bluuebunny/crossref_metadata_2025_split huggingface dataset:
Odour‐mediated preference and prey preference of Macrolophus caliginosus between spider mites and green peach aphids
Authors: Moayeri H. R. S. , Ashouri A. , Brødsgaard H. F. , Enkegaard A. 
Published: October 2006

Abstract  A comparative study between direct prey preference and odour‐mediated preference of the predatory mirid bug, Macrolophus caliginosus, was conducted. We used a Y‐tube olfactometer to determine the attraction of the predator to herbivore‐induced volatiles from Myzus persicae or Tetranychus urticae‐infested sweet pepper plants over clean plants and to direct prey odours over clean air. The mirid bugs showed a stronger response to odours from infested plants than to odours from clean plants. The mirids did, however, not seem to exploit odours emitted directly from the prey themselves. Our results further demonstrated that M. caliginosus prefers M. persicae to T. urticae in a direct two‐choice consumption test. This preference was, however, not reflected in a similar odour‐mediated preference between plant volatiles induced by either of the two preys. Two hypotheses are suggested for this neutral response of the mirids to herbivore‐induced volatiles from a preference prey or a non‐preference prey.
Transport of proteins and ribonacleic acid along nerve axons
Authors: Austin L. , Bray J. J. , Young R. J. 
Published: October 2006

SUMMARYThe distribution of isotope in the sciatic nerve was determined at times up to 22 days after injection of (a) [14C]leucine, or (b) [3H]orotic acid, in the spinal cord of the chicken. The results indicate a distal flow of proteins, RNA precursors and perhaps RNA along the nerve axon.
ALANINE METABOLISM IN RAT CORTEX IN VITRO
Authors: Cory H. Therese , Rose S. P. R 
Published: October 2006

Abstract— (1) The metabolism of [U‐14C]alanine was followed in slices of rat cerebral cortex and its interaction with glucose, pyruvate and the metabolic inhibitors fluoracetate and malonate was studied.(2) Alanine did not stimulate respiration above endogenous levels or affect the rate of oxygen uptake with glucose or pyruvate as cosubstrate. Radioactivity found in CO2 from labelled alanine was only 6 per cent of that from labelled pyruvate. Lactate was not formed from alanine.(3) After 2 h incubation with [U‐14C]alanine the specific activities of glutamate, glutamine and GABA were 20–30 per cent that of alanine. All these specific activities except glutamate were lowered by addition of glucose, but with pyruvate as cosubstrate the specific activity of glutamate was increased by 87 per cent above the level with alanine alone.(4) The effect of alanine as cosubstrate with [U‐14C]pyruvate was to reduce the specific activity of GABA and of glutamine, but not glutamate or lactate; thus there was not an equal dilution of all the metabolites of pyruvate.(5) Fluoracetate diminished respiration and the production of CO2 from [U‐14C]‐alanine only slightly; the addition of malonate as well practically abolished both. Fluoracetate lowered incorporation from alanine into all the amino acids, and radioactivity could not be detected in glutamine at all; addition of malonate lowered the specific activity of glutamate to 25 per cent but increased that into aspartate, GABA and glutamine.(6) The interpretation of these data in terms of known pathways of alanine metabolism is discussed.
BIOSYNTHESE DES GLYCOPROTEINES CEREBRALES: ETUDE DE L'ACTIVITE MANNOSYL‐TRANSFERASE PARTICULEE DU CERVEAU
Authors: Broquet P. , Richard M. , Louisot P. 
Published: October 2006

