Abstract Body: Cardiac arrest (CA) often leads to severe memory impairment, largely due to extensive neuronal loss in brain areas critical for cognitive function, including the hippocampus and amygdala. We demonstrated that physical exercise (PE) following asphyxia CA (ACA) mitigates contextual memory deficits in male rats. Intriguingly, this effect occurs without direct protection of the hippocampus and amygdala, as evidenced by significant cell death in both regions. Instead, PE post-ACA reduces neuronal loss in the medial septum (MS), a forebrain structure essential for regulating limbic system oscillations, and thus memory. This study aims to investigate whether PE post-ACA preserves oscillatory activity within the limbic circuitry and whether it ameliorates other forms of cognitive deficits in both sexes. Methods: Male and female rats are subjected to 8’ ACA. After 5 days of recovery, the animals undergo 5 consecutive days of treadmill running, followed by a battery of cognitive tests. Approximately one-month post-ACA, the animals are anesthetized with urethane for in vivo oscillatory recordings. Results: Having acquired fear conditioning (Figs. 1a and 1d), the animals were tested for cued fear memory and extinction two days later. Post-ACA exercised animals displayed a significant increase in freezing levels compared to non-exercised animals in response to a single re-exposure to the tone, indicating preserved cued fear memory (Fig. 1c). After continuous tone presentations, only the exercised animals displayed a significant decrease in freezing, suggesting they were able to extinguish their fear response (Fig. 1f). The Y-maze test revealed a significant increase in spontaneous alternation in exercised animals (Fig. 1g), indicating improved working memory. These outcomes were not influenced by locomotion (Fig. 1h) or anxiety (Fig. 1i), as confirmed by the open field test. We are currently performing the oscillatory recordings in different limbic system regions. Conclusion: PE post-ACA mitigates different forms of long- and short-term memory deficits in both sexes. This improvement is likely mediated by the preservation of oscillatory power in the MS and hippocampus (to be confirmed), highlighting a potential mechanism by which PE exerts its neuroprotective effects.