bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of catecholamines on behavior
Authors: Torda Clara 
Published: January 2005

AbstractThe potential for at least partial reversible transition of aggression‐ and anxiety‐type symptomatology suggested searching for a potential biochemical link between sub‐cellular mechanisms involved in the execution of aggression and anxiety. The effects of norepinephrine combined with dopamine and of epinephrine on these two types of behavior were tested. Responses to foot‐shock were used to test aggression, extinction of avoidance response was used to test anxiety‐type behavior. The results suggested that one of the possible links between the intracerebral processes responsible for execution of aggression‐ and anxiety‐type behaviors is transmethylation of norepinephrine and/or dopamine to epinephrine.
Effect of acetylcholine on the activity of dopamine β‐hydroxylase in rat brain
Authors: Karahasanoglu A. M. , Edwards E. H. , Tildon J. T. , Ozand P. T. 
Published: January 2005

AbstractSixty percent of the dopamine β‐hydroxylase (DBH) (EC 1.14.2.1) activity in rat brain was found to be bound to membrane fractions. The additions of Triton X‐100 solubilized DBH completely and permitted the estimated of the total enzyme activity. In homogenates the DBH could be detected in the absence of Triton X‐100 but was 30–45% of this total enzyme activity; in crude synaptosomal fractions this value was only 10%. Incubation of brain slices in media containing 2 × 10–3M acetylcholine (ACh) led to an increase by a factor of 2–2.5 in the activity of DBH measured in the absence of detergents; however, total enzyme activity remained the same. The addition of 6 × 10–2 M K+ in place of ACh produced a similar effect; however, the increase in the activity of DBH measured in the absence of detergents was only 25%. The effect of ACh could be reversed by removing it from the medium, or by the addition of diethyl p‐nitrophenyl phosphate (paraoxon) 4 × 10–5 M. The addition of eserine 4 × 10–4 M increased the effect of ACh at 15 min of incubation. Neither acetate nor choline had any effect. Intact cell boundaries appeared to be necessary, since addition of ACh after complete homogenization caused no increase in activity. ACh caused a (9–10)‐fold increase in the specific activity of membrane‐bound DBH but no change in the specific activity of the enzyme in cytosol. Although the effect of ACh mimicked the effect of Triton X‐100, it was not due to the solubilization of DBH. The presence of ACh did not increase the release of DBH into the incubation medium.
Changes of CTP synthetase activity during postnatal rat brain development
Authors: Genchev D. D. , Mandel P. 
Published: January 2005

AbstractThe activity of CTP synthetase (UTP: ammonia ligase (ADP, EC. 6.3.4.2.)) was determined in rat cerebral hemispheres and cerebellum during postnatal development. It was found that enzyme activity, when expressed per unit of protein or wet tissue weight, in both parts of the brain decreased with age, the diminution proceeding more rapidly in the cerebellum than in the hemispheres. When CTP synthetase was expressed on the basis of DNA an activity peak in the hemispheres with a maximum on the 5th day after birth was observed. The enzyme content per cell was several times lower in the cerebellum than in the hemispheres at each age studied, with the exception of 1‐day‐old animals, in which both tissues displayed intensity of RNA synthesis in the developing brain. The conclusion was reached that the changes of CTP synthetase activity were closely related to the RNA metabolism. Therefore the enzyme under study may be one of the factors involved in cell control of RNA synthesis.
Structure of neuronal assemblies in cerebral cortex
Authors: Batuev A. S. , Babmindra V. P. 
Published: January 2005

AbstractInterrelations in the apical dendrite bundles of a single neuronal column were revealed by means of light and electron microscopy in the cat motor cortex. Such column presents an integrated structural module. There were also found wider joinings of several columns, among which complex coordination may exist.
Studies on the effects of chronic ethanol ingestion on the properties of rat brain ribosomes
Authors: Tewari Sujata , Murray Sandara , Noble Ernest P. 
Published: January 2005

