bluuebunny/crossref_metadata_2025 huggingface dataset:
PROXIMO‐DISTAL TRANSPORT OF [14C]NOR‐ADRENALINE AND PROTEIN IN SYMPATHETIC NERVES
Authors: Livett B. G. , Geffen L. B. , Austin L.
Published: October 2006

Abstract— —Both [14C]noradrenaline and [14C]leucine were injected into the coeliac ganglia of cats in an attempt to label the noradrenaline and protein of the granular vesicles, so that their movement in the splenic nerves could be followed.

When a constriction was placed on the nerves, labelled noradrenaline and protein accumulated just proximal to it, but there was no such accumulation below it, nor above a second, more distal constriction placed on the same nerve. This indicated that a neural transport mechanism, rather than uptake from the circulation, was responsible for the accumulation.

Peaks of labelled noradrenaline and protein were observed to move down the axon at about 5 mm/hr. In addition a slow moving component of axonal protein, advancing at about 1 mm/day, was detected.

The results demonstrate a rapid proximo‐distal movement of noradrenaline and protein which could represent the transport of granular synaptic vesicles from their site of manufacture in the cell body to their site of storage in the nerve terminals within the spleen.
DETERMINATION BY NEUTRON ACTIVATION OF COPPER, MANGANESE, AND ZINC IN THE PINEAL BODY AND OTHER AREAS OF BRAIN TISSUE
Authors: Wong P. Y. , Fritze K.
Published: October 2006

Abstract— Neutron activation analysis was used for the simultaneous determination of copper, manganese and zinc in the brains of calves, cows and pigs. Measurements of these three elements in as many as 11 different regions of the brain showed that the highest content is always found in the pineal body. Typical values for calf brains are: Cu, ∼20 μg/g; Mn, ∼3 μg/g; and Zn, ∼90 μg/g dry pineal tissue. As a first approximation, the ratio of Cu:Mn:Zn is roughly constant for all regions.
AMINO ACID UPTAKE AND INCORPORATION INTO MACROMOLECULES OF PERIPHERAL NERVES1
Authors: Caston J. D. , Singer M.
Published: October 2006

Abstract— The uptake and incorporation of various isotopically labelled amino acids by the amphibian peripheral nerve were analysed within 5 to 24 hr after intraperitoneal injection. Amino acid was accumulated rapidly by nerve and some was incorporated into macromolecules. Nerve separated by transection from its cell bodies showed similar accumulation and incorporation. The uptake by nerve was found to be as high as that for brain and liver. A substantial amount of the isotope was recovered in the protein fraction of peripheral nerve. A lesser, but significant, amount was isolated with aminoacyl‐tRNA. The contribution of specific amino acids to the nucleic acid and lipid fractions was also assessed. Finally, the significance of our findings in the understanding of nerve metabolism is discussed.
OCCURRENCE OF A SEROTONIN SULPHOTRANSFERASE IN THE BRAIN
Authors: Hidaka H. , Nagatsu T. , Yagi K.
Published: October 2006

Abstract— —An enzyme catalysing the transfer of sulphate from 3′‐phosphoadenylsulphate to serotonin was purified from rabbit brain. The purification procedure involved ammonium sulphate fractionation of the 200,000 g supernatant of rabbit brain homogenate, treatment with alumina Cγ, and chromatography on DEAE‐cellulose. The enzyme was purified 67‐fold from the 200,000 g supernatant of the brain homogenate. The intracranial distribution of the sulphotransferase was investigated and the cerebellum found to have rather high activity. The sulphotransferase activities of rabbit, dog, rat and bovine brains were compared; rabbit brain had the highest activity, followed by dog, rat and bovine brain.
SPECTROFLUORIMETRIC ASSAY OF VITAMIN B6 ANALOGUES IN BRAIN TISSUE
Authors: Loo Yen Hoong , Badger Linda
Published: October 2006

Abstract— —A method for the simultaneous assay of the predominant forms of vitamin B6 occurring in brain tissue was developed. Quantitative release of the vitamers was effected by partial removal of lipids with an organic solvent followed by extraction with aqueous metaphosphoric acid. The compounds were separated by ion exchange column chromatography and estimated fluorimetrically.
SODIUM‐INDUCED EFFLUX OF CALCIUM FROM BRAIN MICROSOMES
Authors: Robinson J. D.
Published: October 2006

Abstract—

A microsomal preparation from rat brain accumulated 45Ca in the presence of ATP. The uptake of calcium was associated with a corresponding uptake of 32P from [γ‐32P]ATP, with a 32P:45Ca molar ratio of about 0·65.

Microsomes that were first loaded with 46Ca lost radioactivity during a subsequent incubation in the absence of ATP; efflux of previously accumulated 32P (from ATP) corresponded with the calcium efflux. By contrast, the uptake of 14C from [8‐14C]ATP was far less than of 32P, and the efflux did not follow calcium efflux. Thus the movement of 32P probably represented the phosphate anion in association with calcium. Calcium efflux diminished with increasing pH up to 8·6.

Sodium specifically increased the rate of efflux of previously accumulated calcium. This sodium‐induced efflux was associated with a corresponding efflux of 32P (from ATP) and had a pH optimum near 7·8. It was not accompanied by a change in the amount of retained adenine nucleotides nor in the pattern of ATP metabolites, and was unaffected by ouabain or oligomycin.

Low concentrations of certain sulphydryl inhibitors blocked the sodium‐stimulated efflux with little effect either on efflux in the absence of sodium or on 45Ca accumulation.

