Numerous studies have revealed that an enriched environment can enhance the survival-related behaviors and brain functions of animals. However, the effects and specific roles of the enrichment characteristics on animals' innovative capability, a cognitive ability crucial for survival in nature, are still not well known. In this study, we assigned mice to environment-manipulation groups (n = 15 each) to investigate the specific effects of environmental novelty (novel vs. familiar) and environmental complexity (complex vs. normal) on innovative problem solving and its possible neural mechanisms. Results showed that mice in only the novel-environment group performed better at innovative-problem-solving tasks and showed greater numbers of novel explorations and dopaminergic projections from the ventral tegmental area to the nucleus accumbens in the brain. These findings indicate that an enriched environment has the potential to promote the innovative capability of mice by enhancing their novel exploratory motivation, which depends on the novelty of the environment but not its complexity.
Keywords: dopamine; enriched environment; innovative problem solving; novel-seeking motivation; novelty and complexity.