Intracerebroventricular administration of GABA-A and GABA-B receptor antagonists attenuate feeding and sleeping-like behavior induced by L-pipecolic acid in neonatal chicks
✍ Scribed by T. Takagi; T. Bungo; T. Tachibana; E-S. Saito; S. Saito; I. Yamasaki; S. Tomonaga; D.M. Denbow; M. Furuse
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 110 KB
- Volume
- 73
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
Abstract
It has been demonstrated that L‐pipecolic acid (L‐PA), a major metabolic intermediate of L‐lysine (L‐Lys) in the mammalian and chicken brain, is involved in the functioning of the GABAergic system. A previous study has shown that intracerebroventricular (i.c.v.) injection of L‐PA suppressed feeding and induced sleep‐like behavior in neonatal chicks; however, the precise relationship between the GABAergic system and L‐PA has not been clarified. In the present study, the role of the GABA‐A or GABA‐B receptors in the suppression of food intake and induction of sleeping‐like behavior by L‐PA was investigated. Chicks were injected i.c.v. with the GABA‐A antagonist picrotoxin or GABA‐B antagonist CGP54626 along with L‐PA. Although suppression of food intake by L‐PA was restored partially by co‐injection with CGP54626, but not picrotoxin, sleep‐like behavior induced by L‐PA was suppressed significantly by both antagonists. These results suggested that L‐PA activated both GABA‐A and GABA‐B receptors, and GABA‐B receptors alone contributed to food intake whereas both receptors contributed to sleep‐like behavior. © 2003 Wiley‐Liss, Inc.