Effects of Environmental Enrichment on Anxiety Measurements: A Review
Environmental enrichment (EE) is an animal management technique, which aims to provide full welfare and better adaptation to the experimental conditions of laboratory animals. Exposing animals to different behavioral tests can assess the effects of EE. Among its several applications, EE has been identified as a protective factor in the treatment of some stress-related emotional disorders, such as depression. The anxiolytic effects induced by EE, on the other hand, are not as clear. In fact, one hypothesis that has been raised is that EE acts as a mild stressor agent. The present study reviews the literature published from 2006 to 2016 on environmental enrichment, stress and anxiety. The terms "environmental enrichment and stress” and “environmental enrichment and anxiety" were searched in MEDLINE, LILACS and Web of Sciences databases. The results obtained demonstrate that there are a great variety of EE protocols adopted. A significant part of these studies shows that EE reduces stress and anxiety measurements and leads to important neuroplastic changes. Nevertheless, since the EE protocols adopted vary greatly among studies, this might contribute to conflicting results. Standardizing EE protocols would help to understand EE effects on anxiety and stress-related measurements.
Danielle A Lopes, Isabel C Céspedes and Milena B Viana