Maternal deprivation impairs memory and cognitive flexibility, effect that is avoided by environmental enrichment

Maternal deprivation (MD) causes cognitive deficits that persist until adulthood. Thereby, the environmental enrichment (EE) is widely used to increase brain plasticity. Here, pregnant female rats were used and their offspring were submitted to neonatal MD from post-natal day 1-10; after weaning the rats were submitted to EE. MD caused deficits on short and long-term aversive and recognition memory and on cognitive flexibility tested on reversed Morris Water Maze test. MD also promoted the decrease of hippocampal Brain-Derived Neurotropic Factor (BDNF) protein expression. The EE was able to protect against the cognitive deficits, avoiding the memory and the cognitive flexibility disrupting, and normalizing hippocampal BDNF expression of rats submitted to MD. These data confirms that MD promotes long-life memory deficits and demonstrates that MD causes cognitive flexibility disruption; the mechanisms seem involve the decrease of BDNF. We also demonstrate that EE, which improves BDNF, is able to avoid memory deficits and cognitive flexibility disrupts.