bluuebunny/crossref_metadata_2025_split huggingface dataset:
RNA BASE RATIO CHANGES IN PLANARIA DURING CONDITIONING
Authors: Hydén H. , Egyházi E. , John E. R. , Bartlett F. 
Published: October 2006

Abstract— —Four groups of planaria were stimulated with light and shock: Group LAC received light systematically paired with shock delivered while the animal's head was oriented toward the cathode. Group LAA received light systematically paired with shock delivered while the animal's head was oriented toward the anode. Group L=C received light in random temporal relationship to cathodal head shock. Group L=C=A received light in random temporal relationship to randomized cathodal or anodal shock.Groups LAC animals acquired a conditioned flexion reflex in contrast to the other three groups. As each animal in Group LAC reached criterion, one animal which had received an equated amount of light and shock stimulation was selected from each of the other three groups. Each such set of four animals was fixed in Carnoy's solution and imbedded in paraffin. All subsequent analyses were run‘blind’in a different laboratory. Nerve cells from the head ganglion and from the tail were isolated with a micromanipulator after sectioning and pre‐treatment. RNA was extracted and base ratios determined by micro‐electrophoresis.The relationship of base ratio differences between groups to conditioning and stimulation is discussed.
THE EFFECT OF ELECTRICAL STIMULATION UPON THE ACCUMULATION OF ADENOSINE 3′,5′‐PHOSPHATE IN ISOLATED CEREBRAL TISSUE
Authors: Kakiuchi S. , Rall T. W. , McIlwain H. 
Published: October 2006

Abstract—The application of electrical pulses to slices of guinea pig cerebral cortex led to an increase in the levels of adenosine 3′,5′‐phosphate (cyclic 3′,5′‐AMP) of more than 11‐fold within 10 min. This effect of electrical pulses was severely reduced in the presence of theophylline. Cyclic 3′,5′‐AMP accumulation in slices was increased in the presence of norepinephrine and histamine about 1·5‐fold and six‐fold, respectively; the effect of electrical pulses was augmented in the presence of maximal amounts of either amine. For these and other reasons, the accumulation of cyclic 3′,5′‐AMP induced by electrical stimulation cannot be ascribed to the release and action of either histamine or norepinephrine.
METABOLIC EFFECTS OF AZASERINE IN RAT BRAIN
Authors: Held Irene , Wells W. , Koenig H. 
Published: October 2006

Abstract—The de novo biosynthesis of purine nucleotides in rat brain was markedly and rapidly inhibited by intracerebral injections of azaserine. After 48 hr the animals became paraplegic. The biosynthesis of purine and pyrimidine nucleotides, RNA and protein was investigated by radioactive tracer studies over a 4‐day period in an attempt to correlate the azaserine‐induced, metabolic lesions found in rat brain and the manifested, peripheral, neurological disturbance.
BIOCHEMICAL CHANGES IN β,β′‐IMINODIPROPIONITRILE‐TREATED RAT BRAIN AND PREVENTION OF TOXICITY BY ETHIONINE
Authors: Brownlow E. K. , Heath H. 
Published: October 2006

Abstract—The administration of β,β′‐iminodipropionitrile (IDPN) to rats, either in five daily injections of 30 mg, or in a single injection of 100 mg/100 g body wt., resulted in the development of severe damage to the central nervous system and retinal vasculature. These changes were prevented by the daily intraperitoneal injection of 24 mg dl‐ethionine/100 g body wt.Significant increases in the oxygen uptake of IDPN‐treated rat brain were found when measured in the presence of succinate or glutamate as substrates. IDPN (5 mm) did not affect the oxygen uptake of brain homogenates in vitro when measured in the presence of the same substrates.The cytochrome oxidase activity of rat brain was not significantly changed by in vivo administration of IDPN, nor by the presence of 5 mm‐IDPN in vitro.The lactate content of the IDPN‐treated rat brain was significantly increased by the eighth day.There were no changes in the dry wt., total protein, lipid or phospholipid content of the IDPN‐treated rat brain, even after 4 weeks.These findings are discussed with reference to previous experiments on the toxic action of IDPN on the central nervous system and retinal vasculature.
COMPARATIVE STUDIES OF HIGHLY BASIC PROTEINS OF OX BRAIN AND RAT BRAIN. MICROHETEROGENEITY OF BASIC ENCEPHALITOGENIC (MYELIN) PROTEIN
Authors: Martenson R. E. , Gaitonde M. K. 
Published: October 2006

