title: Central administration of L- and D-aspartate attenuates stress behaviors by social isolation and CRF in neonatal chicks.
abstract: Intracerebroventricular (i.c.v.) administration of L-aspartate (L-Asp) attenuates stress responses in neonatal chicks, but the mechanism has not been clarified. In the present study, three behavioral experiments were carried out under socially isolated stressful conditions exacerbated by the use of corticotrophin-releasing factor (CRF). In Experiment 1, i.c.v. injection of L-Asp attenuated behavioral stress responses (distress vocalization and active wakefulness) in a dose-dependent manner. Furthermore, L-Asp increased time spent standing/sitting motionless with eyes open and sitting motionless with head dropped (sleeping posture) in comparison with the group receiving CRF alone. In Experiment 2, i.c.v. injection of D-Asp dose-dependently decreased the number of distress vocalizations and the amount of time spent in active wakefulness. D-Asp increased the time spent standing/sitting motionless with eyes open compared with the group receiving CRF alone. In Experiment 3, we directly compared the effect of L-Asp with that of D-Asp. Both L- and D-Asp induced sedative effects under an acutely stressful condition. However, L-Asp, but not D-Asp, increased the time spent in a sleeping posture. These results indicate that both L- and D-Asp, when present in the brain, could induce a sedative effect, while the mechanism for hypnosis in neonatal chicks may be different for L-Asp in comparison with D-Asp.
authors.affiliation: Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Edi
authors.initials: E
authors.lastname: Erwan
authors.forename: Shozo
authors.initials: S
authors.lastname: Tomonaga
authors.forename: Junki
authors.initials: J
authors.lastname: Yoshida
authors.forename: Mao
authors.initials: M
authors.lastname: Nagasawa
authors.forename: Yumi
authors.initials: Y
authors.lastname: Ogino
authors.forename: D Michael
authors.initials: DM
authors.lastname: Denbow
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Furuse
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001224:Aspartic Acid / Q000494:pharmacology / Q000627:therapeutic use*; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000503:physiopathology; D002645:Chickens; D003346:Corticotropin-Releasing Hormone; D026603:D-Aspartic Acid / Q000494:pharmacology / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D006993:Hypnotics and Sedatives / Q000494:pharmacology / Q000627:therapeutic use*; D007276:Injections, Intraventricular; D012890:Sleep / Q000187:drug effects; D012934:Social Isolation; D013315:Stress, Psychological / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D014828:Vocalization, Animal / Q000187:drug effects; D014851:Wakefulness / Q000187:drug effects
chemical_list: D006993:Hypnotics and Sedatives; D001224:Aspartic Acid; D026603:D-Aspartic Acid; D003346:Corticotropin-Releasing Hormone