bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of S‐laminin and laminin in the developing rat central nervous system
Authors: Hunter Dale D. , Llinas Rafael , Ard March , Merlie John P. , Sanes Joshua R. 
Published: January 2005

AbstractThe extracellular matrix component, s‐laminin, is a homologue of the B1 subunit of laminin. S‐laminin is concentrated in the synaptic cleft at the neuromuscular junction and contains a site that is adhesive for motor neurons, suggesting that it may influence neuromuscular development. To ascertain whether s‐laminin may also play roles in the genesis of the central nervous system, we have examined its expression in the brain and spinal cord of embryonic and postnatal rats. S‐laminin was not detectable in synapse‐rich areas of adults. However, s‐laminin was present in discrete subsets of three laminin‐containing structures: (1) In the developing cerebral cortex, laminin and s‐laminin were expressed in the subplate, a transient layer through which neuroblasts migrate and cortical afferents grow. Both laminin and s‐laminin disappeared as embryogenesis proceeded; however, laminin was more widely distributed and present longer than s‐laminin. (2) In the developing spinal cord, laminin was present throughout the pia. In contrast, s‐laminin was concentrated in the pia that overlies the floor plate, a region in which extracellular cues have been postulated to guide growing axons. (3) In central capillaries, s‐laminin appeared perinatally, an interval during which the blood‐brain barrier matures. In contrast, laminin was present in capillary walls of both embryos and adults.To extend our immunohistochemical results, we used biochemical methods to characterize s‐laminin in brain. We found that authentic s‐laminin mRNA is present in the embryonic brain, but that brain‐derived s‐laminin differs (perhaps by a posttranslational modification) from that derived from nonneural tissues. We also used tissue culture methods to show that glia are capable of synthesizing “brain‐like” s‐laminin, and of assembling it into an extracellular matrix. Thus, glia may be one cellular source of s‐laminin in brain. Together, these results demonstrate that s‐laminin is present in the developing central nervous system, and raise the possibility that this molecule may influence developmental processes. © 1992 Wiley‐Liss, Inc.
Normal development and effects of neonatal infraorbital nerve damage upon the innervation of the trigeminal brainstem complex by primary afferent fibers containing calcitonin gene‐related peptide
Authors: Bennett‐Clarke Carol A. , Chiaia Nicolas L. 
Published: January 2005

AbstractImmunocytochemistry was used to study the normal development and response to infraorbital nerve (ION) damage of the innervation of the trigeminal (V) brainstem complex by axons recognized by an antibody directed against calcitonin gene‐related peptide (CGRP). CGRP‐like immunoreactivity (CGRPLI) was present in axons that occupied the outer V spinal tract (TrV) at all levels of the V brainstem complex. Almost no fibers terminated within V nucleus principalis (PrV), out there was dense CGRPLI in the supratrigeminal nucleus. There was also very little CGRPLI within rostral V subnucleus oralis (SpO). However, in the caudal one‐half of the nucleus, a dense elongated patch of immunoreactivity was consistently present just medial to TrV. Only occasional CGRP‐positive axons could be seen within V subnucleus interpolaris (SpI), but the paratrigeminal nucleus contained dense immunoreactivity. Trigeminal subnucleus caudalis (SpC) also contained CGRPLI that was very dense in lamina I and the outer portion of lamina II. Scattered terminals were also present in layers III and IV and dense terminal clusters were in lamina V. CGRP‐immunoreactive neurons were present in the V ganglion by embryonic (E‐) day 16 and immunoreactive axons could be seen in the V brainstem complex on E–17. At birth, CGRP‐positive axons in the V brainstem complex had achieved a distribution very similar to that in adult rats. The major difference between the patterns of labelling in neonates and adults was the presence of relatively large numbers of CGRP‐positive fibers in ventral PrV and SpO of the former animals. The disappearance of these fibers was completed by the middle of the third postnatal week. Transection of the ION on the day of birth had little effect upon CGRP in SpO, SpI, and SpC, but it did result in an increase in CGRP‐positive fibers in PrV ipsilateral to the damaged nerve. When considered together with previous findings, these results suggest that CGRP‐positive axons express this peptide well after they have entered the V brainstem complex and that the central terminal field of these fibers is not substantially altered by a manipulation which results in the death of nearly 60% of all V primary afferent neurons. © 1992 Wiley‐Liss, Inc.
Three‐dimensional analysis of the structure and composition of CA3 branched dendritic spines and their synaptic relationships with mossy fiber boutons in the rat hippocampus
Authors: Chicurel Marina E. , Harris Kristen M. 
Published: January 2005

