bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differentiation of granule cell dendrites in the dentate gyrus of the rhesus monkey: A quantitative golgi study
Authors: Duffy Charles J. , Rakic Pasko 
Published: December 2004

AbstractThe differentiation of granule cell dendrites in the dentate gyrus of the hippocampal region was studied in a series of developing fetal and postnatal rhesus monkeys whose brains were processed by the rapid Golgi method. The total combined lengths of dendrites, the total number of dendritic spines, and their density on the proximal, middle, and distal thirds of the dendritic shafts were determined at embryonic days 58, 95, 120, 153, term (165), postnatal days 3, 20, 60, 150, 365, and adults. At all ages examined, granule cells exhibited various levels of maturation with the more differentiated cells being situated in the superficial strata of the granular layer and the less mature cells lying in progressively deeper positions, thus conforming to the outside‐to‐inside spatiotemporal gradient of their genesis. Quanti‐tative analysis shows that, in this primate, hippocampal granule cells dif‐ferentiate mainly in the second half of gestation with all measured param‐eters attaining mature values by the time of birth. However, the analysis also reveals a transient phase of exuberant postnatal development which involves excessive dendritic branching, regional changes in dendritic length, overproduction of dendritic spines, and redistribution of spines within the molecular layer. After reaching peak values around the middle of the first year of life, these parameters decrease and in adult monkeys fall back to the neonatal level.
Cell death and changes in the retrograde transport of horseradish peroxidase in rubrospinal neurons following spinal cord hemisection in the adult rat
Authors: Goshgarian Harry G. , Koistinen Jeanne M. , Schmidt Eric R. 
Published: December 2004

AbstractMost of the hypotheses that have been proposed to explain why the injured mammalian spinal cord is not capable of extensive regeneration have suggested that the internal milieu of the injured spinal cord is not conducive to repair. Relatively little attention has been directed toward neuronal cell death as being contributory to the minimal amount of spinal cord regeneration. The present study suggests that the availability of regenerating axons in the injured spinal cord may be limited by the death of axotomized supraspinal neurons in the adult mammal. Adult rats were subjected to a right spinal cord hemisection at T1 followed by a second, more rostral right hemisection at C2 Horseradish peroxidase (HRP) was injected into the rostral hemisection site to acquire information on the metabolic changes that occur in HRP‐labeled rubrospinal neurons after axotomy. In the experimental animals, a delay of 9‐219 days occurred between the two operations whereas there was no delay between the two procedures in the control animals. An analysis of neuronal counts indicated that although there was a statistically significant (P < 0.01) decrease in the number of labeled rubrospinal neurons in the contralateral red nucleus of the experimental animals compared to controls, there was also a smaller, yet significant (P < 0.01) increase in the number of nonlabeled neurons in the experimental animals. The mean total number (both labeled and nonla beled) of neurons in the experimental animals (2,269 ± 348 cells), however, was significantly lower (P < 0.01) than the mean total number of neurons in the control animals (3,473 ± 488 cells). Thus, it is concluded that extensive cell death occurs in the red nucleus of the adult rat following spinal cord hemisection.The increase in the number of nonlabeled neurons coupled with an overall decrease in the intensity of the HRP reaction in labeled neurons of the experimental animals indicates that HRP retrograde transport is reduced in chronically axotomized rubrospinal neurons. This suggests that the retrograde axonal transport system may be used as an instrument to gauge the metabolic state of injured CNS neurons. This technique may enable us to gain a better understanding of degeneration and regeneration in the injured mammalian spinal cord.
Connections of the bullfrog striatum: Efferent projections
Authors: Wilczynski Walter , Northcutt R. Glenn 
Published: December 2004

