Dynamic relation of sleep spindles and K-complexes to spontaneous phasic arousal in sleeping human subjects.
K-complexes unaccompanied by sleep spindles (K0-complexes) and isolated sleep spindles during stage 2, non-rapid eye movement (NREM) sleep were examined before and after transient activation phase (AP) and also pseudo-AP during human sleep to determine the relationship of K0-complexes and sleep spindles to APs. Sixteen sleep records obtained from 16 young adult males were scanned for isolated APs during stage 2 NREM sleep. One hundred APs and 62 pseudo-APs were identified and analyzed. The number of sleep spindles decreased and reached its minimum at the onset of APs, when an increase was observed in the number of K0-complexes. APs occurred when a decrease in sleep spindles was coupled with an increased incidence of K0-complexes, thus forming an antagonistic relation. A similar antagonism was observed between sleep spindles and slow waves. A working hypothesis was formulated to interpret a triad of sleep events: sleep spindles. K0-complexes, and slow wave sleep. Three kinds of sleep--REM, spindles-dominant, and slow-wave-dominant--are suggested as more useful classifications than the Rechtschaffen and Kales categories.
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials; D005072:Evoked Potentials, Auditory; D006801:Humans; D008297:Male; D009433:Neural Inhibition; D012894:Sleep Stages / Q000502:physiology*