Age-related disruptions of circadian rhythm and memory in the senescence-accelerated mouse (SAMP8).

Common complaints of the elderly involve impaired cognitive abilities, such as loss of memory and inability to attend. Although much research has been devoted to these cognitive impairments, other factors such as disrupted sleep patterns and increased daytime drowsiness may contribute indirectly to impaired cognitive abilities. Disrupted sleep-wake cycles may be the result of age-related changes to the internal (circadian) clock. In this article, we review recent research on aging and circadian rhythms with a focus on the senescence-accelerated mouse (SAM) as a model of aging. We explore some of the neurobiological mechanisms that appear to be responsible for our aging clock, and consider implications of this work for age-related changes in cognition.