Higher concentrations of these inhibitors, associated with an increase binding of the reagent, caused a generalized efflux of 45Ca and an inhibition of accumulation. The lipid solubility of a series of mercurial reagents corresponded with efficacy in promoting efflux; this suggested that this second class of reactive sites lay within a lipoidal permeability barrier.
SOME EFFECTS OF MONOAMINE OXIDASE INHIBITORS ON THE METABOLISM OF γ‐AMINOBUTYRIC ACID IN RAT BRAIN
Authors: Popov N. , Matthies H.
Published: October 2006

Abstract—

(1) The inhibitor of γ‐aminobutyrate transaminase (GABA‐T), amino‐oxyacetic acid (AOAA), drastically reduced the activity of GABA‐T to 30 per cent of the control value, with a corresponding increase of brain GABA, but had no effect on the activity of glutamate decarboxylase (GAD).

(2) The monoamine oxidase (MAO) inhibitors phenelzine, phenylpropylhydrazine and phenylvalerylhydrazine, lowered GABA‐T activity to 58, 49 and 48 per cent, respectively; this was associated with a marked elevation of brain GABA.

(3) The action of phenelzine and phenylpropylhydrazine in vivo and in vitro could be abolished by pre‐treatment of the tissue with the structurally related MAO inhibitors phenylisopropylhydrazine and trans‐2‐phenylcyclopropylamine. These had no action on the GABA system in vivo, either on the GABA content or on the GABA‐T activity. These latter drugs, however, were unable to influence the effects of AOAA either on GABA or on GABA‐T.

(4) The possible mechanism of action on GABA and the enzyme activities of the GABA system is discussed.
PROPERTIES OF RNA FRACTIONS FROM NUCLEI OF BRAIN CELLS WHICH STIMULATE INCORPORATION OF AMINO ACIDS BY BRAIN RIBOSOMES1
Authors: Samli Marcqueta H. , Roberts Sidney
Published: October 2006

Abstract— The properties of RNA fractions from nuclei of brain cells which were capable of stimulating amino acid incorporation into proteins of an homologous ribosomal system were investigated. RNA was routinely prepared from crude nuclear preparations of rat brain by a method which involved treatment with sodium dodecyl sulphate and phenol at 65°. The capacity of this preparation to stimulate incorporation of radioactivity from a mixture of 15 l‐[14C]amino acids was greatly enhanced by preliminary incubation of the ribosomal system from brain for 5–20 min. The response was markedly dependent upon the concentrations of ribosomes and of the pH 5 fraction. The optimal level of Mg2+ for basal incorporation of amino acids into protein was 8 mm; however, incorporation in the presence of nuclear RNA was greater at higher concentrations of Mg2+. The response to nuclear RNA was also enhanced as the K+ concentration was increased from 25 to 100 mm. The stimulatory effect of nuclear RNA on incorporation of l‐[12C]eucine was either unaltered or depressed by addition of a mixture of 19 l‐[12C]amino acids each at concentrations, of 10−8, 10−2, or 10−1 mm. Under appropriate conditions of incubation, basal rates of incorporation and rates of incorporation stimulated by nuclear RNA were linear for 30 min. The response was proportional to the concentration of nuclear RNA between 34 and 136 μg. RNA prepared from ribosomes of rat brain essentially failed to stimulate incorporation of amino acids over this range of concentrations.

Fractionation of nuclear RNA by centrifugation in sucrose density gradients revealed that 75 per cent of the stimulatory activity was in the fraction which sedimented below 12 S and contained about 25 per cent of the total RNA. Most of the remaining activity was in the 18 S region. Less than 5 per cent of the RNA in the lightest fraction (< 12 S) exhibited amino acid‐acceptor activity, The stimulatory action of nuclear RNA on incorporation of amino acids was readily destroyed by mild treatment with pancreatic ribonuclease, whereas amino acid‐acceptor activity was relatively resistant to this treatment. The results suggest that the brain may contain low molecular weight RNA with properties of messenger RNA.
SEIZURES INDUCED BY HYPERBARIC OXYGEN AND CEREBRAL γ‐AMINOBUTYRIC ACID IN CHICKS DURING DEVELOPMENT1
Authors: Wood J. D
Published: October 2006

Abstract— The susceptibility of chicks to convulsions induced by hyperbaric oxygen increased with age during the first few weeks of life. The sensitivity of the levels of cerebral GABA to change by oxygen at high pressure (OHP) also increased with age. There was correlation between the rate of decrease in concentration of cerebral GABA and the time to onset of OHP seizures. The anti‐convulsant action of intraperitoneally administered GABA was greater in 6‐9‐day‐old chicks than in 21‐23‐day‐old chicks, consistent with decreasing permeability of the blood‐brain barrier to the amino acid with increasing age.
LIPIDS AND PROTEINS IN MULTIPLE SCLEROSIS WHITE MATTER1
Authors: Gerstl B , Eng L. F , Tavaststjerna M , Smith J. K , Kruse S. L
Published: October 2006

Abstract— Quantitative analyses of white matter from four brains of patients with multiple sclerosis (MS) and four control brains were carried out for total and soluble proteins, individual lipid fractions, and their corresponding fatty acids. In three specimens from two of the MS brains there were reductions of cerebrosides and of the C20:1 acid in the ethanolamine glycerophosphatide (EGP) fraction and a slight increase of tetraenes and trienes, while all other components were present in concentrations similar to those in the controls. In three other samples from two of the MS brains, galactolipids were deficient to a greater extent than cholesterol, EGP or CGP (choline glycerophosphatide), while proteins were within the control range. In samples where thinning of myelin was observed in Luxol‐blue stained sections, there were proportional decreases of all components. The percentage of C20:1 acid in the EGP fraction was reduced in two of three myelin preparations from corresponding samples of MS white matter, and that of C24:1 acid in the cerebroside fraction was reduced in all three MS myelin preparations when compared with the two controls. The data suggest that inadequacy of the fatty acid elongation process together with deficits of cerebrosides represent one of the early biochemical lesions in the white matter of the MS brain.
THE ENZYMIC ACETYLATION OF CHOLINE ANALOGUES1
Authors: Hemsworth B. A. , Smith J. C.
Published: October 2006