Résumé—Dans le cerveau, I'activité mannosyl‐transférase, du GDP‐mannose à un accepteur glycoprotéinique endogène, est localisée au niveau de la fraction des microsomes et fragments de synaptosomes des cellules cérébrales. Ce système polyenzymatique complexe se caractérise par deux maxima d'activitéà deux pH différents, respectivement 5,9 et 7,4. Le système est activé après une pré‐incubation à température supra‐optimale, qui modifie les conditions d'environnement enzyme‐substrat. I1 est également activé par le Triton X‐100 à certaines concentrations, et par les cations Mn2+ et Mg2+. A I'opposé, il est inhibé par les nucleosides‐diphosphates, le GTP et le β‐γ‐methylène‐GTP. Le cycloheximide n'a pas d'effet sur la transglycosylation, mais la puromycine réduit I'activité mannosyl‐transférase. Ceci met en évidence I'importance, dans le modèle cérébral, de la persistance de l'attachement des chaines polypeptidiques aux polysomes pendant I'exécution du processus de transglycosylation.
MEASUREMENT OF THE RATE OF ACETYLCHOLINE DIFFUSION THROUGH A BRAIN SLICE AND ITS SIGNIFICANCE IN STUDIES OF THE CELLULAR DISTRIBUTION OF ACETYLCHOLINESTERASE
Authors: Lancaster R. 
Published: October 2006

Abstract—The rate of ACh diffusion through a 0·8 mm thick slice from the surface of the rat cerebral cortex, under aerobic conditions at 37°C, was determined by bathing the intact surface of the slice (compartment A) with ACh containing buffer and determining the concentration of ACh in buffer bathing the cut surface of the slice (compartment B). With 1 or 5 mM‐ACh in compartment A no ACh was detectable in compartment B within 3 h unless at least 95 per cent of the AChE, as assessed on homogenates, was inhibited. With a given level of AChE inhibition, the rate of ACh diffusion was dependent on its concentration in compartment A. With 1 mM‐ACh in compartment A the difference between the rates of hydrolysis of ACh during diffusion through slices with an AChE inhibition of 98·3 and 99·4 per cent, as assessed by AChE assays of homogenates made from the slices, was only 6 per cent of the difference between the rates of hydrolysis of 1 m‐ACh by the homogenates of that part of the slices through which diffusion took place. For 5 mM‐ACh and levels of 95 and 99·2 per cent inhibition the corresponding value was 10‐3 per cent. Since the concentration of ACh must fall across the slice it is not possible to calculate from these figures the number of enzyme sites involved in the hydrolysis during diffusion, i.e. the concentration of extracellular AChE. The implications of these observations are discussed, particularly in relation to studies of the release of ACh from the cerebral cortex in vivo
OCCURRENCE OF N‐ACETYLALANINE IN THE HUMAN BRAIN1
Authors: Auditore J. V. , Wade L. 
Published: October 2006

Abstract—A substance identical with N‐acetyl‐l‐alanine was isolated from an aqueous extract of human brain by a combination of paper and ion‐exchange Chromatography. The isolated substance did not react with ninhydrin reagent but yielded alanine upon acid hydrolysis. An acetyl hydrazide was identified by paper chromatography of hydrazinolysates of the isolated substance and N‐acetyl‐l‐alanine. The unknown alanine had the l‐configuration. The results of elementary analysis of the isolated compound were in full accord with the analysis calculated for synthetic N‐acetyl‐l‐alanine.
CHANGES IN GLUTAMIC ACID AND GLUTAMINE METABOLISM IN THE RAT BRAIN AFTER WHOLE BODY X‐IRRADIATION
Authors: Hǎulicǎ A. , Trandafirescu M. , Ababei L. 
Published: October 2006

Abstract—After whole body irradiation with X‐rays, an increase in the free ammonia concentration in the rat brain was observed. Parallel to this increase, evidence was found of a strong activation of glutaminase. Incubation increased the endogenous ammonia‐forming capacity of brain homogenates to a much greater extent in irradiated rats than in normal rats.Glutamine synthetase activity decreased within the first 2 h after irradiation but remained unchanged at 24 and 96 h after irradiation. On the other hand, at 48 h after irradiation, glutamate dehydrogenase activity in the brain had fallen by 75 per cent in comparison with the initial activity. It is concluded that metabolic systems other than the glutamine‐glutamic acid system contribute to the ammonia formation in the brain after irradiation.
THE EFFECT OF AUDIOGENIC SEIZURES ON REGIONAL CNS ENERGY RESERVES, GLYCOLYSIS AND CITRIC ACID CYCLE FLUX1
Authors: Ferrendelli J. A. , McDougal D. B. 
Published: October 2006

