The oxidative stress and inflammation provoked by hypoxia can lead to damage to neurons in the hippocampus, a structure that plays a key role in learning and memory processes. Prevention of hypoxia-related damages may be achieved through different means: pharmacologically or behaviorally. Some plants have strong antioxidants properties, such as Guiera senegalensis (GS). Alternatively, performance of free-divers, without memory loss, suggests neuroprotective effects of extended training to apnea. We developed a rat model of hypoxia under voluntary apnea. Training consists of 3 to 4 weeks of habituation to swimming in a serpentine-water maze, followed by 4 weeks of swimming in apnea. For overtraining, there was 4 additional weeks of apnea training. One aim of the study was to observe the effects of GS on hippocampal activation following hypoxia. Rats were divided into 4 groups/categories : swimmer with plant (GS) or water (control), apneist with plant (GS) or water (control). Water and hydroethanolic extract of GS were administered (per oral) for 15 days during training. 90 min after the last session, animals were perfused and their brain taken. C-Fos immunohistochemistry revealed selective changes in CA3, with a decrease of the number of cFos+ cells in the apneists compared with the swimmers, and an increase in cFos+ cells induced by the plant, compared to water, in the apneists. Hypoxia-induced-damage might be prevented by GS administration. Ongoing analyses are now assessing the effect of apnea overtraining, in order to evaluate the extent to which it has a similar neuroprotective effect on hippocampal cells.