—The rates of acetylation of choline and the mono‐, di‐, and tri‐ethyl analogues of choline by choline acetyltransferase (acetyl‐CoA: choline O‐acetyltransferase; EC 2.3.1.6) were studied with a partially purified enzyme from bovine caudate nucleus. All the substrates were acetylated by ChAc. The rates of acetylation at low concentrations of substrate were choline >MEC >DEC >TEC, but at high concentrations MEC was acetylated more rapidly than choline. These results have been compared to those of previous workers. The mode of binding of choline and its analogues to ChAc is discussed, and it is suggested that replacement of methyl by ethyl groups results in a lower energy of binding of the substrate to the active site of the enzyme.
TRANS‐SULPHURATION IN PRIMATE BRAIN: REGIONAL DISTRIBUTION OF CYSTATHIONINE SYNTHASE, CYSTATHIONINE AND TAURINE IN THE BRAIN OF THE RHESUS MONKEY AT VARIOUS STAGES OF DEVELOPMENT
Authors: Volpe J. J. , Laster L.
Published: October 2006

—The regional distributions of cystathionine synthase, cystathionine and taurine in the brain of the Rhesus monkey were determined at various stages of foetal and postnatal development.

Activity of cystathionine synthase was highest in cerebellum, cortical grey areas and globus pallidus, and lowest in subcortical white matter and corpus callosum. There was no marked change in activity in any area during development from the first‐trimester foetus to the juvenile animal.

In the brain of the juvenile monkey concentrations of cystathionine were highest in subcortical white matter, corpus callosum, and globus pallidus, and lowest in cortical grey matter. There was a sharp increase in concentration between late foetal life and the first 2 weeks of postnatal life and a subsequent more gradual increase during the next 2 years.

Concentrations of taurine were highest in lateral cerebellum and neostriatum and lowest in brain stem areas and spinal cord. During the first 6 months of postnatal life, there was a marked decrease in concentration as the brain matured.

The regional distribution of cystathionine in brain suggests that this compound may be synthesized in the perikaryon of the nerve cell and transported down axons into white matter. The changes during development suggest the further possibility that cystathionine may have some relationship to myelin and/or myelination.
NEWLY SYNTHESIZED RNA IN NUCLEI ISOLATED FROM NERVE AND GLIAL CELLS
Authors: Løsvtrup‐Rein Huguette , Grahn Birgitte
Published: October 2006

—Nuclear RNA from neurones, astrocytes and other glial cells was pulse‐labelled in vivo with [3H]uridine and analysed by sucrose density‐gradient centrifugation after various periods of incorporation. Thirty min after the injection of the isotope, rapidly‐labelled RNA appeared in all three cell types, a heterogeneous fraction sedimenting above 30S, the others at 25 and 12S. The transformation rate of the two latter components was equally rapid in all three types of nuclei studied. These components are assumed to be of messenger nature. The heavy fractions underwent transformations which in other cells have been described to lead to rRNA formation. The temporal pattern as well as the sequence of changes were similar in nuclei from neurones and astrocytes, the only difference being that a 35S intermediate was found in the former and a 32S in the latter. In non‐astrocytic glial nuclei, synthesis and transformation of the 45S component were delayed as compared to the other cell types and the processing of this component may involve both a 32S and a 35S intermediate. Moreover, the radioactivity incorporated in all the nuclear RNA species was always lower in these cells.
TRANSPORT OF LYSINE FROM CEREBROSPINAL FLUID OF THE CAT
Authors: Cutler R. W. P.
Published: October 2006

—The clearance from cerebrospinal fluid of l‐[14C]lysine and l‐[3H]arginine was measured during ventriculo‐cisternal perfusions of anaesthetized cats. Increasing in the perfusate the concentration of unlabelled l‐lysine produced a gradual reduction in clearance of the labelled amino acids without altering the uptake of l‐[14C]lysine by the choroid plexus. Net transport of l‐lysine out of cerebrospinal fluid occurred by saturable and non‐saturable components. The saturable component satisfied Michaelis‐Menton kinetics, while the behaviour of the non‐saturable component was consistent with diffusion. A Vmax of 0·017 μmol/min and an affinity constant (kt) of 0·83 mm were estimated.

The clearance of l‐lysine was unaffected by the addition to the perfusate of high concentrations of selected neutral amino acids, but was stimulated by the presence of l‐cystine. Conversely, a high concentration of l‐lysine did not affect the clearance of glycine or cycloleucine.

The dibasic amino acids appear to be removed from cerebrospinal fluid by a relatively specific, mediated transport system which may serve to regulate their concentrations in the cerebrospinal fluid.
AUTORADIOGRAPHIC STUDY OF RNA IN NERVE FIBRES OF EMBRYONIC SENSORY GANGLIA CULTURED IN VITRO UNDER NGF STIMULATION
Authors: Amaldi Paola , Rusca Graziella
Published: October 2006

Abstract— The presence and distribution of RNA in nerve fibres was studied by autoradiographic detection of [3H]uridine incorporation in chick embryo sensory nerve cells cultured in vitro under the effect of the Nerve Growth Factor. The presence of RNA in these fibres, free from satellite cells, is demonstrated. The cellular origin of the fibre RNA is, at least in part, proved.
METABOLISM OF AMINO ACIDS IN INCUBATED SLICES OF MOUSE BRAIN1
Authors: Sadasivudu B. , Lajtha A
Published: October 2006

Abstract—

Slices of mouse brain were incubated with [U‐14C]alanine, valine, leucine, phenylalanine, proline, histidine, lysine, arginine or aspartic acid, and the extent of metabolism was estimated by analyses utilizing paper chromatography of the tissue extracts and with an amino acid analyser.