Abstract—(1) The total amount of highly basic proteins in acid extracts of whole ox brain, ox white matter and ox grey matter was determined quantitatively after electrophoresis on 5% polyacrylamide gels at pH 10‐6 in the presence of 8 M‐urea.(2) Ox white matter gave 13 mg and ox grey matter 2 mg of highly basic proteins per g fresh tissue on treatment with 0‐03 n‐HCl. The yield of total basic proteins of ox white matter increased to 17‐6 mg/g fresh brain on stepwise extraction at pH 3‐0, 2‐0 and 1‐0; the extract at pH 3.0 accounted for 90 per cent of the total basic proteins.(3) The high encephalitogenic activity of the fraction of highly basic proteins extracted at pH 3.0 from ox white matter indicated that these basic proteins were derived from myelin. It is suggested that the amount of basic proteins in a sample of brain extracted under these conditions is proportional to the amount of white matter in the sample.(4) The encephalitogenic (myelin) basic protein fraction was homogeneous with respect to molecular size but could be resolved into at least six components by electrophoresis at high pH.(5) The myelin basic proteins extracted from ox white matter had lower electrophoretic mobilities at high pH than did those of two basic proteins of rat brain apparently derived from myelin.
GLUCOSE AND AMINO ACID METABOLISM IN SOME INVERTEBRATE NERVOUS SYSTEMS
Authors: Bradford H. F. , Chain E. B. , Cory Helene T. , Rose S. P. R. 
Published: October 2006

Abstract—(1) The in vitro metabolism of [U‐14C]glucose and [U‐14C]glutamate was compared in snail, octopus and locust ganglia, and in rat cerebral cortex.(2) The metabolic patterns are quantitatively similar. The major labelled metabolites formed from glucose or glutamate by rat cortex and the invertebrate systems were CO2, aspartate, glutamate, glutamine and alanine. γ‐Aminobutyric acid (GABA) was formed in substantial amounts only by locust and rat.(3) A much larger proportion of labelled glucose and glutamate was converted to alanine by the invertebrates compared with rat cortex, although 14CO2 production was lower.(4) The effect of glucose in reducing aspartate formation and stimulating glutamine formation from [U‐14C]glutamate in mammalian cortex was observed in the locust but not in the molluscs.(5) Labelled citric acid cycle intermediates were formed in substantial quantities from glucose and glutamate only by snail and locust.
GLUCOSE AND AMINO ACID METABOLISM IN OCTOPUS OPTIC AND VERTICAL LOBES IN VITRO
Authors: Cory Helene T , Rose S. P. R. 
Published: October 2006