AbstractThis paper is the third in a series to quantify differences in the composition of subcellular orgunelles and three‐dimensional structure of dendritic spines that could contribute to their specific biological properties. Proximal apical dendritic spines of the CAS pyramidal cells receiving synaptic input from mossy fiber (MF) boutons in the adult rat hippocampus were evaluated in three sets of serial electron micrographs. These CAS spines are unusual in that they have from 1 to 16 branches emerging from a single dendritic origin. The branched spines usually contain subcellular organelles that are rarely found in adult spines of other brain regions including ribosomes, multivesicular bodies (MVB), mitochondria, and microtubules. MVBs occur most often in the spine heads that also contain smooth endoplasmic reticulum, and ribosomes occur most often in spines that have spinules, which are small nonsynaptic protuberances emerging from the spine head.Most of the branched spines are surrounded by a single MF bouton, which establishes synapses with multiple spine heads. The postsynaptic densities (PSDs) occupy about 10–15% of the spine head membrane, a value that is consistent with spines from other brain regions, with spines of different geometries, and with immature spines. Individual MF boutons usually synapse with several different branched spines, all of which originate from the same parent dendrite. Larger branched spines and MF boutons are more likely to synapse with multiple MF boutons and spines, respectively, than smaller spines and boutons.Complete three‐dimensional reconstructions of representative spines with 1, 6, or 12 heads were measured to obtain the volumes, total surface areas, and PSD surface areas. Overall, these dimensions were larger for the complete branched spines than for unbranched or branched spines in other brain regions. However, individual branches were of comparable size to the large mushroom spines in hippocampal area CA1 and in the visual cortex, though the CA3 branches were more irregular in shape. The diameters of each spine branch were measured along the cytoplasmic path from the PSD to the origin with the dendrite, and the lengths of branch segments over which the diameters remained approximately uniform were computed for subsequent use in biophysical models. No constrictions in the segments of the branched spines were thin enough to reduce charge transfer along their lengths. The complex geometry of these spines and their subcellular constituents could modulate postsynaptic responses, however, during synaptic activation or plasticity such as long term potentiation, in ways that can now be evaluated on the basis of the complete dimensions and descriptions reported here. © 1992 Wiley‐Liss, Inc.
Antibody to NGF inhibits collateral sprouting of septohippocampal fibers following entorhinal cortex lesion in adult rats
Authors: Van Der Zee Catharina E. E. M. , Fawcett Jim , Diamond Jack 
Published: January 2005

AbstractWe have used an antiserum raised against mouse 2.5S NGF to examine the involvement of endogenous neurotrophins in the collateral sprouting of septohippocampal fibers in the adult rat brain. The antiserum was administered intraventricularly. Immunocytochemical techniques indicated that the injected antibodies penetrated into brain tissue that included the basal forebrain, cortex, striatum, corpus callosum, and hippocampus. Unilateral lesioning of the entorhinal cortex was done to evoke the sprouting of the cholinergic septohippocampal fibers. At 8 days postlesion, the sprouting was much advanced, as evidenced by an increase in density of the acetylcholinesterase (AChE) staining in the outer molecular layer (OML) of the dentate gyrus and by the associated increase in the absolute number of AChE‐positive fibers in the OML. As well, there was a widening of the inner molecular layer (IML), interpreted as being due to sprouting of noncholinergic axons in that region. In rats injected daily with anti‐NGF or anti‐NGF Fab fragments, no increase in AChE density, or in the population of AChE‐positive fibers, was observed in the OML. In contrast, the widening of the IML seemed to be unaffected by the anti‐NGF treatment. No changes were observed in the AChE related parameters in the dentate gyrus of nonlesioned animals treated similarly for 8 days with anti‐NGF; there was, however, a decrease of choline acetyltransferase (ChAT) immunostaining in the ChAT‐positive cells of the basal forebrain. Our findings and the confirmation that our polyclonal anti‐NGF also recognizes other members of the NGF neurotrophin family, specifically brain‐derived neurotrophic factor and neurotrophin‐3, indicate that at least one of these neurotrophins plays a key role in the collateral sprouting of the cholinergic septohippocampal fibers (but not that presumed to occur within the IML) following an entorhinal cortex lesion. © 1992 Wiley‐Liss, Inc.
An electron microscopical study of calcitonin gene‐related peptide‐like immunoreactive innervation of the anterior pituitary in the dog
Authors: Ju Gong , Zhang Xu 
Published: January 2005

