Central L-cysteine induces sleep, and D-cysteine induces sleep and abnormal behavior during acute stress in neonatal chicks.
L-cysteine (L-Cys) is a non-essential and glycogenic amino acid. Previously, we reported that the intracerebroventricular (i.c.v.) injection of L-Cys induced sedative effects under isolation-induced stress in neonatal chicks. L-Cys has an optical isomer, D-Cys. The aim of this study was to clarify the effect of L-Cys and D-Cys during a stressful condition in chicks. The i.c.v. injection of L-Cys and D-Cys (0.84 micromol) decreased both distress vocalization and spontaneous activity induced by isolation. However, the two cysteine isomers induced different behaviors. L-Cys increased sleep-like behavior while D-Cys caused abnormal behavior including syncope as well as sleep-like behavior. In conclusion, while both L-Cys and D-Cys caused a sedative effect when injected i.c.v, D-Cys caused abnormal behavior and may be detrimental to neonatal chicks.
Yamane
Haruka
H
Laboratory of Advanced Animal and Marine Bioresources, Graduate School of Bioresources and Bioenvironmental Sciences, Kyushu University, Higashi, Fukuoka, Japan.
Asechi
Mari
M
Tsuneyoshi
Yousuke
Y
Denbow
D Michael
DM
Furuse
Mitsuhiro
M
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001522:Behavior, Animal / Q000187:drug effects*; D002645:Chickens / Q000502:physiology*; D003545:Cysteine / Q000494:pharmacology*; D012890:Sleep / Q000187:drug effects*; D013237:Stereoisomerism; D013315:Stress, Psychological / Q000503:physiopathology*
D003545:Cysteine