Aging has 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. Whether these are related to each other is the focus of the current paper. Here the authors find that age-related medial prefrontal cortex (mPFC) gray-matter atrophy is associated with reduced NREM SWA in older adults. These in turn were associated with 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. Together, these data support a model in which age-related mPFC atrophy diminishes SWA, the functional consequence of which is impaired long-term memory. The authors suggest that sleep disruption in the elderly, mediated by structural brain changes, represents a contributing factor to age-related cognitive decline in later life.
Mander BA, Rao V, Lu B, Saletin JM, Lindquist JR, Ancoli-Israel S, Jagust W, Walker MP: Prefrontal atrophy, disrupted NREM slow waves and impaired hippocampal-dependent memory in aging. Nature Neuroscience [Epub ahead of print January 27, 2013; doi: 10.1038/nn.3324.]