Persistent anxiety-like behavior in marmosets following a recent predatory stress condition: Reversal by diazepam

• Published in: Pharmacology, biochemistry and behavior biochemistry and behavior, 2007-04, Vol.86 (4), p.705-711
• Main Authors: Barros, Marilia, Giorgetti, Marco, Souto, Anna América Vieira, Vilela, Gabriela, Santos, Katarina, Boas, Naiá Vilas, Tomaz, Carlos
• Format: Article
• Language: English
• Subjects: Animals; Anti-Anxiety Agents - pharmacology; Anxiety; Anxiety - drug therapy; Behavior, Animal - drug effects; Biological and medical sciences; Callithrix; Callithrix - psychology; Callithrix penicillata; Defensive behavior; Diazepam; Diazepam - pharmacology; Fear; Fear - drug effects; Female; Habituation, Psychophysiologic; Male; Marmosets; Maze Learning; Medical sciences; Neuropharmacology; Pharmacology. Drug treatments; Predatory Behavior; Predatory stress; Primates; Psycholeptics: tranquillizer, neuroleptic; Psychology. Psychoanalysis. Psychiatry; Psychopharmacology; Stress, Psychological
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/j.pbb.2007.02.016

Initial investigations indicated the use of the Marmoset Predator Confrontation Test (MPCT) as an experimental procedure to measure fear/anxiety-related behaviors in non-human primates. However, possible long-term habituation effects and re-use of experimental subjects need to be verified. This study, therefore, compared the behavioral response of experienced versus naïve adult black tufted-ear marmosets ( Callithrix penicillata) in the MPCT, with/without diazepam administrations. Subjects were tested in the figure-8 maze and confronted with a taxidermized wild-cat predator stimulus. After four initial 20-min maze habituation sessions, each subject was submitted to two randomly-assigned 20-min predator confrontation sessions: vehicle and 2 mg/kg of diazepam. Confrontation with the predator induced significant behavioral changes; i.e., proximic avoidance and tsik-tsik alarm call. Diazepam administration, concomitant to predator exposure, reversed the behavioral changes observed. In both the experienced and naïve marmosets a similar behavioral profile and response pattern to diazepam was detected, corroborating the important selective pressure that felines seem to have on marmoset behavioral ecology. Therefore, during a more naturalistic-like regimen — i.e., recurring intermittent predator encounters — the general response pattern remains highly consistent, regardless of prior experience. One may consider the re-use of marmoset subjects in the MPCT, particularly under these specific conditions (i.e. repeated 20-min confrontations, 72-h apart).