bluuebunny/crossref_metadata_2025_split huggingface dataset:
FLUID COMPARTMENTATION AND ELECTROLYTES OF CAT CEREBRAL CORTEX IN VITRO–II SODIUM, POTASSIUM AND CHLORIDE OF MATURE CEREBRAL CORTEX
Authors: BOURKE ROBERT S. , TOWER DONALD B. 
Published: October 2006

SUMMARYThe contents of K+, Na+ and Cl− in various incubation media and in slices of adult cat cerebral cortex incubated in vitro under a variety of conditions have been determined in conjunction with studies on slice swelling and fluid compartmentation reported in the preceding paper (Bourke and Tower, 1966).Cortical slices incubated in media containing 16 Or 27 mm‐K+ exhibit contents of K+ and Na+ most nearly comparable to those found in viuo. Substitution of isethionate− For Cl− or omission of Ca2+ in such media have little effect on slice cation composition. Rb+ can effectively substitute for K+, but substitution of Li+ or choline+ for most of the naf in incubation media is associated with accumulation of these cations in slices at the expense of both K+ and Na+.Compared to values in vivo for net contents and/or concentrations of electrolytes in the non‐sucrose spaces of cortical slices, conditions yielding most favourable data in vitro appeared to be incubation of cortical slices in 16 mm‐K+ medium or in 27 mm‐K+ medium with either omission of Ca2+ or replacement of Cl− by isethionate.Essentially complete inhibition of maintenance of K+ and extrusion of Na+ in slices of cat cerebral cortex occurs upon incubation with 10−5 or 10−4m‐ouabain, with 50 per cent inhibition of cortical slice electrolyte metabolism occurring at about 8 × 10−7m‐ouabain.Cortical slices incubated in 27 mm‐K+ medium in the presence of 42K exhibited rates of exchange and turnover of slice K+ (in non‐sucrose spaces) of 0·7 μequiv./min and 6.45 per cent respectively. In the presence of 10−5m‐ouabain, a maximal ratio of slice specific activity/medium specific activity is attained within about 5 min after 42K addition, compared to >20 min for control slices. In neither case does the maximal specific activity ratio exceed about 0.85; this suggests that some 10‐15 per cent of total cortical K+ comprises a “slowly exchangeable” fraction.In the presence of Ca2+ (1.3 mm) slice oxygen consumption is markedly stimulated (39 per cent) and aerobic glycolysis is markedly depressed (54 per cent) in the presence of 10−5m‐ouabain; whereas on omission of Ca2+ from incubation media, both respiration and glycolysis are normally stimulated but, with 10−5m‐ouabain present, both are significantly depressed (20 per cent and 37 per cent respectively). Possible relevance of these effects to mobilization of tissue Ca2+ by ouabain and to effects of intracellular Ca2+ on mitochondrial respiratory metabolism is discussed.
BRAIN GANGLTOSIDE PATTERN IN THREE FORMS OF AMAUROTIC IDIOCY AND IN GARGOYLISM
Authors: Borri P. F. , Hooghwinkel G. J. M. , Edgar G. W. F. 
Published: October 2006

SUMMARYBrain ganglioside pattern was studied in one case of Tay‐Sachs’disease, two cases of Late Infantile Amaurotic Idiocy (L.I.A.I.) two cases of Juvenile Amaurotic Idiocy (J.A.I.), three cases of Gargoylism together with three normal adults and one 7‐year‐old normal child. Our findings in Tay‐Sachs’disease conformed with those reported by previous authors. In J.A.I. and L.I.A.I. the percentage distribution of N‐acetylneuraminic acid in individual gangliosides has been found to be similar to the normal. No evidence of storage of any single ganglioside has been found in L.I.A.I. All cases of gargoylism showed a clear‐cut increase of the two fastest monosialogangliosides.Literature concerning Amaurotic Idiocy and Gargoylism is reviewed and briefly discussed in connection with the present findings.
BIOCHEMICAL EFFECTS OF THYROID DEFICIENCY ON THE DEVELOPING BRAIN
Authors: Balázs R. , Kovács S. , Teichgräber P. , Cocks W. A. , Eayrs J. T. 
Published: October 2006

