bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphine dependence in the rat: The appearance in the spinal cord of a dorsal root ganglion cell neurotrophic factor
Authors: Hendry I. A. , Duggan A. W. , Hall J. G. 
Published: January 2005

AbstractAn increase in neurotrophic activity for the survival of dissociated sensory neurones has been found in the spinal cord of morphine dependent rats. This activity is not due to morphine itself and is not due to an increase in the nerve growth factor as antibodies to nerve growth factor fail to block the response. A new hypothesis is presented that some of the spinal effects of morphine dependence may be due to and increase in the level of neurotrophic factors as a response to an apparent denervation of the target cells in the spinal cord.
Arachidonic acid, stearic acid, and diacylglycerol accumulation correlates with the loss of phosphatidylinositol 4,5‐bisphosphate in cerebrum 2 seconds after electroconvulsive shock: Complete reversion of changes 5 minutes after stimulation
Authors: Reddy T. S. , Bazan N. G. 
Published: January 2005

AbstractThe effects of electroconvulsive shock (750 msec, 130 V, 150 pps) on the endogenous content of rat cerebral lipids were studied 2, 5, 10, 20, 30, 60, and 300 sec after stimulation. Rapid enzyme inactivation in situ was attained by high‐power head‐focused microwave irradiation (6.5 kW, 2450 MHz). At 10 sec, phosphatidylinositol 4,5‐bisphosphate (PIP2) mass had decreased by 249 nmol per g wet wt, mainly due to loss of arachidonate and stearate. At the same time, the stearoyl‐arachidonoyl glycerol accumulated, although to a lesser extent than the loss exhibited in PIP2. Changes in phosphatidylinositol and in phosphatidylinositol 4‐phosphate mass were not statistically significant. Free fatty acids and diacylglycerold accumulated to 395 nmol per g wet wt; arachidonic and stearic acids composed 322 nmol of these lipids. Hence, the reduction in content PIP2 is sufficient to account 80% of the increases in free fatty acid and diacylglycerol mass. Thirty‐three and 12 nmol of accumulated free palmitic and scosahexaenoic acids, respectively, are not accounted for by the loss of PIP2. Sixty seconds after stimulation, PIP2 content returned to 90% of control levels, while diacylglycerol tended to remain below control levels. Free fatty acids had not returned to control levels by 60 sec, with the exception of docosahexaenoic acid. At 300 sec, PIP2, diacylglycerol, and free fatty acids had all returned to control levels. It is proposed that the elctroshock‐induced release of neurotransmitters is associated with stimulation of phospholipases A1 and A2 at the presynaptic membrane followed by receptor‐linked phosphodiesteratic cleavage of PIP2 at the postsynaptic membrane, and that Ca2+ influx resulting from membrane depolarization activates the deacylation of stearoyl‐arachiodonoyl glycerol.
Ultrastructure of ependymal cells in primary cultures of cerebral cortex
Authors: Rieke G. K. , Wynder H. J. , Jordan F. L. , Thomas W. E. 
Published: January 2005

AbstractUltrastructural features of ependymal cells growing in primary cultures of dissociated cerebral cortical tissue were investigated using electron microscopy. The ependyma exhibited a specific orientation in tissue culture such that the cell surface corresponding to the apical surface in situ was directed toward the culture medium. The membrane on the apical surface of cultured ependyma was characterized by the presence of cilia and microvilli. The lateral margins were marked by a variety of junctions: zonula occludens, zonula adherens, and membrane interdigitations. The cell cytoplasm contained pleomorphic mitochondria, Golgi profiles, clusters of ribosomes, rough endoplasmic reticulum, and particularly profuse scattered plasmic reticulum, and particularly profuse scattered microfilaments and microtubules. These features support the identity of the cells as ependymal in the cultures and establish them as a relatively accurate reflection of ependyma in situ.
Effect of collagenase treatment and subsequent culture on rat muscle fiber acetylcholinesterase activity
Authors: Glavinović M. I. , Lee S. , Miledi R. 
Published: January 2005

