title: Acute social defeat stress increases the conditioned rewarding effects of cocaine in adult but not in adolescent mice.
abstract: Stressful experiences modify activity in areas of the brain involved in the rewarding effects of psychostimulants. In the present study we evaluated the influence of acute social defeat (ASD) on the conditioned rewarding effects of cocaine in adolescent (PND 29-32) and adult (PND 50-53) male mice in the conditioned place preference (CPP) paradigm. Experimental mice were exposed to social defeat in an agonistic encounter before each session of conditioning with 1mg/kg or 25mg/kg of cocaine. The effects of social defeat on corticosterone levels were also evaluated. Adult mice exposed to ASD showed an increase in the conditioned reinforcing effects of cocaine. Only these mice developed cocaine-induced CPP with the subthreshold dose of cocaine, and they needed a higher number of extinction sessions for the 25mg/kg cocaine-induced CPP to be extinguished. In adolescent mice, on the other hand, ASD reduced the conditioned reinforcing effects of cocaine, since CPP was not produced with the lower dose of cocaine and was extinguished faster when they were conditioned with 25mg/kg. Adult mice exposed to social defeat displayed higher levels of corticosterone than their controls and adolescent mice. Our results confirm that the effect of social defeat stress on the acquisition and reinstatement of the CPP induced by cocaine varies depending on the age at which this stress is experienced.
authors.affiliation: Unidad de Investigación Psicobiología de las Drogodependencias, Departamento de Psicobiologia, Facultad de Psicología, Universidad de Valencia, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Montagud-Romero
authors.affiliation: Unidad de Investigación Psicobiología de las Drogodependencias, Departamento de Psicobiologia, Facultad de Psicología, Universidad de Valencia, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Aguilar
authors.affiliation: Unidad de Investigación Psicobiología de las Drogodependencias, Departamento de Psicobiologia, Facultad de Psicología, Universidad de Valencia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Maldonado
authors.affiliation: Unidad de Investigación Psicobiología de las Drogodependencias, Departamento de Psicobiologia, Facultad de Psicología, Universidad de Valencia, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Manzanedo
authors.affiliation: Unidad de Investigación Psicobiología de las Drogodependencias, Departamento de Psicobiologia, Facultad de Psicología, Universidad de Valencia, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Miñarro
authors.affiliation: Unidad de Investigación Psicobiología de las Drogodependencias, Departamento de Psicobiologia, Facultad de Psicología, Universidad de Valencia, Spain. Electronic address: marta.rodriguez@uv.es.
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez-Arias
mesh_terms: D000374:Aggression / Q000523:psychology; D000375:Aging / Q000523:psychology*; D000378:Agonistic Behavior / Q000187:drug effects; D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000523:psychology*; D003216:Conditioning, Operant / Q000187:drug effects*; D003345:Corticosterone / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005108:Extinction, Psychological / Q000187:drug effects; D008297:Male; D051379:Mice; D012201:Reward; D013315:Stress, Psychological / Q000523:psychology*
chemical_list: D003042:Cocaine; D003345:Corticosterone
keywords: Acute social defeat; Cocaine; Conditioned place preference; Corticosterone; Mice