, Volume 100, Issue 2, pp 281–282 | Cite as

One-trial tolerance to the anxiolytic effects of chlordiazepoxide in the plus-maze

  • Sandra E. File
Rapid Communications


Chlordiazepoxide (CDP 7.5 mg/kg) had a significant anxiolytic effect in rats tested on the plus-maze for the first time. On a second trial the control scores did not change, but those of the CDP group did and they no longer differed from controls. Rats previously tested undrugged or after flumazenil (4 mg/kg) also failed to show an anxiolytic response to CDP. Thus this phenomenon of one-trial tolerance depended on prior experience with the plus-maze. It also depended on CDP acting at the benzodiazepine receptors on trial 2, since the joint administration of CDP and flumazenil on trial 2 reversed the phenomenon.

Key words

Learned tolerance Anxiety Benzodiazepines 


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Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • Sandra E. File
    • 1
  1. 1.Psychopharmacology Research Unit, Division of PharmacologyUMDS Guy's HospitalLondonUK

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