Abstract—(1) The metabolism of glucose and amino acids in vitro was compared in the rat cerebral cortex and the optic and vertical lobes of the octopus brain.(2) Specific activities and pool sizes of the five amino acids, glutamate, aspartate, glutamine, alanine and γ‐aminobutyric acid (GABA), were determined in octopus and rat brain slices after 2 hr incubation with 10 mm‐[U‐14C]glucose, 10 mm‐L‐[U‐14C]glutamate, and 10mm‐L‐[U‐14C]glutamate with added 10 mM‐glucose. Amino acid pool sizes were similar in rat and octopus brain, with the exception of alanine, which was higher in the octopus. Generally specific activities were from four‐ to 20‐fold higher in rat brain. With [U‐14C]glucose as substrate, specific activities of GABA and glutamate were highest in rat; those of alanine and glutamine highest in octopus brain. With L‐[U‐14C]glutamate the specific activities of GABA and aspartate were highest in rat, that of aspartate highest and GABA lowest in octopus. The addition of glucose to L‐[U‐14C]glutamate as substrate had little effect on the specific activities of any of the amino acids.(3) The uptake of some amino acids was determined by incubation with [U‐14C]amino acids for 2 hr, and 14CO2 formation was also measured. The amount of label taken up by octopus was uniformly 20‐25 per cent of that found for rat brain. The amount of 14CO2, however, differed according to the amino acid. Four times as much 14CO2 was generated from alanine by octopus optic lobe and twice as much by the vertical lobe than rat cortex, but from glutamate, only 24 per cent in the optic and 15 per cent in the vertical lobe. No 14CO2 was generated from [U‐14C]GABA in the octopus, by contrast with the rat.(4) Activity of some of the enzymes involved in amino acid metabolism was determined in homogenates of rat cortex and octopus optic and vertical lobes, with and without activation by Triton X‐100. Enzymic activities in the octopus, with the exception of alanine aminotransferase, were lower than in the rat, and glutamate decarboxylase could not be detected in octopus brain, in the absence of detergent.
STUDIES ON THE LABELLING PATTERNS OF RNA FROM CEREBRAL CORTEX NUCLEI
Authors: Dutton G. R. , Campagnoni A. T. , Mahler H. R. , Moore W. J. 
Published: October 2006

Abstract—RNA labelling patterns in nuclei from rat cerebral cortex were investigated subsequent to intracerebral injection of [3H]uridine. Although there was a rapid uptake of label into the ‘heavy’ regions when nuclear RNA was analysed in density gradients, it was not possible to show conclusive evidence for 455 ribosomal precursor RNA. Methyl‐ation of 18S and 28S nuclear RNA became evident only after 2 hr and did not appear to involve the intermediacy of RNA species of higher molecular weight.
CARBOXYMETHYLATION OF SULPHYDRYL GROUPS IN PROTEOLIPIDS1
Authors: Lees Martorie B. , Leston J. A. , Marfey P. 
Published: October 2006

Abstract—(1) The sulphydryl groups of brain white matter proteolipids were studied by alkylation with iodoacetic acid and iodoacetamide in an organic solvent medium. To make sterically hindered sulphydryl groups available, the reaction was also carried out in the presence of sodium dodecyl sulphate.(2) In all cases, iodoacetamide was a better alkylating agent than was iodoacetic acid.(3) Only minimal alkylation of crude white matter proteolipids was obtained in the absence of detergent; addition of sodium dodecyl sulphate increased the availablity of SH groups.(4) Purified proteolipids prepared by column chromatography were alkylated to a lesser degree than were crude proteolipids.(5) Prior reduction with mercaptoethanol resulted in the quantitative conversion of cysteine to S‐carboxymethylcysteine with either alkylating agent and in both preparations.(6) The possibility of a conformational difference between the protein in the crude and purified preparations is discussed.
STOFFWECHSELUNTERSUCHUNGEN DES CERE‐BRALEN ANFALLSGESCHEHENS
Authors: Wiechert P. , Göllnitz G. 
Published: October 2006

Zusammenfassung— Die Aktivität der Glutaminase und Glutaminsynthetase sowie die Konzentration des freien Ammoniaks werden im Gehirn von Ratten während und vor cerebralen Anfällen bestimmt. Mit Einsetzen des Krampfes, nach i.e. Injektion von Pyridoxal‐5‐phosphat bereits in der Phase der sham rage, steigt die Aktivität der Glutaminase stark an. Der hierdurch bedingte erhöhte Substratumsatz führt zur Anhäufung von freier Glutaminsäure und Ammoniak im Hirngewebe. Diese Stoffwechselentgleisung ist möglicherweise eine weitere Ursache für das Entstehen cerebraler Anfälle.Die Glutaminsynthetase ist am Zustandekommen der von uns untersuchten experimentellen Krampfanfälle nicht merklich beteiligt.Die Konzentration des Ammoniaks ist sowohl in der präkonvulsiven als auch in der tonischen Phase des Krampfanfalls erhöht. Die beobachteten Veränderungen werden übereinstimmend mit anderen Autoren als Folge eines veränderten Stoffwechsels im erregten Nervengewebe angesehen, jedoch nicht als spezifisches oder auslösendes Merkmal cerebraler Anfälle.
EFFECTS OF LEUCINE ON BRAIN SEROTONIN
Authors: Ramanamurthy P. S. V , Srikantia S. G 
Published: October 2006

