined the effects of unilateral cochlea ablation on calretinin immunoreactivity and mRNA levels in the VCN. Calretinin mRNA was labeled by in situ hybridization histochemistry using a radioactive oligonucleotide probe and was quantified by optical density measures on autoradiograms. Survival times of 1, 7, and 56 days postlesion were examined.The results revealed a consistent increase in calretinin mRNA in the rostral portion of the ipsilateral anterior VCN 1 day postlesion but no effect on calretinin mRNA in this region at 7 and 56 days postlesion. The intensity of immunohistochemical label was also increased at 1 and 7 days after surgery. In contrast, calretinin mRNA was not affected 1 day postlesion in the ipsilateral posterior VCN but was decreased at both 7 and 56 days postlesion. The decrease in calretinin mRNA in the posterior VCN at longer survival times was accompanied by decreased immunolabeling of fibers projecting from VCN cells to the superior olivary complex. These results suggest that calretinin gene expression is regulated in part by auditory nerve activity in some cochlear neurons but that additional factors related to the unique cellular milieu also control calretinin expression. © 1995 Wiley‐Liss, Inc.
A histochemical study of iron‐positive cells in the developing rat brain
Authors: Connor James R. , Pavlick Geno , Karli David , Menzies Sharon L. , Palmer Charles 
Published: January 2005

AbstractThe establishment of normal iron levels in the neonatal brain is critical for normal neurological development. Studies have shown that both iron uptake and iron concentration in the brain are relatively high during neonatal development. This histochemical study was undertaken to determine the pattern of iron development at the cellular level in the rat forebrain. Iron‐stained cells were observed as early as postnatal day (PND) 3, which was the earliest time point examined. At PND 3, there were four major foci of iron‐containing cells: the subventricular zone and three areas within the subcortical white matter. These latter foci are associated with myelinogenic regions. The blood vessels were prominently stained for iron throughout the brain. At PND 7, as in PND 3, the majority of the iron‐containing cells were in white matter. However, there were also patches of iron staining located specifically in the layer IV of the somatosensory cortex. These cortical patches were no longer visible by PND 14. At PND 14, numerous iron‐stained cells were dispersed throughout White matter regions and the tanycytes aligning the third ventricle were prominently stained. The blood vessel staining was less prominent than at earlier time periods. By PND 28, the adult pattern of iron staining was emerging. Iron‐stained cells were aligned in rows in white matter and had an apparent preference for a location near blood vessels. This clustering of iron‐positive cells around blood vessels gave the white matter a “patchy” appearance. The pattern of development, cell distribution, and morphological appearance of the iron‐stained cells are consistent with that reported for oligodendrocytes. That iron‐positive cells in the neonate may be oligodendrocytes is consistent with the reports for iron staining in adult brains. The recent reports that oligodendrocytes are highly susceptible to oxidative damage would be consistent with the high iron levels found in these cells, These results indicate that oligodendrocytes play a major role in the development of iron homeostasis in the brain. The role of iron in oligodendrocytes may be associated with metabolic demands of myelinogenesis, including cholesterol and fatty acid synthesis. However, these cells may be a morphologically similar but functionally distinct subset of oligodendrocytes whose function is to regulate the availability of iron in the brain.
Two modes of hair cell loss from the vestibular sensory epithelia of the guinea pig inner ear
Authors: Li Lin , Nevill Graham , Forge Andy 
Published: January 2005

AbstractIn the vestibular and auditory neurosensory epithelia of poikilothermic vertebrates and of birds, damaged sensory “hair” cells are often deleted by extrusion from the apical surface. In contrast, in the adult mammalian auditory epithelium (the organ of Corti), the bodies of damaged hair cells degenerate within the epithelium. To determine whether this apparent difference is species related or is associated with the differing structural organisation of the epithelia, hair cell deletion in the mammalian vestibular end‐organs was examined. The structural organisation of these tissues is closer to that of the inner ear epithelia of lower vertebrates than to the organ of Corti. Hair cell loss was induced by chronic, systemic treatment of guinea pigs with the ototoxic aminoglycoside antibiotic gentamicin. The vestibular sensory epithelia were examined at various times after treatment via scanning electron microscopy, thin sectioning, and staining f‐actin with fluorescently labelled phalloidin. Two distinct modes of hair cell loss were identified: (1) degeneration of hair cells within the epithelium, which often showed morphological features consistent with those described for apoptosis, and (2) extrusion of intact cells from the apical surface. Neither process caused the formation of obvious lesions through the epithelial surfaces. Expansion of adjacent supporting cells during hair cell deletion resulted in repair that appeared to preserve permeability barriers. There was also no evidence of inflammation accompanying hair cell removal. Thus, with both modes of hair cell loss, it appeared that deletion of hair cells was achieved without disruption of tissue architecture or integrity. This may be important for subsequent repair and regeneration processes to operate.
Barreloids in adult rat thalamus: Three‐dimensional architecture and relationship to somatosensory cortical barrels
Authors: Land Peter W. , Buffer Sam A. , Yaskosky Jamie Dawn 
Published: January 2005

AbstractHistochemical staining for cytochrome oxidase (CO) and axonal transport of horseradish peroxidase (HRP) were used to investigate thalamocortical connections in the vibrissa‐barrel system of adult rats. CO staining revealed that the medial division of the ventrobasal thalamic nucleus (VBm) consists of intensely stained rod‐like configurations, containing thalamocortical projection neurons and intervening neuropil, separated by lighter‐stained septa. CO‐dark rods span the thickness of VBm, are arranged in a pattern of rows and arcs that resembles the distribution of vibrissae on the mystacial pad, and are similar to the cytoarchitectonic structures termed “barreloids” in the mouse thalamus. Based upon the dimensions of CO‐dark structures and the numerical density of neurons in VBm we estimated that a barreloid in the rat may contain 250‐300 neurons.HRP injections into lamina IV of the somatosensory cortex led to retrograde labeling of neurons within one or more barreloids. When injections were centered within the CO‐dark hollows of cortical barrels about 95% of retrogradely labeled neurons were located in the barreloid that is isomorphic to the injected barrel; up to 5% of labeled neurons were located within a single adjacent barreloid. Barrel hollow injections that also included a barrel side yielded a larger proportion of labeled neurons in non‐isomorphic barreloids. Interestingly, such extra‐barreloid labeling was topologically consistent in that HRP‐labeled neurons were distributed among barreloids that corresponded to cortical barrels nearest the injected barrel side. Injections into the septa between barrels similarly resulted in labeling within barreloids that corresponded to cortical barrels flanking the septal injection site.Following lamina IV injections the density of labeled neurons tended to be highest in the ventrolateral one‐half to two‐thirds of VBm. Retrograde labeling of neurons in the dorsomedial one‐third to one‐half of VBm was more often observed after HRP injections at the lamina V/VI border. Thus, barreloid neurons may be heterogeneous with respect to their laminar pattern of terminations within the somatosensory cortex. Some HRP injections in the cortex resulted in orthograde labeling of corticothalamic axons in the barreloids. When observed, labeled corticothalamic axons arborized principally within the barreloid isomorphic to the injected barrel column. Indeed, terminal labeling was densest in the vicinity of neurons retrogradely labeled by the same injection.