title: Ethopharmacological evaluation of the rat exposure test: a prey-predator interaction test.
abstract: The rat exposure test (RET) is a prey (mouse)-predator (rat) situation that activates brain defensive areas and elicits hormonal and defensive behavior in the mouse. Here, we investigated possible correlations between the spatiotemporal [time spent in protected (home chamber and tunnel) and unprotected (surface) compartments and frequency of entries into the three compartments] and ethological [e.g., duration of protected and unprotected stretched-attend postures (SAP), duration of contact with the rat's compartment] measures (Experiment 1). Secondly, we investigated the effects of systemic treatment with pro- or anti-aversive drugs on the behavior that emerged from the factor analysis (Experiment 2). The effects of chronic (21 days) imipramine and fluoxetine on defensive behavior were also investigated (Experiment 3). Exp. 1 revealed that the time in the protected compartment, protected SAP and rat contacts loaded on factor 1 (defensive behavior), while the total entries and unprotected SAP loaded on factor 2 (locomotor activity). Exp. 2 showed that alprazolam (but not diazepam) selectively changed the defensive factor. Caffeine produced a mild proaversive-like effect, whereas yohimbine only decreased locomotor activity (total entries). Fluoxetine (but not imipramine) produced a weak proaversive-like effect. 5-HT(1A)/5-HT(2) receptor ligands did not change any behavioral measure. In Exp. 3, chronic fluoxetine (but not imipramine) attenuated the defensive behavior factor without changing locomotion. Given that the defensive factor was sensitive to drugs known to attenuate (alprazolam and chronic fluoxetine) and induce (caffeine) panic attack, we suggest the RET as a useful test to assess the effects of panicolytic and panicogenic drugs.
authors.affiliation: Laboratory of Pharmacology, School of Pharmaceutical Sciences, Universidade Estadual Paulista, UNESP, Araraquara, SP 14801-902, Brazil.
authors.forename: Kelciane Ferreira Caetano
authors.initials: KF
authors.lastname: Campos
authors.forename: Vanessa Cristiane Santana
authors.initials: VC
authors.lastname: Amaral
authors.forename: Javier Leonardo
authors.initials: JL
authors.lastname: Rico
authors.forename: Tarciso Tadeu
authors.initials: TT
authors.lastname: Miguel
authors.forename: Ricardo Luiz
authors.initials: RL
authors.lastname: Nunes-de-Souza
mesh_terms: D058669:Adrenergic alpha-2 Receptor Antagonists / Q000494:pharmacology*; D000525:Alprazolam / Q000494:pharmacology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D000928:Antidepressive Agents / Q000494:pharmacology*; D002110:Caffeine / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003975:Diazepam / Q000494:pharmacology; D004924:Escape Reaction / Q000187:drug effects*; D005163:Factor Analysis, Statistical; D005473:Fluoxetine / Q000494:pharmacology; D020387:Food Chain; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D011187:Posture; D011235:Predatory Behavior / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D013997:Time Factors; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D058669:Adrenergic alpha-2 Receptor Antagonists; D014151:Anti-Anxiety Agents; D000928:Antidepressive Agents; D000697:Central Nervous System Stimulants; D005473:Fluoxetine; D015016:Yohimbine; D002110:Caffeine; D007099:Imipramine; D003975:Diazepam; D000525:Alprazolam