Prefrontal atrophy, disrupted NREM slow waves and impaired hippocampal-dependent memory in aging.
Aging has independently been associated with regional brain atrophy, reduced slow wave activity (SWA) during non-rapid eye movement (NREM) sleep and impaired long-term retention of episodic memories. However, whether the interaction of these factors represents a neuropatholgical pathway associated with cognitive decline in later life remains unknown. We found that age-related medial prefrontal cortex (mPFC) gray-matter atrophy was associated with reduced NREM SWA in older adults, the extent to which statistically mediated the impairment of overnight sleep-dependent memory retention. Moreover, this memory impairment was further associated with persistent hippocampal activation and reduced task-related hippocampal-prefrontal cortex functional connectivity, potentially representing impoverished hippocampal-neocortical memory transformation. Together, these data support a model in which age-related mPFC atrophy diminishes SWA, the functional consequence of which is impaired long-term memory. Such findings suggest that sleep disruption in the elderly, mediated by structural brain changes, represents a contributing factor to age-related cognitive decline in later life.
Sleep and Neuroimaging Laboratory, University of California, Berkeley, California, USA. bamander@berkeley.edu
Bryce A
BA
Mander
Vikram
V
Rao
Brandon
B
Lu
Jared M
JM
Saletin
John R
JR
Lindquist
Sonia
S
Ancoli-Israel
William
W
Jagust
Matthew P
MP
Walker
D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology* / Q000502:physiology / Q000523:psychology; D001284:Atrophy / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008568:Memory / Q000502:physiology*; D061212:Memory, Episodic; D009483:Neuropsychological Tests; D009929:Organ Size; D017286:Polysomnography; D017397:Prefrontal Cortex / Q000473:pathology* / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D055815:Young Adult