摘要:

Abstract—Changes in memory, electrocorticograms (ECoG), protein, DNA, RNA, neurotransmitters, enzyme activity and neuronal ultrastructure were examined after deuteron irradiationof the brain in C57B1/10 mice. Twenty animals served as sham‐irradiated controls, while three irradiated groups received a dose of either 500, 5000 or 10,000 rads covering an area of 9 × 5 mmover the dorsal surface of the brain and extending to a depth of 2 mmfrom the skull. The 10,000 rad group differed significantly in retention of spontaneous locomotor performance and dark maze exploration during a 16‐month post‐irradiation period. Desynchronization with an overall amplitude reduction of both spontaneous and light evoked ECoG was observed in the 10,000 rad group. There was a dose‐dependent decrease in protein, DNA and RNA content but not in their concentrations. Brain irradiation resulted in a significant change in content as well as concentration of 5‐HT and in acetylcholinesterase activity both per brain and per gram fresh weight. Morphologically, there was a significant reduction in brain and pituitary weight. Histochemical observations indicated a uniform and dose‐dependent reduction in vascular alkaline phosphatase activity and a selective decrease in staining for cellular DNA and RNA in different regions of the irradiated tissue of the brain. Electron microscopic comparisons of nuclear and cytoplasmic changes indicated serration of some nuclear membranes in the 10,000 rad group, accumulation of glycogen, numerous phagocytes and formation of multi‐lamellar intraneuronal membranes. Prominent synaptic changes were not observed in the remaining neurons within the irradiated tissue of the brain. From the multidisciplinary comparisons it was concluded that deuteron irradiation of the CNS can be used as another approach for relating changes in such unique functions as learning and memory to subcellular and cellular changes in specific regi

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05901.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—Different subcellular fractions prepared from developing rat cerebrum were quantified by determinations of dried weights and protein contents. It was found that there is an increase of 2–2·5 times in the weights of synaptosomes and mitochondria/g of tissue during the first 20 days of extrauterine life.A period of fast synthesis of gangliosides, with a similar pattern of increase for the different subcellular particles, was found during the first 15 days of life by study of the incorporation of injectedd‐[1‐14C]glucosamine in rats at different stages of development. Attempts to find out if gangliosides from a certain fraction are precursors of those of other fractions indicated that in all fractions the gangliosides increase independently of the other fractions. It is concluded that the enzymic systems of synthesis of these glycolipids are presentin vivoin all the fractions co

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05902.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Zusammenfassung—Die Aktivität der Glutamat‐Decarboxylase im Gehirn von Ratten während und vor experimentell ausgelösten cerebralen Anfällen wird der von Kontroll‐ratten gegenübergestellt. Es konnte eine Hemmung der Enzymaktivitat im tonischen Krampf nach i.c. Injektion vonl‐Glutamat, Pyridoxal‐5‐phosphat, nach audiogener Reizung, nach intraperitonealer Injektion von Pentamethylentetrazol und im Elektrokrampf beobachtet werden. Im prakonvulsiven Stadium ist das Enzym nach i.c. Injektion vonl‐Glutamat,l‐Aspartat und nach audiogener Reizung stark gehemmt. Lediglich nach i.c. Injektion von Pyridoxal‐5‐phosphat ist die Enzymaktivitat gegeniiber von Kontroll‐ratten unverändert. Insbesondere wird auf die unterschiedliche Wirkung aufl‐Glutamat und Pyridoxal‐5‐phosphatin vivoundin vitroauf die Glutamat‐Decarboxylase hingewiesen. Die Hemmung dieses Enzymsin vivowird als eine der moglichen Ursachen für die En

