Tags

Type your tag names separated by a space and hit enter

Effects of chronic corticosterone and imipramine administration on panic and anxiety-related responses.
Braz J Med Biol Res. 2011 Oct; 44(10):1048-53.BJ

Abstract

It is known that chronic high levels of corticosterone (CORT) enhance aversive responses such as avoidance and contextual freezing. In contrast, chronic CORT does not alter defensive behavior induced by the exposure to a predator odor. Since different defense-related responses have been associated with specific anxiety disorders found in clinical settings, the observation that chronic CORT alters some defensive behaviors but not others might be relevant to the understanding of the neurobiology of anxiety. In the present study, we investigated the effects of chronic CORT administration (through surgical implantation of a 21-day release 200 mg pellet) on avoidance acquisition and escape expression by male Wistar rats (200 g in weight at the beginning of the experiments, N = 6-10/group) tested in the elevated T-maze (ETM). These defensive behaviors have been associated with generalized anxiety and panic disorder, respectively. Since the tricyclic antidepressant imipramine is successfully used to treat both conditions, the effects of combined treatment with chronic imipramine (15 mg, ip) and CORT were also investigated. Results showed that chronic CORT facilitated avoidance performance, an anxiogenic-like effect (P < 0.05), without changing escape responses. Imipramine significantly reversed the anxiogenic effect of CORT (P < 0.05), although the drug did not exhibit anxiolytic effects by itself. Confirming previous observations, imipramine inhibited escape responses, a panicolytic-like effect. Unlike chronic CORT, imipramine also decreased locomotor activity in an open field. These data suggest that chronic CORT specifically altered ETM avoidance, a fact that should be relevant to a better understanding of the physiopathology of generalized anxiety and panic disorder.

Links

FREE Publisher Full Text

Authors+Show Affiliations

Diniz L
Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, SP, Brasil.
Dos Reis BB
No affiliation info available
de Castro GM
No affiliation info available
Medalha CC
No affiliation info available
Viana MB
No affiliation info available

MeSH

AnimalsAntidepressive Agents, TricyclicAnxietyBehavior, AnimalCorticosteroneEscape ReactionImipramineMaleMaze LearningMotor ActivityPanic DisorderRatsRats, Wistar

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

21915474

Citation

Diniz, L, et al. "Effects of Chronic Corticosterone and Imipramine Administration On Panic and Anxiety-related Responses." Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Medicas E Biologicas, vol. 44, no. 10, 2011, pp. 1048-53.
Diniz L, Dos Reis BB, de Castro GM, et al. Effects of chronic corticosterone and imipramine administration on panic and anxiety-related responses. Braz J Med Biol Res. 2011;44(10):1048-53.
Diniz, L., Dos Reis, B. B., de Castro, G. M., Medalha, C. C., & Viana, M. B. (2011). Effects of chronic corticosterone and imipramine administration on panic and anxiety-related responses. Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Medicas E Biologicas, 44(10), 1048-53.
Diniz L, et al. Effects of Chronic Corticosterone and Imipramine Administration On Panic and Anxiety-related Responses. Braz J Med Biol Res. 2011;44(10):1048-53. PubMed PMID: 21915474.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of chronic corticosterone and imipramine administration on panic and anxiety-related responses. AU - Diniz,L, AU - Dos Reis,B B, AU - de Castro,G M, AU - Medalha,C C, AU - Viana,M B, Y1 - 2011/09/09/ PY - 2011/02/18/received PY - 2011/08/23/accepted PY - 2011/9/15/entrez PY - 2011/9/15/pubmed PY - 2012/10/31/medline SP - 1048 EP - 53 JF - Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas JO - Braz J Med Biol Res VL - 44 IS - 10 N2 - It is known that chronic high levels of corticosterone (CORT) enhance aversive responses such as avoidance and contextual freezing. In contrast, chronic CORT does not alter defensive behavior induced by the exposure to a predator odor. Since different defense-related responses have been associated with specific anxiety disorders found in clinical settings, the observation that chronic CORT alters some defensive behaviors but not others might be relevant to the understanding of the neurobiology of anxiety. In the present study, we investigated the effects of chronic CORT administration (through surgical implantation of a 21-day release 200 mg pellet) on avoidance acquisition and escape expression by male Wistar rats (200 g in weight at the beginning of the experiments, N = 6-10/group) tested in the elevated T-maze (ETM). These defensive behaviors have been associated with generalized anxiety and panic disorder, respectively. Since the tricyclic antidepressant imipramine is successfully used to treat both conditions, the effects of combined treatment with chronic imipramine (15 mg, ip) and CORT were also investigated. Results showed that chronic CORT facilitated avoidance performance, an anxiogenic-like effect (P < 0.05), without changing escape responses. Imipramine significantly reversed the anxiogenic effect of CORT (P < 0.05), although the drug did not exhibit anxiolytic effects by itself. Confirming previous observations, imipramine inhibited escape responses, a panicolytic-like effect. Unlike chronic CORT, imipramine also decreased locomotor activity in an open field. These data suggest that chronic CORT specifically altered ETM avoidance, a fact that should be relevant to a better understanding of the physiopathology of generalized anxiety and panic disorder. SN - 1414-431X UR - https://www.unboundmedicine.com/medline/citation/21915474/Effects_of_chronic_corticosterone_and_imipramine_administration_on_panic_and_anxiety_related_responses_ L2 - https://www.scielo.br/scielo.php?script=sci_arttext&amp;pid=S0100-879X2011007500117&amp;lng=en&amp;nrm=iso&amp;tlng=en DB - PRIME DP - Unbound Medicine ER -