Abstract— The effects of neonatal thyroidectomy on some constituents of the cerebrum, cerebellum and liver of the rat have been studied during the first 7 weeks of life. In the normal rat between the 6th and 14th post‐natal days the RNA content per unit of DNA in the brain increased by 70 per cent. Although the brain continued to grow from the 14th to the 35th day, the amount of RNA relative to DNA decreased by about 20 per cent. The ratio of protein to DNA increased during the whole period studied and in the cerebral cortex it was more than trebled between the age of 6 and 35 days. The growth of the cerebellum extended over a longer period than that of the cerebrum, its weight increasing by 88 per cent between the ages of 14 and 35 days as compared with a cerebral increase of 34 per cent. The DNA content showed a 50 per cent increase during this period.Qualitatively these maturational changes were not affected by neonatal thyroidectomy. Quantitative changes, which applied equally to the cerebral cortex and brain as a whole, were observed. At the age of 35 days, the weights of the cerebral hemispheres and cerebellum were reduced by thyroidectomy by 20 per cent; the overall DNA content per organ did not change, but the amounts of protein and RNA relative to DNA decreased significantly. It is therefore inferred that thyroid deficiency affects the size of the cells in brain and cerebellum rather than their total number. Conversely, the cell population of the liver was only a quarter of that in the control. There was a small but significant decrease in the hepatic protein and RNA content in the hypothyroid animal.The activities of the following enzymes which served as markers for subcellular fractions in homogenates of cerebral cortex were determined: lactate dehydrogenase for the supernatant, glutamate dehydrogenase for the mitochondrial and glutamate decarboxylase for the synaptosomal fractions. When the activities were expressed on a fresh weight basis a significant decrease by comparison with the control values was observed only in the case of glutamate decarboxylase (—15 per cent at the age of 17–32 days); when the activities were based on DNA content all values were reduced, probably as a result of the general decrease in cell size.Pyrimidine metabolism of brain and liver, studied after the administration of [6‐14C]‐orotic acid, was not affected in either tissue by neonatal thyroidectomy. A small but significant reduction in the incorporation of labelled pyrimidine nucleotides in liver RNA was observed, but no significant decrease in the incorporation in cerebral RNA was found in the hypothyroid rats.
POTASSIUM EFFECTS ON ION TRANSPORT IN BRAIN SLICES
Authors: Hertz L. 
Published: October 2006

Abstract—(1) Fluxes of sodium, potassium, chloride and glutamate ions were studied in brain slices by aid of radio‐isotopes. Desaturation curves showed the efflux to occur from at least two compartments with widely different kinetics.(2) The slowly exchanging component comprises from about 10 (sodium, potassium, chloride) to about 30 (glutamate) per cent of the radioactivity in the tissue. An energy‐requiring uptake of potassium and extrusion of sodium seems to occur in this compartment, which probably includes the nerve cells.(3) A rather slow efflux of especially potassium ions from the rapidly exchanging fraction indicates that this component may not be purely extracellular, but also seems to include cells, which possibly are neuroglial. The hypothesis of a cellular origin is supported by the demonstration of an increase in the rate constant of the potassium efflux evoked in the presence of oxygen by high concentrations of potassium.(4) Evidence is presented that the increase in the rate constant of the potassium efflux is due to a potassium‐induced stimulation of active transport. No coupling seems to occur between the stimulated potassium transport and movements of sodium, but potassium ions may be accompanied by glutamate ions.
ACIDIC PROTEINS IN RAT BRAIN NUCLEI: DISC ELECTROPHORESIS
Authors: Dravid A. R. , Burdman J. A. 
Published: October 2006

Abstract—Disc electrophoretic patterns of soluble, acidic proteins in brain and liver nuclei and in the respective tissue homogenates were studied.In brain nuclei, a fast component moving with the electrophoretic front constitutes a relatively large amount of the acidic proteins which migrate toward the anode. Electrophoretic patterns obtained with fractionated brain nuclei (neuronal, astrocytic and glial) were similar to those obtained with total brain nuclei. The S‐100 protein could not be detected in any of the nuclei examined.Protein patterns in brain and liver nuclei markedly differed both quantitatively and qualitatively.
EFFECTS OF OUABAIN ON ACID‐SOLUBLE PHOSPHATES AND ELECTROLYTES OF ISOLATED CEREBRAL TISSUES IN PRESENCE OR ABSENCE OF CALCIUM
Authors: Swanson P. D. 
Published: October 2006

