摘要:

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 ce

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02216.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract—Incorporation of [8‐14C]adenine into a rapidly‐labelled fraction of RNA derived from the nucleus, and into a cytoplasmic RNA of high molecular weight was studied in brain slices from new born rats. The kinetic behaviour of the two fractions of RNA was compatible with a precursor‐product relationship between them. The change in the specific activity of adenine and the reduction of radioactivity in prelabelled RNA of brain slices in the presence of actinomycin D, suggest that the observed degradation of nuclear RNA is not due to random changes, but is limited to a relatively small fraction, presumably messen

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02217.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract—Free inositol was measured in peripheral nerves of the monkey, rabbit, rat, frog and lobster; levels in mammalian nerve were similar, and two to three times greater than in the other species. Concentrations of myo‐inositol in rabbit tibial nerve increased from proximal to distal segments; in optic nerve the concentrations decreased with greater distance from the retina. In the early stages of Wallerian degeneration rabbit tibial nerve contained 25 per cent less free myo‐inositol, rat nerve 50 per cent less. Rabbit nerves were analysed at 2 and 5 weeks after section; by 5 weeks levels of myo‐inositol had increased to 50 per cent above normal. Similar changes were found in degenerating rabbit optic nerve. The combination of galactose feeding and nerve section resulted in reduction of the myo‐inositol in rat sciatic nerve to one‐fifth of the control value; galactitol in the nerve decreased by 50 per cent after section. The evidence suggests that myo‐inositol in nerve is located mainly in Schwann

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02218.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract—An investigation of the types of RNA present in the whole abdominal ganglia ofAplysiaand in single identified neurons was made. Because of the longin vitrofunctioning 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 14Smolecule is descri

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02219.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract—Quantitative analyses performed on the lipids of cerebral grey matter from brains of a normal child and a child with Tay‐Sachs (T‐S) disease were compared with such analyses on the brain of a 6‐year‐old, non‐Jewish male with systemic GM2‐gangliosidosis of a late infantile type (GM2‐LI). Analysis of gangliosides showed a 3·5‐fold increase of total gangliosides in the GM2‐LI brain and a six‐fold increase in the T‐S brain, compared to normal brain. Both pathological brains had similar distribution patterns for gangliosides, with the GM2‐ganglioside component constituting more than 80 per cent of the total. Lipid components in the T‐S brain were below normal values except for lecithin and cholesterol, while in the GM2‐LI brain there were increases in sulphatides, cerebrosides, sphingomyelin and cholesterol. Approximately twice as much ceramide trihexoside was present in the T‐S brain as in the GM2‐LI brain, and none could be detected in the normal brain. The clinical, pathological and biochemical data support the conclusion that this case represents a new variant of systemic late‐infantile gangliosidosis in which there is an accumulation of the GM2‐gang

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02220.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract—Essential fatty acid (EFA) deficiency initiated in rats prior to birth and continued for one year affects brain lipids to an extent which differs in the two sexes. It was found that:(1) Brain weight and lipid content were decreased in deficient conditions, especially in males.(2) Total phospholipids were present in lower concentrations, particularly in the deficient male brain, while the percentage of the major phospholipid classes‐ethanolamine phosphoglyceride (EPG), choline phosphoglyceride (CPG) and serine phosphoglyceride (SPG) did not change.(3) Brain EPG, CPG and SPG had distinctive fatty acid patterns differing greatly in polyunsaturation content. PE acids of control females had elevated monoenes and reduced saturates in comparison with control males. This sex difference was lost in the deficient animals.(4) Polyunsaturated fatty acids of EPG, CPG and SPG were markedly changed in animals lacking dietary linoleic acid. Trienoic (C20and C22) and docosapentaenoic acids were greatly increased, whereas arachidonic, docosatetraenoic and docosahexaenoic acids were much decreased.(5) In spite of the changes in fatty acid composition each of the three phospholipid classes maintained its particular level of unsaturation during EFA deficiency.(6) EPG aldehydes did not change appreciably in deficient conditi

