Prior cocaine exposure disrupts extinction of fear conditioning

  1. Kathryn A. Burke1,2,
  2. Theresa M. Franz2,
  3. Nishan Gugsa4, and
  4. Geoffrey Schoenbaum2,3,4,5
  1. 1 Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21230, USA;
  2. 2 Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21230, USA;
  3. 3 Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland 21230, USA;
  4. 4 Department of Psychology, University of Maryland, Baltimore County, Maryland 21230, USA

Abstract

Psychostimulant exposure has been shown to cause molecular and cellular changes in prefrontal cortex. It has been hypothesized that these drug-induced changes might affect the operation of prefrontal-limbic circuits, disrupting their normal role in controlling behavior and thereby leading to compulsive drug-seeking. To test this hypothesis, we tested cocaine-treated rats in a fear conditioning, inflation, and extinction task, known to depend on medial prefrontal cortex and amygdala. Cocaine-treated rats conditioned and inflated similar to saline controls but displayed slower extinction learning. These results support the hypothesis that control processes in the medial prefrontal cortex are impaired by cocaine exposure.

Footnotes

  • 5 Corresponding author.

    5 E-mail schoenbg{at}schoenbaumlab.org; fax (410) 706-2512.

  • Article published online before print. Article and publication date are at http://www.learnmem.org/cgi/doi/10.1101/lm.216206

    • Received February 7, 2006.
    • Accepted April 4, 2006.
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