AbstractSelected energy reserves, glycolytic intermediates and citric acid cycle intermediates were measured in the cerebral cortex, thalamus, brain stem, cerebellum and spinal cord of susceptible mice during audiogenic seizures. Changes in energy reserves (ATP, phosphocreatine and glucose) differed strikingly in extent and temporal pattern from region to region. The audiogenic seizure produced a transient, large decrease in thalamic energy reserves during the early, pretonic phase of the seizure. Less extensive decreases were observed in brain stem and spinal cord; but in these latter regions the changes persisted throughout the pretonic and tonic phases of the seizures. In cerebellum there was a biphasic decrease in energy reserves; a small decrease was observed immediately after the sound stimulus and a second much greater decrease was observed during the tonic phase of the seizure. No change in energy reserves was observed in cerebral cortex. Changes in glycolytic intermediates (glucose 6‐phosphate, fructose diphosphate, pyruvate and lactate) also varied from region to region in response to the decreases in energy reserves. In contrast, changes in the two citric acid cycle intermediates, α‐oxoglutarate and malate, were essentially the same in all regions studied. α‐Oxoglutarate decreased during the tonic phase of the seizure and rose during recovery. Malate remained at control levels throughout the seizure and then slowly increased.These findings are interpreted as indicating regional variations in nueronal activity during audiogenic seizures. During the period when clinical seizure activity is apparent neuronal activity increases in the subcortical regions. This is reflected by an increase in energy utilization and an increase in glycolytic flux in these areas. However, a concomitant increase in citric acid cycle flux does not seem to occur during this period. Citric acid cycle flux does appear to increase after the seizure is over.
PYRIMIDINE BIOSYNTHESIS IN RAT BRAIN1
Authors: Bourget P. A. , Tremblay G. C. 
Published: October 2006

Abstract—Studies on the incorporation of [14C]NaHCO3 into both orotic acid and RNA in tissue slices reveal the occurrence of the complete orotate pathway for the de novo biosynthesis of pyrimidines in the rat brain. A comparison of the rates of incorporation of bicarbonate into orotic acid and RNA in tissue slices of brain and liver indicate the brain to be one‐fourth to one‐half as active as the liver in the de novo biosynthesis of pyrimidines. The results of this study favor the proposal that the adult rat brain can meet its needs for pyrimidines through de novo synthesis and is not dependent upon salvage activity and an extraneural supply of pyrimidines.
BIOSYNTHESIS OF SEROTONIN IN RAPHÉ NUCLEI OF RAT BRAIN: EFFECT OF p‐CHLOROPHENYLALANINE1
Authors: Deguchi T. , Sinha A. K. , Barchas J. D. 
Published: October 2006

AbstractThe activity of tryptophan hydroxylase (EC 1.99.1.4) in the region of the raphé nuclei of rat brain was higher than that of any other brain area. The content of serotonin and the rate of serotonin synthesis were also highest in the raphé nuclei. Following the administration of p‐chlorophenylalanine the injection of tryptophan and pargyline increased the content of serotonin in the region of the raphé nuclei of rat brain. The results suggest that the raphé nuclei retained the capacity to hydroxyl‐late tryptophan to some extent after the injection of p‐chlorophenylalanine.
RESPIRATION BY CULTIVATED ASTROCYTES AND NEURONS FROM THE CEREBRAL HEMISPHERES
Authors: Dittmann L. , Sensenbrenner M. , Hertz L. , Mandeli P. 
Published: October 2006

