The Significance of Exogenous and Endogenous Factors in the Hereditary Differences in Learning Ability of Rats

  • H. Müller-Calgan
  • E. Schorscher


Rats from the strain Wistar/WU/Ivanovas were trained to jump over a hurdle to avoid an electric shock. Learning experiments performed on rats selected for good (GL) and bad (BL) learning, (plus unselected control groups), yielded the following results:
  1. 1.

    F7 – F14 BL no longer react to the selection bias and the corresponding GL react only very feebly.

  2. 2.

    In comparison with the F1 and F2 generations of GL and BL the variability decreases. The animals become less sensitive to exogenous factors.

  3. 3.

    Details are given on exogenous (and endogenous) factors with or without influence on the learning results.



Avoidance Conditioning Avoidance Training Relative Frequency Distribution Ditioned Stimulus Cage Population 
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  1. La Barba, R. C., and J. L. White: Litter size variations and emotional reactivity in Balb/c mice. J. comp. phys. Psychol. 75, 254–257 (1971).CrossRefGoogle Scholar
  2. Barry, H. and J. P. Buckley: Drug effects on animal performance and the stress syndrome. J. Pharmac. Sci. 55, 1159–1183 (1966).CrossRefGoogle Scholar
  3. Bell, R. W., C. E. Miller, and J. M. Ordy: Effects of population density and living space upon neuroanatomy, neurochemistry, and behavior in the C57B1/10 mouse. J. comp. phys. Psychol. 75, 258–263 (1971).CrossRefGoogle Scholar
  4. Booth, D. A.: Neurochemical changes correlated with learning and memory retention. In: Molecular Mechanisms in Memory and Learning (G. Ungar, ed.), pp. 54–55, Plenum Press, New York (1970).Google Scholar
  5. Bovet, D., and G. L. Gatti: Pharmacology of instrumental avoidance conditioning. In: Pharmacology of Conditioning Learning and Retention, M. Ya. Mikhelson and V. G. Longo, eds.), pp. 75–89, Pergamon Press Ltd., Czechosl. Med. Press, Praha (1965).Google Scholar
  6. Broadhurst, P. L.: Experiments in psychogenetics. In: Experiments in Personality (H. J. Eysenck, ed.), Vol. I: Psychogenetics and Psychopharmacology, pp. 3–102, Routledge and Kegan Paul, London (1960).Google Scholar
  7. Correll, W.: Lernpsychologie. Grundfragen und pädagogische Konsequenzen, 8. Auflage, Verlag Ludwig Auer, Donauwörth (1970).Google Scholar
  8. Campbell, B. A., and J. M. Bloom: Relative aversiveness of noise and shock. J. comp. physiol. Psychol. 60, 440–442 (1965).CrossRefGoogle Scholar
  9. Chocholova, L.: The reactibility of rats with defined susceptibility to an acoustic epileptogenic stimulus, to some acoustic and optic stimuli. Physiol, bohemoslov. 15, 337–343 (1966).Google Scholar
  10. Doty, B. A., and L. A. Doty: Effect of age and chlorpromazine on memory consolidation. J. comp. physiol. Psychol. 57, 331–334 (1964).CrossRefGoogle Scholar
  11. Dye, C. J.: Effectsof interruptions of initial learning upon retention in young, mature and old rats. J. Geront. 24, 12–17 (1969).Google Scholar
  12. Feigley, D. A., and N. E. Spear: Effect of age and punishment condition on long-term retention by the rat of active- and passive-avoidance learning. J. comp. physiol. Psychol. 73, 515–526 (1970).CrossRefGoogle Scholar
  13. Glick, St.: Pharmacological, surgical and environmental influences upon arousal and learning. Yeshiva University, Univ. Microfilsm, Inc. Ann Arbor, Mich. Nr. 70–1457, Ph.D. (1969).Google Scholar
  14. Goodrick, Ch. L.: Learning, retention, and extinction of a complex maze habit for mature-young and senescent Wistar albino rats. J. of Gerontol. 23, 298–304 (1968).Google Scholar
  15. Jay, G. E.: Genetic strains and stocks. In: Methodology in Mammalian Genetics ( W. J. Burdette, ed.), Holden-Day, San Francisco (1963).Google Scholar
  16. Latane, B., Social deprivation, housing density and gregariousness in rats. J. comp. phys. Psychol. 70, 221–227 (1970).CrossRefGoogle Scholar
  17. Lindzey, G., and H. Winston: Maze learning and effects of pretraining in inbred strains of mice. J. comp. phys. Psychol. 55, 748–752 (1962).CrossRefGoogle Scholar
  18. Müller-Calgan, H.: Einige verhaltensphysiologische Grundlagen des Lernens und Gedächtnisses. Interne Symposia, E. Merck, Mai 1970 und Januar 1971.Google Scholar
  19. Müller-Calgan, H.: A model for inherited learning in the rat. Z. Versuchstierk. (in prep. ) 1973.Google Scholar
  20. Müller-Calgan, H.: Does active 2-way avoidance learning (jumping a hurdle) mean pure avoidance learning or conditioned fear and/or conditioned social response to the experimentator? In prep.Google Scholar
  21. De Nelsky, G. Y., and V. H. Denenberg, Infantile stimulation and adult exploratory behaviour in the rat. Anim. Behav. 15, 568–573 (1967).CrossRefGoogle Scholar
  22. Rapaport, A., et F. Bourliere: La facilitation sociale de l’apprentissage d’une tache operationelle chezle rat age. Gerontologia 12, 74–78 (1966).CrossRefGoogle Scholar
  23. Reynierse, J. H.: Differences in emotionality and avoidance in two stocks of rats. J. comp, physiol. Psychol. 72, 233–237 (1970).CrossRefGoogle Scholar
  24. Rosenzweig, M. R., W. Love, and E. L. Bennett: Enriched experience for two hours a day alters brain chemistry and anatomy in rats. Fed. Proc. 27, 2 (1968).Google Scholar
  25. Schreiber, R. A.: Effect of housing density on the incidence of audiogenic seizures in DBA/2 J mice. J. comp, physiol. Psychol. 76, 300–304 (1971).CrossRefGoogle Scholar
  26. Verzar, E. J., and B. Mcdougall: Studies in learning and memory in ageing rats. Gerontologia 1, 65–85 (1957).CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1973

Authors and Affiliations

  • H. Müller-Calgan
    • 1
  • E. Schorscher
    • 1
  1. 1.Department of Pharmacology Medical Research DivisionE. MerckDarmstadtW. Germany

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