Abstract—(1) Cerebral slices were incubated in Ca2+‐free media or in media which contained 2.8 mm‐Ca2+. Omission of Ca2+ brought about a drop in creatine phosphate content of 28 per cent, as well as a drop of 3–10 per cent in non‐inulin K+ content. There was little change in content of 10‐min phosphate or of non‐inulin Na+.(2) Ouabain in concentrations of to M increased the loss of K+ from the slice and caused a rise in Na+ content. The changes were most marked in Ca2+‐free media. Creatine phosphate levels were depressed by ouabain both in the presence or absence of Ca2+. In the absence of Ca2+, the lowering of phosphocreatine did not occur until significant shifts in K+ had taken place. In contrast, slices incubated in Ca2+‐containing media lost creatine phosphate and K+ at about the same rate.(3) When ouabain and labelled phosphate were added simultaneously, there was little difference in the rate of incorporation of label into creatine phosphate in media which differed in Ca2+ concentration. However, incorporation of azP‐labelled phosphate into creatine phosphate was decreased by 30–40 per cent in media which lacked Ca2+ when ouabain was added 15 min prior to the labelled phosphate. This change was not observed when the media contained Ca2+.(4) Ouabain did not affect oxidative phosphorylation or respiratory control when added directly to bovine brain mitochondrial preparations.(5) The results suggest that the previously observed depression of respiration brought about by ouabain in Ca2+‐deficient media is not a good indicator of the proportion of the cell's metabolism used for active cation transport. Under these conditions, the inhibition of cation transport is accompanied by a drop in slice content of high‐energy phosphate which may represent a secondary effect of ouabain, or of cytoplasmic alterations brought about by ouabain, on energy‐producing processes.
EFFECT OF TRANQUILIZERS ON REGIONAL DISTRIBUTION OF ASCORBIC ACID IN THE RAT BRAIN
Authors: Rajalakshmi R. , Patel A. J. 
Published: October 2006

Abstract—Studies were made of the effects of fluphenazine, chlorpromazine and triflupromazine on tissue concentration, liver synthesis of ascorbic acid and its distribution in different areas of the brain. All the three drugs were found to increase liver concentration and synthesis of the vitamin at 24 hr after administration of a single oral dose of the vitamin, but only fluphenazine was found to increase its concentration in the adrenals and brain; the increase in the latter case was found to vary in different regions of the brain, the olfactory lobes, hypothalamus and residual brain showing maximum increases, andthe basal ganglia, visual cortex and remaining dorsal cortex showing minimum increases. The effects were found to be reversed 72 hr after drug treatment.
HOMOCARNOSINE IN HUMAN CEREBROSPINAL FLUID: AN AGE‐DEPENDENT PHENOMENON1
Authors: Perry T. L. , Hansen Shirley , Stedman Dorothy , Love Donna 
Published: October 2006

Abstract—Homocarnosine, rather than carnosine, is the major imidazole dipeptide present in human CSF. This compound can be readily detected in the CSF of normal infants and young children, while it is either not detectable or is present only in very small concentrations in the CSF of normal adult subjects. Slightly greater amounts of homocarnosine can be found in the CSF of some adults with neurological disorders.
GRAMICIDIN INDUCED ION TRANSPORT IN BRAIN MITOCHONDRIA PREPARATIONS
Authors: Moore C. L. 
Published: October 2006

Abstract— —(1) Gramicidin at low concentrations induces an uptake of K+ and Na+ in brain mitochondria in a manner similar to that observed with liver mitochondria.(2) The cation uptake is energy dependent, and is accompanied by an ejection of H+ ions and a slight increase in respiration in the absence of added permeant anion.(3) The cation uptake and hydrogen ion release are both inhibited by agents which inhibit electron transport. Barbiturates and chlorpromazine inhibit the transport phenomenon by inhibiting electron transport.(4) In the presence of permeant anions (phosphate and acetate) respiration is stimulated quite significantly.(5) At high gramicidin concentrations there is a release of Na+ and K+ from the mitochondria and uptake of H+. There is also a cyclic reduction‐oxidation of the nicotinamide adenine dinucleotides, which is believed to be due to the release from the mitochondria of the reduced dinucleotides followed by their subsequent oxidation.(6) The effect of high gramicidin on the mitochondrial nicotinamide‐adenine dinucleotides and cation distribution is irreversible and is not blocked by individual inhibitors of respiration and of phosphorylation, but is prevented by prior addition of a mixture of these inhibitors.(7) Gramicidin is therefore believed to have a bimodal function; one on the mitochondrial membrane per se, and the other on the energy dependent ion accumulation apparatus.(8) A model of induced mitochondrial ion accumulation is presented.
FRACTIONATION OF OLFACTORY TISSUE HOMOGENATES. ISOLATION OF A CONCENTRATED PLASMA MEMBRANE FRACTION
Authors: Koch R. B. , Norring N. L. 
Published: October 2006