Abstract‐Rates of oxygen uptake were measured in chick and/or rat astrocytes and neuronal cells cultivated for 2–4 weeks in Falcon flasks or Rose chambers. All the preparations were found to have respiratory rates between 0.4 and 0.8 × 10−5μl/h O2 per cell. Based upon measurements of cell diameters these values were recalculated to about 570 μmol/g wet wt. for the neuronal cells and 130 μmol/g wet wt. for the glial cells. The results are compared with previous data of oxygen uptake by neurons and glial cells separated by other procedures.
DEPOLARIZING STIMULI AND THE RELEASE OF PHYSIOLOGICALLY ACTIVE AMINO ACIDS FROM SUSPENSIONS OF MAMMALIAN SYNAPTOSOMES
Authors: Bradford H. F. , Bennett G. W. , Thomas A. J. 
Published: October 2006

Abstract—Potassium causes increased metabolism and release of physiologically active amino acids from suspensions of mammalian synaptosomes. Sheep and rat hypothalamic synaptosomes, and rabbit, sheep and rat cortical synaptosomes show respiratory and glycolytic response to electrical stimulation and show a parallel calcium‐dependent differential release of physiologically active amino acids. Attempts were made to eliminate the actions of heating and electrode products as the agents causing the observed effects and the case is made that depolarization is the trigger mechanism.
BIOCHEMICAL COMPOSITION OF DIFFERENT REGIONS IN BRAINS OF SMALL‐FOR‐DATE INFANTS
Authors: Sarma M. K. Janardana , Rao Kalluri Subba 
Published: October 2006

AbstractDifferent regions of the brains of babies born with low birth weights for the gestational age (small‐for‐date infants) were analysed for various chemical constituents. The brains of small‐for‐date babies were reduced in size. On a percentage basis, cerebellum and medulla oblongata were more affected than cerebrum. Cellularity, estimated by DNA content, was affected only in the cerebrum. However, the cell size and the concentrations of various constituents (proteins, lipids, different classes of lipids) studied in different regions of the brains of small‐for‐date infants remained unaffected compared to those found in the normal brains.
EFFECTS OF CHRONIC ETHANOL INGESTION ON BRAIN AMINOACYL‐tRNA SYNTHETASES AND tRNA
Authors: Fleming E. W. , Tewari S. , Noble E. P. 
Published: October 2006

Abstract—The effects of chronic ethanol ingestion on the in vivo aminoacylation of brain transfer RNA (tRNA) were examined in C57BL/6J mice. A pronounced inhibition in the formation of [14C]leucy]‐tRNA and [14C]phenylalanyl‐tRNA was observed in the ethanol drinking mice. Properties of aminoacyl‐tRNA synthetases and tRNA were examined following their separation and isolation on a DEAE‐cellulose column. Synthesis of [14C]leucyl‐tRNA was found to have a complete dependence on ATP and Mg2+. Incubations were carried out by cross‐matching tRNA from control rat brain with synthetases obtained from the brains of control or ethanol‐drinking mice. Under these conditions, a decreased ability for aminoacylation could be demonstrated when the source of enzyme was derived from ethanol‐treated brain. The data indicate that the major effect of ethanol ingestion on the aminoacylation reaction is exerted on aminoacyl‐tRNA synthetases.
GAS CHROMATOGRAPHIC–MASS SPECTROMETRIC ANALYSIS OF BIOGENIC AMINES IN IDENTIFIED NEURONS AND TISSUES OF HIRUDO MEDICINALIS
Authors: McAdoo D. J. , Coggeshall R. E. 
Published: October 2006

Abstract—Previous workers have reported that the colossal cells of Retzius in the segmental ganglia of the medicinal leech contain about 2.3 pmol of 5‐hydroxytryptamme (5‐HT)/cell body. We verify the identify of 5‐HT in the Retzius cells by gas chromatography‐mass spectrometry and derive concentrations of 1.3–4.1 pmol/neuron by analyses of eight individually dissected Retzius cell bodies. The Retzius cell bodies contain about 30% of the 5‐HT in each ganglion. An average of 25 pmol 5‐HT/mg tissue, a concentration about 500 times lower than that in the Retzius cell, was found in the fibrous, pigmented tissue surrounding the leech nervous system. We could not detect γ‐aminobutyric acid, octopamine, dopamine or norepinephrine in the Retzius cells, in the pigmented tissue, or, with the possible exception of dopamine (±0.4 pmol/ganglion), in whole ganglia. Furthermore, we could not detect 5‐HT in pooled samples of 100 non‐chromaffin control neurons.
PROTEINS AND GLYCOPROTEINS IN MYELIN PURIFIED FROM THE DEVELOPING BOVINE AND HUMAN CENTRAL NERVOUS SYSTEMS
Authors: Everly J. L. , Quarles R. H. , Brady R. O. 
Published: October 2006