AbstractAfter collagenase treatment and mechanical disruption, acetycholinestrase (AChE) activity on the surface of individual flexor brevis muscle fibers fell by 88%. During the next 48 hr in culture, surface AChE activity continued to decline, while intracellular activity changed little. After 1 week in culture total muscle fiber AChE activity fell to very low levels and intracellular AChe activity could no longer be detected, probably as a result of reduced synthesis and rapid externalization of intracellular AChE. Apart from the removal of most of the surface activity, cultured muscle fibers had similar AChE activity to muscle fibers that had been denervated in vivo, suggesting that the change observed in culture reflect the loss of neuro muscular interaction and not to any contributory effects of the dissociation process.It is to be hoped that these results, along with the published results of Bekoff and Betz [J. Physiol, 271:25–40, 537‐547], will serve as useful background data for those continuing to use adult dissociated muscle fibers in their studies.
Changes in the pattern of expression of pp60c‐src in cerebellar mutants of mice
Authors: Brugge J. S. , Lustig A. , Messer A. 
Published: January 2005

AbstractCultures of neurons from rat embroyos have been show previously to express high levels of a unique from of pp60c‐src [Brugge et al (1985): Nature 316:524‐526], the cellular homologue of the transforming protien of Rous sarcoma virus. This altered form of pp60c‐src(+), designated pp60c‐src(+), displays a retarded electroretic mobility due to a structural alteration within the aminoterminal region of the molecule [Brugge et al, 1985]. In order to investigate the distribution and possible role of pp60c‐src(+) in intact brain, we have examined the expression of pp60c‐src in extracts from developing cerebella from wild‐type mice and mutant mice that display progressive degeneration of specific classes of cerebellar neurons. The loss of pp60c‐src(+) generally correlated with the loss of granule cells and Purkinje cells from the cerebella of mice carrying the staggerer (sg/sg) and Lurcher (Lc/+) mutation, with the most pronounced changes observed in cerebella from the more severely affected sg/sg mice. The experssion of pp60c‐src(+) in weaver wv/wv mice is qualitatively and quantitatively quite different. From the earliest time points, there was a significant reduction in the levels of pp60c‐src(+), with no further loss of this form during the period of maximal neuronal differentiation. This suggests an maximal neuronal differentiation. This suggests an early, predegenerative absence of pp60c‐src(+) in this mutant strian, which is defective in granule‐cell migration.
Neuron‐Enriched cultures of adult rat dorsal root ganglia: Establishment, characterization, survival, and neuropeptide expression in response to trophic factors
Authors: Grothe C. , Unsicker K. 
Published: January 2005

AbstractIt is unknown whether adult dorsal root ganglion (DRG) neurons require trophic factors for their survival and maintenance of neuropeptide phenotypes. We have established and characterized neuron‐enriched cultures of adult rat DRGs and investigated their responses to nerve growth factor (NGF), ciliary neuronotrophic factor (CNTF), pig brain extract (PBE, crude fraction of brain‐derived neuronotrophic factor, BDNF), and laminin (LN).DRGs were dissected from levels C1 through L6 and dissociated and freed from myelin fragments and most satellite (S‐100‐immunoreactive) cells by Centrifugation on Percoll and preplating. The enriched neurons, characterized by their morphology and immunoreactivity for neuron‐specific enolase, constityted a population representative of the in vivo situation with regard to expression of substance P (SP), somatostatin (SOM), and cholecystokinin‐8 (CCK) immunoreactivities. In the absence of trophic factors and using polyornithine (PORN) as a substratum, 60‐70% of the neurons present initially (0.5 days) had died after 7 days.LN as a substratum did not prevent a 30% loss of neurons up to day 4.5, but it subsequently maintanied DRG neurons at a plateau. This behavior might reflect a cotrophic effect of LN and factors provided by non‐neuronal cells, whose proliferation between 4.5 and 7 days could not be prevented by addition of mitotic inhibitors of γ‐irradiation.CNTF, but not NGF, slightly enhanced survival at 7 days on either PORN or LN. No neuronal losses were found in non‐enriched cultures or when enriched neurons were supplemented with PBE, indicating that non‐neuronal cells and PBE provide factor (S) essential for adult DRG neuron survival. Proportions of SP‐, SOM‐, and CCK‐immunoreactive cells were unaltered under any experimental condition, with the exception of a numerical decline in SP cells in 7‐days cultures with LN, but not PORN, as the substratum.Our data, considered in the context of recent in vivo and vitro studies suggest that a combination of tropic factors or an unidentified factor, rather than the established NGF, CNTFl, and BDNF, which address embryonic and neonatal DRG neurons, are required for the in vitro maintenance of adult DRG neurons.
Capacity for substrate utilization in oxidative metabolism by neurons, astrocytes, and oligodendrocytes from developing brain in primary culture
Authors: Edmond J. , Robbins R. A. , Bergstrom J. D. , Cole R. A. , de Vellis J. 
Published: January 2005

