Recovery of fEPSP amplitude in hippocampal slices from 1–2, 3–6, 12–20, >22 months old rats following varying lengths of hypoxia post-hsd (0.25, 2.5, 5 and 10 min). Following 2.5 min of hypoxia post-hsd, fEPSP recovery differed significantly between slices from 3–6 months old (116 ± 47%, n = 8) and >22 months old rats (40 ± 49%, n = 9) (*p < 0.05) while following 5 min hypoxia post-hsd, the recovery of fEPSP in slices from 1–2 months old rats (54 ± 32%, n = 8) was significantly greater than the recoveries in slices from all older age groups [(3–6 months, 14 ± 32%, n = 7, *p < 0.05); (12–20 months, 7 ± 15%, n = 6, **p < 0.01); (>22 months, 3 ± 8%, n = 9, ***p < 0.001)].