Abstract—Myclin was purified from bovine and human midbrain at various stages of prenatal and postnatal development. Basic protein and proteolipid proteins were the major individual proteins at all stages. The specific activity of 2′3′‐cyclic nucleotide 3′‐phosphohydrolase remained constant in the bovine myclin during development but decreased slightly in human myelin. A high molecular weight glycoprotein with electrophoretic mobility similar to that previously reported in rodent myelin (QUARLES et al., 1973) was present in both bovine and human myelin at all stages of development. The intensity of staining of this glycoprotein with periodic acid‐Schiff reagents per mg total myelin protein was less in mature bovine and human myelin than in rat myelin.
THE SYNTHESIS OF ACETYLCHOLINE FROM ACETYL‐CoA, ACETYL‐DEPHOSPHO‐CoA AND ACETYLPANTETHEINE PHOSPHATE BY CHOLINE ACETYLTRANSFERASE
Authors: Banns Heather , Hebb Catherine , Mann S. P. 
Published: October 2006

Abstract— The synthesis of ACh by choline acetyltransferase (ChAc) has been examined using acetyl‐CoA, acetyl‐dephospho‐CoA and acetylpantetheine phosphate. At pH 7.5 Km values of 25.7 μm for acetyl‐CoA, 54.8 μm for acetyl‐dephospho‐CoA and 382 μm for acetylpantetheine phosphate were obtained and are similar to those at pH 6.0. This indicates that the 3‐phosphate may not be required for binding the substrate to the enzyme unlike carnitine acetyltransferase.Inhibitor constants (Ki) for CoA, dephospho‐CoA and pantetheine phosphate were also measured and when considered with the Km values obtained for the acetyl derivatives it is concluded that acetyl‐dephospho‐CoA could be a successful acetyl donor in the synthesis of ACh.Acetyl‐dephospho‐CoA was found to be less satisfactory as a substrate for citrate synthase.
ACTIONS OF l‐ AND d‐HOMOCYSTEATE IN RAT CNS: A CORRELATION BETWEEN LOW‐AFFINITY UPTAKE AND THE TIME COURSES OF EXCITATION BY MICROELECTROPHORETICALLY APPLIED L‐GLUTAMATE ANALOGUES
Authors: Cox D. W. G. , Headley M. H. , Watkins J. C. 
Published: October 2006

Abstract— A correlation has been attempted between the uptake characteristics of l‐ and d‐homocysteate and the time courses of neuronal excitation by these and other amino acids related to l‐glutamate.The uptake of l‐ and d‐homocysteate and of l‐[35S]homocysteate was studied in individual slices of rat cerebral cortex at 37°C. Tissue: medium ratios attained over l0 min for the unlabelled enantiomers at 2.5 mM were 3.7 for l‐homocysteate but only 0.8 for the d‐isomer. The uptake of l‐[35S]homocysteate over the concentration range 0.09 μm‐2 mm can be attributed mainly to a low‐affinity transport process with Km approx 3 mm and Vmax 1.7 μmol/g/min, but a high‐affinity process of low Vmax may make a minor contribution at the lower concentrations within this range. In terms of dependence on energy metabolism and [Na+], and on inhibition by p‐chloromercuriphenylsulphonate, ouabain and structural analogues of the amino acid, the main uptake system for L‐[35S]homocysteate appears to be similar to that mediating low‐affinity uptake of l‐glutamate and other acidic amino acids. d‐Homocysteate was but a weak inhibitor of this uptake system compared with other structural analogues.The time courses of excitation by 6 amino acids were determined by microelectrophoretic application to rat spinal neurones. d‐Homocysteate induced responses with recovery times considerably longer than those of the other amino acids; this correlates with the absence of rapid uptake systems demonstrated for this amino acid in cortical tissue. d‐Glutamate and l‐homocysteate, which are only accumulated by low‐affinity transport mechanisms, induced responses with recovery periods similar to those of l‐glutamate, l‐aspartate and d‐aspartate, which are accumulated by both high‐ and low‐affinity uptake systems. Although contributions of other factors to the observed time courses, such as rates of association and dissociation of the amino acid‐receptor complexes, cannot be excluded, the present results are consistent with the hypothesis that low‐affinity uptake systems of high Vmax play an important role in the rapid termination of the effects of amino acid excitants.
[3H]GLYCOGEN HYDROLYSIS IN BRAIN SLICES: RESPONSES TO NEUROTRANSMITTERS AND MODULATION OF NORADRENALINE RECEPTORS
Authors: Quach T. T. , Rose C. , Schwartz J. C. 
Published: October 2006

