bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numbers of axons in lateral and ventral funiculi of rat sacral spinal cord
Authors: Chung Kyungsoon , Coggeshall Richard E. 
Published: December 2004

AbstractThe present study determines the numbers of myelinated and unmye‐linated axons in the ventral and lateral funiculi of rat sacral spinal cord. On average, there are 55,000 myelinated and 110,000 unmyelinated axons in the lateral funiculus and 26,000 myelinated and 9,000 unmyelinated axons in the ventral funiculus at these levels. These figures combined with data from earlier studies of the posterior funiculus and the tract of Lissauer give approximate figures of 88,500 myelinated and 131,500 unmyelinated axons for the entire white matter of one side of the rat sacral spinal cord. Thus unmyelinated axons predominate in the white matter of the rat sacral spinal cord.The majority of axons, particularly the unmyelinated axons, are located in the lateral funiculus. The axons are concentrated in the dorsalateral part of the lateral funiculus, and so the dorsal part of the lateral funiculus, of ten referred to as the dorsolateral funiculus, contains more than half the fibers in the white matter of the spinal cord. A small nick in the dorsal and lateral part of the lateral funiculus, which is often done for various experimental reasons, could thus remove 40% of the axons in the white matter of rat sacral spinal cord.The data reported in the present paper will serve as a basis for future studies on the white matter of the isolated spinal cord.
Midbrain nuclei projecting to the medial medulla oblongata in the monkey
Authors: Chung Jin Mo , Kevetter Golda A. , Yezierski Robert P. , Haber Lawrence H. , Martin Richard F. , Willis William D. 
Published: December 2004

AbstractTo identify the midbrain nuclei that project to the medial part of the lower brainstem in the monkey, labeled cells were mapped in the midbrain following the injection of horseradish peroxidase into the medial medulla oblongata. After the general distribution of labeled cells was observed in three animals with large injections, more discrete injections of HRP were made in different locations in six additional animals. The small injections were centered in the nucleus raphe magnus, nucleus reticularis giganto‐cellularis, or nucleus medullae oblongatae centralis. The five labeled mid‐brain nuclei were the periaqueductal gray, nucleus cuneiformis, deep layers of the superior colliculus, nucleus of Darkschewitsch, and the interstitial nucleus of Cajal. In addition, the parvocellular division of the red nucleus and the posterior pretectal nucleus contained large numbers of cells when the injection spread into the inferior olive. No major differences in the distribution of labeled cells between different injection sites were found with the exception that the superior colliculus did not contain any labeled cells when the injection was restricted to midline structures. The functional implications of these anatomical findings are discussed in relation to the descending control of pain.
A system of rat spinal cord lamina 1 cells projecting through the contralateral dorsolateral funiculus
Authors: McMahon S. B. , Wall P. D. 
Published: December 2004

AbstractThe aim of these experiments was to sample the properties of lamina I neurones with long ascending projections. Recordings have been made from 136 units at the LA/5 level, with ascending axons reaching C2. More than 80% of the units projected via the contralateral dorsolateral white matter and only 10% via the contralateral ventral quadrant. None projected via the dorsal columns. Receptive fields were typically 1–2 cm2 and although a substantial number of units responded to a limited range of intense stim‐uli, a greater number of units were fired by both low‐ and high‐threshold stimulation. In contrast to cells of deeper laminae, the majority of units were excited following activation of descending pathways in the dorsolateral funiculus.The functional role of these units is not obvious, but the location of the ascending projection and the influence of descending pathways does not support the notion that the output of lamina 1 constitutes a simple “pain pathway”.
Qualitative and quantitative development of the visual cortex in man
Authors: Sauer B. , Kammradt G. , Krauthausen I. , Kretschmann H.‐J. , Lange H. W. , Wingert F. 
Published: December 2004

AbstractAnatomical parameters derived from an analysis of 35 male brains, ranging in age from 137 days after conception (DAC) to 99 years, were studied in reference to the development of the human visual cortex (area 17). Distinct structuring of laminae V and VI of area 17 is present at 137 DAC, contrasting with the relative undifferentiation of area 18 at this time. Both the differentiation of the visual cortex into the fundamental six laminae of Brodmann and the emergence of the stripe of Gennari occur between 180 and 190 DAC. At this time, sublamina IVa emerges as a separate entity, external to a transient, trilaminated cortical complex of which the two internal components form sublamina IVc while the external component becomes a part of sublamina IVb (stripe of Gennari). Lamination in area 18 follows a different time course than area 17, appearing at about 160 DAC and achieving a definite six‐layered structure at the 185th DAC. The widths of the laminae in both areas continue to fluctuate after the 190th DAC while the cellular density appears to decrease. The fresh volume of the visual cortex was determined from stained serial sections of the brain, following adjustment for artifactual shrinkage. Approximations of values utilizing the 3‐, 4‐, and 5‐parametric logistic functions reveal that maximum growth of this area occurs at birth, with area 17 attaining 50% of its maximum volume. The maximum volume is reached at the 300th DAC and it apparently begins to decrease in the first decade. The visual cortex develops at a considerably faster rate and reaches its maximal volume much earlier than does the whole brain, cerebellum, or hippocampal formation.
The superior vestibular nucleus: An intracellular hrp study in the cat. I. Vestibulo‐ocular neurons
Authors: Mitsacos Ada , Reisine Harvey , Highstein Stephen M. 
Published: December 2004

AbstractSuperior vestibular neurons were penetrated with horseradish perox‐idase (HRP)‐loaded glass microelectrodes in anesthetized cats. Responses to electrical stimulation of the oculomotor complex and the vestibular nerves were characterized and selected neurons were injected with HRP. Neurons antidromically activated by oculomotor complex stimulation were generally monosynaptically excited by the ipsilateral vestibular nerve. Notable was the absence of strong commissural inhibition by stimulation of the contra‐lateral vestibular nerve. Light microscopy of antidromically identified injected cells demonstrated that these cells are predominantly located at the central levels of the superior vestibular nucleus along the incoming vestibular nerve fibers but a few are found at more caudal levels. Cell bodies, elongated or pyramidal, are mainly medium‐sized to large (30–50 μm). Dendritic trees extend in a plane at an acute angle to the collaterals of the vestibular nerve fibers. Dendrites remain within the nuclear territory and generally display an isodendritic branching pattern. Dendritic spines and appendages are mainly distributed on secondary and distal dendrites. A few terminal enlargements similar to growth cones are observed in these neurons.Axons of these neurons project rostrally via the medial longitudinal fasciculus, while a minor projection via the brachium conjunctivum is also found. Axon collaterals, when present, originate in the nucleus itself and in the pontine reticular formation.
Gradients of cellular maturation and synaptogenesis in the superior colliculus of the fetal rhesus monkey
Authors: Cooper Michael Lee , Rakic Pasko 
Published: December 2004

AbstractLight (LM) and electron microscopic (EM) qualitative and quantitative analyses were employed to determine the tempo and spatial gradients of Synaptogenesis and cellular differentiation in the superficial superior collic‐ulus (SC) of the rhesus monkey between embryonic (E) days E47 and E84. 3y E47, a majority of the neurons of the prospective superficial gray layer (SGS) have arrived at their final positions and contribute to a uniform band of small, darkly Nissl‐stained neurons at the outer surface of the SC. By E54, cells in the middle of the rostral pole of the superficial SC become considerably larger, paler staining, and less densely packed than the more medially or laterally located cells. These regional differences, which extend posteriorly through about the middle of the SC at this age, are evident on both the LM and EM levels and were confirmed by a quantitative EM analysis of the cytodifferentiation and Synaptogenesis in the SGS. Several overlapping EM probes made across the medial, middle, and lateral regions of the SGS at each of three coronal levels reveal consistently more developed neuropil and smaller amounts of extracellular space in the middle region than in the medial and lateral portions of the more anterior SC. Further the densities of synapses, both in terms of synapses/μm2 of totalcross‐secti area and synapses/μm2 of neuropil alone, are also higher in the middle than the peripheral regions. Most of the middle‐peripheral differences found in the mid‐E.50s are still evident by the early E60s, but have disappeared by midgestation (E80s). The present results are interpreted to indicate that the middle region of the SGS at a given transverse level begins to mature significantly earlier than the medial or lateral areas. Since our previous 3H‐thymi‐dine analysis (Cooper and Rakic, 1981 a) failed to reveal significant regional variation in the time of neuron origin in the superficial SC, the observed spa‐tiotemporal gradients of neuronal maturation in the primate SGS probably do not arise from underlying gradients of cellular proliferation.
Somatosensory properties of the inferior olive of the cat
Authors: Gellman Reuben , Houk James C. , Gibson Alan R. 
Published: December 2004

