Environmental Enrichment and the Effects on Drug Abuse Vulnerability: The Last Ten Years

Environmental enrichment in rats during development has been shown to reliably alter the sensitivity to various drugs of abuse. The current chapter will attempt to summarize new research that has come out investigating the effects of environmental enrichment on different drugs of abuse in the last 10 years. At the same time the chapter also aims to give a detailed description of the methods we employ in the environmental enrichment model used in our laboratory. We focused on details in the different the use of the environmental conditions that are often not reported in peer-reviewed publications. The review of studies conducted in the past decade indicated that studies continue to confirm that animals raised in enriched conditions show a protective effect in the behavioral sensitivity to different drugs of abuse relative to the impoverished condition counterparts. Studies focusing on changes in the nervous system indicate changes in mesolimbic structures as a result of enrichment, areas like the NAcc, VTA, and the bed nucleus of the stria terminalis. There are also alterations in the HPA-axis in enriched vs. impoverished animals that plays a role in differences seen in stimulant self-administration. Future studies using the environmental enrichment model should focus on understudied drugs like cannabinoids, opiates, and nicotine.