Abstract— The effect of excess leucine in the diet on serotonin metabolism in the brain was investigated in experimental animals. It was found that:(1) Animals receiving diets containing 3 % and 8 % leucine and those receiving jowar diets had significantly lower levels of serotonin in the brain.(2) Intraperitoneal administration of the precursor amino acid 5‐HTP increased the serotonin concentration in brain in both control and leucine‐fed animals. However, the serotonin concentration in leucine‐fed animals was significantly lower than that of pairfed controls. Larger amounts of the synthesized serotonin were found to be catabolized in 3 hr in leucine‐fed animals than in control animals.(3) The in vitro uptake of [14C]5‐HTP by brain slices of animals fed leucine was found to be similar to that of control animals.(4) The basal concentration of 5‐HIAA in brain was higher in leucine‐fed animals, suggesting a higher rate of catabolism of serotonin.(5) Administration of nicotinic acid resulted in a further fall of serotonin concentration in the brains of leucine‐fed animals but not in control animals.
PROTEIN SYNTHESIS IN FRACTIONS FROM ISOLATED BRAIN CELL NUCLEI
Authors: Burdman J. A , Haglid K , Dravid A. R 
Published: October 2006

Abstract— 1. The incorporation in vivo and in vitro of isotopically labelled leucine into fractions of nuclear proteins from young and adult rat brain was investigated.2. During post‐natal cerebral maturation, the ability of nuclei from brain cells to synthesize proteins decreased. The specific activities of all the fractions of nuclear protein were highest in 3‐day‐old rats and declined thereafter. Nuclei from adult brain cells exhibited only 10 per cent of the activity found in nuclei from brain cells of 3‐day‐old rats.3. The ‘residual protein’ fraction was most rapidly labelled, peak activity being reached within 30 min after injection. In vitro, the ‘residual protein’ fraction attained maximum activity within 40 min.4. The specific activity of the chromatin acidic proteins (HCl‐insoluble) was considerably higher than that of the histones both in vivo and in vitro. Histones were the most inert of all the nuclear protein fractions studied.The possible functional significance of the various protein fractions during the process of cerebral maturation and in the adult brain is discussed.
THE NATURE OF SULPHATION OF URONIC ACID‐CONTAINING GLYCOSAMINOGLYCANS CATALYSED BY BRAIN SULPHOTRANSFERASE
Authors: George Elizabeth , Singh Manoranjan , Bachhawat B. K. 
Published: October 2006

Abstract—A sulphotransferase system of rat brain catalyses the transfer of sulphate from 3′‐phosphoadenosine 5′‐phosphosulphate to the low‐sulphated glycosaminoglycans isolated from normal adult human brain. These were shown to be precursors of higher‐sulphated glycosaminoglycans by DEAE‐Sephadex column chromatography and paper electrophoresis. Nitrous acid degradation and mild acid hydrolysis of enzymically‐sulphated fractions further confirmed the presence of heparan sulphate in human brain.A partially purified sulphotransferase preparation was obtained from neonatal human brain using chondroitin‐4‐sulphate as sulphate acceptor. This sulphotransferase catalyses the transfer of sulphate to the various uronic acid containing glycosaminoglycans. Heparan sulphate was the best sulphate acceptor followed by dermatan sulphate, N‐desulphoheparin, chondroitin‐4‐sulphate and chondroitin‐6‐sulphate in decreasing order. Sulphotransferase obtained from 1‐day‐old rat, rabbit and guinea pig brain also had the same pattern of specificity towards various sulphate acceptors.This sulphotransferase catalyses both N‐sulphation and O‐sulphation. Studies on the sulphotransferase obtained from both rat and human brain of various age groups indicate that the ratio of N‐sulphation: O‐sulphation decreases as the brain matures.
CEREBRAL LIPID METABOLISM IN EXPERIMENTAL HYPERPHENYLALANINAEMIA: INCORPORATION OF 14C‐LABELLED GLUCOSE INTO TOTAL LIPIDS*
Authors: Shah S. N. , Peterson N. A. , McKean C. M. 
Published: October 2006