AbstractNeuron, astrocyte, and oligodendrocyte cultures which were established from developing rat brain were examined for their utlization of glucose, ketone bodies, and free fatty acids by oxidative processes. 14CO2 production was measured in these cells from [1‐14C] or [6‐14C]glucose; [1‐14C] and [1‐14C], [6‐14C], or [6‐14C]palmitate; and [3‐14C]acetoacetate and D(‐)‐3‐hydroxy[3‐14C]butyrate. Pyruvate dehydrogenase (EC 1.2.4.1.) abd 3‐oxoacid‐CoA transferase (EC 2.8.3.5.) activites were found at high levels in each of the cell population. Astrocytes and oligodendrocytes produced much more 14CO2 from [1‐14C]glucose than from [6‐14C]glucose, indcating substantial hexose monophosphate shunt activity. This process was not as active in neurons. All three cell populations readily utilized the ketone bodies for oxidative metabolism at rates 7–9 times greater than they utilize glucose. Only astrocytes were able to utilize fatty acids for 14CO2 production, and the rate of utilization was greater than of the ketone bodies. We found that the metabolic patterns of thesse brain cells which were derived from the developing brain complement the nature of the diet of the duckling animal which is rich fat and low in carbohydrate. They readily utilized the ketone bodies or fatty acids and spared glucose for processes that metabolites of fat cannot fulfill.
Selective enhancement of tubulingene expression and increase in oligo (dT)‐bound RNA in the rat brain after nigrostriatal pathway unilateral lesion and treatment with ganglioside
Authors: Yavin E. , Gil S. , Consolazione A. , dal Toso R. , Leon A. 
Published: January 2005

AbstractPartial hemitransection of the rat nigrostriatal pathway has been applied to study changes in the expression of tulbulin and actin cytoskeletal genes. RNA was isolated from ipsilateral and contralateral structures of substantia nigra and striatum tissues of lesioned or sham‐operated animals by a combined proteinase K and oligo(dT)‐celluloseaffinity purification procedure. A significant increase in the oligo(dT)‐cellulose‐eluted RNA was observed in the lesioned substantia nigra and striatal tissues compared to naive controls. By 5 days, the RNA content of the lesioned nigra reached a value of 96–114.5 μg/mg DNA compared to 45.7–52.9 μg/mg DNA.Administration of GMI gangliosides at daily intervals resulted by day 5 in a further increase (131.8–141.5 μg/mg DNA) in the RNA content of the lesioned but also of the sham‐operated (81.9–97.8 μg/mg DNA) animals. By 18 hr, the lesioned nigra exhibited a fourfold increase in tubulin messenger RNA (mRNAtub) gene expression in comparison to the sham‐operated animals. The substantia nigra tissue of GM1‐treated animals exhibited a hybridization value for mRNAtub twice as high compared to GM1‐untreated, lesioned animals. The effectof GM1 appearedselective for α‐tubulin and β‐tubulin compared to actin transcript. The latter was also elevated in the lesioned nigra tissue above the naive or sham‐operated animals.The data suggest that, after injury, cytoskeletal RNA transcripts are elevated and that GM1 may play a role in the regulation of their steady‐state levels.
Ultrastructural reversible changes in fish neuromuscular junctions after chronic exercise
Authors: Palacios‐Prü E. , Colasante C. 
Published: January 2005

AbstractNeuromuscular junctions (NJs) of fin muscles of teleostean fishes, Lebistes reticulatus, were ultrastructurally analyzed during 60 min of chronic exercise and a subsequent period of 90 min of induced recovery. NJs from 30‐min‐exercised fishes showed an almost complete depletion of synaptic vesicles (SVs), corresponding to 83% of SV consumption; 76% of axon terminals were branched at the end of this period. During the recovery period, it was possible to observe the reversibility of the changes induced by the exercise and the transitory events that lead to the reacquirement of the normal NJ morphology. After 15 min of rest, SV population increased to a value of 54.6 SVs/μm2 and the percentage of branched axons was 66.5%. At 60 min of recovery the number of SVs reached a value of 84.6 SVs/νm2. The SV population was fully reestablished at 80 min of rest, while the percentage of branched axons was found within normal ranges after 90 min of recovery. These results demonstrate that chronic exercise induced physiological depletion of NJ SVs and other axon terminal morphological changes, as well as that postexercise rest induces the reestablishment of the normal NJ morphology.
Region‐specifi neuro‐astroglial interactions: Ultrastructural study of the in vitro expression of neuronal polarity
Authors: Autillo‐Touati A. , Chamak B. , Araud D. , Vuillet J. , Seite R. , Prochiantz A. 
Published: January 2005

