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Related Concept Videos

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Desensitization and Tachyphylaxis

Tachyphylaxis is described as a rapid decrease in response to a drug after repeated or continuous administration of the same drug dose. It is a phenomenon where the body becomes less responsive to a particular substance or intervention over time, requiring higher doses or stronger interventions to achieve the same effect. It results from adaptive changes in the body's receptors, signaling pathways, or physiological processes that occur in response to prolonged exposure to a stimulus.
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Indirect-Acting Cholinergic Agonists: Mechanism of Action01:18

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Classical Conditioning in Daily Life01:17

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Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship01:29

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Related Experiment Video

Updated: May 18, 2026

Extinction Training During the Reconsolidation Window Prevents Recovery of Fear
11:17

Extinction Training During the Reconsolidation Window Prevents Recovery of Fear

Published on: August 24, 2012

Cholinergic blockade frees fear extinction from its contextual dependency.

Moriel Zelikowsky1, Timothy A Hast, Rebecca Z Bennett

  • 1Departments of Psychology and Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.

Biological Psychiatry
|September 18, 2012
PubMed
Summary

Low doses of scopolamine (Scop) administered systemically during extinction training can reduce fear renewal by disrupting contextual processing. This finding suggests Scop may enhance exposure therapy by improving relapse resistance.

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Last Updated: May 18, 2026

Extinction Training During the Reconsolidation Window Prevents Recovery of Fear
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09:26

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Area of Science:

  • Neuroscience
  • Pharmacology
  • Behavioral Psychology

Background:

  • Extinction training reduces maladaptive fears but is context-sensitive, leading to fear renewal.
  • The hippocampus is crucial for contextualizing fear extinction.
  • Systemic scopolamine (Scop) can block contextual fear conditioning.

Purpose of the Study:

  • To investigate if noninvasive systemic scopolamine can block the contextualization of fear extinction.
  • To assess the effects of low-dose scopolamine on fear renewal after extinction training.

Main Methods:

  • Rats underwent tone fear conditioning and extinction with systemic scopolamine or saline.
  • Fear renewal was tested in the same or a shifted context off-drug.
  • Various doses of scopolamine were administered during extinction training.

Main Results:

  • Low-dose scopolamine significantly attenuated fear renewal in both same and novel contexts.
  • Scopolamine slowed long-term extinction memory formation, which was overcome by extended training.
  • The drug was effective only when administered during, not after, extinction.

Conclusions:

  • Disrupting contextual processing with scopolamine during extinction blocks subsequent fear renewal.
  • Low-dose scopolamine shows potential as a clinical adjunct to exposure therapy for reducing relapse.