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02221.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract(1)Dopamine–In slices from guinea pig corpus striatum, dopamine significantly inhibited incorporation of32P into phosphatidylethanolamine‐plus‐phosphatidylserine at a concentration of 0001 mM, and into phosphatidylinositol and phosphatidylcholine at 001 mM. In eight areas of the guinea pig brain in which the effects of 01 mM‐dopamine were studied, the only significant increase in incorporation of32P into phosphatides was into phosphatidic acid in the hypothalamus; there was significant inhibition of incorporation of32P into phosphatidylcholine in cerebellar cortex and thalamus, and into phosphatidylethanolamine‐plus‐phosphatidylserine in the olfactory bulbs.(2)Gamma‐aminobutyric acid—In slices of guinea pig cerebral cortex, GABA (1 mM) significantly inhibited incorporation of32P into only phosphatidic acid, diphosphoinositide and phosphatidylinositol and did not significantly affect the level or the specific activity of the nucleotide ∼P. GABA (10 mM), significantly inhibited incorporation of32P into diphosphoinositide, phosphatidylinositol and phosphatidylcholine, and significantly lowered the specific activity of the nucleotide ∼P.(3)5‐Hydroxytryptamine—In slices of guinea pig cerebral cortex, 5HT, (1 mM) significantly increased incorporation of32P into phosphatidic acid; in a concentration of 10 mM, 5HT increased incorporation of32P into phosphatidic acid four‐fold and into both diphosphoinositide and phosphatidylinositol two‐fold; other phosphatides were not significantly affected and the specific activity of the nucleotide ∼P was not significantly different. In eight brain areas studied, 5HT (10 mM) significantly increased incorporation of32P into phosphatidic acid in all areas; into phosphatidylinositol in six areas (excepting cerebellar cortex and hypothalamus); and into diphosphoinositide in the olfactory bulbs, cerebral cortex, hypothalamus and corpus striatum. Incorporation of32P into triphosphoinositide was not significantly affected in any area. Incorporation of32P into phospha‐tidylethanolamine‐plus‐phosphatidylserine was significantly greater than the control in the olfactory bulbs and incorporation of32P into phosphatidylcholine was significantly less than the control in the cerebellar cortex, olfactory bulbs and hypothalamus.(4) The possibility is discussed that increased incorporation of32P into phosphatidic acid and/or phosphatidylinositol in response to neurotransmitters might be associated with excitatory, but not inhibitory, neurotransmission; and that inhibition of incorporation of32P into various phosphatides may be associated with inhibitory n

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02222.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract—Developmental changes in composition of sphingosine bases of cerebrosides, sulphatides and sphingomyelins were investigated in samples from brain stem or corpus callosum from premature infants and patients aged 14 months, 39 and 59 years who died of non‐neurological causes. Since insufficient material was obtainable from the premature brains, sulphatides were studied only in older cases. Individual sphingolipids were isolated by combinations of column chromatography and TLC, and were examined for purity by analytical TLC. Sphingosine bases were released by acid‐catalysed methanolysis, and analysed as aldehydes by GLC. Effectiveness and limitations of methods used for analyses of sphingosine bases were evaluated.In contrast to adult sphingolipids in which approximately 95 per cent of the sphingosine bases was 18: sphingosine, as much as 10 per cent of the total was 18: dihydrosphingosine in immature sphingolipids. A compound tentatively identified as 20: sphingosine was present in foetal, infant and adult sphingomyelin at 5, 3 and 1 per cent of the total, respectively. Composition of sphingosine bases of non‐ganglioside sphingolipids in human brain varies with age, presumably in a complex

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02223.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

Abstract—The effect on seizure threshold of the acute intraperitoneal administration of dl‐phenylalanine in varying doses to the albino rat at different ages was investigated. Seizure threshold was measured by the technique using the volatile convulsant, hexafluorodiethylether. The alterations in seizure threshold associated with administration of the amino acid were correlated with blood and brain levels of phenylalanine and tyrosine. In 3‐ to 4‐week‐old albino rats the reduction in seizure threshold was directly related to the amount of phenylalanine administered. The effect was detected at 30 min after injection and had returned to control levels by 2 hr after administration of 20 or 40 mg of Dl‐phenylalanine and by 3 hr following the injection of 80 mg. There was a decreasing susceptibility to reduction in seizure threshold associated with phenylalanine administration with increasing age of the animals. The time course of reduction in seizure threshold in the youngest animals was temporally related more to the rise and fall of concentrations of phenylalanine in brain than to plasma levels of phenylalanine. The seizure threshold in 10‐week‐old animals was not reduced in spite of comparable elevation of blood and brain phenylalanine to the levels effective in 3‐ to 4‐week‐old animals. The results have been discussed in relation to previous studies on chronic, oral administration of phenylalanine to the rat and to possible

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02224.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

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 × 105molar concentration of an anticholinergic benzilate compound and is completely blocked by the same compound at 3 × 103m.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

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1970.tb02225.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY