The anxiogenic beta-carboline FG-7142 inhibits locomotor exploration similarly in postweanling and adult rats.
The beta-carboline FG-7142 exerts many stress-like effects in the adult rat, including the inhibition of locomotor exploration. However, comparable effects in immature animals have not been reported. Stress-like effects of FG-7142 are mediated via its inverse agonist actions on gamma-aminobutyric acid (GABA) receptors. GABA systems change considerably with development and GABA agonists such as diazepam have opposite behavioral actions in immature and adult rats. Accordingly, we compared FG-7142 effects on locomotor exploration in postweanling and adult rats. Postweanling male rats (24 days) and adult rats (90 days) received a single injection of vehicle or FG-7142 (15 mg/kg i.p.) and 15 min later were placed in photocell monitors for 1 h. Although postweanling animals traveled a smaller distance overall than adults, FG-7142 inhibited locomotor exploration to a similar degree in both groups. We conclude that FG-7142 exerts stress-like effects in postweanling rats and may be considered for use as a model of childhood stress.
Jaskiw
George E
GE
Louis Stokes Cleveland Veterans Administration Medical Center, Cleveland, OH 44141, USA. gxj75@po.cwru.edu
Lipska
Barbara K
BK
Weinberger
Daniel R
DR
D000367:Age Factors; D000818:Animals; D001007:Anxiety / Q000139:chemically induced* / Q000523:psychology; D002243:Carbolines / Q000633:toxicity*; D005106:Exploratory Behavior / Q000187:drug effects* / Q000502:physiology; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D013315:Stress, Psychological / Q000139:chemically induced / Q000523:psychology; D014886:Weaning
D002243:Carbolines; C035874:FG 7142