The metabolism of Ala and Asp was high; of Leu and Pro, moderate; and of Lys, Arg and Phe, low; the metabolism of Val and His was not significant. The time‐course of metabolism in most cases showed varying rates, indicating heterogeneous metabolic compartments for the amino acids.

Production of CO2 was high from Asp, moderate from Ala, and low from Leu; the other amino acids were not oxidized to CO2 to any significant extent. A large portion of the metabolized label was trapped in the form of Glu or Asp.

Metabolism increased with increasing concentration of amino acid to some extent and was largely inhibited by omission of glucose, by anaerobic conditions, or by cyanide. Although these conditions also inhibit uptake, the time‐course and extent of inhibition uptake and metabolism were different.

With Asp, Ala and Phe, metabolism was lowest in slices from pons‐medulla; the brain area exhibiting the highest metabolism differed for each amino acid. The metabolism of Asp was lower in brain samples from newborn than in those from adults; the metabolism of Leu was higher in slices from newborn brain.

The results indicate that the majority of the amino acids can be metabolized in brain tissue and that the metabolic rates are influenced by a number of factors, among them the level of amino acids and the level of available energy.
HISTOCHEMISTRY OF MYELIN. XIII DIGESTION OF BASIC PROTEIN OUTSIDE ACUTE PLAQUES OF MULTIPLE SCLEROSIS
Authors: Adams C. W. M. , Hallpike J. F. , Bayliss O. B.
Published: October 2006

Abstract— Plaques of multiple sclerosis from a patient with a short clinical history were investigated by qualitative and quantitative histochemical methods. One of three plaques examined showed perivenous lymphocytic infiltration; this plaque was regarded as a particularly early acute lesion. In this plaque a relatively wide zone of diminished staining for basic protein extended outwards around the edge of the lesion. A narrower and irregular zone of diminished cerebroside staining was also seen around the plaque. Staining for phosphoglycerides and cholesterol was relatively normal up to the edge of the lesion; no zone of reduced staining for these lipids was seen outside the plaque. Proteolytic activity was increased throughout the lesion (pH 3.5 > 7.4). The two less acute plaques showed no obvious loss of basic protein and cerebroside outside the plaque. Addendum: Two further acute plaques of multiple sclerosis obtained recently, showed a similar loss of basic protein outside of lesion.
A STUDY OF THE CHANGES IN PROTEIN COMPOSITION OF MOUSE BRAIN DURING ONTOGENETIC DEVELOPMENT1
Authors: Grossfeld R. M. , Shooter E. M.
Published: October 2006

Abstract—

Of the total protein in an adult mouse brain, 35 per cent is water‐soluble and 65 per cent water‐insoluble. Using an extraction scheme of sequential treatment with water, Triton X‐100, and sodium lauryl sulphate, it was possible to solubilize at least 90 per cent of this total in distinct groups. Qualitative analysis of the extracts was achieved by electro‐phoresis in porosity gradient polyacrylamide gels. In this way, each fraction was resolved into 20‐50 protein bands.

This sequential extraction‐fractionation procedure was employed in a study of the onto‐genetic changes in mouse brain proteins. The most pronounced accumulation of protein and alteration of protein composition occurred during the first few weeks after birth. Beyond that period, both quantitative and qualitative changes were much less dramatic, except in the 1 % SLS fraction, which continued to increase in size throughout the mouse's lifespan. Whereas the aqueous‐soluble proteins predominated during the very early stages of development, the detergent‐soluble constituents accounted subsequently for a steadily increasing proportion of the total protein.
RAPID INTRACELLULAR TRANSPORT OF FUCOSE‐CONTAINING GLYCOPROTEINS IN RETINAL GANGLION CELLS
Authors: Karlsson J.‐O. , Sjöstrand J.
Published: October 2006

[3H]Fucose was incorporated into glycoproteins in the rabbit retinal ganglion cells and subsequently transported at a rapid rate along the optic pathway to the nerve terminals of the lateral geniculate body and the superior colliculus. Radioautographic results indicated a preferential labelling of the terminal part of the axon. Cell fractionation showed that the major part of the transported fucose‐containing glycoproteins were associated with membranes. Sodium dodecy 1 sulphate electrophoresis of rapidly transported glycoproteins showed that most of the polypeptides had a mol. wt. of more than 40,000.
MYELIN SYNTHESIS IN VITRO: A COMPARATIVE STUDY OF CENTRAL AND PERIPHERAL NERVOUS TISSUE
Authors: Rawlins F. A. , Smith Marion E.
Published: October 2006

Abstract— Brain, spinal cord and sciatic nerve from rats at different ages were incubated for 2 h in a medium containing [14C]acetate and [14C]leucine as the precursors for synthesis of lipids and proteins. Myelin was purified from the incubated tissues and the specific and total radioactivites of myelin lipids and protein were determined. The uptake of radioactive precursors decreased with increasing age up to 6 months of postnatal age, the decrease following the same pattern for the three types of myelin. After age 6 months the uptake of the protein and lipid precursors reached a plateau that persisted up to 18 months, the oldest postnatal age studied. The amount of myelin isolated and the total myelin lipids extracted from both the central and peripheral nervous systems increased continuously from age 25 days to 18 months after birth. Consequently we suggest that myelination is a process that continues during the whole life of the rat.

