bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prenatal exposure to ethanol alters the postnatal development and transformation of radial glia to astrocytes in the cortex
Authors: Miller Michael W. , Robertson Shirley 
Published: January 2005

AbstractPostmitotic neurons migrate from a zone(s) near the ventricles to the neocortex. During this migration, neurons associate with radial glia. After serving their role as guides for neuronal migration, the radial glia transform into astrocytes. Prenatal exposure to ethanol causes abnormal neuronal migration. We examined the effects of gestational exposure to ethanol on radial glia and astrocytes. Radial glia were stained immunohistochemically with the antibody RAT‐401, and astrocytes were labeled with an antibody directed against glial‐fibrillary acidic protein (GFAP). The subjects were the offspring of rats fed an ethanol‐containing liquid. diet (Et), pair‐fed a liquid control diet (Ct), or fed chow and water (Ch). During the first postnatal week, radial glial fibers (in Et‐treated rats and controls) stretched from the ventricular surface through the developing. cerebral wall to the pial surface. In the Et‐treated rats, the radial processes were less dense and more poorly fasciculated than they were in the Ch‐and Ct‐treated rats. Moreover, by postnatal day (P) 5, there was a significant reduction in RAT‐401 immunostaining in the Et‐treated rats, particularly in the superficial cortex. A similar reduction in control rats did not begin until P10. In all three treatment groups, GFAP‐immunoreactive astrocytes were in the cortex throughout the period from P1 to P45. In neonates, GFAP‐positive cells were distributed in the marginal zone (layer I) and the intermediate zone (the white matter). The number of GFAP‐positive cells in the cortical plate increased steadily with time so that, by P26, GFAP‐immunoreactive astrocytes were distributed evenly through all cortical laminae. Interestingly, between P5 and P12, the number of astrocytes was significantly greater in Et‐treated rats than in controls.Thus prenatal exposure to ethanol induces the premature loss of RAT‐401‐positive processes and the precocious increase in GFAP immunostaining. These ethanol‐induced changes in glial development indicate that ethanol accelerates the transformation of radial glia into astrocytes. Moreover, the ethanol‐induced premature degradation of the network of radial glial fibers may underlie the migration of late‐generated neurons to ectopic sites. © 1993 Wiley‐Liss, Inc.
The A‐1 antigen: A novel marker in experimental peripheral nerve injury
Authors: Azzarelli Biagio , Woodburn Robert , Olivelle Suman , Kimbro Sean , Siakotos Aristotle , Taylor Milton , Lee Chao‐Hung , Yen Margaret , Paulsrud John 
Published: January 2005

AbstractExpression of the Schwann cell phenotype is regulated by signals from the adjoining axon. After axotomy, the Schwann cell ceases the production and maintenance of the myelin sheath and assumes phagocytic properties necessary to digest its own myelin. The molecular mechanisms responsible for this behavior remain unclear. A monoclonal antibody termed BIKS was produced after the immunization of mice with guinea pig lymphoid tissue. This antibody recognizes a cytoplasmic vesicle‐associated molecule (A‐1 antigen) which is abundant in all tissue macrophages but is also expressed in small amounts in normal Schwann cells. Following axotomy, the A‐1 antigen appears to be translocated from a perinuclear site to accumulate in large quantities around myelin ovoids in Schwann cells, as well at the nodes of Ranvier‐sites where Wallerian degeneration is known to commence. The level of the antigen remains high when axons are prevented from regeneration. During repair of crush injury, however, the level of antigen drops concomitant with the ingrowth of regenerating axons, suggesting axonal control of A‐1 antigen expression. © 1993 Wiley‐Liss, Inc.
The innervation of the mystacial pad of the rat as revealed by PGP 9.5 immunofluorescence
Authors: Rice Frank L. , Kinnman Erik , Aldskogius Håkan , Johansson Olle , Arvidsson Jan 
Published: January 2005

