Atropine disrupts passive avoidance learning in young chicks

Abstract

Four-day-old Vantress × Arbor Acre chicks were first trained to key-peck for heat reinforcement and then tested for passive avoidance learning following an intraperitoneal injection of atropine sulfate or saline. Chicks injected with 1.0 mg/kg of atropine responded more quickly than saline-injected chicks when their key-peck responses were punished with aversive wing-shocks. These findings, therefore, are consistent with the view that cholinergic mechanisms are involved in inhibitory behavior in the young domestic chick.