The metabolic activity of peripheral nerve myelin was higher than myelin from the CNS at all ages studied. Although myelination in the sciatic nerve begins before that in brain and spinal cord, the three types of myelin apparently reach maturity at the same age. Lecithin exhibited the highest metabolic activity of the individual myelin lipids at all ages in both the central and peripheral nervous system. The metabolic activity of cholesterol in myelin from the 25‐day‐old rats was similar to that of lecithin but decreased to very low levels in myelin from the 18‐month‐old rats.
LIPID COMPOSITION OF HUMAN CEREBRAL WHITE MATTER AND MYELIN IN PHENYLKETONURIA1
Authors: Shah S. N. , Peterson N. A. , McKean C. M.
Published: October 2006

Abstract— White matter and purified myelin from cerebral tissue obtained at autopsy from four phenylketonuric and five non‐phenylketonuric mentally‐retarded patients were analysed for lipids, DNA and protein. The lipid composition of the white matter and myelin was compared with that of a representative non‐myelin component of white matter, the crude mitochondrial fraction. The total lipid content was significantly lower and the ratio of cholesterol to galactolipid was significantly higher in the white matter from the PKU patients than in that from the non‐PKU patients. The lipid compositions of the myelin and ‘mitochondrial’ fraction, although differing from each other, did not exhibit appreciable differences between the PKU and non‐PKU brain samples. However, the amount of myelin recovered from the brains of the PKU patients was, on the average, 40 percent lower than that recovered from non‐PKU brains. The abnormal cholesterol: galactolipid ratio of PKU white matter could be accounted for by the altered proportion of myelin to non‐myelin lipid components. The finding in PKU brains of a normal composition of lipids in the purified myelin and the absence of cholesterol esters in the white matter suggest that the deficiency in myelin may reflect an early arrest of myelination.
INHIBITION OF ACETYLCHOLINESTERASE IN THE BRAIN AND DIAPHRAGM OF RATS BY A TERTIARY ORGANOPHOSPHOROUS ANTICHOLINESTERASE AND ITS QUATERNARY ANALOGUE; IN VIVO AND IN VITRO STUDIES
Authors: Lancaster R.
Published: October 2006

Abstract— Pinacolyl S‐(2‐dimethylaminoethyl)methylphosphonothioate (compound I) and its quaternary analogue (compound II), are potent anticholinesterases, that form a very stable phosphonylated AChE and differ in their in vitro anticholinesterase potency by a factor of two, but have widely differing lipid solubilities.

In vitro, compound I diffused through a cerebral cortex slice when applied to the intact surface at twelve times the rate of compound II and through a diaphragm segment at four times the rate. When applied to the intact surface of a cerebral cortex slice or a diaphragm segment for 10 min, compound I gained access to AChE sites more readily than compound II but the difference was much less than the difference in their lipid solubilities. There was no discontinuity in the percentage AChE inhibition versus logarithm of the concentration of compound II, indicating that there was no clear separation of AChE into two fractions which differed greatly in their accessibility to quaternary compounds. Both compounds gained access to AChE sites in cerebral cortex slices more readily than in diaphragm segments.

In vivo, the peak plasma levels and the rates of removal from the plasma of free inhibitor were similar for both compounds, given subcutaneously in equimolar amounts. Compound I in high doses inhibited over 90 per cent of the AChE in the cerebral cortex and the diaphragm; compound II even in lethal doses produced only marginal inhibition of AChE in the cerebral cortex and only 50–60 per cent inhibition of AChE in the diaphragm.

These results indicate that the in vivo distribution of quaternary compounds is different from that observed in vitro. The implications of this are discussed.
PHOSPHOCHOLINE DIGLYCERIDE TRANSFERASE ACTIVITY DURING DEVELOPMENT OF THE CHICKEN BRAIN
Authors: Freysz L. , Lastennet A. , Mandel P.
Published: October 2006

Abstract— The activity of chicken brain phosphocholine diglyceride transferase was followed during pre‐ and postnatal development. The specific activity of this enzyme increases from the 10th day of embryonic life, reaches a maximum at hatching and decreases thereafter. Total brain activity increases in parallel with the increase of brain lecithins. The apparent Km of the enzyme for CDP choline is 1.5 × 10‐4m before the 10th day of embryonic life, 2.5 × 10‐5m between the 13th day of the embryo and the 10th day after hatching, and finally 1.3 × 10‐4m after the 38th day of postnatal life. These data suggest the existence of isoenzymes, one of which appears at the beginning of myelination.
THE GLUTAMATE AND GLUTAMINE CONTENT OF RAT BRAIN AFTER PORTOCAVAL ANASTOMOSIS
Authors: Williams A. H. , Kyu Ma Hta , Fenton J. C. B. , Cavanagh J. B.
Published: October 2006

Abstract— Rats have been subjected to portocaval anastomosis and the ammonium ion in plasma and the glutamate and glutamine levels in plasma, red cells and brain have been estimated up to 6 weeks after operation. The glutamine, but not the glutamate, levels in brain were consistently raised, being about 2.5 times greater than normal and the level can be correlated with the level of plasma ammonium ion. Consideration is given to the possibility that the glutamine may be in the greatly enlarged neuroglial compartment in this abnormal metabolic state.
PROPERTIES OF CELL NUCLEI ISOLATED FROM VARIOUS REGIONS OF RAT BRAIN: DIVERGENT CHARACTERISTICS OF CEREBELLAR CELL NUCLEI
Authors: McEwen B. S. , Plapinger Linda , Wallach Gislaine , Magnus C.
Published: October 2006