AbstractThe innervation of the mystacial pad in the rat was investigated with the aid of antihuman protein gene product (PGP) 9.5 immunofluorescence. PGP 9.5 is ubiquitin carboxyl‐terminal hydrolase, which is distributed throughout neuronal cytoplasm. This technique revealed all previously known innervation as well as a wide variety of small‐caliber axons and some endings of large‐caliber afferents that had not been observed before. Newly revealed innervation affiliated with vibrissal‐follicle sinus complexes included (1) fine‐caliber, radially oriented processes in the epidermal rete ridge collar; (2) a loose network of fine‐caliber, circumferentially arrayed processes in the centrifugal part of the mesenchymal sheath at the level of the ring sinus; (3) a loose haphazard network of fine‐caliber and medium‐caliber processes in the mesenchymal sheath and among the trabeculae of the cavernous sinus; (4) a loose network of circumferentially arrayed processes within the mesenchymal sheath of the cavernous sinus and in close proximity to the basement membrane; (5) a dense network of reticular‐like endings provided by large‐caliber afferents to the mesenchymal sheath in the upper part of the cavernous sinus; and (6) fine‐caliber innervation to the dermal papilla at the base of all vibrissal shafts. In the intervibrissal skin, a dense distribution of fine‐caliber individual and clustered profiles was detected in the epidermis. In addition to previously known innervation, Merkel endings were consistently observed in the epidermis at the mouths of guard hairs, loose networks of fine‐caliber axons were found around the necks of occasional guard hairs, and fine‐caliber profiles were frequently affiliated with vellus hairs. Vascular profiles were heavily innervated throughout the dermis. Axons and motor end plates of the facial nerve innervation to papillary muscles also were labeled. Transection of the infraorbital nerve eliminated all but the facial nerve innervation. Unilateral removal of the superior cervical ganglion eliminated the innervation to the dermal papillae but caused no other noticeable reduction. PGP 9.5‐like immunofluorescence was also moderately expressed in apparent Schwann cells, in Merkel cells only in the external root sheath of vibrissal follicles, and in apparent dendritic and/or Langerhans cells usually located in the epidermis and occasionally in the follicles. PGP 9.5‐like immunofluorescence persisted in highly vacuolated profiles along the usual courses of medium to large‐caliber axons 2 weeks after nerve transection. The possible functional role of the newly discovered innervation is considered along with that of previously identified afferents. © 1993 Wiley‐Liss, Inc.
Ramification pattern and ultrastructural characteristics of the serotonin‐immunoreactive neuron in the antennal lobe of the moth Manduca sexta: A laser scanning confocal and electron microscopic study
Authors: Sun X. J. , Tolbert L. P. , Hildebrand J. G. 
Published: January 2005

AbstractThe two antennal lobes, the primary olfactory centers of the brain, of the moth Manduca sexta each contain one neuron that displays serotonin immunoreactivity. The neuron projects out of the antennal lobe and sends branches into ipsi‐ and contralateral protocerebral areas. An axon‐like process extends from the contralateral protocerebrum to, and terminates in, the contralateral antennal lobe. In order to begin to investigate the possible role of this unique neuron in olfactory information processing, we have used laser scanning confocal microscopic and electron microscopic immunocytochemical techniques to study the ramification pattern, ultrastructural characteristics, and synaptic connections of the neuron in the antennal lobes of female adult Manduca sexta. The neuron ramifies extensively in the antennal lobe contralateral to the cell body. The ramifications, mainly in the base and center of each glomerulus, do not overlap with those of the sensory axons from the antenna. This finding suggests that the serotonin‐immunoreactive neuron may not receive direct input from sensory neurons, and that it may modulate the activity of the neurons of the antennal lobe rather than that of the sensory neurons. In the electron microscope, the neuron exhibits large dense‐cored vesicles and small, clear round vesicles. In the antennal lobe ipsilateral to the cell body, the primary neurite of the serotonin‐immunoreactive neuron is unbranched and lacks detectable synaptic connections. The ramifications in the contralateral antennal lobe, however, participate in synaptic connections. At very low frequency, contralateral branches form synapses onto unlabeled processes and also receive synapses from unidentified neurons in the glomeruli, indicating that the neuron may participate directly in synaptic processing of olfactory information. The high ratio of output to input synapses made by the serotonin‐immunoreactive processes in the contralateral antennal lobe is consistent with the idea that this neuron may receive synaptic input via its bilateral branches in the protocerebrum and then send information to the contralateral antennal lobe where the neuron may exert feedback or modulatory influences on olfactory information processing in the glomeruli. © 1993 Wiley‐Liss, Inc.
GABAergic innervation of the Mauthner cell and other reticulospinal neurons in the goldfish
Authors: Lee Robert K. K. , Finger Thomas E. , Eaton Robert C. 
Published: January 2005