Abstract—1. Effects of the administration of phenylalanine to rats on incorporation in vivo or in vitro of [U‐14C]glucose into cerebral lipids were studied during the first 5–10 days of postnatal development. In addition, the effects of added phenylalanine and its deaminated metabolites on incorporation of [U‐14C]glucose by homogenates into lipids of developing rat brain were investigated. Hyperphenylalaninaemia reduced incorporation both in vivo and in vitro of [U‐14C]glucose into cerebral lipids.2. Phenylalanine or tyrosine added in vitro at concentrations equivalent to those in the brain of the hyperphenylalaninaemic rat (0‐1 μmole/ml incubation medium) did not inhibit incorporation of [U‐14C)glucose into lipids, although at much higher concentrations of phenylalanine (36 μumoles/ml incubation medium) slight inhibition (10 per cent) of incorporation of [U‐14C]glucose into lipids was observed.3. In contrast, the deaminated metabolites in general exerted greater inhibitory effects at lower concentrations. Phenyllactic acid, in comparison to phenylpyruvic and phenyl‐acetic acid, was the most potent inhibitor of the incorporation in vitro of [U‐14C]glucose into cerebral lipids. These results indicated that these metabolites of phenylalanine were the more potent inhibitors of cerebral lipid metabolism in immature animals.
THE DISC ELECTROPHORETIC SEPARATION OF PROTEINS FROM VARIOUS PARTS OF THE GUINEA PIG BRAIN1
Authors: Ewart Davies W. 
Published: October 2006

Abstract—Disc electrophoresis was used to study the saline‐soluble and detergent‐soluble proteins of various parts of the auditory pathway in the guinea pig brain. The five areas studied were the cochlear nucleus, olivary complex, inferior colliculus, medial geniculate and the auditory cortex. A study was also made of the proteins extracted from subcellular fractions obtained from guinea pig cerebral cortex.The electrophoretic patterns showed small but significant differences in the five areas of the brain, both in the fast‐running acidic proteins and in the very slow‐moving proteins. The higher levels of the auditory pathway, to which the more complex information processing and storage is normally attributed, showed more complex electrophoretic patterns than the lower areas. Gross differences also occurred in the patterns of both the saline‐soluble and T‐X‐100‐soluble proteins of the subcellular fractions obtained by gradient density centrifugation. The simplest patterns were obtained from the myelin‐rich fraction and the mitochondrial fraction whilst the most complex patterns were given by the proteins of the nerve ending fraction and the cell soluble fraction.
RNA IN SINGLE IDENTIFIED NEURONS OF APLYSIA1
Authors: Price Peterson R. 
Published: October 2006

Abstract—An investigation of the types of RNA present in the whole abdominal ganglia of Aplysia and in single identified neurons was made. Because of the long in vitro functioning of the ganglion and large size of the neurons, adequate labelled precursor was incorporated to allow gel electrophoretic or sedimentation analysis of RNA isolated from a single nucleus or from cytoplasm.When labelled RNA is analysed a number of distinct peaks are found. Most of these are related to rRNA. In an effort to discern possible precursor‐product relations and localization of these RNA species, RNA from the nucleus and the cytoplasm of neuron R2 was analysed after varying lengths of labelling time with tritiated precursors, in some cases followed by incubation with actinomycin. The results support the notion of a large transcribed precursor which is subsequently processed to form finished rRNA. Differences in rate of rRNA maturation among neurons are indicated and a previously unreported 14 S molecule is described.
FURTHER EXPERIMENTS ON THE UPTAKE OF ACETYLCHOLINE AND ATROPINE AND THE RELEASE OF ACETYLCHOLINE FROM MOUSE BRAIN CORTEX SLICES AFTER TREATMENT WITH PHOSPHOLIPASES
Authors: Heilbronn Edith 
Published: October 2006