Abstract— Cell nuclei were isolated in yields ranging from 38 to 61 per cent from six anatomically defined brain regions of the albino rat. To provide basic information for further studies of altered genomic activity in brain cell nuclei, various properties of these isolated nuclei were measured, including counts of their number, estimates of the distribution of sizes, amounts of RNA, DNA and protein, and endogenous RNA polymerase activity. DNA content per nucleus approximated the accepted value of 6 pg per diploid set of chromosomes. Distributions of nuclear size showed a sensitivity to the concentration of divalent cation, with a shift toward larger nuclear diameters as the Mg concentration was reduced. Cell nuclei from hippocampus, hypothalamus‐preoptic region, cerebral cortex, amygdala and midbrain plus brainstem were generally similar in yield, distribution of size, and RNA, DNA and protein content. Cell nuclei from cerebellum differed from those of other brain regions, in all of these parameters. The cerebellum contained a high content of DNA and had an enormous number (8 × 108 per g wet wt.) of cell nuclei of predominantly very small size and characterized by lower ratios of RNA, histones and non‐histone protein to DNA and lower endogenous activity of RNA polymerase than nuclei from other brain structures. These properties correlated well with properties of cerebellar tissue, namely, high content of small granule neurons and low ratio of RNA to DNA, and suggest that the small cerebellar nuclei may have relatively inactive genomes. The relationship of ‘large’ and ‘small’ cell nuclei to cell types in the brain is discussed.
EFFECTS OF ESSENTIAL FATTY ACID DEFICIENCY ON MYELIN AND VARIOUS SUBCELLULAR STRUCTURES IN RAT BRAIN
Authors: Galli C. , Trzeciak H. I. , Paoletti R.
Published: October 2006

Abstract— Essential fatty acid deficiency initiated in rats prior to birth and continued for 140 days after birth affects the fatty acid composition of ethanolamine phosphoglyceride of brain subcellular fractions (myelin, microsomes, mitochondria and synaptosomes). It was confirmed that the fatty acid composition of the same phospholipid class differs considerably among the various subcellular fractions: myelin has the highest concentration of long‐chain monoenes, while in the other fractions saturates and polyenes predominate. In EFA deficiency it was found that (1) trienes are elevated and tetraenes decreased in all fractions, (2) the triene/tetraene ratio, which is considered a biochemical index of essential fatty acid deficiency, is highest in myelin and lowest in the synaptosomal fraction, and (3) in all fractions there is a shift towards more unsaturated members of the same fatty acid family.
ACETYLCHOLINE, CHOLINE AND CHOLINE ACETYLTRANSFERASE ACTIVITY IN THE DEVELOPING BRAIN OF NORMAL AND HYPOTHYROID RATS1
Authors: Ladinsky H. , Consolo S. , Peri G. , Garattini S.
Published: October 2006

Abstract— Acetylcholine, choline and choline acetyltransferase activity were measured in the whole brains of normal and hypothyroid rats during development. At 1 day postpartum, brain acetylcholine was 73 per cent of adult levels. Propylthiouracil‐induced hypothyroidism up to age 20 days did not alter brain acetylcholine concentrations, but at 30 days resulted in significantly decreased levels. At day 1, brain choline was 20 per cent higher than adult levels and decreased between days 8 and 10. In hypothyroid rats this phenomenon did not occur until days 15–20. At day 1 postnatally, choline acetyltransferase activity was only 7 per cent of adult levels, then between days 5 and 20 rose to 77 per cent of adult levels. Beginning at day 8, hypothyroidism resulted in significantly decreased enzyme levels. This effect could be reversed at day 17 by concurrent tri‐iodothyronine substitution therapy. In hypothyroid rats, maximum brain choline acetyltransferase activity was 30 per cent less than normal adult levels.
ISOLATION AND CHARACTERIZATION OF A SOLUBLE GLUCOSE‐CONTAINING SIALOGLYCOPROTEIN FROM THE CORTICAL GREY MATTER OF CALF BRAIN
Authors: Amerongen A. van Nieuw , Eijnden D. H. van den , Heijlman J. , Roukema P. A.
Published: October 2006

A sialoglycoprotein has been isolated from the cortical grey matter of calf brain after homogenization in 0.32 M‐sucrose or in 0.15 M‐NaCl. The sialoglycoprotein is present in the supernatant obtained after centrifugation at 100,000 g for 60 min. It is designated GP‐350 on account of its elution with 350 mM‐NaCl on a DEAE‐cellulose column. From DEAE‐cellulose chromatography it is evident that compounds comparable to GP‐350 occur in the brain of calf and sheep, whereas they seem to be absent in calf liver and kidney. After purification, with polyacrylamide gel electrophoresis only one band can be shown both at pH 8.9 and 7.5. GP‐350 consists of about 83 percent of protein and about 17 per cent of carbohydrate. The polypeptide core has an acidic character: amino acid analysis gives 26 per cent for glutamic acid plus aspartic acid and their amides, with a ratio of acidic to basic amino acids of 3.3. The carbohydrate moiety contains 2.4% sialic acid, 5.5 % hexosamine and 9.4% hexose. It is remarkable that this brain sialoglycoprotein comprises 4% glucose. Care was taken to prevent contamination with glucose‐containing materials during the purification procedure of GP‐350. The complete absence of other glucose‐containing compounds which occur in brain, Le. glycogen and gangliosides, was demonstrated. GP‐350 accounts for at least 3 per cent of the total saline‐extractable protein and about 20 per cent of the total saline‐extractable protein‐bound sialic acid of the cortical grey matter of calf brain. These percentages correspond to 390 pg of protein and to 14 μg of sialic acid per g wet weight. GP‐350 remains soluble when the pH is brought to 3.9 or when ethanol is added to 70 % (v/v).
DNA CONTENT OF PURIFIED PREPARATIONS OF MOUSE PURKINJE NEURONS ISOLATED BY A VELOCITY SEDIMENTATION TECHNIQUE
Authors: Cohen J. , Mareš V. , Lodin Z.
Published: October 2006

