This Adverse Outcome Pathway (AOP) describes the linkage between binding to proteins involved in protection against oxidative stress and impairment in learning and memory. Production, binding and degradation of Reactive Oxygen Radicals are tightly regulated in the body, and an imbalance between production and protection may cause oxidative stress, which is common to many toxicity pathways. Oxidative stress may lead to an imbalance in glutamate neurotransmission, which is involved in learning and memory. Oxidative stress may also cause cellular injury and death. During brain development and in particular during the establishment of neuronal connections and networks, such perturbations may lead to functional impairment in learning and memory. The weight-of-evidence supporting the relationship between the key events described in this AOP is based mainly on developmental effects observed after an exposure to mercury, a heavy metal known for its strong affinity to many proteins having anti-oxidant properties. This AOP is referred to as AOP 17 in the Collaborative Adverse Outcome Pathway Wiki (AOP-Wiki).