AbstractWe examined the somatosensory properties of 391 neurons in the inferior olive in 20 cats that were anesthetized with barbiturate or decere‐brated. A response consisted of a single spike with a variable number of wavelets followed by a long refractory period. Neurons responsive to natural somatosensory stimuli were recorded in all olivary subdivisions. The dorsal accessory olive (DAO) contained the highest proportion of responsive units (96%), compared with 66% for the medial accessory olive (MAO) and 43% for the principal olivary (PO) nucleus. Within the rostral DAO we found a refined cutaneous map of the entire contralateral body surface. In the caudal DAO responsiveness to manipulation of deep tissues became prominent, and both individual limbs and bilateral pairs were represented. In the medial region of the PO responsiveness to taps predominated and bilaterally symmetrical fields were frequent. The lateral PO was unresponsive under the conditions of these experiments. The MAO was distinguished by a greater complexity of receptive field and by a preponderance of deep over cutaneous modality. The lateral part of caudal MAO contained cells with interesting spatial patterns of excitation and inhibition, whereas most cells in the rostral MAO had purely excitatory fields. A teleceptive area receiving visual and auditory input was recognized in the medial MAO and nearby structures such as the dorsal cap. Contact and proprioceptive signals arriving via climbing fibers may provide the cerebellum with information necessary to relate the body to external objects.
Early prenatal development of the human precommissural septum
Authors: Brown Jerry William 
Published: December 2004

AbstractThe development of the septum was studied in human embryos and fetuses ranging from 8 to 24.5 weeks of menstrual age (22.2 to 216 mm crown‐rump length). Neuroblasts migrating from the ventricular layer of the ventromedial hemispheric wall form a narrow intermediate layer that constitutes the primordial septum (8 weeks). Only a primordial nucleus of the diagonal band is identifiable within the gradually enlarging primordial septum at early stages. By 10 weeks the primordial septum is subdivided into medial and lateral zones. At 11.5 weeks well‐defined medial nuclei and the nucleus of the diagonal band are evident within the medial zone. Differentiation within the lateral zone occurs by 12.5 weeks with the appearance of nucleus lateralis pars interna. Nucleus dorsalis is developing in the lateral zone by 14.5 weeks and, by 15.5 weeks, well‐defined nuclei are present throughout the lateral zone. Further neuronal maturation and conforma‐tional changes result in the nearly adult appearance of the septum in older fetuses. Although a definite mediolateral differentiation‐gradient occurs, individual nuclei appear to differentiate along their own longitudinal gradient. Evidence presented suggests that the earliest fibers within the primordial septum are related to the tuberculum olfactorium and the medial forebrain bundle, that septohippocampal fibers appear at 10 weeks, hippocamposeptal fibers by 11.5 weeks, and that, later, stria terminalis fibers develop. The suggested developmental relationships of the septum with the hypothalamus (and brainstem), tuberculum, hippocampus, and amygdala emphasizes its role as an internode in the limbic system.
Rat ciliary neurotrophic factor (CNTF): Gene structure and regulation of mRNA levels in glial cell cultures
Authors: Carroll Patrick , Sendtner Michael , Meyer Michael , Thoenen Hans 
Published: December 2004

AbstractThe structure of the rat ciliary neurotrophic factor (CNTF) gene and the regulation of CNTF mRNA levels in cultured glial cells were investigated. The rat mRNA is encoded by a simple two‐exon transcription unit. Sequence analysis of the region upstream of the transcription start‐site did not reveal a typical TATA‐box consensus sequence. Low levels of CNTF mRNA were detected in cultured Schwann cells, and CNTF mRNA was not increased by a variety of treatments. Three‐week‐old astrocyte‐enriched cell cultures from new‐born rat brain contained easily detectable CNTF mRNA. In astrocyte‐enriched cultures, upregulation of CNTF mRNA levels was observed after treatment with IFN‐γ. CNTF mRNA levels were down‐regulated in these cells by treatments that elevate intracellular cyclic AMP and by members of the fibroblast growth factor (FGF) family. The implications of these results for potential in vivo functions of CNTF are discussed. © 1993 Wiley‐Liss, Inc.
Early and rapid de novo synthesis of Alzheimer βA4‐Amyloid precursor protein (APP) in activated microglia
Authors: Banati R. B. , Gehrmann J. , Czech C. , Mönning U. , Jones L. L. , König G. , Beyreuther K. , Kreutzberg G. W. 
Published: December 2004