AbstractMesencephal;ic neurons were cultured for 2 days on mesencephalic or striatal astrocyte monolayers. The morphology of these neurons was studied in electron microscopy. The number of dendritic profiles was higher on mesencephalic astrocytes (homotopic neuroastroglial co‐cultures) than on striatal astrocytes (heterotopic co‐cultures). This increase in the number of dendrites correlated with a more mature aspect of the meurons. Striatal neurons were also cultured on the astrocytic monolayers. The state of maturation of these neurons was more advanced, and the number of their dendrites was higher on striatal than on mesencephalic astrocytes. These results confirm and extend the fact that neuronal maturation and dendritic growth can be regulated through region‐specific neuro‐astroglial interactions (Denis‐Donini et al., 1984; Chamak et al., 1987).
Distribution of glutamic acid decarbocylase and gamma‐aminobutyric acid in thehypoglossal nucleus in the rat
Authors: Aldes L. D. , Chronister R. B. , Marco L. A. 
Published: January 2005

AbstractImmunocytochemistry was used to investigate the distribution of glutamic acid decarboxylase (GAD) and gamma‐aminobutyric acid (GABA) in the hupoglossal nucleus (XII) of the adult rat. The distribution of GAD and GABA was found to be co‐extensive throughout XII. Although immunoreactivity was moderately dense in all regions, the intensity of staining was greatest in the ventral district of XII particularly ventromedially in the caudal half of the nucleus. Immunoreactive terminal‐like profiles were observed around motoneuron somata and dendrites. There also was evidence of sparse mediolaterally‐oriented densities of immunoreactivety at the junction of XII and the dorsal vagal nucleus and between dorsal and ventral districts of XII. In addition, neurons staining positive for GABA were found scattered within XII laterally and immediately outside of XII in and around the nucleus of Roller. These observations suggest a complex, differential distribution of GABA in XII and are discussed in relation to tongue motor behavior.
Maternal dietary restriction causes myelin and lipid deficits in the brain of offspring
Authors: Yeh Y.‐Y. 
Published: January 2005

AbstractThe relationship between brain myelination and nutritional insufficiencey in suckling rats whose dams had a restricted dietary intake was studied. The undernourished pups were characterized by body weight and brain weight that were 40‐70% and 82‐88% that6 of controls througthout the suckling period. Myelin concentrations, whether expressred as mg protein or as mg myelin dry weight per g wet brain, were 30‐40% of normally fed controls. Myelin of undernourished rats contained total lipid, cholesterol, phospholipids, and sphingolipids, that were 42, 54, 39, and 48%, respectively of the control counterparts. There was no change in the mole ratio of cholesterol:phospholipids:sphingolipids (i.e., cerebroside + sulfatide) in myelin from undernoufished rats. Concentrations of individual phospholipids and sphingolipids were lowered by approximately the same percentage. Despite long‐lasting, irreversible stunting of whole‐body and brain growth, concentrations of myelin and myelin lipids returned to control levels after nutritional rehabilitation. Since the observed effects are different from those of more commonly used models, the present form of undernutrition may offer a useful system for studying the relationship between myelin lipids and brain development.
Development expression of glial‐specific mRNAs in primary cultures of rat brain visualized by in situ hybridization
Authors: Holmes E. , Hermanson G. , Cole R. , de Vellis J. 
Published: January 2005

