Differential involvement of amygdaloid CRH system(s) in the salience and valence of the stimuli

Authors

Zul Merali, Aga Khan UniversityFollow
David Michaud, Consumer and Clinical Radiation Protection Bureau, Canada
Judy McIntosh, University of Ottawa, Canada
Pamela Kent, University of Ottawa, Canada
Hymie Anisman, Carleton University, Canada

Document Type

Article

Department

Brain and Mind Institute

Abstract

Anxiety is a heterogeneous term encompassing not only state or trait characteristics but also a wide range of pathologies such as generalized anxiety disorders, phobias, panic and obsessive–compulsive disorders, acute stress disorder, and posttraumatic stress disorder. Given that diverse forms of anxiety exist, numerous animal models have been developed, which are considered to be useful in identifying mechanisms underlying anxiety states. Examples of such animal models include paradigms that assess the behavioral response to neurogenic (or painful stimuli) or psychogenic stressors or to cues that had previously been associated with painful stimuli. The present report presents data regarding the impact of stressors on corticotropin-releasing hormone (CRH), and relates these to changes in anxiety-like states. Specifically, we demonstrate that (1) psychogenic stressors influence the in vivo release of CRH at the central nucleus of the amygdala (CeA); (2) although CRH changes within the CeA are exquisitely sensitive to stressors, they are also elicited by positive stimuli; and (3) while treatment with diazepam attenuates behavioral signs of anxiety, the CRH release associated with a stressor is unaffected by the treatment. The position is offered that although release of CRH within the CeA is increased under stressful conditions, it is not a necessary condition for the consequent behavioral expression of anxiety-like reactions, at least not in minimally threatening situations. We suggest that the CRH responses at the CeA may be involved in a preparatory capacity and, as such, may accompany a range of emotionally significant stimuli, be they appetitive or aversive.

Comments

This work was published before the author joined Aga Khan University.

Publication (Name of Journal)

Progress in Neuro-Psychopharmacology and Biological Psychiatry

Recommended Citation

Merali, Z., Michaud, D., McIntosh, J., Kent, P., Anisman, H. (2003). Differential involvement of amygdaloid CRH system(s) in the salience and valence of the stimuli. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 27(8), 1201-1212.
Available at: https://ecommons.aku.edu/bmi/362