AbstractAutoradiographic and degeneration techniques were used to describe striatal efferents in the bullfrog (Rana catesbeiana). Horseradish peroxidase (HRP) was then placed in the major terminal fields to reveal the striatal cells responsible for these projections. Except for the small ventral eminence of the lateral pallium immediately adjacent to the dorsal striatum, no pallial region receives a striatal projection. Most striatal efferents descend in the lateral forebrain bundle (LFB), passing through the anterior entopedun‐cular nucleus, where one large fascicle decussates in the anterior commissure and innervates the contralateral anterior entopeduncular nucleus and caudal ventral striatum. A smaller fascicle exits the LFB to terminate in the ipsilateral lateral amygdala. The remaining efferents continue caudal in the LFB through the posterior entopeduncular nucleus, with sparse projections to the ventral thalamus, the adjacent preoptic areas, and the posterior tuberculum leaving the bundle at various points. At pretectal levels, some efferents leave the LFB to run dorsally, through the caudal pole of the central thalamic nucleus and into the posterior division of the lateral nucleus and the lateral portion of the posterior thalamic nucleus. Efferents also continue caudal, through the superficial tegmental cell groups (nucleus profundus mesencephali and superficial isthmal reticular nucleus) before turning dorsomedially into the ventral anterodorsal, lateral anteroventral, and rostral pole of the posterodorsal tegmental fields. A small superficial projection continues to isthmal levels but cannot be traced beyond. Tegmental HRP injections retrogradely fill cells in the dorsal and ventral striatum as well as nucleus accumbens and the anterior entopeduncular nucleus. Pretectal HRP injections fill cells only in the caudal ventral striatum and anterior entopeduncular nucleus. Anterior entopeduncular nucleus HRP injections fill numerous cells in all striatal divisions, but some of this filling may be due to interrupted fibers of passage. Thus the anuran striatum, which receives its major input from thalamic nuclei relaying tectal and toral input, can in turn influence the midbrain roof via several disynaptic pathways: through the anterior entopeduncular nucleus, pretectum, and tegmentum, all of which project directly to the tectum and torus (Wilczynski and Northcutt, ′77; Wilczynski, ′81). Additional trisynaptic routes through the anterior entopeduncular nucleus and its pretectal and tegmental connections parallel the striatal routes.
Rapid fiber reorganization after early olfactory tract section and bulbectomy in the hamster
Authors: Small Rochelle K. , Leonard Christiana M. 
Published: December 2004

AbstractDetails of neuronal reorganization were investigated in golden hamster pups 10 days after neonatal olfactory lesions. Pups sustained unilateral olfactory tract section (ULOT) or unilateral olfactory bulbectomy (UOB) on postnatal day 5 (P5) and were then behaviorally tested through P15. UOBs were sacrificed after P15 to assess the extent of lesions. ULOTs were processed with degeneration techniques to demonstrate the terminal distribution of bulb fibers whose path had been either deflected or severed by the early tract section.Ten days after complete tract section, extensive sprouting of bulb fibers had occurred rostral to the cut in olfactory as well as adjacent nonolfactory (e.g., neocortical) regions. The pattern of rostral sprouting was similar to, and in some cases exceeded, that described in adults subjected to neonatal tract sections (Devor, 76b). Fibers grew caudally past the cut following aberrant paths to reinnervate limited regions of the olfactory tubercle and less frequently, the piriform cortex. Unlike the continuous band of terminals soon in the caudal field of adults given neonatal tract sections, at this early stage of regrowth, fibers were organized in small discontinuous fascicles that tended to cluster at the islands of Calleja of the tubercle. Although these fibers innervated a relatively restricted region in comparison with normal innervation, their connections were apparently functional, as measured by a thermotaxis behavioral assay for the effects of UOB. The ther‐motaxis behavior of most pups showing tubercle reinnervation returned to normal, while the behavior of pups without tubercle reinnervation remained similar to UOBs (Small and Leonard, ′82). Excessive rostral sprouting and invasion of neocortex were seen in all tract‐sectioned pups and were, therefore, apparently not sufficient to sustain normal behavior on this assay.Regrowth of sensory olfactory fibers and extensive formation of glo‐meruli in the anterior olfactory nucleus and, occasionally, in prefrontal neocortex were found following olfactory bulbectomy. There was no correlation between the extent of glomerulization and the behavioral performance, however.The olfactory system provides an appropriate system for investigating the parameters governing age‐dependent axonal sprouting and functional recovery following early brain damage.
Postnatal development of auditory callosal connections in the kitten
Authors: Feng Jia Zhen , Brugge John F. 
Published: December 2004