AbstractOur previous studies have demonstrated the presence of a considerable number of substance P‐, calcitonin gene‐related peptide (CGRP)‐, and galanin‐like immunoreactive (LI) nerve fibers in the anterior pituitary in several mammalian species. The present study investigated the ultrastructure of the CGRP‐LI innervation of this gland in the dog. The CGRP‐LI nerve fibers were unmyelinated, with a wealth of yaricosities containing both small clear synaptic vesicles and large dense‐cored vesicles. They were found to be in direct contact with every cell type of the anterior pituitary. However, only on corticotropes and somatotropes were CGRP‐LI synaptic contacts identified. Most of them were asymmetrical in type. Occasional symmetrical synaptic contacts were also found. It is considered likely that direct neural factors may play a role in the regulation of the anterior pituitary. © 1992 Wiley‐Liss, Inc.
Postnatal development of area 17 callosal connections in Tupaia
Authors: Kretz R. , Rager G. 
Published: January 2005

AbstractThe goal of the present study was to investigate the pattern of maturation of callosal projecting neurons in a well‐studied mammalian visual system with unique structural and functional properties. Studies of the distribution pattern of interhemispheric connections in the adult tree shrew primary visual cortex reveal not only a high concentration of labeled neurons along the area 17/18 border, as in standard experimental animals such as the cat and monkey, but also numerous callosal projecting neurons in the adjacent dorsal part of area 17, which largely corresponds to the binocular visual field (Kretz and Rager, Exp. Brain Res. 82:271, '90).Callosal projections were anatomically traced in 11 tree shrews (Tupaia belangeri) at various ages between postnatal day 7 (7,9,10,13,15,17,19, and 26 days old) and adulthood (107 days old). In each animal, four injections of wheat germ agglutinin conjugated to horseradish peroxidase were made in a standard configuration into the striate cortex of one hemisphere. In young tree shrews only 7 and 9 days old, heavily labeled terminal axon structures could be seen in the white matter and in layer VI of the opposite hemisphere. Only a few labeled neurons, however, were detected in layer III. The small number of labeled neurons indicated that early in postnatal development, only a few callosal axons had invaded the upper cortical layers. By 10 days of age, the number of supragranular neurons was increasing and the maximal value was counted in a 13‐day‐old tree shrew. A sharp decline in the number of labeled supragranular neurons was noticed—about 94% in our case—between days 13 and 15. In animals more than 15 days old, the distribution pattern and the density of the neurons looked like the pattern seen in the adult Tupaia brain. The labeled cells were mostly concentrated in layers II and III. The majority of neurons resembled typical pyramidal cells. However, some of the neurons in sublayer IIIc had elongated cell bodies oriented parallel to the laminar boundaries. In contrast to the supragranular cells found in all stages investigated, small populations of labeled cells in layer VI were observed in 9‐ to 17‐day‐old tree shrews only. In young postnatal animals 7 to 13 days old, a peculiar cell type was labeled on the ipsilateral side. In coronal sections these cell bodies formed a continuous band that extended from the ventricular wall to the subcortical white matter. These cells might belong to a population of cells still in migration. © 1992 Wiley‐Liss, Inc.
Effects of neonatal transection of the infraorbital nerve upon the structural and functional organization of the ventral posteromedial nucleus in the rat
Authors: Chiaia Nicolas L. , Bauer William R. , Zhang Shujie , King Tod A. , Wright Paul C. , Hobler Scott C. , Freeman Keith A. 
Published: January 2005