AbstractPrevious observations have demonstrated decreased in vivo and in vitro protein synthesis by brain ribosomal systems following long‐term ethanol ingestion. For further investigation of the properties of brain ribosomes, the 40S and 60S ribosomal subunits were successfully isolated from control and chronic 10% ethanol‐drinking rats. For a successful dissociation of ribosomes into subunits NH4CI, puromycin and a high‐salt treatment at 10°C were essential with a critical concentration of Mg2+ since ribosomes could not be resolved at less than 7 mM Mg2+. Analysis of the A260 profile of the subunits on the sucrose gradients showed no significant differences between the control and ethanol‐ingesting groups. Studies on 3H‐labeled ribosomes following in vivo RNA labeling showed correspondence of the radioactive profiles from the incorporation of [5‐3H] orotic acid into RNA with the sucrose gradient absorbance profile of 60S and 40S ribosomal subunits. Furthermore, active reassociation of both subunits occurred at 37°C as demonstrated by the increased [14C]‐phenylalanine incorporation in the presence of poly(U). Results further showed that the poly(U)‐dependent [14C] phenylalanine incorporation was significantly reduced by the subunits from the ethanol‐ingesting animals. These findings suggest that long‐term ingestion of ethanol caused functional changes in the properties of brain ribosomes, specifically on the reassociation process of the two subunits.
Intracortical horizontal connections of neurons in cat and monkey motor cortex
Authors: Novojilova A. P. , Babmindra V. P. 
Published: January 2005

AbstractThe present paper deals with the study of the structure of horizontal neuron chains, one of the aspects of intracortical intraneuronal relationships. The motor cortex (field 4) of cats and lower monkeys (Papio hamadryas and Macacus rhesus s. M. Mullata) was treated by the impregnating method of Golgi‐Kopsh. The drawings of neurons from 90‐μm sections were made by means of a camera lucida.Three possible pathways of impulse transmission along neuron chains in a horizontal direction were revealed. These were: a pyramido‐pyramidal system of connections which may possibly spread excitatory influence among several columns; a basket‐pyramidal connection system; and connections which arise from successive switchings between neighboring neurons of one layer.
Regional distribution of myelin basic protein in the central nervous system of quaking, jimpy, and normal mice during development and aging
Authors: Delassalle A. , Zalc B. , Lachapelle F. , Raoul M. , Collier P. , Jacque C. 
Published: January 2005

AbstractMyelin basic protein (MBP) was quantified using a RIA technique in the spinal cord, cerebellum, diencephalon plus brainstem region and cerebral hemispheres of two dysmyelinating murine mutants, quaking (qk) and jimpy (jp) mice. Comparison was made with normal control values. The whole life‐span has been investigated: ie, ages ranging from 0 to 26 days for the jp, 0 to one year for the qk, and prenatal stage to three years for the control animals. Assays in the mutants at early ages were rendered feasible by the use of marker genes, which has allowed the diagnosis of the mutation at birth, 12 days before the expression of their typical tremor phenotype. Special care was given to the period of early myelinogenesis in order to clarify the dysynchrony between the various parts of the central nervous system.In normal mice, MBP was already detected in the brain of 19‐day‐old embryos. During development, rapid accumulation of MBP first occurred in the spinal cord then in the diencephalon, the brainstem, the cerebellum, and finally in the cerebral hemispheres.In the 25‐day‐old jimpy mutant, levels of MBP were found dramatically decreased, never exceeding 6% of the normal controls in any of the areas investigated.The situation for the quaking mouse was quite different. This mutant could be investigated up to one year old. At that age, a high discrepancy was observed between the values found in the brain and in the spinal cord (respectively, 10% and 35%) compared to normal controls.In both mutants, not only were the levels of MBP decreased, but also its appearance during development was delayed. Nevertheless, in both mutants the caudo‐rostral timing of myelination as assayed by MBP levels was maintained. Furthermore, the later myelination occurred, the stronger was the deficit in MBP. Interestingly, in the quaking mutant, the specific plasticity of the spinal cord was exemplified by its ability to reduce constantly, even at an advanced age, its initial deficit of MBP.
Laminar distribution of cholinergic markers in neocortex: Effects of lesions
Authors: Johnston M. V. , Young A. C. , Coyle J. T. 
Published: January 2005