AbstractTritiatedproline or horseradish peroxidase (HRP) was injected into the middle ectosylvian auditory cortex (AI) of one hemisphere in kittens during the first few weeks postpartum. Survival time was 24–96 hours. The tetra‐methylbenzidine (TMB) (Mesulam '78) method was used to process the HRP material. By the first postnatal day (PND 1) most neurons retrogradely filled in the contralateral auditory cortex form a densely packed, continuous band that presumably represents mainly layer III. This continuous pattern is in contrast to that seen in the adult cat where callosal neurons tend to aggregate in clusters. Other retrogradely labelled cells are more sparsely distributed in deeper layers with the greatest accumulation being in layer VI. At this time callosal neurons are elongated, with their long axes parallel to radial cell columns. In autoradiographs on PND 2, silver grains are seen throughout the thickness of the cortex, indicating that callosal axons have reached the upper layers of the gray matter. Neither the alternating vertical columns nor the laminar bands of callosal afferents that characterize this projection in the adult are clearly seen in kittens of this age. By PND 8–12 the segregation of callosal afferents into vertical bands is evident in the gray matter; by PND 18 this pattern is well developed. On the other hand, the somata of callosal neurons of layer III retain their juvenile distribution well into the seventh postnatal week and show adultlike aggregations sometime around the 14th week after birth. Projections to the medial geniculate body, inferior colliculus, putamen, caudate nucleus, and pons are clearly evident early in the first postnatal week.
The use of kainic acid for tracing neuroanatomical connections in the septohabenvilointerpeduncular system of the rat
Authors: Contestabile A. , Villani L. 
Published: December 2004

AbstractIntracerebral injections of the neuron‐destroying agent, kainic acid, and electron microscopic examination of the injected and the target areas, have been used in order to confirm some controversial anatomical connections in the Septohabenulointerpeduncular system. Kainic acid injections in the lateral habenula (LHb) caused the selective degeneration of several LHb neurons, sparing the neurons of the medial habenula (MHb). Degenerating terminals were found in well‐known target areas of the LHb (dorsal and median raphe nuclei) and, in addition, in the interpeduncular nucleus (IPN), thus confirming the existence of a small LHb‐IPN projection. Kainic acid injections in the nucleus of the diagonal band of Broca (NDBB) resulted in severe ncuronal degeneration in the nucleus itself and in terminal degeneration in the LHb and MHb as well as, to a lesser extent, in the IPN. No evidence of distant neuronal damage was apparent by light (conventional and cupric‐silver stain) and electron microscopic examination, in nuclei receiving afferent inputs from the injected areas and projecting in turn to the target areas. Furthermore, terminal degeneration was not observed in the Hb and IPN after injections of kainic acid in areas not projecting toward these nuclei (hippocampus and striatum). In the present study, therefore, problems of interpretation due to the possible occurrence of distant neuronal damage could be overcome by control tests.On the basis of the selectivity and sensitivity of its action, kainic acid seems particularly useful in the study of small projections and in attempts to discriminate between differential connections of adjacent neuronal populations.
Cortical and thalamic afferent connections of the insular and adjacent cortex of the rat
Authors: Guldin W. O. , Markowitsch H. J. 
Published: December 2004

AbstractThalamic and cortical afferents to the insular and perirhinal cortex of the rat were investigated, Unilateral injections of horseradish peroxidase (HRP) were made iontophoretically along the rhinal sulcus. HRP injections covered or invaded areas along the rhinal fissure from about the level of the middle cerebral artery to the posterior end of the fissure. The most anterior injection labeled a few cells in the mediodorsal nucleus. More posterior injections labeled neurons in the basal portion of the nucleus ventralis medialis, thus suggesting that this cortical region constitutes the rat's gustatory (insular) cortex. We consider the cortex situated posterior to the gustatory cortex in and above the rhinal sulcus as the core region of the rat's (associative) insular cortex, as this cortex receives afferents from the regions of and between the nuclei suprageniculatus and geniculatus medialis, pars magnocellularis. It includes parts of the cortex termed perirhinal in other studies. The cortex dorsal and posterior to the insular cortex we consider auditory cortex, as it receives afferents from the principal part of the medial geniculate nucleus, and the cortex ventral to the insular cortex (below the fundus of the rhinal sulcus) we consider to constitute the pre‐piriform cortex, which is athalamic. The posterior part of the perirhinal cortex (area 35) receives afferents from nonspecific thalamic nuclei (midline nuclei).Cortical afferents to the injection loci arise from a number of regions, above all from regions of the medial and sulcal prefrontal cortex. Those injections confined to the projection cortex of the suprageniculate‐magno‐cellular medial geniculate nuclear complex also led to labeling in contra‐lateral prefrontal regions, particularly in area 25 (infralimbic region).A comparison of our results with those on the insular cortex of cats and monkeys suggests that on the basis of thalamocortical connections, topographical relations, and involvements of neurons in information processing and overt behavior, the insular cortex has to be regarded as a heterogeneous region which may be separated into prefrontal insular, gustatory (somato‐sensory) insular, and associative insularportions.
A light and electron microscopic study of premotor neurons for the trigeminal motor nucleus
Authors: Mizuno Noboru , Yasui Yukihiko , Nomura Sakashi , Itoh Kazuo , Konishi Akira , Takada Masahiko , Kudo Motoi 
Published: December 2004