Abstract— The DNA content of mouse Purkinje neurons was investigated employing a biochemical approach. Material for the biochemical assay was provided by means of a sedimentation velocity separation technique which yields bulk quantities of well‐preserved Purkinje perikarya in a high degree of purity. The same amount of DNA/cell was recorded for mixed cerebellar cell somata (7·6 ± 0±2 pg/cell), as for the Purkinje perikarya enriched fractions (7±2 & 0·2 pg/cell). No evidence could be found for the existence of a tetraploid DNA complement in mouse Purkinje neurons despite indications to the contrary from a parallel cytophotometric study.
PHOSPHOINOSITIDES AND OTHER PHOSPHOLIPIDS IN SYMPATHETIC GANGLIA AND NERVE TRUNKS OF RATS
Authors: White G. L. , Larrabee M. G.
Published: October 2006

Abstract— Paired vagus nerves, phrenic nerves or superior cervical sympathetic ganglia from adult white rats were incubated for 4 h at 37°C in a bicarbonate‐buffered physiological solution containing glucose and 32P1. At the end of incubation triphosphoinositide (TPI) contained more 32P than any other lipid in the vagus nerves and was second only to phosphatidylcholine (PC) in the phrenic nerves. In the sympathetic ganglia phosphatidylinositol (PI) contained more 32P than did TPI, but both had less than PC. Conducted nerve impulses, initiated by electrical stimulation during the final 3 h of incubation, caused a highly significant increase in the [32P]‐labelling of PI in ganglia (as previously reported) probably decreased the labelling of TPI in the vagus nerves, and decreased the labelling of phosphatidylethanolamine (PE) in the ganglia. Addition to the incubation medium of §‐ or γ‐hexachlorocyclohexane (analogs of inositol) reversibly blocked transmission through the sympathetic ganglia at concentrations less than 0·1 mM. The §‐isomer also blocked conduction along axons at similar concentrations; only the γ‐isomer (lindane) exerted a selective effect on synaptic transmission. In the ganglia, the §‐isomer increased the [32P]‐labelling of PI and diphosphoinositide (DPI) relative to that of PC. The γ‐isomer did not affect the relative labelling of PI in the ganglia, whereas it decreased that of TPI, but only at relatively high concentrations. Thus, various affects of the hexachlorocyclohexanes were not explicable by assuming that they acted as analog inhibitors of inositol metabolism. In the ganglia, the hexachlorocyclohexanes reduced the effect of neuronal activity on the labelling of PI in proportion to the extent by which they blocked transmission. This metabolic effect was therefore presumed to be secondary to a ganglionic blocking action.
CONVERSION OF D‐ AND L‐TRYPTOPHAN TO BRAIN SEROTONIN AND 5‐HYDROXYINDOLEACETIC ACID AND TO BLOOD SEROTONIN1
Authors: Yuwiler A.
Published: October 2006

Abstract— Intraperitoneal administration of both D‐ or L‐tryptophan elevated the levels of serotonin and 5‐hydroxyindoleacetic acid in the brains of hypophysectomized and intact rats. In intact rats, the increase in brain 5‐hydroxyindoles was slower after D‐tryptophan than after L‐tryptophan. Similarly, brain tryptophan rose more slowly after administration of D‐tryptophan. The uptake of L‐tryptophan from blood into brain was at a rate about one‐third that of 3H2O. D‐tryptophan uptake was at 1/25 that of 3H2O. Brain and liver tryptophan aminotransferase activities were stereospecific for the L‐isomer and no evidence could be found for a tryptophan racemase in brain. Evisceration prevented the increase in brain 5‐hydroxyindoles following peripheral administration of D‐tryptophan administration but not that after L‐tryptophan. The serotonin ratios between the two brain regions examined remained constant following administration of either D‐ or L‐tryptophan. On the basis of these results we concluded that the increase in brain 5‐hydroxyindoles following administration of L‐tryptophan was not dependent upon stress‐induced changes in pituitary hormones and that the elevations after D‐tryptophan were dependent upon its prior conversion to L‐tryptophan via peripheral deamination and subsequent transamination.
[2‐3H]GLYCEROL AS A PRECURSOR OF PHOSPHOLIPIDS IN RAT BRAIN: EVIDENCE FOR LACK OF RECYCLING
Authors: Benjamins Joyce A. , McKhann G. M.
Published: October 2006

Abstract— When [2‐3H]glycerol was injected intracranially into young rats, it was presented as a pulse label, leaving the brain rapidly and giving up much of its labelled hydrogen to water. [2‐3H]glycerol was efficiently incorporated into brain lipids, especially into choline and ethanolamine phospholipids. Following injection of a mixture of [3H]‐ and [14C]‐labelled glycerol, the ratio of 3H to 14C in the phospholipids of both whole brain and the microsomal fraction decreased as a function of time after injection. This finding indicated less recycling of the tritium label. This lack of recycling was further indicated by the finding that 94 per cent of the tritium label of phosphatidyl choline was in the glycerol portion of the molecule rather than in the fatty acids. At 2 weeks following injection with [3H]glycerol, 93 per cent of the total radioactivity in brain appeared in the lipid fraction. In contrast, following injection with [14C]glycerol, only 57 per cent of the radioactivity appeared in lipid, with about 20 per cent in protein.
The relative constancy of the glycogen content of guinea pig brain
Authors: Phillips M. E. , Coxon R. v.
Published: October 2006

Using mice and rats as experimental animals, a variety of treatments have been reported which bring about a marked increase in the glycogen content of the brain. These treatments have included injections of phenobarbitone (Nelson, Schulz, Passonneau and Lowry, 1968), methionine sulphoxime (Folbergrová, Passonneau, Lowry and Schulz, 1969), lithium (Rafaelson, Plenge and Mellerup, 1969) and a glucocorticoid (Timiras, Woodbury and Baker, 1956), and also manipulation of the blood sugar level with and without concomitant administration of insulin (Nelsonet al., 1968; Prasannan, Rajan and Subraharyam, 1963; Prasannan and Subrahmanyam, 1965). The present communication is concerned with the response of the guinea pig to these treatments and demonstrates that, in this animal, they are either totally without effect or are less effective than in mice and rats.
POLYAMINES: DEVELOPMENTAL ALTERATIONS IN REGIONAL DISPOSITION AND METABOLISM IN RAT BRAIN1
Authors: Shaskan E. G. , Haraszti J. H. , Snyder S. H.
Published: October 2006

