Age-dependent differences in the rat's conditioned defensive burying behavior: effect of 5-HT1A compounds.
The ontogeny of conditioned defensive-burying behavior was studied in rats from 2 to 21 weeks of age. At early ages this parameter shows low values that gradually increase until the 11th week, decreasing steadily thereafter. Reactivity, measured by the burying-behavior latency, appeared increased in 2-week-old rats. The effect of the serotonergic1A compounds: 8-OH-DPAT (0.25 and 0.5 mg/kg), ipsapirone, buspirone, and indorenate (at 2.5 and 5.0 mg/kg) was studied at 3, 7, 11, and 21 weeks of age. All compounds produced a dose-dependent decrease in burying behavior in rats of 7 and 11 weeks, while at the Week 21, only 8-OH-DPAT and indorenate reduced it. At 3 weeks of age, burying-behavior latency was increased by all compounds, but burying behavior was not altered. Motor coordination was affected by buspirone at all ages and by 8-OH-DPAT at the Week 21. Data are discussed on the bases of the development of defensive behaviors.
Lopez-Rubalcava
C
C
Departamento de Farmacologia y Toxicologia, CINVESTAV, Instituto Mexicano de Psiquiatria, Mexico.
Fernandez-Guasti
A
A
Urba-Holmgren
R
R
D000375:Aging / Q000187:drug effects*; D000818:Animals; D003214:Conditioning, Classical / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005239:Fear / Q000187:drug effects*; D005260:Female; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009048:Motor Skills / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects*; D018490:Serotonin Agents / Q000494:pharmacology*; D013239:Stereotyped Behavior / Q000187:drug effects*
D011985:Receptors, Serotonin; D018490:Serotonin Agents