Friday, April 20, 2012

Does abnormal NREM sleep impair declarative memory consolidation?

Finally got to uploading the review paper Robert Goder and I had written recently on sleep and memory. You can download it HERE. Essentially, we describe a possible mechanism by which abnormal NREM sleep processes (i.e. reduced slow-wave sleep and sleep spindles) contribute to declarative memory impairment and concomittant sleep disruption in certain neuropsychiatric disorders including Alzheimer's, schizophrenia, and fibromyalgia. Underneath, I posted what the tentative model looks like (click to enlarge). Would love to hear your thoughts. 



Fig. 1. During NREM sleep, abnormal thalamocortical structures may be unable to generate sufficient slow oscillations to drive the reactivation of hippocampal memory traces. These same structures may also be unable to facilitate normal spindle activity, preventing efficient declarative memory consolidation due to an absence in cortical plastic changes. Decreases in spindle activity lead to failure in inhibiting sensory information from reaching the neocortex. Thus, the individual is awakened and kept awake by sensory information, consequently experiencing disturbed NREM sleep.

Reference:

Lu, W., & Göder, R. (2011). Does abnormal non-rapid eye movement sleep impair declarative memory consolidation? Sleep Medicine Reviews DOI: 10.1016/j.smrv.2011.08.001