AbstractThe distribution of presynaptic markers for cholinergic and GABAergic neurons in the various layers of the lateral neocortex was determined with a techique in which sections of increasing depth horizontal to the pial surface were obtained on a frozen‐stage microtome and analyzed for the markers. The specific activities of choline acetyltransferase and acetylcholinesterase had an uneven distribution in the cortex with lowest levels of activity associated with lamina II and III, whereas glutamate decarboxylase activity was highest in lamina II, III, and IV. Fetally‐induced hypoplasia of the cortex resulted in an enrichment in both choline acetyltransferase and acetylcholinesterase activity in all layers with no significant change in the activity of glutamate decarboxylase. Lesion of the nucleus basalis–cortical cholinergic pathway resulted in marked reductions in the activities of acetylcholinesterase and choline acetyltranferase in all cortical layers and an elimination of the uneven distribution of these markers within the cortex. These results provide further evidence that acetylcholinesterase activity is specifically associated with cortical cholinergic afferents and support the existence of cortical intrinsic cholinergic neurons.
Choline acetyltransferase: Further studies on the reverse reaction
Authors: Hsu Louise L. , Chao Li‐Pen 
Published: January 2005

AbstractIn order to further characterize the reaction mechanism of brain ChAc in its purified form, we have investigated the reverse reaction of ChAc in terms of pH optimum, salt effects, and substrate kinetics using a radiochemical assay. We directly measured the reaction product acetylcoenzyme A which was separated from the substrate ACh by a cation exchange column, Dowex 50W‐X8 (Na+ form). The reverse reaction of ChAc was linear with incubation time up to 40 minutes, and with enzyme protein concentration up to 5 μg. It had a pH optimum at 7.0. At 0.22 M the monovalent chloride and bromide salts activated the reverse ChAc activity by 23–47% but the fluoride and iodide salts inhibited the reverse enzyme activity by 10–30%. Kinetic studies in the absence of salt showed that KACh was 0.62 ± 0.06 mM, KCoA·SH was 12.68 ± 1.21 μM, and Vmax was 11.6 ± 1.0 nmol AcCoA/mg protein/min. These data are in disagreement with the values reported on partially purified ChAc from bovine brain by Glover and Potter [1971] and Hersh [1980]. This indicates that further investigations are necessary to clarify or resolve these differences.
Lipophilin‐induced experimental allergic encephalomyelitis in guinea pigs
Authors: Madrid R. E. , Wisniewski H. M. , Hashim G. A. , Moscarello M. A. , Wood D. D. 
Published: January 2005

AbstractClinical signs of EAE were infrequently observed (1/20) in adult Hartley guinea pigs challenged with isolated human myelin lipophilin in complete Freund's adjuvant. However, CNS vasculitis and parenchymal infiltration by inflammatory cells were found in 10 of 20 inoculated animals. Localized, nonconfluent, small demyelinated lesions were detected in the brain and spinal cord of 5/20 Hartley guinea pigs during an observation period of 120 days. The frequency of both inflammatory and demyelinated lesions in Hartley animals appeared to be dosedependent, but extensive demyelinated lesions were not induced. Persistent residual inoculation mixture at the site of injection was found in animals showing CNS inflammatory and/or demyelinated lesions. In contrast to the Hartley strain, young strain 13 guinea pigs were clincally and pathologically unresponsive to challenge with lipophilin and mycobacteria in water‐in‐oil emulsion.
Isoelectric focusing of the chick eye ciliary neuronotrophic factor
Authors: Manthorpe Marston , Barbin Gilles , Varon Silvio 
Published: January 2005

AbstractA procedure is presented in which a crude extract from selected chick embryo intraocular tissues is submitted to analytical polyacrylamide slab gel isoelectric focusing. The extract contains a protein, ciliary neuronotrophic factor (CNTF) which can be eluted in active form from focused gels in a region occupied by only two protein bands. A “slot” technique is presented in which we demonstrate that the eluted CNTF activity focuses in the very restricted region between the two visible bands and is not associated with either band. Silver stain‐densitometry is used to correlate staining intensity with protein concentration and from such an analysis it is concluded that the CNTF protein represents an extremely low proportion of total extract protein and that the minimum CNTF specific activity eluted from gel slices is 106 trophic units per mg protein. This one‐step procedure will be used in the future to prepare highly purified CNTF for antibody generation.
Molecular requirements for survival of cultured avian and rodent dorsal root ganglionic neurons responding to different trophic factors
Authors: Skaper Stephen D. , Selak Ivan , Varon Silvio 
Published: January 2005