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05903.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—Prolonged (6 hr) anaesthesia with phenobarbital in mice or rats results in a doubling or tripling of brain glycogen. Increases were also observed if high levels of plasma glucose were maintained for 6 hr. In alloxan diabetes brain glycogen was not elevated in spite of the high plasma glucose concentrations. However, administration of insulin to such diabetic animals, together with enough glucose to maintain high plasma levels, resulted in at least a doubling of brain glycogen in 6 hr. Phenobarbital can still increase brain glycogen in diabetic animals.In all of the conditions associated with increased glycogen deposition, increases were found in the ratio of brain glucose to plasma glucose. Cerebral glucose‐6‐P levels were also increased whereas there were no substantial changes in levels of UDP‐glucose or glucose‐1,6‐

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05904.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—The amino acid composition of human, monkey and bovine centrum ovale myelin, of bovine optic nerve myelin, and of bovine spinal cord white matter myelin has been determined. In general, the amino acid patterns of the centrum ovale myelin of these species and the optic nerve myelin are identical. Differences are noted when these are compared to the spinal cord white matter myelin. It is shown that the amino acid composition of myelin cannot be duplicated by any combination of the Folch–Lees proteolipid protein and the basic protein fraction of myelin. It is necessary to postulate the existence of a third protein fraction that is rich in dicarboxylic amino ac

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05905.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—A method for the isolation of peripheral nerve myelin is described. Peripheral nerve myelin differs from centrum ovale myelin in its amino acid composition, in that it contains a greater proportion of protein that is digestible with trypsin and pepsin, and in the insolubility of its proteins in chloroform–metha

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05906.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—The properties ofl‐alanyl‐β‐naphthylamidase were studied in purified myelin of the spinal cord. The enzyme could be partially extracted with Triton‐X‐100, but some activity was lost by this operation.l‐Alanyl‐β‐naphthylamidase migrated anodally in acrylamide gel, and the bulk of the activity did not appear to be associated with the basic protein or with the proteolipid protein of myelin. This enzyme is somewhat elevated with acute EAE, but subcellular fractionation of the spinal cord showed that the increased activity was not in the myelin but in the heavier particulate fractions. The relatively small increase in enzyme activity with EAE indicates that this enzyme is probably not a major causative age

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05907.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—Glial cells were isolated from bovine white matter by differential centrifugation. The fatty aldehyde and fatty acid compositions of ethanolamine glycerophosphatides (EGP), serine glycerophosphatides (SGP) and choline glycerophosphatides (CGP) were determined by gas‐liquid chromatography. The fatty acid compositions of the sphingo‐lipids including sphingomyelin, cerebroside and cerebroside sulphate, and of minor lipid components including cholesterol esters and triglycerides, were also determined by gas‐liquid chromatography. The relative proportions correlated closely with the results obtained by O'Brienand Sampson(1965b) for adult human brain. The fatty aldehyde compositions of the glycerophosphatides were more closely related to the corresponding fatty acid compositions of the plasma membrane than of the mitochondria. Long‐chain fatty acids (19–26 carbon atoms) were detected in sphingomyelin, cerebroside and cerebroside sulphate; this indicates that chain‐elongation beyond C18occurs in th

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05908.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—Unconjugated bilirubin caused uncoupling of oxidative phosphorylation in brain mitochondria prepared from mature or weanling rats. Human serum albumin in an amount sufficient to bind 100 per cent of the added bilirubin was able to protect the mitochondria from the inhibitory effects of bilirubin. Bilirubin inhibited both the endogenous and DNP‐activated ATPase activities but had no effect upon the Mg2+‐stimulated ATPase; albumin prevented the inhib

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05909.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

Abstract—Chick embryo sympathetic chains were grown in tissue culture and pulse labelled with tritiated catecholamines. The uptake was restricted to sympathetic nerve cells. The capability of these cells to take up radioactive dopamine and norepinephrine from the culture media was retained after one month in tissue culture. The uptakes of both [3H]norepinephrine and [3H]dopamine were inhibited when nonradioactive DOPA, dopamine, norepinephrine or epinephrine were present in the pulse medi

ISSN:0022-3042    

DOI:10.1111/j.1471-4159.1968.tb05910.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY