Regulation of Cholinergic Activity in the Rat Hippocampus: InVivo Effects of Oxotremorine and Fenfluramine

  • H. Ladinsky
  • S. Consolo
  • A. S. Tirelli
  • G. L. Forloni
  • M. Segal
Part of the Advances in Behavioral Biology book series (ABBI, volume 25)


Oxotremorine (OTMN) is a powerful muscarinic receptor agonist whose profound effects on cholinergic neurons of the hippocampus have been particularly well characterized. The drug increases the content and decreases the turnover (TRACh) and release of acetylcholine (ACh). In addition, it depresses the sodium dependent high affinity uptake of choline (SDHACU) into the cholinergic terminals (see Table 1). The biochemical effects are indicative of a depressant action of OTMN dn cholinergic neurons. It is implicit that when the muscarinic receptor sites are occupied by this agonist the regulatory mechanism of ACh synthesis receives a signal to slow down its activity. The location of the sites at which the signal starts is a matter of controversy at the moment. OTMN acts directly on muscarinic receptors which may be located either on the presynaptic cholinergic terminals as suggested by Szerb et al. (23) or postsynaptically on non-cholinergic neurons, and thereby operates through a neuronal feedback loop. The latter hypothesis appears more likely since it has been found that reserpine, as well as atropine blocked the effect of OTMN on whole brain (3) and striatal (24) ACh content.


Muscarinic Receptor Cholinergic Neuron Kainic Acid Serotonergic Neuron Noradrenergic Neuron 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Atweh, S., Simon, J.R. and Kuhar, M.J. (1975): Life Sci. 17:1535–1544.CrossRefGoogle Scholar
  2. 2.
    Corrodi, H., Fuxe, K., Hammer, W., Sjoqvist, F. and Ungerstedt, U. (1967): Life Sci. 6:2557–2566.CrossRefGoogle Scholar
  3. 3.
    Cox, B. and Potkonjak, D. (1970): Brit. J. Pharmacol. 38:171–180.CrossRefGoogle Scholar
  4. 4.
    Euvrard, C., Javoy, F., Herbert, A. and Glowinski, J. (1977): Eur. J. Pharmacol. 41:281–289.CrossRefGoogle Scholar
  5. 5.
    Frankhuyzen, A.L. and Mulder, A.H. (1980): Eur. J. Pharmacol. (1980): Eur. J. Pharmacol. 63:179–182.CrossRefGoogle Scholar
  6. 6.
    Glisson, S.N., Karczmar, A.G. and Barnes, L. (1972): Neuropharmacology 11:465–477.CrossRefGoogle Scholar
  7. 7.
    Hadhazy, P. and Szerb, J.C. (1977): Brain Res. 123:311–322.CrossRefGoogle Scholar
  8. 8.
    Jaim-Etdheverry, G. and Zieher, L.M. (1980): Brain Res. 188:513–523.CrossRefGoogle Scholar
  9. 9.
    Jonsson, G., Ponzio, F. and Ross, S. (1978): IN Abstracts Seventh International Congress of Pharmacology (IUPHAR) (eds) J.R. Boissier and P. Lechat, Pergamon Press, Oxford, p. 926.Google Scholar
  10. 10.
    Keller, R., Oke, A., Mefford, I. and Adams, R.N. (1976): Life Sci. 19:995–1004.CrossRefGoogle Scholar
  11. 11.
    Kostowski, W., Samanin, R., Bareggi, S.R., Marc, V. Garattini, S. and Valzelli, L. (1974): Brain Res. 82:178–182.CrossRefGoogle Scholar
  12. 12.
    Ladinsky, H., Consolo, S., Bianchi, S. and Jori, A. (1976): Brain Res. 108:351–361.CrossRefGoogle Scholar
  13. 13.
    Ladinsky, H., Consolo, S., Tirelli, A.S. and Forloni, G.L. (1980): Brain Res. 187:494–498.CrossRefGoogle Scholar
  14. 14.
    Lindvall, O. and Bjorklund, A. (1974): Acta Physiol. Scand. Suppl. 412:1–48.Google Scholar
  15. 15.
    Paalzow, G. and Paalzow, L. (1975): Eur. J. Pharmacol. 31:261–272.CrossRefGoogle Scholar
  16. 16.
    Ponzio, F. and Jonsson, G. (1979): J. Neurochem. 32:129–132.CrossRefGoogle Scholar
  17. 17.
    Racagni, G., Cheney, D.L., Trabucchi, M., Wang, C. and Costa, E. (1974): Life Sci. L5:1961–1975.CrossRefGoogle Scholar
  18. 18.
    Rommelspacher, H. and Kuhar, M.J. (1975): N.-S. Arch. Pharmacol. 291:17–21.CrossRefGoogle Scholar
  19. 19.
    Ross, S.B. (1976): Brit. J. Pharmacol. 513:521–527.CrossRefGoogle Scholar
  20. 20.
    Saelens, J.K., Allen, M.P. and Simke, J.P. (1970): Arch. Int. Pharmacodyn. 186:279–286.Google Scholar
  21. 21.
    Samanin, R., Quattrone, A., Peri, G., Ladinsky, H. and Consolo, S. (1978): Brain Res. 151:73–82.CrossRefGoogle Scholar
  22. 22.
    Sehwarcz, R., Zaczek, R. and Coyle, J.T. (1978): Eur. J. Pharmacol. 50:209–220.CrossRefGoogle Scholar
  23. 23.
    Szerb, J.C., Hadhazy, P. and Dudar, J.D. (1977): Brain Res. 128:285–291.CrossRefGoogle Scholar
  24. 24.
    Tirelli, A., Forloni, G., Consolo, S. and Ladinsky, H. (1978): IN Abstracts of the XIX Congress Italian Pharmacological Society Meeting, Abst. No.92, p. 415.Google Scholar
  25. 25.
    Westfall, T.C. (1974): Life Sci. 14:1641–1652.CrossRefGoogle Scholar
  26. 26.
    Yamamura, H.I. and Snyder, S.H. (1974): Brain Res. 78:320–326.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1981

Authors and Affiliations

  • H. Ladinsky
    • 1
  • S. Consolo
    • 1
  • A. S. Tirelli
    • 1
  • G. L. Forloni
    • 1
  • M. Segal
    • 2
  1. 1.Istituto di Ricerche Farmacologiche Mario NegriMilanItaly
  2. 2.Isotope DepartmentThe Weizmann Institute of ScienceRehovotIsrael

Personalised recommendations