AbstractWe have previously demonstrated that both peripheral and central neurons from 8 day embryonic chick and newborn mouse can be maintained in a serum‐free medium using the N1 supplement consisting of insulin, transferrin, putrescine, progesterone, and selenite. In the present studies we show that dorsal root ganglionic (DRG) neurons from embryonic chick (E7–E15) and neonatal mouse can be cultured in a serum‐free environment with only the addition of insulin and transferrin, plus Nerve Growth Factor (NGF). Chick DRG from E10–E15 contain a population of neurons sensitive to a chick embryo eye‐derived ganglionic neuronotrophic factor (GNTF), which is distinct from the neuronal subset dependent upon NGF. The GNTF‐dependent chick neurons can also be maintained in culture with insulin and transferrin supplements. Neonatal mouse DRG neurons, whether supported by NGF or eye‐derived GNTF, likewise survive in serum‐free medium with only insulin and transferrin. Limited numbers of neurons survive for the first 24 hours in a serum‐free medium lacking insulin or transferrin, but failed to display neurite outgrowth even in the presence of added trophic factor.
Role of the plasmin‐generating system in the developing nervous tissue: I. Proteolysis as a mitogenic signal for the glial cells
Authors: Kalderon Nurit 
Published: January 2005

AbstractThe role of the plasmin‐generating system, a serum component, in the development of dissociated embryonic chick spinal cord cells in culture was studied. Studies were performed in a defined system where the cells were maintained in a serum‐free medium. Under these conditions the cells produce plasminogen activator. It was found that plasminogen, when added to the chemically defined culture medium at concentrations of 0.2–0.75 μg/ml, stimulates [3H]thymidine uptake (as expressed per total DNA) in a dose‐response manner. This mitogenic effect is abolished by the protease inhibitors leupeptin and aprotinin. Trypsin, but not chymotrypsin, can produce similar effects. It is concluded that plasmin, which is produced as a result of the activation of plasminogen, is a component that serves as a proliferation factor in developing spinal cords in culture.
Chicken serum transferrin duplicates the myotrophic effects of sciatin on cultured muscle cells
Authors: Oh Tae H. , Markelonis George J. 
Published: January 2005

AbstractSciatin, a glycoprotein purified from chicken sciatic nerves, has been shown to have trophic effects on chicken skeletal muscle cells in culture. Since we recently observed pronounced structural similarities between sciatin and chicken serum transferrin [Markelonis et al, 1982a], we decided to investigate the muscle growth‐promoting activity of transferrin on cultured muscle cells. Serum transferrin was isolated by the same protocol used to purify sciatin, viz., affinity chromatography on concanavalin Aagarose followed by ion‐exchange chromatography on DEAE cellulose. The serum protein recovered by this purification scheme was indistinguishable immunologically from sciatin as evidenced by a positive precipitin reaction against goat anti‐sciatin serum on double immunodiffusion in agar. Purified serum transferrin had myotrophic effects identical to those of sciatin when added to skeletal muscle cells in vitro. For example, even when chicken embryo extract—a constituent normally required for chicken muscle cell differentiation in vitro—was omitted from culture medium, either serum transferrin or sciatin promoted myogenesis in culture as measured by a stimulation of the fusion index. Furthermore, both proteins caused a significant increase in the level of protein synthesis, the number of acetylcholine receptors and the activity of acetylcholinesterase in treated muscle cultures. By contrast, commercially obtained ovotransferrin (conalbumin) or FeSO4 (100 μM) were unable to fully support myogenesis of skeletal muscle in vitro if embryo extract was omitted from the culture medium. From these data, we conclude that the neuronal myotrophic protein sciatin is both structurally and biologically related to serum transferrin. Furthermore, we suggest that sciatin may represent a neuronal form of this iron‐transport protein.
Dose‐dependent initiation of myogenesis by neurotrophic factor
Authors: Popiela Heinz , Ellis Stanley , Festoff Barry W. 
Published: January 2005