AbstractThe localization of mRNAs which encode the gilialspecific maker proteins, glial fibrillary acidic protein (GFAP), glycerol phosphate dehydrogenase (GPDH, EC 1.1.1.8), and myelin basic protein (MBP), was mapped by in situ hybridization in primary cultures of 1–2‐day‐old rat brain in serum‐supplemented medium. Developmental changes of these expressed mRNAs were examined after various times in culture ranging from 8 to 5 days and were correlated with the histological morphological and positional characteristics of the cell. By day 8, the culture stratified into a population of flat polygonal astrocytes covered by another populatioan of phase‐dark process‐bearing cells. When counterstained with May‐Grunwald histological stain, astrocytes appeared pale blue, whereas two subpopulations of phase‐dark cells stained differentially; one was dark blue while the other was red and smaller GFAP‐specific sequences were abundant at day 8, increased in the astrocyte bedlayer as the culture became confluent, and plateaued at approximately day 16. A minor proportion of blue phase‐dark cell contained GFAP mRNA although at a lower abundance. In contrast, GPDH mRNA positive blue phase‐dark cells were seem scattered throughout the upper layer of the culture and also around the perimeter of large clumps of red phase‐dark cells. These cells were infrequent at day 8 but increased in number at later time points. The expression of MBP mRNA differed from GPDH in that it was more abundant at early time points, plateaued between day 20 and day 24, and was predominantly localized in red phase‐dark cells. Initially small and round, the MBP mRNA‐positive cells extended long processes, which then appeared to make connections with other process‐bearing cells and reorganize into clumps that dominated the culture. By day 40, MBP mRNA was scattered over membranous expanses. Thus, in situ hybridization has revealed differential gene expression and abundance of glial‐specific mRNAs in morphologically and histochemically distinct cell populations in uninduced mixed glial cultures. In future studies, the hormonal regulation of glial‐specific mRNAs will be compared to the basal genes activation presented here.
In vitro nerve‐growth‐promoting activity of human plasma α1‐acid glycoprotein
Authors: Liu H. M. , Takagaki K. , Schmid K. 
Published: January 2005

AbstractHuman plasma α1‐acid glycoprotein or orosomucoid (OR), and its derivatives, prepared by sequential enzymatic cleavage of the carbohydrate units, were tested for their nerve‐growth‐promoting activities with explants of whole dorsal root ganglia from chick embryos. The results showed that the OR derivatives with terminal galactose, N‐acetylglucosamine, or mannose have marked neurite‐promoting activities. These preparations at a concentration of 100 μg/ml are equivalent to 5% fetal bovine serum (protein concentration 3,000 μg/ml) in their ability to elicit extensive neurite outgrowth and collateral branching. The asialo‐OR, or ASOR, is the most potent form: its activity is estimated to be 20 times higher than that of transferrin and 100 times over that of fibronectin; it is approximately 1/1,500 that of NGF. The neuritepromoting activity of OR is independent of the nonneuronal cells and their products and can be blocked by a specific antiserum against OR. The mode of action of OR on the in vitro nerve growth is discussed and the pathophysiological significance of this plasma glycoprotein is considered in light of data from recent clinical and pathological studies.
Traumatic spinal cord injury in rats causes increases in tissue thromboxane but not peptidoleukotrienes
Authors: Demediuk Paul , Faden A. I. 
Published: January 2005

AbstractSpinal cord samples from rats subjected to three different levels of impact trauma (25, 50, 100 g‐cm) were examined for immunoreactive thromboxane B2 and 6‐sulfidopeptide‐containing leukotrienes, using specific radioimmunoassays. Trauma resulted in pronounced increases in thromboxane levels as early as 5 min after injury, with maximum values at 1 hr. Although thromboxane values then slowly declined, they remained significantly above control values for up to 7 days. Significantly smaller thromboxane values were found in rats subjected to mild injury (25 g‐cm) than in those that received more severe, irreversible impact injury (50 and 100 g‐cm). No statistically significant changes were observed in leukotriene levels in any of the experimental groups. These findings are consistent with the hypothesis that cyclooxygenase products of arachidonic acid metabolism may contribute to secondary injudy after spinal cord trauma and provides the rationale for the use of cyclooxygenase inhibitors in the treatment of such injury.
Effects of acetylcholine and other agents on 32P‐prelabeled phosphoinositides and phosphatidate in crude synaptosomal preparations
Authors: White H. L. 
Published: January 2005

AbstractExperimental conditions are described which permit effects of various agents on polyphosphoinositides and phosphatidic acid (PA) to be evaluated simultaneously in crude nerve‐ending preparations from rat brain. Acetylcholine (3‐100 μM) or carbachol (30‐1,000 μM) induced the hydrolysis of prelabeled polyphosphoinositides and, at the same time, stimulated the net label incorporated in phosphatidic acid. All muscarinic effects were blocked by atropine or pirenzepine. Nonmuscarinic agonists (glutamate, adenosine, norepinephrine) stimulated polyphosphoinositide hydrolysis in this preparation, but of these only norepinephrine affected phosphatidic acid turnover. A Potentiation of acetylcholine‐induced phosphoinositide turnover by KCI was observed, as well as an apparent selective inhibition of PIP2 hydrolysis by LiCl. Acetylcholinestimulated turnover of PA was not necessarily coupled to phosphoinositide hydrolysis.