Abstract
Diazepam (0.3, 0.6, 1.2, or 2.5 mg/kg) produced a dose-dependent reduction of the potentiated startle effect where acoustic startle amplitude is normally increased in the presence of a light previously paired with a shock. Even the lowest dose tested (0.3 mg/kg) significantly attenuated potentiated startle. The effect was selective since the same doses did not depress baseline startle amplitude measured in the same animals in the same test session. A 2×2 design in which rats were trained and tested under the same or different drug condition (diazepam or saline) showed the results could not be explained by state-dependent learning. The primary effect of diazepam was to block expression of rather than acquisition of fear as measured by potentiated startle. Flurazepam (2.5, 10, or 20 mg/kg) also reduced potentiated startle selectively but was 6–8 times less potent than diazepam. These and other results suggest that the potentiated startle paradigm, as a measure of classical conditioning that involves no operant, might provide a useful adjunct to behavioral methods currently being used to analyze antianxiety compounds.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Anderson, D. C., Johnson, D., Kemptom, H.: Second order fear conditioning as revealed through augmentation of a startle response: Part I. Psychon. Sci. 16, 5–7 (1969)
Bridger, W. H., Mandel, I. J.: The effects of dimethoxyphenylethylamine and mescaline on classical conditioning in rats as measured by the potentiated startle response. Life. Sci. 6, 775–781 (1967)
Brown, J. S., Kalish, H. I., Farber, I. E.: Conditional fear as revealed by magnitude of startle response to an auditory stimulus. J. Exp. Psychol. 41, 317–327 (1951)
Chalmers, D. V., Hofh, J. C., Levine, S.: The effects of prior shock stimulation on the behavioral and physiological responses to intense acoustic stimuli. Physiol. Behav. 12, 711–718 (1974)
Chi, C. C.: The effect of amobarbital sodium on conditional fear as measured by the potentiated startle response in rats. Psychopharmacologia. 7, 115–122 (1965)
Cook, L., Sepinwall, J.: Behavioral analysis of the effects and mechanisms of action of benzodiazepines. In: Mechanism of action of benzodiazepines, E. Costa and P. Greengard, eds., pp. 1–28. New York: Raven Press 1975
Davis, M., Astrachan, D. I.: Conditioned fear and startle magnitude: Effects of different footshock and backshock intensities in training. J. Exp. Psychol.: Anim. Behav. Proc. 4, 95–108 (1978)
Davis, M., Wagner, A. R.: Startle responsiveness following habituation to different intensities of tone. Psychon. Sci. 12, 337–338 (1968)
Galvani, P. F.: Air-puff-elicited startle: Habituation over trials and measurement of a hypothetical emotional response. Behav. Res. Meth. Instrum. 2, 232–233 (1970)
Goodman, L. S., Gilman, A.: The pharmacological basis of therapeutics. New York: The MacMillan Co. 1973
Gray, J. A.: Drug effects on fear and frustration: Possible limbic site of action of minor tranquilizers. In: Handbook of psychopharmacology, L. L. Iverson, S. D. Iverson, and S. H. Synder, eds., vol. 8, pp. 433–529. New York: Plenum Press 1977
Kurtz, K. H., Siegel, A.: Conditional fear and magnitude of startle response: A replication and extension. J. Comp. Physiol. Psychol. 62, 8–14 (1966)
Miller, N. E., Barry, H. III.: Motivational effects of drugs: methods which illustrate some general problems in psychopharmacology. Psychopharmacologia 1, 169–199 (1960)
Overton, D. A.: Dissociated learning in drug states (state-dependent learning). In: D. H. Efron et al., eds., Psychopharmacology: A review of progress 1957–1967. U.S. Public Health Service Publication No. 1836, U.S. Govt. Printing Office, Washington, D.C. pp. 918–930, 1968
Overton, D. H.: Experimental methods for the study of state-dependent learning. Fed. Proc. 33, 1800–1813 (1974)
Wagner, A. R., Siegel, L. S., Fein, G. S.: Extinction of conditioned fear as a function of percentage of reinforcement. J. Comp. Physiol. Psychol. 63, 160–164 (1967)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Davis, M. Diazepam and flurazepam: Effects on conditioned fear as measured with the potentiated startle paradigm. Psychopharmacology 62, 1–7 (1979). https://doi.org/10.1007/BF00426027
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00426027