Abstract— Differential and sucrose‐density‐gradient centrifugation techniques were used for studies on the separation of subcellular particles from rabbit brain and olfactory tissue. Comparisons were made among various fractions from the two types of tissue. These comparisons included protein concentration and enzyme activities of the individual fractions as well as their distribution in subfractions from density gradient separations.In tissue whole homogenates, the percentage of total ATPase activity as ouabain sensitive Na+‐K+ ATPase activity was about 4 times greater in brain cortex (63 per cent) than in olfactory tissue (17 per cent). Cytochrome oxidase and Na+‐K+ ATPase activities were used to indicate the presence and the concentration of mitochondria and of the plasma membranes. A fraction with properties similar to the mitochondria plus nerve ending fraction from brain homogenates (fraction B) was obtained from olfactory tissue. Nerve ending concentration subfractions (B2) were prepared from the B primary fractions. Plasma membrane subfractions were obtained by osmotic shock treatment of B2, In the fraction of plasma membrane from olfactory tissue (E2), 56 per cent of the total ATPase activity was Na+‐K+ ATPase activity. In E2 from brain 71 per cent was Na+‐K+ ATPase activity.Deoxycholate (DOC)‐treated fractions containing nerve endings from brain preparations showed much greater increase in cytochrome oxidase activity than did similar fractions from olfactory tissue.DOC treatment increased the NADH cytochrome c reductase activity of all fractions and subfractions from brain, while it decreased activity in all but one fraction from olfactory tissue. DOC treatment decreased both the Mg2+ and Na+‐K+ ATPase activities in both types of tissue.Electron photomicrographs of olfactory B2, B3, E2 and E3 show clear morphological differences among these subfractions. The presence of possible cilia and basal bodies on vesicles in B2 gives morphological evidence for the presence of terminal swellings in this subtraction in agreement with enzyme marker activity results.
INFLUENCE OF AGE ON THE INCORPORATION OF [14C]GLYCINE INTO PROTEIN IN CHICKEN PERIPHERAL NERVE
Authors: Matheson D. F. 
Published: October 2006

Abstract—

The conditions for incorporation of [14C]glycine in vitro into proteins in the sciatic nerve of chickens have been studied and found to be similar to those of rat nerve.
Its incorporation decreases, however, linearly with age.
The content of RNA and of DNA of peripheral nerve and the RNA/DNA ratio alter linearly with age.
There is also a linear relationship between the specific radioactivity of the protein extract and the RNA content of the nerve.
There is a linear decline with age in the specific radioactivity of the protein fraction when expressed against the DNA content.
A linear relationship exists between the logarithm of the specific radioactivity and the length of the femur.
THE UPTAKE OF METHONIUM COMPOUNDS BY ISOLATED SLICES OF RAT CEREBRAL CORTEX1
Authors: Taylor D. B. , Lu T. C. , Creese R. , Steinborn J. 
Published: October 2006

Abstract— The uptakes of a series of methonium compounds, C2, C4, C6, C7, C8, C9 and C10, by isolated slices of rat cerebral cortex were measured.Analyses of the kinetics of uptake of C7, C8, C9 and C10 indicate that their initial influxes consist of two components. A Michaelis‐Menten type uptake by carrier can account for the saturable fraction. C7 had the lowest affinity for the carrier, with values increasing for C8, C9 and C10, while C10 had the smallest maximum influx with values increasing for C9, C8 and C7. The unsaturable fraction corresponded to the slow continuous swelling of the tissue.The uptake of C8 was inhibited by other methonium compounds, choline, ACh, physostigmine, ouabain and morphine. C8 could be counter‐transported by C7.There is evidence that the main driving force for uptake is the transmembrane potential, but the steric factor may be a restricting influence.
A COMPARISON OF CEREBROSIDES, PROTEOLIPID PROTEINS, AND CHOLESTEROL AS INDICES OF MYELIN IN THE ARCHITECTURE OF RAT CEREBRUM1
Authors: Bass N. H. , Hess Helen H. 
Published: October 2006

