, Volume 53, Issue 1, pp 73–78 | Cite as

Effects of orotic acid and pirazetam on cortical bioelectrical activity in rabbits

  • M. Krug
  • T. Ott
  • Karin Schulzeck
  • H. Matthies
Animal Studies Original Investigations


In order to obtain further evidence of the pharmacological effects of retention-facilitating substances, the influence of sodium-orotate, methylglucamine orotate, and pirazetam on the bioelectrical activity of central nervous system structures were studied. Sodium orotate showed no influence on the cortical and hippocampal spontaneous EEGs of conscious nonimmobilized rabbits. The amplitude of the first surface-positive wave of the cortical evoked potential that was elicited by stimulation of tooth pulp was, however, significantly increased in long-lasting terms by both pirazetam and the two salts of orotic acid. Similarly, the three substances also influenced the changes in excitability induced by PTP of tooth pulp. The findings suggest that these chemicals facilitate in nonspecific manner responses to externally applied stimuli through central structures. The relationships between the altered stimulus response and the retention-facilitating action of these substances are discussed.

Key words

Orotic acid Pirazetam EEG Evoked potentials PTP Cortex 


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  1. Borbely A. A.: Pharmacological modifications of evoked brain potentials Berne-Stuttgart-Vienna Huber (1973)Google Scholar
  2. Eccles, J. C.: Possible ways in which synaptic mechanisms participate in learning, remembering and forgetting. In. The anatomy of memory, Vol. 1, D. P. Kimble, ed., pp. 12–87, Palo Alto: Science and Behavior Books 1965Google Scholar
  3. Esplin, D. W.: Effects of diphenylhydantoin on synaptic transmission in cat spinal cord and stellate ganglion. J. Pharmacol. exp. Ther. 120, 301–323 (1957)Google Scholar
  4. Giurgea, C. E.: New approaches to the pharmacology of the brain. In: N.A.T.O. Symposium “Drugs, Sleep, and Behaviour”. Aviemore 1972Google Scholar
  5. Giurgea, C. E., Moyersoons, F. E.: On the pharmacology of cortical evoked potentials. Arch. int. Pharmacodyn. 199, 67–78 (1972)Google Scholar
  6. Hahn, F.: Analeptics. Pharmacol. Rev. 12, 447–530 (1960)Google Scholar
  7. Izquierdo, I.: Hippocampal physiology. Experiments on regulation of its electrical activity on the mechanism of seizures and on an hypothesis of learning. Behav. Biol. 7, 669–698 (1972)Google Scholar
  8. Kandel, E. R., Spencer, W. A.: Cellular neurophysiological approaches in the study of learning. Physiol. Rev. 48, 65–135 (1968)Google Scholar
  9. Khazan, N.: Electrophysiological correlates of the action of drugs in the brain. In: An introduction to psychopharmacology, R. H. Rech and K. E. Moore, eds., pp. 175–211 New York: Raven Press 1971Google Scholar
  10. Killam, E. K.: Drug action on the brainstem reticular formation. Pharmacol. Rev. 14, 175–223 (1962)Google Scholar
  11. Krug, M., Schmidt, J.: Langdauernde Erregbarkeitsänderungen im sensomotorischen Kortex von Kaninchen nach tetanischer Reizung der Zahnpulpa. Acta biol. med. germ. 34, 135–141 (1975)Google Scholar
  12. Krug, M., Schmidt, J., Kluba, U., Kluba, J.: Der Einfluß von RNS-Präkursoren auf neokortikale Fazilitationsprozesse. 16th Annual Meeting of the GDR Society of Pharmacology and Toxicology, Zinnowitz, September 25–28, 1974Google Scholar