AbstractThe present study examined the way in which an indirect partial deafferentation of the medial portion of the ventrobasal complex (VPM/VPL) induced by neonatal transection of the infraorbital nerve (ION) altered the structural and functional properties of its constituent neurons. This manipulation significantly reduced the volume of the contralateral VPM/VPL. In addition, cell counts in Nissl‐stained material revealed a significant reduction of the number of VPM/VPL neurons contralateral to neonatal ION transection. We also analyzed the effect of neonatal ION transection on the soma‐dendritic morphology of individual neurons in the ventral posteromedial nucleus of the thalamus (VPM) by intracellular injection of horseradish peroxidase (HRP) in vivo and Lucifer yellow in fixed slices. Neonatal transection of the ION resulted in increased dendritic length, area, and volume of VPM neurons in both preparations; however only the changes observed in fixed slices reached statistical significance. Alterations in the functional characteristics of VPM neurons were also observed following neonatal nerve damage. There was a significant decrease in the percentage of vibrissae‐sensitive neurons and a corresponding increase in the percentages of neurons responsive to guard hair deflection or that were unresponsive to peripheral stimulation. Neonatal nerve damage also resulted in significantly longer latencies of VPM cells after stimulation of either trigeminal nucleus principalis or subnucleus interpolaris.The present results indicate that the development of normal response properties and soma‐dendritic morphology of VPM neurons is dependent upon intact afferent input during development. Indirect partial deafferentation of VPM/VPL by neonatal transection of the ION results in reduced neuron number, which may result in decreased competition among the dendrites of these neurons. This proposal is consistent with observations of increased dendritic dimensions of VPM neurons contralateral to neonatal ION damage. © 1992 Wiley‐Liss, Inc.
Serotoninergic innervation of the dorsal column nuclei and its relation to cytoarchitectonic subdivisions: An immunohistochemical study in cats and monkeys (Aotus trivirgatus)
Authors: Blomqvist Anders , Broman Jonas 
Published: January 2005

AbstractThe serotoninergic innervation of the dorsal column nuclei (DCN) was investigated in cats and owl monkeys (Aotus trivirgatus) with immunohistochemical methods. A dense network of serotonin‐immunoreactive fibers was present in the reticular regions of DCN in cats, and in the pars triangularis of the cuneate nucleus and the peripheral and caudal regions of the gracile nucleus in owl monkeys. The cat's cluster regions and the monkey's rotund regions were more sparsely innervated. Electron microscopic examination showed that the labeled fibers were thin and unmyelinated. Vesicle‐containing, terminal‐like structures were small. They were in contact with dendrites, other terminals and cell bodies, but synapses were rare.The results demonstrate that the serotoninergic projection to the DCN in both cats and owl monkeys is heterogeneously distributed in a pattern that is faithfully related to the cytoarchitectonic subdivisions of the DCN. The densely innervated reticular regions in the DCN of cats and the corresponding regions in monkeys are predominantly involved in the processing of sensory information to the cerebellum, either directly, or indirectly through projections to the inferior olive, pontine gray, tectum, pretectum, red nucleus, or zona incerta. Thus, the present findings suggest that the serotoninergic innervation of the DCN is primarily related to the DCN's involvement in motor functions. © 1993 Wiley‐Liss, Inc.
Distribution of noradrenaline‐immunoreactivity in the brain of the mormyrid teleost Gnathonemus petersii
Authors: Meek J. , Joosten H. W. J. , Hafmans T. G. M. 
Published: January 2005

AbstractThe distribution of noradrenaline‐immunoreactivity in the brain of the mormyrid fish Gnathonemus petersii was studied in order to evaluate the noradrenergic innervation of a number of specialized mormyrid brain regions, including electrosensory centers and a gigantocerebellum. Noradrenaline‐immunoreactive (NAi) neurons occur in the hypothalamic paraventricular organ (PVO), the locus coeruleus, and the caudal rhombencephalon. In the PVO, NAi cerebrospinal fluid (CSF)‐contacting neurons are located in the same regions where dopamine‐ and serotonin‐containing CSF contacting neurons occur. The locus coeruleus consists, on each side, of at least 30 rather large NAi neurons with ventrolaterally directed dendrites and dorsolaterally coursing axons. In the caudal rhombencephalon, NAi neurons are located in the transition region between the ventromedial motor zone and the dorsolateral sensory zone.The density of NAi fibers is very high in the efferent tract of the locus coeruleus, the medial forebrain bundle, and two telencephalic, one preoptic, and one rhombencephalic subependymal axonal plexus. A marked NAi innervation is present in the dorsomedial and ventral telencephalon, the preoptic region, periventricular hypothalamic and thalamic regions, the midbrain tectum, cerebellar granular layers, the electrosensory lateral line lobe, the rhombencephalic transition region between the sensory and motor zones, and the area postrema. Other regions are more sparsely innervated by NAi fibers, but regions completely devoid of NAi fibers were not observed. Interestingly, NAi fibers form large club endings in some subdivisions of the precerebellar nucleus lateralis valvulae, and parallel fibers in the cerebellar granular layer.Comparison with the distribution of NAi or dopamine‐β‐hydroxylase‐immunoreactivity in other species shows that all teleosts studied to date have noradrenergic cells in the locus coeruleus and the caudal rhombencephalon. However, NAi CSF‐contacting PVO cells have been described only in the teleost Gnathonemus petersii and the lizard Gekko gecko (Smeets and Steinbusch: J. Comp. Neurol. 285:453–466, 89). It is possible that they might pick up catecholamines as well as serotonin from the CSF, into which monoamines might be released by telencephalic and preoptic subependymal axonal plexuses. © 1993 Wiley‐Liss, Inc.
Spinal neurogenesis and axon projection: A correlative study in the rat
Authors: Nandi Kailas N. , Knight David S. , Beal John A. 
Published: January 2005

AbstractThe purpose of the present study was to determine the relationship between the duration of a spinal neuron's neurogenic period and the length of its axon or level of projection. Spinal segment L1 was chosen for examination and neurons were divided into four projection groups: (1) supraspinal projection (SSp), (2) long ascending propriospinal (LAPr), (3) short ascending propriospinal (SAPr), and (4) descending propriospinal (DPr). To determine the duration of the neurogenic period for each group, 3H‐thymidine was administered to fetal rats during the proliferative period for spinal neuroblasts on one of embryonic (E) days E13 through E16. Between 50 and 100 days after birth neurons in each group were labeled with the retrograde fluorescent tracer Fluoro‐Gold. To demonstrate nerve cells with SSp projections, spinal cords were hemisected at spinal segment C3 in one group of animals and Fluoro‐Gold was applied to the sectioned surface of the cord. Three additional sets of animals were used to label nerve cells with LAPr, SAPr, and DPr projections by injecting Fluoro‐Gold into the gray matter at spinal segments C6, T12, and L5, respectively. Neurons labeled with both Fluoro‐Gold and 3H‐thymidine and neurons labeled with Fluoro‐Gold alone in each animal in each group were counted and the data statistically analyzed. Results showed that within each spinal lamina neurons with different projections were generated, i.e., completed cell division, at significantly different rates. Neurons with the longest axons, those with SSP projections, were generated first. These were followed by those with LAPr projections, and finally those with SAPr and DPr projections. In most laminae there was no significant difference between the neurogenic periods of rostrally projecting short propriospinal (SAPr) neurons versus caudally projecting short propriospinal (DPr) neurons. It was concluded that the duration of the neurogenic period for a given group of neurons within each spinal lamina is inversely related to the distance between the nerve cell and its projection site regardless of the direction of its projection. © 1993 Wiley‐Liss, Inc.
Carbocyanine dye labeling reveals a new motor nucleus in octopus brain
Authors: Robertson J. David , Schwartz Owen M. , Lee Psyche 
Published: January 2005

AbstractThis work aims at a better understanding of the organization of the brain of Octopus vulgaris, emphasizing the touch and visual learning centers. We injected the carbocyanine dye, DiI, into the cerebrobrachial connectives and, separately, into the brachial nerves of living octopuses. In both experiments, retrogradely transported granules of DiI appeared in motor neurons in the superior buccal, posterior buccal and subvertical lobes and in a hitherto unsuspected motor nucleus of several hundred neurons in the posterior dorsal basal and median basal lobes.In addition we labeled afferent fibers by injecting DiI into the caudal (sensory) division of the cerebrobrachial connective on one side; the label spread throughout the superior buccal, posterior buccal and the lateral and median inferior frontal lobes mainly on the injected side. It extended through the cerebral tract into the subvertical lobe, into the superior frontal lobe through the interfrontal tract, through the posterior buccal commissure into the opposite posterior buccal lobe and into the median inferior frontal lobe.The work suggests a new function for the posterior dorsal and median basal lobes, which are shown for the first time to project through the inferior frontal lobe system into the brachial nerves. In addition it represents the first full report of the successful use of the carbocyanine dyes DiI and DiO for labeling nerve tissue in a live invertebrate animal. © 1993 Wiley‐Liss, Inc.