Abstract—Uptake of acetylcholine (ACh) in mouse brain cortex slices, previously shown with ACh synthesized from tritiated choline is confirmed with acetyl[1‐14C]choline. Radioactivity from tritiated sodium acetate also accumulates in slices, but forms hardly any ACh. Uptake of ACh increases in a Ca2+‐free medium, decreases again upon addition of a 3 × 105 molar concentration of an anticholinergic benzilate compound and is completely blocked by the same compound at 3 × 103 m.Slices preloaded with labelled ACh release, after extensive washing, some of their radioactivity into an outer medium free from ACh. Phospholipase, A or C, increases the release of radioactivity from the slices. An equilibrium is reached both with controls and phospholipase‐treated slices. Remaining radioactivity seems to be due to bound ACh. Calcium and magnesium ions have no effect on the uptake of tritiated atropine, although low concentrations of Ca2+ decrease the effects of phospholipase C on atropine uptake. The inhibitory effect of K+ on atropine uptake disappears completely after treatment with small amounts of phospholipase A, but even high concentrations of phospholipase C have no effect.
THE SUBCELLULAR DISTRIBUTION OF ACETYLCHOLINE, CHOLINE ACETYLTRANSFERASE AND CHOLINESTERASES IN LOBSTER WALKING LEG NERVES1
Authors: Welsch F. , Dettbarn W‐D. 
Published: October 2006

Abstract—Nerve bundles from the walking legs of the lobster have been homogenized in either isosmotic or hyperosmotic sucrose solutions and subjected to differential and discontinuous density gradient centrifugation. The resulting subcellular fractions were analysed for their concentrations of acetylcholine (ACh), choline acetyltransferase (ChAc) and cholinesterase (ChE). Enzymic characteristics were used for a biochemical identification of the subfractions. Regardless of the osmotic conditions, ACh was always found in the free form; there was no evidence of any‘bound’ester. After ultracentrifugation of homogenates in the hyperosmotic medium a pellet floating atop was formed; it consisted of membrane fragments and contained more than 30 per cent of the choline‐esterhydrolysing enzymes, with a 3 to 4‐fold increased specific activity. ChAc was found to be increasingly soluble if the ionic concentration was raised to that of the haemolymph body fluid of the lobster. Thus, all the components of the ACh system were present in substantial amounts but the question of their physiological function remains open.
KRAMPFAKTIVITÄT NACH INTRACEREBRALER INJEKTION VON l‐GLUTAMAT SEIZURES AFTER INTRACEREBRAL INJECTION OF l‐GLUTAMATE
Authors: Knaape H. H. , Wiechert P. 
Published: October 2006

Zusammenfassung—In akuten Versuchen an nicht narkotisierten, relaxierten, aufgespannten Katzen löst stereotaktisch in verschiedene Hirnregionen injiziertes Natriumglutamat eine generalisierte bioelektrische Krampfaktivität aus. Von allen untersuchten Regionen wurde für den Hippocampus die niedrigste Krampfschwelle nachgewiesen. Andere Hirngebiete sowie der Ventrikel reagierten nicht Oder nur auf höhere Glutamat‐Konzentrationen mit einem Krampf. Als krampfauslösende Ursachen werden Konzentrationsverschiebungen im Glutaminsäurestoffwechsel diskutiert.Abstract—Sodium glutamate stereotactically injected into different cerebral regions of cats caused generalized electroencephalographic seizures. The hippocampus was shown to have the lowest seizure threshold of all regions investigated. Other cerebral regions and the ventricle did not react at all or only to higher concentrations of glutamate. Differences in the activity of the glutamic acid metabolism are discussed as releasing factors for seizures.