  13. Longo, V., Loizzo, A.: Effects of drugs on the hippocampal θ-rhythm. Possible relationships to learning and memory processes. In. Pharmacology and the Future of Man. Proc. 5th Int. Congress on Pharmacology, San Francisco 1972, Vol. 4, pp 46–54 Basel: Karger 1973Google Scholar
  14. Matthies, H.: The intracellular regulation of the interneuronal connectivity-the molecular foundation of learning processes. Ergebn. exp. Med. 10, 25–55 (1972)Google Scholar
  15. Matthies, H., Lietz, W.: Die Bedeutung der Applikationsart und Applikationsdauer für die Wirkung von Orotsäure auf ein einfaches Modell eines Lernvorganges. Acta biol. med. germ. 19, 1053–1055 (1967)Google Scholar
  16. McGaugh, J. L.: Modification of learning and memory by CNS-stimulants and electrical stimulation of the brain. In: Pharmacology and the future of man. Proc. 5th Int. Congress on Pharmacology, San Francisco 1972, Vol. 4, pp. 39–45, Basel:Karger 1973Google Scholar
  17. McGaugh, J. L., Petrinovich, L. F.: Effects of drugs on learning and memory. Int. Rev. Neurobiol. 8, 139–196 (1965)Google Scholar
  18. Monnier, M., Gangloff, H.: Atlas for stereotaxic brain research on conscious rabbit. Amsterdam-London-New York: Elsevier 1962Google Scholar
  19. Myslivecek, J., Hassmanova, J.: An electrophysiological analysis of action of Pirazetam in rats. Activ. nerv. sup. (Praha) 16, 242–244 (1974)Google Scholar
  20. Ott, T., Lössner, B., Matthies, H.: Die Wirkung von Nucleotid-Monophosphaten auf die Acquisition und Extinktion bedingter Reaktionen. Psychopharmacologia (Berl.) 23, 261–271 (1972)Google Scholar
  21. Ott, T., Matthies, H.: Die Wirkung von Orotsäure auf die durch elektrokonvulsiven Schock ausgelöste retrograde Amnesie. Psychopharmacologia (Berl.) 20, 16–21 (1971)Google Scholar
  22. Ott, T., Matthies, H.: Significance of RNA precursors in the formation and maintenance of long-term memory: Pre- and posttraining hippocampal and cortical applications of RNA precursors. Psychopharmacologia (Berl.) 28, 195–204 (1973)Google Scholar
  23. Roberts, C. A.: Anticonvulsant effects of uridine: Comparative analysis of metrazol and penicillin induced foci. Brain Res. 55, 291–308 (1973)Google Scholar
  24. Rüthrich, H.-L., Pohle, W., Matthies H.: Increase of guanosine incorporation into RNA of hippocampal neurones by application of uridine monophosphate during a learning experiment. Brain Res. 69, 49–55 (1974)Google Scholar
  25. Schmidt, J. Guhlke, I.: Die Beeinflussung kortikaler Fazilitations-und Depressionsvorgänge durch Strychnin, Pikrotoxin und Pentetrazol. Acta biol. med. germ. 23, 659–668 (1969)Google Scholar
  26. Schmidt, J., Kluba, J., Kluba, U. Der Einfluß von Orotsäure auf durch exterozeptive Reize ausgelöste kortikale Potentiale. Acta biol. med. germ. 33, 211–222 (1974)Google Scholar
  27. Schulzeck, S., Popov, N., Kammerer, E., Matthies, H.: Die Verteilung der Orotsäure in einigen Organen der Ratte. Ergebn. exp. Med. 3, 295–298 (1970)Google Scholar
  28. Suria, A., Costa, E.: Benzodiazepines and posttetanic potentiation in sympathetic ganglia of the bullfrog. Brain Res. 50, 235–239 (1973)Google Scholar
  29. Valdman, A. V.: Pharmacology of the brain. Progr. Brain Res. 20, 1–92 (1967)Google Scholar

Copyright information

© Springer-Verlag 1977

Authors and Affiliations

  • M. Krug
    • 1
  • T. Ott
    • 1
  • Karin Schulzeck
    • 1
  • H. Matthies
    • 1
  1. 1.Institut für Pharmakologie und ToxikologieMedizinische Akademie MagdeburgMagdeburgGerman Democratic Republic

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