AbstractUpon acute activation, microglia, the immuneffector cells of the brain parenchyma, express the amyloid precursor protein (APP) that is otherwise prominent in pathological structures related to Alzheimer's disease. In this disease complex amyloidbearing neuritic plaques contain βA4‐amyloid protein, the APP, and numerous inflammatory proteins. The accompanying activation of microglia has mostly been viewed as a secondary reaction to amyloid deposits.Activation of microglia was performed in a graded fashion. Transection of peripheral nerves such as the facial or sciatic nerve causes a microglial reaction within hours in the nucleus of origin or in projection areas of the CNS. A predominantly glial up‐regulation of APP mRNA and protein could be detected as early as 6 h post lesion not only at the site of affected neuronal cell bodies but also in corresponding projection areas. Its time course suggests rapid transneuronal signalling to glial cells in the projection area. Light and electron microscopy demonstrate that microglia, which are cells of mononuclear phagocyte lineage and comprise up to 20% of all glial cells, are the dominant source for non‐neuronal APP expression. Ultrastructurally, brain perivascular cells within the basal lamina constitutively express APP and thus are a possible source of vascular amyloid.Additionally, microglia express leukocyte‐derived (L)‐APP mRNA and protein that have recently been described in mononuclear cells of the immune system. Increased L‐APP expression may serve as a potential marker for glial/microglial activation. Such immune‐mediated amyloidogenesis initiated by microglia might have implications for the treatment of neurodegenerative diseases. © 1993 Wiley‐Liss, Inc.
A depolarization‐stimulated, bafilomycin‐inhibitable H+ pump in hippocampal astrocytes
Authors: Pappas Christopher A. , Ransom Bruce R. 
Published: December 2004

AbstractRelatively little is known about the mechanisms of pHi regulation in mammalian glial cells. We analyzed pHi regulation in rat hippocampal astrocytes in vitro using the pH‐sensitive dye BCECF. All experiments were carried out in CO2/HCO3‐free solutions. Recovery from NH+4‐induced acid loads was strongly dependent on the presence of extracellular Na+ and was inhibited by amiloride and its more specific analog EIPA, indicating the presence of Na+‐H+ exchange in these cells. Removing bath Na+ or adding amiloride caused resting pHi to shift in the acid direction. Even in the absence of bath Na+ or presence of Na+/H+ inhibitors, however, these astrocytes continued to show significant recovery from acid loads. The mechanism of this amiloride‐insensitive and Na+‐independent pHi recovery process was sought and appeared to be a proton pump. In the absence of Na+, recovery from an acid load was completely blocked by the highly specific blocker of vacuolar‐type (v‐type) H+ ATPase, bafilomycin A1 (BA1). In normal Na+containing solutions, exposure to BA1 caused a small acid shift in baseline pHi and slowed recovery rate from NH+4‐induced acid loads by about 32%. The rate of Na+‐independent pHi recovery was increased by depolarization with 50 mM [K+] solution, and this effect was rapidly reversible and blocked by BA1. These results indicate that, in CO2/HCO−3‐free solution, pHi regulation in hippocampal astrocytes was mediated by Na+−‐H+ exchange and by a BA1‐inhibitable proton pump. Because the proton pump's activity was influenced by membrane potential, this acid exporting mechanism could contribute to the depolarization‐induced alkalinization that is seen in astrocytes. Although v‐type H+−ATPase had been previously isolated from the brain, this is the first report indicating that it has a role in regulating pHi in brain cells. © 1993 Wiley‐Liss, Inc.
Untersuchungen über stereoisomere Salze des Leucin‐methylesters
Authors: Weil K. , Kuhn Werner 
Published: December 2004

AbstractEs wurden die Eigenschaften, insbesondere die Löslichkeiten diastereomerer Salze von d(−)‐ und von l(+)‐Leucin‐methylester mit optisch aktiven Säuren untersucht. Aus solchen Löslichkeitsbestimmungen lassen sich Schlüsse ziehen auf die Verwendbarkeit der einzelnen Säuren für die Eliminierung des im natürlichen Leucin in grosser Menge vorhandenen häufigen und damit für eine Anreicherung des seltenen Antipoden.
Etudes sur les matières végétales volatiles. XLIII. Présence de nérolidol dans des huiles essentielles de papilionacées
Authors: Naves Y. R. 
Published: December 2004

