The environmental enrichment (EE) paradigm has been evaluated as a means of counteracting some of the consequences of chronic stress in rodents as well as a model of protective environment against drug abuse development. In the present chapter, our main aim is to describe the models of EE and chronic social stress and how they can be applied jointly in order to evaluate the effects of early psychosocial stress in animals exposed of different environments (enriched environment or standard environment). Furthermore, both paradigms could be applied in animal models of nicotine addiction, so the guidelines for the application of a chronic oral nicotine treatment in mice will be described. The heterogeneity of the procedures carried out in different laboratories makes it interesting to specify their characteristics in order to obtain replicable and valid animal models.
Keywords: Addiction; Animal model; Chronic social stress; Environmental enrichment; Mice; Nicotine; Rats.