title: Repeated predictable or unpredictable stress: effects on cocaine-induced locomotion and cyclic AMP-dependent protein kinase activity.
abstract: Stressful experiences appear to have a strong influence on susceptibility to drug taking behavior. Cross-sensitization between stress and drug-induced locomotor response has been found. Locomotor response to novelty or cocaine (10 mg/kg, i.p.), cyclic AMP-dependent protein kinase (PKA) activity in the nucleus accumbens and basal corticosterone levels were evaluated in male adult rats exposed to acute and chronic predictable or unpredictable stress. Rats exposed to a 14-day predictable stress showed increased locomotor response to novelty and to cocaine, whereas rats exposed to chronic unpredictable stress demonstrated increased cyclic AMP-dependent PKA activity in the nucleus accumbens. Both predictable and unpredictable stress increased basal corticosterone plasma levels. These experiments demonstrated that stress-induced early cocaine sensitization depends on the stress regime and is apparently dissociated from stress-induced changes in cyclic AMP-dependent PKA activity and corticosterone levels.
authors.affiliation: Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1524, 05508-900, SP, São Paulo, Brazil
authors.forename: Ana Paula N
authors.initials: AP
authors.lastname: Araujo
authors.forename: Roberto
authors.initials: R
authors.lastname: DeLucia
authors.forename: Cristoforo
authors.initials: C
authors.lastname: Scavone
authors.forename: Cleopatra S
authors.initials: CS
authors.lastname: Planeta
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D003042:Cocaine / Q000378:metabolism / Q000494:pharmacology*; D003345:Corticosterone / Q000097:blood; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D009714:Nucleus Accumbens / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000097:blood / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology
chemical_list: D017868:Cyclic AMP-Dependent Protein Kinases; D003042:Cocaine; D003345:Corticosterone