AbstractLe d‐nérolidol présent dans le baume du Pérou n'est pas ou n'est qu'en partie le fruit de processus pathologiques. Associé à une petite proportion de farnésol, il constitue plus de 80% des essences de bois de Myrocarpus fastigiatus et M. frondosus Allem. (légumineusespapilionacées).
Etudes sur les matières végétales volatiles. XLIV. Présence de nérolidol dans les huiles essentielles de papilionacées. (2ème communication)
Authors: Naves Y.‐R. 
Published: December 2004

AbstractL'essence du bois rouge (vraisemblablement Myrospermum erythroxylon Fr. Allem.) possède une composition analogue à celle des huiles essentielles de bois d'autres sophorées, elle est constitée en majeure partie de d‐nérolidol.
Acetoxytropyliumbromid: Synthese, Strukturbeweis, Verhalten in Lösung
Authors: Engel Peter , Keller Urs Martin , Bigler Peter , Neuenschwander Markus 
Published: December 2004

Acetoxytropyliumbromide: Synthesis, Structural Evidence, Behaviour in Solution.Acetoxytropyliumbromide (9) is formed from tropone and acetylbromide. In solution the tropylium salt equilibrates with the educts, 9 being favored at low temperature in polar aprotic solvents. The structure of the title compound has been proved by X‐ray analysis, as well as by investigation of the 1H‐NMR. spectra of solutions of 9.
Über Pterinchemie. 56. Mitteilung. Die Kristallstruktur von Xanthopterin‐hydrochlorid
Authors: Bieri Jost H. , Hummel Willi‐Peter , Viscontini Max 
Published: December 2004

The crystal structure of xanthopterine‐hydrochloride.The crystal structure of the title compound, a pterine, has been determined by X‐ray analysis (direct methods) and refined with 1332 structure amplitudes to R = 0.027. The crystal system is monoclinic, space group P21/c, with unit cell dimensions a = 7.942, b = 8.417, c = 12.076 Å, β = 93.77°. The molecule is protonated at the N(1)‐position. The angle between the planes of the pyrimidine and pyrazine rings is 2.02°.
An ESR. and ENDOR. Study of the Radical Anions of Cyano‐ and Nitro‐Monosubstituted Naphthalenes
Authors: Fürderer Peter , Gerson Fabian 
Published: December 2004

Abstract1H‐ and 14N‐coupling constants have been determined by ESR. and ENDOR. spectroscopy for the radical anions of 1‐ and 2‐cyano‐, and 1‐ and 2‐nitronaphthalene.
Synthesis with 1,2‐Oxazines. I. A Synthesis of 4,5‐Dihydro‐6H‐1,2‐Oxazin‐6‐one Derivatives
Authors: Hardegger Bruno , Shatzmiller Shimon 
Published: December 2004

AbstractA synthesis of some 4,5‐dihydro‐6H‐1,2‐oxazin‐6‐one derivatives is described.
The Reaction of Singlet and Triplet Oxygen with 2‐Phenylnorbornene
Authors: Jefford Charles W. , Boschung André F. , Rimbault Christian G. 
Published: December 2004

AbstractThe reaction of singlet oxygen with 2‐phenylnorbornene (1) in aprotic solvents gives 3‐formylcyclopentyl phenyl ketone (2) (10%) and uncharacterized polymer (90%). When methanol is used as solvent, endo‐2‐phenyl‐exo‐2‐methoxy‐exo‐3‐hydroperoxynorbornane (4) and endo‐2‐(anti‐1′, 4′‐epidioxy‐5′,6′‐epoxycyclohex‐2′‐enyl)‐exo‐2,3‐epoxynorbornane (6 and 7) are obtained in addition to 2. Triplet oxygen with 1 gave 2, endo‐2‐phenyl‐exo‐2,3‐epoxynorbornane (8), and the trimer 9 or 10 of exo‐2,3‐epidioxy‐endo‐2‐phenylnorbornane. With protic solvents the amount of epoxide increased at the expense of trimer. The singlet and triplet oxygen reactions are discussed in the light of possible intermediates.