Abstract— —Serial frozen section sampling and microspectrophotometric assays were used to compare the fidelity of cerebrosides, proteolipid proteins (PLP) and cholesterol as indices of myelinated fibres in the somatosensory region of rat cerebrum.Cerebrosides (including sulphatides) were a satisfactory index regardless of the mode of expression. Per unit dry wt., they were lowest in layer II (4 per cent) and increased with the subpial depth to 16 percent in white matter. Elevations were seen at the locations of: the outer tangential plexus (1); the stripe of Kaes‐Bechterew (2); the outer and inner stripes of Baillarger (3,4); and the inner tangential plexus (5), respectively. Expression in terms of residue protein, total lipid or DNA gave somewhat sharper profiles of the myeloarchitecture.PLP per unit dry wt. were lowest in layers I, II and III (2 per cent) and increased to 5·5 per cent in white matter. Peaks occurred near (3), (4) and (5). The PLP per cell and per unit residue protein rose six‐fold, from the upper layers of cortex to white matter, and depicted the myeloarchitecture more faithfully. In general outline, PLP paralleled cerebrosides in distribution, in contrast with previous findings in human prefrontal cortex. Human cortex may contain more non‐myelin PLP in the upper cortical layers owing to its greater wealth of neuropil and synapses.Cholesterol per unit dry weight was a poor index of the myeloarchitecture; it was lowest in layer II (5 per cent) and increased to 13‐5 per cent in white matter without revealing the five horizontal bands of myelinated fibres. Expression of cholesterol in terms of total lipid or DNA improved its value as an index, but it was less satisfactory than cerebrosides.
AN ENZYMIC BARRIER MECHANISM FOR MONOAMINE PRECURSORS IN THE NEWLY‐FORMING BRAIN CAPILLARIES FOLLOWING ELECTROLYTIC OR MECHANICAL LESIONS
Authors: Björklund A. , Falck B. , Hromek F. , Owman Ch. 
Published: October 2006

Abstract— The intracerebral capillaries of the rat constitute an enzymic trapping mechanism for certain systemically administered monoamine precursors, which are taken up into the capillary walls, decarboxylated locally to the corresponding amine and this is then metabolized by monoamine oxidase. The amine can be directly demonstrated histochemically in the endothelial cells and pericytes of the capillaries, particularly after inhibition of monoamine oxidase.The question of whether or not these barrier properties appear also in the regenerating capillaries following electrolytic or mechanical lesions in the cerebellar parenchyma was studied after intraperitoneal injection of l‐DOPA to rats pretreated with nialamide. A very pronounced formation of new capillaries, starting at the periphery of the lesions, could be established 3–4 weeks postoperatively. Also these new, regenerating capillaries were able to trap l‐DOPA in a manner indistinguishable from that of the normal capillaries in the surrounding parenchyma. It is concluded that a complete barrier mechanism with regard to the enzymic trapping of certain monoamine precursors can reestablish after complete regeneration of the brain capillary bed in unspecific lesions.
PROTEIN SYNTHESIS IN THE MEDULLA OF THE RAT BRAIN. REPRODUCIBILITY OF THE RESULTS
Authors: Foulkes J. A. , Robinson N. 
Published: October 2006

Abstract— [14C]Leucine was injected intracranially into the brainstem reticular formation at the level of the upper medulla by the stereotaxic method. Subcellular fractions prepared 3 hr after injection showed that the specific activities of leucine‐incorporated proteins decreased in the order soluble, microsomal, nuclear and mitochondrial fractions. Specific activities of proteins in the sera were 2·2 per cent of whole homogenate proteins.The results from 27 experiments showed that 66·6 per cent of the mean specific activities of proteins extracted from whole homogenates fell within ·1 s.d. and 100 per cent within ± 2 s.d. (close to a normal distribution). The coefficients of variation were between 40 and 50 per cent for whole homogenates, sera and all subcellular fractions. Reproducibility of results and factors concerned with possible errors in the technique are discussed.