Figure 3. Hippocampal fissure volume (cm3) and cardiovascular fitness (mL/min/Kg) at age 45. (A) The hippocampal formation, which supports episodic memory and cognition, is comprised of multiple subregions (inset) that follow independent aging trajectories . The hippocampal fissure is an interstitial space separating two of these subregions, the dentate gyrus and the subiculum. (B) Graph showing the correlation between average hippocampal fissure volume (cm3, y-axis) and VO2Max (mL/min/kg; x-axis). Study members with higher cardiovascular fitness at age 45 had smaller mean volume of the hippocampal fissure (β = -0.18, 95% CI = -0.26 to -0.09, p<0.001). Results pictured are adjusted for sex. cm3 = centimeters cubed; mL/min/kg = milliliters per minute per kilogram; VO2Max = volume of maximum oxygen uptake; β = standardized coefficient; CI = confidence interval.