Abstract— Different agents have been investigated for their effects on [C3H]glycogen synthesized in mouse cortical slices. Of these noradrenaline, serotonin and histamine induced clear concentration‐dependent glycogenolysis.[C3H]Glycogen hydrolysis induced by noradrenaline appears to be mediated by beta‐adrenergic receptors because it is completely prevented by timolol, while phentolamine is ineffective. It seems to involve cyclic AMP because it is potentiated in the presence of isobutylmethylxanthine; in addition dibutyryl cyclic AMP (but not dibutyryl cyclic GMP) promotes glycogenolysis.Lower concentrations of noradrenaline were necessary for [C3H]glycogen hydrolysis (EC50= 0.5μM) than for stimulation of cyclic AMP accumulation (EC50= 8μM).After subchronic reserpine treatment the concentration‐response curve to noradrenaline was significantly shifted to the left (EC50= 0.09 ± 0.02 μM as compared with 0.49 ± 0.08 μM in saline‐pretreated mice) without modifications of either the basal [C3H]glycogen level, maximal glycogenolytic effect, or the dibutyryl cAMP‐induced glycogenolytic response.In addition to noradrenaline, clear concentration‐dependent [3H]glycogen hydrolysis was observed in the presence of histamine or serotonin. In contrast to the partial [3H]glycogen hydrolysis elicited by these biogenic amines, depolarization of the slices by 50 mM K+ provoked a nearly total [C3H)glycogen hydrolysis.
MEASUREMENT OF NEURON‐SPECIFIC (NSE) AND NON‐NEURONAL (NNE) ISOENZYMES OF ENOLASE IN RAT, MONKEY AND HUMAN NERVOUS TISSUE
Authors: Marangos P. J. , Schmechel D. , Parma A. M. , Clark R. L. , Goodwin F. K. 
Published: October 2006

AbstractFour double antibody solid‐phase radioimmunoassay systems are described for the measurement of neuron‐specific enolase (NSE) and non‐neuronal enolase (NNE) from rat, monkey and human brain tissue. NSE and NNE are antigenically distinct, making their respective assays specific. The levels of neuronal and non‐neuronal enolase (an enolase recently shown to be localized in glial cells) are determined in various regions of rat, monkey and human nervous system. Both neuronal and glial enolases are major proteins of brain tissue with each representing about 1.5% of total brain soluble protein. NSE levels are highest and NNE levels lowest in brain areas having a high proportion of grey matter, such as the cerebral cortex. The reverse is true for areas high in white matter, such as the pyramidal tract and the corpus callosum. Peripheral nervous system levels of NSE are much lower than those of brain with the spinal cord intermediate between the two.Radioimmunological and immunocytochemical data show that neuron‐specific enolase is also present in neuroendocrine cells located in non‐nervous tissue, which include pinealocytes, parafollicular cells of the thyroid, adrenal medullary chromaffin cells, glandular cells of the pituitary and Islet of Langerhans cells in the pancreas. Unlike neurons, these cells also contain non‐neuronal enolase in high amounts.