AbstractThe kinetics of primary chick muscle cells in response to partially purified neurotrophic factor (NTF) were investigated. Chick muscle cells are routinely plated in the absence of NTF but in the presence of horse serum to allow cell attachment to the substratum; a maximum number of cells attaches 5–8 hr after plating, but cells do not proliferate in the absence of NTF, or do so extremely slowly. Subsequent to a routine attachment period of 6 hr, the medium is aspirated and replaced with medium containing 2–20 μg/ml of NTF as well as horse serum. Dose responsiveness at elevated NTF concentrations is observed only if F12 medium, supplemented with serum, insulin, transferrin, and selenium is used. In the presence of commercial F10, although supplemented with serum, dose responsiveness is not apparent at more than 2 μg/ml of NTF. Upon exposure to NTF, in the presence of supplemented F12 and serum, an 8‐hr lag ensues; then, thymidine is incorporated at NTF dose‐dependent rates by growing cell populations. The rates of incorporation into cell populations depend on the initial number of cells plated and the amount of NTF supplied. Cell counting indicates that dose‐dependent proliferation of muscle cells has occurred during the first 48 hr of exposure to NTF. The specific activity of NTF is repeatedly shown to be at least 10‐fold greater than unfractionated nerve extract. Shortly after 48 hr of exposure to NTF, myoblasts characteristically begin to fuse with one another, and myogenesis is visible. These studies show that the initiation of in vitro myogenesis in primary chick muscle cells depends on the amount of NTF supplied. The work also indicates a requirement for optimum medium conditions in order to detect dose–responses to NTF.
Acute and chronic effects of antidepressant drugs on β‐adrenergic function in astrocytes in primary cultures: An indication of glial involvement in affective disorders?
Authors: Hertz L. , Richardson J. S. 
Published: January 2005

AbstractAcute and chronic effects of the antidepressant drugs tranylcypromine, a monoamine oxidase inhibitor, and amitriptyline, a monoamine uptake inhibitor, were studied on β‐adrenergic receptor function in mouse astrocytes in primary cultures. In clinically relevant concentrations, acute administration of either antidepressant drug had a direct inhibitory effect on the binding of the β‐adrenergic ligand dihydroalprenolol and on the isoproterenol‐induced accumulation of cyclic AMP. However, in the absence of isoproterenol, these drugs enhanced the formation of cyclic AMP in the astrocytes. Chronic exposure to amitriptyline or tranylcypromine led to a decrease in isoproterenol‐induced accumulation of cyclic AMP, and the time course for the development of this phenomenon was similar to that reported for whole brain in vivo. These findings suggest that these antidepressant drugs act as partial agonists at β‐adrenergic receptors on astrocytes, and that the down‐regulation of β‐adrenergic activity that occurs in vivo after chronic administration of antidepressant drugs may, to a large extent, take place in astrocytes and may result from the partial /3‐agonist nature of the drugs.
Serum‐ and substratum‐dependent modulation of neuritic growth
Authors: Skaper Stephen D. , Selak I. , Varon S. 
Published: January 2005

AbstractExplants of embryonic day 8 (E8) chicken dorsal root ganglia (DRG) have been cultured with medium containing serum or the serum‐free supplement N1 on one of three substrata: collagen, polyornithine (PORN), or PORN exposed to a polyornithine‐binding neurite‐promoting factor (PNPF‐PORN). Replicate cultures were maintained with or without nerve growth factor (NGF). NGF elicited its classical neuritic outgrowth on all three substrata in serum‐containing or serum‐free medium. In the absence of NGF, however, a gradation of increasing neurite growth was seen with: PNPF‐PORN > PORN > collagen. This response occurred in both media. In addition, the neuritic halo in each instance was markedly more developed in the absence of serum, especially on PNPF‐PORN. Nonneuronal behaviors reflected both serum and substratum influences: thus, nonneuronal outgrowth consisted mainly of flat cells with serum and collagen, was nonexistent with serum and PORN or PNPF‐PORN, and involved mostly Schwann‐like scattered cells in the absence of serum on any one substratum. The serum‐dependent behaviors of ganglionic neurites were examined further with explants from chicken E11 sympathetic ganglia. A single substratum was used (PORN), without exogenous trophic factor. Neurite outgrowth was depressed by the presence of fetal calf serum, thus supportig the generality of this phenomenon. Lastly, PC12 cells, a clonal line of rat pheochromocytoma, will grow neurites in the presence of NGF after 48 hr in serum‐free, but not serum‐containing media. Addition of serum to serum‐free cultures at this time results in the rapid and complete retraction of neurites.