Intracerebroventricular injection of pipecolic acid inhibits food intake and induces sleeping-like behaviors in the neonatal chick

Abstract

It has been demonstrated that l-pipecolic acid ( l-PA), a major metabolic intermediate of l-Lysine ( l-Lys) in the brain, is involved in the functioning of Γ-aminobutyric acid. In the present work the effect of intracerebroventricular (i.c.v.) administration of l-PA, and its relatives, on food intake and behavior in neonatal chicks was investigated. The i.c.v. injection of 1 mg of l-PA and d-PA significantly inhibited food intake during the 2 h following injection, whereas greater than 2 mg of l-Lys was required to inhibit food intake. In behavioral tests, the i.c.v. injection of l-PA reduced active wakefulness and feeding behavior while inducing sleeping-like behavior in chicks. These results suggest that l-PA has an important role for the regulation of behaviors in the neonatal chick after conversion from l-Lys in the brain.