title: High novelty-seeking predicts greater sensitivity to the conditioned rewarding effects of cocaine.
abstract: Novelty-seeking in rodents, defined as enhanced specific exploration of novel situations, is considered to predict the response of animals to drugs of abuse and, thus, identify "drug-vulnerable" individuals. The main objective of this work was to determine the capacity of two animal models-the novel object recognition task and the novel environment test-for evaluating to what extent novelty-seeking can predict greater sensitivity to the rewarding properties of cocaine in young adult (PND 56) and adolescent (PND 35) OF1 mice of both sexes. Conditioned place preference, a useful tool for evaluating the sensitivity of individuals to the incentive properties of addictive drugs, was induced with a sub-threshold dose of cocaine (1 mg/kg, i.p.). Three factors that predispose individuals to addiction were considered: age, sex and novelty-seeking trait. CPP was detected only in the young adults that spent most time exploring the novel environment (High Novel Environment Seekers, High-Environment-NS). The novel environment test seemed to be more effective than the novel object recognition task in identifying young adults vulnerable to drugs; specifically, it revealed a distinction between High- and Low-Environment-NS mice that predicted greater sensitivity to the rewarding properties of cocaine among young adults but not among adolescents. Although our results reveal a higher novelty preference among young adult females than among their male counterparts in the two NS tests, both sexes showed similar susceptibility to the rewarding effects of a sub-threshold dose of cocaine in the CPP. These findings suggest that screening can identify humans at-risk of becoming drug users, and may contribute to the development of prevention strategies based on specific vulnerabilities.
authors.affiliation: Unidad de Investigación Psicobiología de las Drogodependencias, Departamento de Psicobiología, Facultad de Psicología, Universitat de València, Valencia, 46010, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Vidal-Infer
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Arenas
authors.forename: Manuel
authors.initials: M
authors.lastname: Daza-Losada
authors.forename: M Asunción
authors.initials: MA
authors.lastname: Aguilar
authors.forename: José
authors.initials: J
authors.lastname: Miñarro
authors.forename: Marta
authors.initials: M
authors.lastname: Rodríguez-Arias
mesh_terms: D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D003213:Conditioning, Psychological / Q000187:drug effects* / Q000502:physiology; D005106:Exploratory Behavior / Q000187:drug effects* / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012201:Reward
chemical_list: D003042:Cocaine