Induction and Expression of Fear Sensitization Caused by Acute Traumatic Stress.
Fear promotes adaptive responses to threats. However, when the level of fear is not proportional to the level of threat, maladaptive fear-related behaviors characteristic of anxiety disorders result. Post-traumatic stress disorder develops in response to a traumatic event, and patients often show sensitized reactions to mild stressors associated with the trauma. Stress-enhanced fear learning (SEFL) is a rodent model of this sensitized responding, in which exposure to a 15-shock stressor nonassociatively enhances subsequent fear conditioning training with only a single trial. We examined the role of corticosterone (CORT) in SEFL. Administration of the CORT synthesis blocker metyrapone prior to the stressor, but not at time points after, attenuated SEFL. Moreover, CORT co-administered with metyrapone rescued SEFL. However, CORT alone without the stressor was not sufficient to produce SEFL. In these same animals, we then looked for correlates of SEFL in terms of changes in excitatory receptor expression. Western blot analysis of the basolateral amygdala (BLA) revealed an increase in the GluA1 AMPA receptor subunit that correlated with SEFL. Thus, CORT is permissive to trauma-induced changes in BLA function.
Department of Psychology, University of California at Los Angeles, Los Angeles, CA, USA.
Jennifer N
JN
Perusini
Division of Oral Biology & Medicine, School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA.
Edward M
EM
Meyer
Department of Psychology, University of California at Los Angeles, Los Angeles, CA, USA.
Virginia A
VA
Long
Department of Psychology, University of California at Los Angeles, Los Angeles, CA, USA.
Vinuta
V
Rau
Department of Psychology, University of California at Los Angeles, Los Angeles, CA, USA.
Nathaniel
N
Nocera
Department of Psychology, University of California at Los Angeles, Los Angeles, CA, USA.
Jacob
J
Avershal
Division of Oral Biology & Medicine, School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA.
James
J
Maksymetz
Division of Oral Biology & Medicine, School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA.
Igor
I
Spigelman
Department of Psychology, University of California at Los Angeles, Los Angeles, CA, USA.|Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, CA, USA.
Michael S
MS
Fanselow
D000208:Acute Disease; D000818:Animals; D066272:Basolateral Nuclear Complex / Q000378:metabolism* / Q000473:pathology; D003345:Corticosterone / Q000378:metabolism; D005239:Fear / Q000502:physiology* / Q000523:psychology; D006801:Humans; D013313:Stress Disorders, Post-Traumatic / Q000378:metabolism* / Q000473:pathology / Q000523:psychology; D013315:Stress, Psychological / Q000378:metabolism / Q000473:pathology / Q000523:psychology
D003345:Corticosterone