Slow rhythms and sleep spindles in early infancy

Objective: To investigate the slow rhythm and its relationship to spindling in early infancy. Methods: We analyzed sleep MEG recordings containing sleep spindles, taken from 7 normal, healthy subjects at conceptional age 46-63 weeks in 21 sessions. Results: We show that the sleep MEG in early infancy contains a slow rhythm, centered at approximately 0.2 Hz, which showed a striking association with spindling. The slow rhythm grouped sleep spindles, which were clock-like with a recurrence rate of approximately 0.1 Hz. Conclusions: The association of the 0.2 Hz oscillation and low delta rhythms with spindling was so strong as to suggest that they may play a critical role during brain development in the genesis of sleep spindles. Significance: Infant brain rhythms exhibit relatively simple, regular behavior, allowing the relationships between them to be more easily discerned. (C) 2016 Elsevier Ireland Ltd. All rights reserved.