Diphenyl diselenide induces anxiolytic-like and sedative effects on the chick social separation-stress behavior

► (PhSe) 2 attenuated spontaneous activity, number of vocalizations and jumps in chicks. ► At the dose of 10 mg/kg, (PhSe) 2 caused an anxiolytic-like effect in chicks. ► Anxiolytic-like and sedative effects were observed in chicks treated with (PhSe) 2 50 mg/kg. The purpose of this research was to investigate the anxiolytic-like effect of diphenyl diselenide [(PhSe) 2] on the chick social separation-stress behavior. Male chicks (six day-old) received, per oral route, a single administration of (PhSe) 2 at doses of 1, 10 and 50 mg/kg. Thirty minutes after treatment, chicks were submitted to the behavioral tests. The behavioral tests: number of separation-induced distress vocalizations and jumps, time of active wakefulness, time of standing/sitting motionless with eyes open, time of standing motionless with eyes closed and time of sleeping posture, during 10 min, were recorded. (PhSe) 2 at doses of 10 and 50 mg/kg reduced the number of vocalizations and jumps and the time of active wakefulness and increased the time of standing/sitting motionless with eyes open of chicks. The sleeping posture time was increased in animals treated with (PhSe) 2 at the dose of 50 mg/kg. In conclusion, treatment with (PhSe) 2, in a dose dependent-manner, caused anxiolytic-like and sedative effects in chicks.