AbstractPremotor neurons sending their axons to the trigeminal motor nucleus were observed in the cat by light and electron microscopy after labeling the neurons retrogradely or anterogradely with horseradish peroxidase (HRP).After HRP injection into the trigeminal motor nucleus, retrogradely labeled neurons were seen most frequently in the parvocellular reticular formation bilaterally. Many labeled neurons were also seen contralaterally in the intermediate zone at the rostralmost levels of the cervical cord and its rostral extension into the caudalmost levels of the medulla oblongata. Additionally, some neurons were labeled ipsilaterally in the mesencephalic tri‐geminal nucleus, contralaterally in the main sensory trigeminal nucleus and the trigeminal motor nucleus, and bilaterally in the oral and interpolar sub‐nuclei of the spinal trigeminal nucleus. Only a few labeled neurons were seen in the confines of the gigantocellular reticular formation. All labeled neurons were small or of medium size; no large neurons were labeled.After HRP injection into the regions around the trigeminal motor nucleus or the parvocellular reticular formation, axodendritic terminals containing HRP granules were found contralaterally within the trigeminal motor nucleus. Some of these labeled terminals were filled with round synap‐tic vesicles and others contained pleomorphic synaptic vesicles. The varied morphology of labeled axon terminals was considered to reflect the functional heterogeneity of the premotor neurons for the trigeminal motor nucleus.
Characterization of the peripheral‐type benzodiazepine receptors in cultured astrocytes: Evidence for multiplicity
Authors: Itzhak Yossef , Baker Linnell , Norenberg Michael D. 
Published: December 2004

AbstractIn mammalian brain peripheral benzodiazepine (PBZD) receptors are predominantly localized on astroglial cells. Previous studies utilizing whole membrane preparations from brain and peripheral organs of various species have indicated several distinctions between the drug‐receptor interactions of the two prototypic PBZD receptor ligands, PK 11195 and Ro5‐4864. The present study was undertaken to determine whether putative differences in the binding of PBZD receptor ligands in homogenates of primary astrocyte cultures can be interpreted as the labeling of PBZD receptor subtypes. Equilib‐rium competition and saturation binding experiments in homogenate preparations of primary astrocytes from cerebral cortex of new born rats revealed that [3H]PK 11195 labels twice the number of [3H]Ro5‐4864 binding sites. Unlabeled Ro5‐4864 competes for [3H]PK 11195 binding in a manner suggesting the existence of multiple PK 11195 bind‐ing sites. The competition binding experiments, using various benzodiazepines, indicate that one binding component of PK 11195 corresponds to Ro5‐4864 binding sites, whereas the second is different. The latter binding site does not correspond to the central BZD receptor but displays the pharmacological properties of the PBZD receptor. Further differences between the binding of PK 11195 and Ro5‐4864 in astrocytes were detected in the presence of ethanol which was more effective in inhibiting the binding of the latter. Subcellular distribution studies indicated, however, that the binding of both [3H]PK 11195 and [3H]Ro5‐4864 is associated primarily with the mitochondrial fraction of astro‐cytes. Taken together, the present study indicates the existence of non‐overlapping PBZD binding sites in astrocytes and thus suggests the existence of PBZD receptor subtypes. It appears, however, that there is no distinction in the subcellular localization of the putative subtypes of the PBZD receptor. © 1993 Wiley‐Liss, Inc.
Binding of atrial and brain natriuretic peptides to cultured mouse astrocytes from different brain regions and effect on cyclic GMP production
Authors: Yeung V. T. F. , Ho S. K. S. , Leung D. H. Y. , Stadlin A. , Nicholls M. G. , Cockram C. S. 
Published: December 2004

