Vascular hippocampal plasticity after aerobic exercise in older adults

Abstract

Aerobic exercise in young adults can induce vascular plasticity in the hippocampus, a critical region for recall and recognition memory. In a mechanistic proof-of-concept intervention over 3 months, we investigated whether healthy older adults (60-77 years) also show such plasticity. Regional cerebral blood flow (rCBF) and volume (rCBV) were measured with gadolinium-based perfusion imaging (3 Tesla magnetic resonance image (MRI)). Hippocampal volumes were assessed by high-resolution 7 Tesla MRI. Fitness improvement correlated with changes in hippocampal perfusion and hippocampal head volume. Perfusion tended to increase in younger, but to decrease in older individuals. The changes in fitness, hippocampal perfusion and volume were positively related to changes in recognition memory and early recall for complex spatial objects. Path analyses indicated that fitness-related changes in complex object recognition were modulated by hippocampal perfusion. These findings indicate a preserved capacity of the aging human hippocampus for functionally relevant vascular plasticity, which decreases with progressing age.

Relationships between cardiorespiratory fitness, hippocampal volume, and episodic memory in a population at risk for Alzheimer's disease

“…Interestingly, neither baseline CRF nor change in CRF was related to hippocampal volume in the cognitively healthy participants of either study (Honea et al., 2009; Vidoni et al., 2012). More recently, change in CRF following an exercise intervention has been positively associated with hippocampal head volume (Maass et al., 2015) and hippocampal tissue density (Kleemeyer et al., 2015) in cognitively healthy older adults. Overall, current research demonstrates inconsistent associations between CRF and hippocampal volume.…”

“…In older adults, large‐scale cross‐sectional studies have reported contradictory associations. Positive associations between CRF/physical activity and RAVLT performance have been reported (Boots et al., 2014; Pizzie et al., 2014; Zhu et al., 2014) while others studies did not observe such associations (Maass et al., 2015; Varma et al., 2015). Randomized controlled trials provide evidence that aerobic exercise (Klusmann et al., 2010) and resistance exercise (Cassilhas et al., 2007) training can improve episodic memory in cognitively healthy older adults.…”

“…Randomized controlled trials provide evidence that aerobic exercise (Klusmann et al., 2010) and resistance exercise (Cassilhas et al., 2007) training can improve episodic memory in cognitively healthy older adults. Additionally, changes in physical activity/CRF following an exercise intervention have been positively associated with episodic memory performance (Maass et al., 2015; Ruscheweyh et al., 2011). The findings of the current study are in part consistent and show that in addition to self‐reported physical activity and estimated fitness, objectively measured CRF (VO 2 peak) is associated with episodic memory in at‐risk older adult men.…”

“…In older adults, CRF has been reported to be positively associated episodic memory (Etnier et al., 2007; Hayes, Forman, & Verfaellie, 2016; Zhu et al., 2014), while others have not observed such associations in similar populations (Bugg et al., 2012; Maass et al., 2015). Moreover, both self‐reported physical activity (Pizzie et al., 2014) and estimated fitness (Boots et al., 2014; Freudenberger et al., 2016) have been shown to be positively associated with episodic memory in older adulthood.…”

Exercise Regulation of Cognitive Function and Neuroplasticity in the Healthy and Diseased Brain

“…This increase in blood flow appears to aid in earlier recall for complex spatial objects. 8,9 Further, in elderly subjects, 6 months of aerobic training has been shown to mitigate age-related decline in both verbal and spatial memory, 10 while a low activity, 8-week yoga intervention significantly improved performance on task switching, working memory, and the n-back task. 11 In young males, high-intensity cycling has been associated with better acquisition and retention 7 days later on the visuomotor tracking task.…”