The construction and use of a permanent, implanted plastic camnula for intraventricular injections in rat brain is described. The cannula can be used in either acute or chronic experiments.

A method of analysis for oxygen 18 is described, based on the anodic oxidation of specially prepared tantalum wires implanted through cannulas into the tissue of living animals. The thin anodic oxide layer formed on these wires is then analyzed by the 18O(p,alpha)15N reaction. The isotopic oxygen concentration of water in the brain obtained by this method compares very well with the values obtained by conventional analysis using mass spectrometry. This in vivo method of nuclear microanalysis has been used in both metabolic and equilibration experiments involving oxygen 18. The half-life for the turnover of 18O in body water was found to be about 3 days. A simple three-pool model is presented which can account for the experimental results obtained from the dilution by body water of interperitoneally injected water highly enriched in 18O.

AbstractA new method for measuring the uptake of materials labeled with radioactive phosphorus (32P) in the brain of a freely moving rat is described. The rat of uptake in the brain of a single animal of 32P‐labeled phosphate was compared to the uptake rate in the animal's blood or liver. A comparison was made between the uptake following an intravenous (IV) or an intraperitonel (IP) injection. The effect of convulsions caused by injections of metrazol on the kinetics of 32P uptake in the brain is described.

Journal of Neuroscience ResearchVolume 1, Issue 5-6 p. 495-499 Article The use of 18O2 in studying oxygen metabolism in various behavioral situations Dr. A. Mayevsky, Corresponding Author Dr. A. Mayevsky Department of Life Sciences, Bar Ilan University, Ramat Gan The Isotope Department, The Weizmann Institute of Science, Rehovot, IsraelDepartment of Life Sciences, Bar-Ilan University, Ramat-Gan, IsraelSearch for more papers by this authorD. Samuel, D. Samuel Department of Life Sciences, Bar Ilan University, Ramat Gan The Isotope Department, The Weizmann Institute of Science, Rehovot, IsraelSearch for more papers by this author Dr. A. Mayevsky, Corresponding Author Dr. A. Mayevsky Department of Life Sciences, Bar Ilan University, Ramat Gan The Isotope Department, The Weizmann Institute of Science, Rehovot, IsraelDepartment of Life Sciences, Bar-Ilan University, Ramat-Gan, IsraelSearch for more papers by this authorD. Samuel, D. Samuel Department of Life Sciences, Bar Ilan University, Ramat Gan The Isotope Department, The Weizmann Institute of Science, Rehovot, IsraelSearch for more papers by this author First published: 1975 https://doi.org/10.1002/jnr.490010516AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL References Ingvar, D. H., and Risberg, J. (1967): Exp. Brain Res. 3: 195. Lübbers, D. W., Ingvar, D. H., Betz, F., Fabel, H., and Schnahl, F. (1964): Pflügers Arch. Ges. Physiol. 281: 58. Mayevsky, A., and Samuel, D. (1974): Physiol. Behav. 12: 679. Reivich, M. (1972): In “ Progress in Brain Res.” Vol. 35, S. Meyer and J. P. Schade (Eds.). Elsevier. Samuel, D. (1962): In “ Oxygenases.” O. Hayaishi (Ed.). Academic Press, Inc., New York. 31– 86. Sokoloff, L., Mangold, R. Wechsler, R. L., Kennedy, C., and Kety, S. S. (1955): J. Clin. Invest. 34: 1101. Travis, R. P., and Clark, L. C. (1965): EEG Clin. Neurophysiol. 19: 484. Volume1, Issue5-61975Pages 495-499 ReferencesRelatedInformation

Publisher Summary This chapter reviews the oxygen-18 in measurement of dopamine (DA) turnover in rat brain. Mass spectrometric evidence was obtained for the incorporation of at least one oxygen isotope in brain homovanillic acid (HVA) following in vivo exposure of rats to atmospheres highly enriched with oxygen-18. The high mass range in the mass spectra of the methyl ester heptafluorobutyryl derivative of authentic HVA and apparent HVA from brain extracts is demonstrated. HVA has the molecular ion at m/e 392 which is also the base peak. An abundant fragment is also present at m/e 333. An almost identical spectrum was obtained from brain extracts of animals exposed to a 16O2 containing atmosphere. On the other hand, in animals exposed to 18O2 gas, abundant. The atmospheric origin of the 180 atom incorporated was proved by injecting 18O labeled water into the animals which was not followed by incorporation of significant amounts of 18O in brain HVA. The usefulness of the technique for studies on brain DA turnover was demonstrated by studying the effect of chlorpromazine treatment on 18O, incorporation in brain HVA.

The system described in this paper permits the control of the air composition while the animals are under different behavioral situations. A special air-tight operant conditioning (Skinner) box was used. We used oxygen-18 in this system in order to measure the oxygen metabolism under different physiological and psychological situations.

Rats were exposed to air containing 18O2 at atmospheric pressure. In vivo incorporation of 18O in brain homovanillic acid (HVA) was determined by gas chromatography-mass spectrometry. One 18O atom was incorporated into each molecule of HVA indicating that tyrosine is the predominant precursor of brain dopamine and that the oxygen in the 3-position is of atmospheric origin. Intraperitoneal administration of 18O-enriched water did not alter the 18O content of brain HVA Mass fragmentography (2) was used to measure the increase in 18O and the decrease in 16O in HVA from rat brain over several hours of exposure to an 18O enriched atmosphere. These experiments demonstrate the possibility to pulse label brain dopamine and its metabolites by in vivo inhalation of stable oxygen isotopes. The procedure should be useful for quantitative determinations of the turnover of brain dopamine in animals and man.