AbstractThe Mauthner cells are pair of identifiable hindbrain neurons that participate in the escape response of fishes. Membrane excitability in these cells is regulated by inhibitory neurons that use glycine as a transmitter. We examined the possibility that the inhibitory transmitter gamma‐amino butyric acid (GABA) may also act on the Mauthner cells.We used immunocytochemical methods involving an antibody against glutamic acid decarboxylase (GAD), the synthesizing enzyme for GABA. Our study revealed dense GAD immunoreactive terminals surrounding the Mauthner cells. Puncta counts showed that the distribution of GAD immunoreactivity was densest at the distal lateral dendrite of the Mauthner cells; the distribution of puncta tapers gradually in regions closer to the soma. The axon cap was devoid of GABAergic immunoreactivity.We also performed unilateral lesions of the octaval nuclei to evaluate the origin of the GAD immunoreactive terminals. Following the lesions, we found marked decreases in GAD immunoreactive terminals on the proximal lateral dendrite, soma, and proximal ventral dendrite of both Mauthner cells. These results suggest that the octaval region contributes to bilateral inhibition of the Mauthner cells. The distal lateral dendrite of the ipsilateral Mauthner cell also showed a reduction in GAD immunoreactive terminals. This suggests that GABA mediates remote dendritic inhibition of this cell.GAD immunoreactive puncta also surrounded other large reticulospinal neurons, some of which are serially reiterated along the anterior‐posterior axis of the hindbrain. Thus, GABA may also exert an influence not only on the Mauthner cells, but also on other reticulospinal neurons. © 1993 Wiley‐Liss, Inc.
Rapid increase in mitochondrial volume in nucleus magnocellularis neurons following cochlea removal
Authors: Hyde Gregory E. , Durham Dianne 
Published: January 2005

AbstractSecond‐order auditory neurons in nucleus magnocellularis (NM) of the chick brainstem undergo a series of rapid metabolic changes following unilateral cochlea removal, culminating in the death of 25% of NM neurons. Within hours of cochlea removal, ipsilateral NM neurons show marked increases in histochemical staining for the mitochondrial enzymes succinate dehydrogenase and cytochrome oxidase. We investigated corresponding ultrastructural changes in NM neurons by preparing animals undergoing unilateral cochlea removal for transmission electron microscopy. We quantified changes in NM mitochondrial volume by stereological methods and qualitatively compared mitochondrial morphology between NM neurons destined to survive and those destined to die after cochlea removal.Within hours of cochlea removal, ipsilateral NM neurons show striking increases in mitochondrial volume (84% at 12 hours and 236% at 12 hours after cochlea removal compared to unoperated, control animals). At 2 week survival times, ipsilateral NM neurons contain fewer mitochondria than contralateral neurons. Surprisingly, anesthesia alone causes short‐term increases in NM mitochondrial volume. Animals anesthetized with pentobarbital and ketamine and sacrificed 6 or 12 hours later showed a 45% increase in mitochondrial volume compared to previously unanesthetized animals. NM neurons destined to die within days of cochlea removal can be identified within several hours after deafferentation by the appearance of their ribosomes. We observed qualitative differences in mitochondrial morphology in dying neurons. Mitochondria in neurons destined to die consistently showed mitochondrial swelling and vacuolization indicative of metabolic dysfunction. Similar mitochondrial changes have been reported when mitochondria take up excess calcium. Ultrastructural changes in NM after cochlea removal display features of both programmed and pathological cell death, in which increased intracellular calcium is thought to play a role. © 1994 Wiley‐Liss, Inc.
The hippocampal CA3 network: An in vivo intracellular labeling study
Authors: Li X.‐G. , Somogyi P. , Ylinen A. , Buzsáki G. 
Published: January 2005

AbstractThe intrahippocampal distribution of axon collaterals of individual CA3 pyramidal cells was investigated in the rat. Pyramidal cells in the CA3 region of the hippocampus were physiologically characterized and filled with biocytin in anesthetized animals. Their axonal trees were reconstructed with the aid of a drawing tube. Single CA3 pyramidal cells arborized most extensively in the CA1 region, covering approximately two‐thirds of the longitudinal axis of the hippocampus. The total length of axon collaterals in the CA3 region was less than in CA1 and the axon branches tended to cluster in narrow bands (200–800 μm), usually several hundred microns anterior or posterior to the cell body. The majority of the recurrent collaterals of a given neuron remained in the same subfield (CA3a, b, or c) as the parent cell. CA3a neurons innervated predominantly the basal dendrites, whereas neurons located proximal to the hilus (CA3c) terminated predominantly on the apical dendrites of both CA1 and CA3 cells. Two cells, with horizontal dendrites and numerous thorny excrescences at the CA3c–hilus transitional zone, were also labeled and projected to both CA3 and CA1 regions. All CA3 neurons projected some collaterals to the hilar region. Proximal (CA3c) neurons had numerous collaterals in the hilus proper. One CA3c pyramidal cell in the dorsal hippocampus sent an axon collateral to the inner third of the molecular layer. CA3c pyramidal cells in the ventral hippocampus had extensive projections to the inner third of the dentate molecular layer, as well as numerous collaterals in the hilus, CA3, and CA1 areas, and several axon collaterals penetrated the subiculum. The total projected axon length of a single neuron ranged from 150 to 300 mm. On the basis of the projected axon length and bouton density (mean interbouton distance: 4.7 μm), we estimate that a single CA3 pyramidal cell can make synapses with 30,000–60,000 neurons in the ipsilateral hippocampus. The concentrated distribution of the axon collaterals (“patches”) indicates that subpopulations of neurons may receive disproportionately denser innervation, whereas innervation in the rest of the target zones is rather sparse. These observations offer new insights into the physiological organization of the CA3 pyramidal cell network. © 1994 Wiley‐Liss, Inc.
Substance P‐, calcitonin gene‐related peptide, growth‐associated protein‐43, and neurotrophin receptor‐like immunoreactivity associated with unmyelinated axons in feline ventral roots and pia mater
Authors: Risling M. , Dalsgaard C.‐J. , Frisén J. , Sjögren A.‐M. , Fried K. 
Published: January 2005

AbstractThe spinal pia mater receives a rich innervation of small sensory axons via the ventral roots. Other sensory axons enter the ventral roots but end blindly or turn abruptly in hairpin loop‐like formations and continue in a distal direction. In the present study, the content of substance P (SP)‐, calcitonin gene‐related peptide (CGRP)‐, growth‐associated protein (GAP‐43)‐, and low‐affinity neurotrophin receptor protein (p75NGFr)‐like immunoreactivity (‐LI) associated with these different types of sensory axons was assessed with light and electron microscopic immunohistochemical techniques. In addition, the binding of antibodies against synthetic peptides representing unique sequences of residues in the products of the trk and trkB protooncogenes was analyzed. These genes encode membrane spanning proteins, which have been shown to constitute specific high affinity binding sites for several members of the nerve growth factor family of neurotrophic factors.The results of the present study imply that the ventral root afferents comprise several different types of sensory axons, which all contain SP‐, CGRP‐, GAP‐43‐, and p75NGFr‐like immunoreactivities. In addition, at least some of the presumed sensory fiber bundles in ventral roots and the pia mater were immunoreactive for the trkB gene product. Moreover, leptomenin‐geal cells and nonneuronal cells of the ventral roots were shown to bind antibodies to both the trk and trkB gene products. The ventral root afferents seem to share their immunohistochemical pattern with pain‐transducing axons at some other locations, such as the tooth pulp. The contents of SP‐ and CGRP‐LI in sensory axons that reach the central nervous system (CNS) through the ventral root indicate that ventral root afferents may be involved in sensory mechanisms, such as the ventral root pain reaction, as well as in the control of the pial blood vessels. The demonstration of GAP‐43 and neurotrophin receptor‐immunoreactivities associated with unmyelinated fibers in ventral roots and the pia mater is discussed in relation to previous reports on postnatal plasticity in these axonal populations. © 1994 Wiley‐Liss, Inc.
Topography of neurons expressing luteinizing hormone‐releasing hormone gene transcripts in the human hypothalamus and basal forebrain
Authors: Rance Naomi E. , Young W. Scott , McMullen Nathaniel T. 
Published: January 2005

AbstractThe distribution of neurons expressing luteinizing hormone‐releasing hormone (LHRH) gene transcripts was mapped in the human hypothalamus and basal forebrain by in situ hybridization and computer‐assisted microscopy. Hypothalamic blocks were dissected from five adult males and one adult female and snap frozen in isopentane. The blocks were serially sectioned either in the coronal or in the sagittal plane at a thickness of 20 μm. Approximately every twentieth section was incubated with a 35S‐labeled cDNA probe complementary to LHRH mRNA. Specificity was confirmed by hybridization of adjacent sections with a probe targeted to the gonadotropin‐associated protein (GAP) region of LHRH messenger ribonucleic acids (mRNA). Maps of neurons containing LHRH mRNA were manually digitized with the aid of an image‐combining computer microscope system. We report a much wider distribution and greater numbers of LHRH neurons than have been previously described in the human brain. Three morphological subtypes were observed based on cell size and labeling density: (1) small, heavily labeled, oval or fusiform neurons, located primarily in the medial basal hypothalamus, ventral preoptic area, and periventricular zone; (2) small, oval, sparsely labeled neurons located in the septum and dorsal preoptic region and scattered from the bed nucleus of the stria terminalis to the amygdala (“extended amygdala”); and 3) large round neurons (> 500 μm2 sectional profile area), intermediate in labeling density, scattered within the magnocellular basal forebrain complex, extended amygdala, ventral pallidum, and putamen. The pronounced differences in morphology, labeling density, and location of the three subtypes suggest that distinct functional subgroups of LHRH neurons exist in the human brain. © 1994 Wiley‐Liss, Inc.
Projections of the dorsal raphe nucleus to the brainstem: PHA‐L analysis in the rat
Authors: Vertes Robert P. , Kocsis Bernat 
Published: January 2005

AbstractEarly studies that used older tracing techniques reported exceedingly few projections from the dorsal raphe nucleus (DR) to the brainstem. The present report examined DR projections to the brainstem by use of the anterograde anatomical tracerPhaseolus vulgarisleucoagglutinin (PHA‐L). DR fibers were found to terminate relatively substantially in several structures of the midbrain, pons, and medulla. The following pontine and midbrain nuclei receive moderate to dense projections from the DR: pontomesencephalic central gray, mesencephalic reticular formation, pedunculopontine tegmental nucleus, medial and lateral parabrachial nuclei, nucleus pontis oralis, nucleus pontis caudalis, locus coeruleus, laterodorsal tegmental nucleus, and raphe nuclei, including the central linear nucleus, median raphe nucleus, and raphe pontis. The following nuclei of the medulla receive moderately dense projections from the DR: nucleus gigantocellularis, nucleus raphe magnus, nucleus raphe obscurus, facial nucleus, nucleus gigantocellularis‐pars alpha, and the rostral ventrolateral medullary area. DR fibers project lightly to nucleus cuneiformis, nucleus prepositus hypoglossi, nucleus paragigantocellularis, nucleus reticularis ventralis, and hypoglossal nucleus.Some differences were observed in projections from rostral and caudal parts of the DR. The major difference was that fibers from the rostral DR distribute more widely and heavily than do those from the caudal DR to structures of the medulla, including raphe magnus and obscurus, nucleus gigantocellularis‐pars alpha, nucleus paragigantocellularis, facial nucleus, and the rostral ventrolateral medullary area. A role for the dorsal raphe nucleus in several brainstem controlled functions is discussed, including REM sleep and its events, nociception, and sensory motor control. © Wiley‐Liss, Inc.