The polyamines spermidine and spermine and the activity of the polyamine synthesizing enzyme, S‐adenosyl‐L‐methionine (SAM) decarboxylase, were measured in regions of adult rat brains and during postnatal development. In the adult, although spermidine levels tended to correlate with the relative amounts of white matter in some areas, there were striking exceptions. SAM decarboxylase activity of the adult brain was higher than in most other mammalian tissues, although brain levels of polyamines were among the lowest. SAM decarboxylase activity appeared to be localized to cellular cytoplasm. Its activity increased with age in contrast to the levels of spermine, spermidine, DNA and RNA which decreased during postnatal development.
THE EFFECT OF IONIZING RADIATION UPON MITOCHONDRIA OF THE CENTRAL NERVOUS SYSTEM
Authors: Cohan S. L. , Abbott J. R. , Catravas G. N.
Published: October 2006

After irradiation of rats with a linear electron accelerator, the respiratory rate in rat brain mitochondria was studied in the presence of substrate + ADP and after the conversion of ADP → ATP. After 20,000 rads of irradiation to the head there was a transient diminution of mitochondrial respiratory control when glutamate was used as the substrate, but no changes were observed when succinate was the substrate. Irradiation with 10,000 rads had no effect upon respiratory control. The addition of NADH2 to irradiated mitochondria had no effect upon mitochondrial respiration. Irradiation of the brain with 20,000 rads failed to produce mitochondrial peroxidation or swelling, even in the presence of FeNH4(SO4)2 or ascorbate. The slight changes in respiratory control of brain mitochondria following irradiation is in marked contrast to the susceptibility of mitochondria from other organs. The comparative radioresistance of brain mitochondria may be the result of greatly diminished radiation‐induced peroxidation of cerebral mitochondrial membranes.
THE EFFECT OF PHENOBARBITONE ANAESTHESIA UPON SOME ORGANIC PHOSPHATES, GLYCOLYTIC METABOLITES AND CITRIC ACID CYCLE‐ASSOCIATED INTERMEDIATES OF THE RAT BRAIN
Authors: MacMillan V. , Siesjö B. K.
Published: October 2006

In order to study the effect of phenobarbitone anaesthesia upon the energy metabolism of the brain, organic phosphates, glycolytic metabolites and citric acid cycle intermediates were measured in rats anaesthetized with 175‐200 mg/kg of phenobarbitone, and the results were compared to those obtained in rats anaesthetized with halo‐thane or with nitrous oxide. An attempt was made to separate the effects of the phenobarbitone anaesthesia from those caused by the accompanying intracellular alkalosis by exposing one group of animals to hypercapnia of such a degree that normalization of the intracellular pH was achieved. Phenobarbitone anaesthesia did not alter the tissue concentrations of ATP, ADP or AMP, but led to a moderate increase in the phosphocreatine concentration. However, since this increase was reversed in the hypercapnic group it is concluded that it may be due partly to a pH‐dependent shift in the creatine phosphokinase equilibrium. There was a decrease in the tissue concentrations of all measured substrates from pyruvate and onwards. The results indicate that phenobarbitone leads to a primary inhibition of glycolysis, which cannot be related to detectable changes in ATP, ADP or AMP. The resulting lowering of the tissue concentrations of a number of metabolic acids may be part of the explanation why barbiturate anaesthesia is associated with an intracellular alkalosis.
AMINO ACID DISTRIBUTION IN THE NERVOUS SYSTEM OF THE CRAB, CARCINUS MAENAS (L.)
Authors: Evans P. D.
Published: October 2006

The free amino acid levels in the peripheral nerve of the crab, Carcinus maenas, have been measured using various extraction procedures. A comparison of the amino acid levels of the peripheral and central nervous system of the crab has revealed marked differences in the levels of certain amino acids. Aspartate and glutamate were much lower in central nervous tissue than peripheral whilst glycine was much higher. The results are discussed in relation to the extreme steepness of the concentration gradient for amino acids across the neuronal membranes of crustaceans and a comparison is made with other groups. The significance of the differences in amino acid concentration in specific areas of nervous tissue is discussed in relation to the functions of the amino acids and to possible transmitter activity.
THE DISTRIBUTION AND AXONAL TRANSPORT OF FREE AMINO ACIDS AND RELATED COMPOUNDS IN THE DORSAL SENSORY NEURON OF THE RAT, AS DETERMINED BY THE DANSYL REACTION
Authors: Roberts P. J. , Keen P. , Mitchell J. F.
Published: October 2006

A method is reported for the quantitative analysis of free amino acids and related substances by the dansyl reaction, and the technique has been used for the analysis of tissues of the dorsal sensory neuron of the rat. A comparison of dorsal and ventral roots revealed no major qualitative differences, but glutamate and the very much less abundant amino acids, threonine and arginine occurred in significantly higher concentrations in dorsal roots as compared with ventral roots. After an 8 h period of dorsal root ligation in vivo, an apparently selective accumulation of alanine, glutamate, glycine and tyrosine occurred. These findings are compatible with the postulated transmitter role of glutamate at the terminals of primary afferent fibres and may indicate its subsequent transport towards the cord after synthesis in the ganglion. After the injection of [14C]glucose into the dorsal root ganglion, no rapid transport of any radiolabelled material along the axon could be detected. This finding is discussed in relation to current knowledge of the metabolic pathways involved in the synthesis of glutamate and related amino acids.