Ethopharmacological analysis of the open elevated plus-maze in mice

Author(s)

Sorregotti, Tatiani ^{[1, 2]} ; Mendes-Gomes, Joyce ^[1] ; Rico, Javier Leonardo ^{[1, 3]} ; Rodgers, Robert John ^[4] ; Nunes-de-Souza, Ricardo Luiz ^{[1, 2, 5]}

Affiliation

^[1] Univ Estadual Paulista, UNESP, Sch Pharmaceut Sci, Pharmacol Lab, BR-14801902 Araraquara, SP - Brazil

^[2] UFSCar UNESP, Joint Grad Program Physiol Sci, BR-13565905 Sao Carlos, SP - Brazil

^[3] Fdn Univ Konrad Lorenz, Lab Anim Behav, Bogota - Colombia

^[4] Univ Leeds, Inst Psychol Sci, Behav Neurosci Lab, Leeds, W Yorkshire - England

^[5] Univ Sao Paulo, Inst Neurosci & Behav IneC, BR-14040901 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Behavioural Brain Research; v. 246, n. 1, p. 76-85, JUN 1 2013.
• Web of Science Citations: 19

Abstract

Exposure of rodents to an open elevated plus-maze (oEPM) elicits antinociception and increases plasma corticosterone levels. However, no studies have yet assessed the defensive behaviour repertoire of animals in this modified test. In Experiment 1, factor analysis was employed to characterise the behavioural profile of mice exposed to the oEPM. Experiments 2 and 3 assessed the effects of acute alprazolam (0.5-1.5 mg/kg; diazepam 0.5-1.5 mg/kg), pentylenetetrazole (10.0-30.0 mg/kg), yohimbine (2.0-6.0 mg/kg), mCPP (0.3-3.0 mg/kg), and acute and chronic fluoxetine (10.0-30.0 mg/kg) and imipramine (1.0-15.0 mg/kg) on behaviours identified in Experiment 1. The factor analyses revealed that behaviour in the oEPM can largely (77% total variance) be accounted for in terms of 3 factors: factor 1 ('depth exploration'; e.g. head-dipping on the arms), factor 2 ('cautious exploration of arms'; e.g. flat-back approach), and factor 3 ('risk assessment'; stretched attend postures - SAP). Experiments 2 and 3 showed that, over the dose range used, alprazolam selectively attenuated all measures of defensiveness. Similar, though more modest, effects were seen with diazepam. Confirming the intensity of the emotional response to the oEPM (nociceptive, endocrine and behavioural), relatively few significant behavioural changes were seen in response to the anxiogenic compounds tested. Although acute fluoxetine or imipramine treatment failed to modify behaviour in the oEPM, chronic fluoxetine (but not chronic imipramine) attenuated total flat back approach and increased head dipping outside the central square. Together, the results indicate that the oEPM induces behavioural defensive responses that are sensitive to alprazolam and chronic fluoxetine. (C) 2013 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 10/13441-7 - Ethopharmacological analysis of an open elevated plus-maze to evaluate defensive behaviors and fear-induced antinociception in mice
• Grantee: Tatiani Sorregotti
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 05/01988-3 - Role of dorsal and ventrolateral portions of the periaqueductal gray in the modulation of defensive behaviors and antinociception induced by aversive situations in mice
• Grantee: Joyce Mendes Gomes Tessari
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)