AbstractWe prepared primary cultures of mouse astrocytes from the cerebral cortex, hypothalamus, and cerebellum to examine the possibility of regional disparity in binding of human atrial and porcine brain natriuretic peptides (hANP, pBNP) and their effect on cyclic guanosine monophosphate (cGMP) production. 125I‐hANP and 125I‐pBNP bound in a specific and saturable manner to all three regions. For both peptides, Scatchard analysis suggested a single population of binding sites on astrocytes from all three regions. No significant differences were observed in the maximal binding capacities (Bmax) or binding dissociation constants (KD) between the two peptides in the astrocyte preparations from different regions. ANP and BNP also evoked cGMP stimulation in a similar, dose‐dependent fashion in astrocytes from all three regions, with maximal responses to both peptides reached at a concentration above 1 μM. While BNP elicited a greater maximal cGMP accumulation than ANP, no difference could be demonstrated in the cGMP responses to either peptide between brain regions. Thus we have been unable to demonstrate regional heterogeneity in the responsiveness of astrocytes to ANP and BNP. © 1993 Wiley‐Liss, Inc.
Cytokine receptors on glial cells
Authors: Otero Glen C. , Merrill Jean E. 
Published: December 2004

AbstractGiven what evidence there is for the molecular and functional nature of cytokines and their cognate binding proteins in the immune system and the emerging similarities or even identities for these ligands and receptors in the nervous system, two general models may be relevant. The first emerging pattern is that receptors for related but distinct trophic factors in the CNS are in many instances multichain complexes with one or more shared components. The shared components of the receptor complex may be either signal‐ or nonsignal‐transducing chains. A second emerging motif is that related ligands and related receptors fall into gene families. Undoubtedly, these models will facilitate the cloning of novel members of these families whose function is quite specific to the nervous system and in particular to glial cells. This article will review the function of the receptors for cytokines and families of differentiation/survival/growth factors as they operate on astrocytes, microglia, and oligodendrocytes in development, health, and disease. © 1994 Wiley‐Liss, Inc.
Beitrag zur Emissionsspektralanalyse von Molekeldämpfen
Authors: Handelsmann M. 
Published: December 2004

AbstractEs wird der minimale Sättigungsdruck bestimmt, bei dem sich die Salzdämpfe der Halogenide von Quecksilber, Cadmium und Zink auf Grund ihrer charakteristischen Bandenspektren in einem mit Aussenelektroden versehenen Entladungsrohre noch nachweisen lassen. Der mittlere Wert der minimalen Sättigungsdrucke beträgt 0,01 mm. Die untere Grenze für die absolute Nachweisbarkeit liegt im Falle von HgCl2 bei ca. 3 γ.
Der Abbau der Behensäure im Tierkörper
Authors: Bernhard Karl , Vischer Ernst 
Published: December 2004

Abstract1. Wir hydrierten aus Rapsöl gewonnene Erucasäure mit schwerem Wasserstoff und fütterten Ratten, einem normalen Futter beigemischt, Deuteriobehensäure‐äthylester. Die Resorption betrug bei Zulagen von 5 und 10% Ester zur Nahrung berechnet auf Behensäure rund 40%.
Synthèse de la 6‐ et de la 8‐trifluorométhyl‐quinoléine
Authors: Pouterman E. , Girardet A. 
Published: December 2004

AbstractAu cours de ce travail nous avons amélioré la préparation du trifluorotoluéne et avons montré que la décomposition du phénylchloroforme observée par Swarts doit être imputée aux impuretés contenues dans ce produit. Nous avons également montré, que lors de la chloruration du p‐nitrotoluéne à température élevée en présence de pentachlorure de phosphore ou d'anhydride phosphorique, il y a substitution du groupe nitro par le chlore, avec formation du chlorure de l'acide p‐chlorobenzoïque.