title: Dual control of the brainstem on the spindle oscillation in humans.
abstract: In human subjects, the excitability change of the brainstem was investigated over the course of the spindle oscillation. The investigation was carried out by a sequential analysis of brainstem auditory evoked potentials (BAEPs) with reference to one sequence of spindle oscillation. The method was based on the characteristics of BAEPs, i.e. far-field evoked potential. The brainstem revealed two types of excitability change: one in the lower ventral brainstem (wave-III components), and the other in the upper dorsal brainstem (wave-V components). The excitability in the dorsal brainstem showed an oscillation with one cycle period of about 1.5 s, whereas in the ventral brainstem, the excitability showed a long-range biphasic (decaying-growing) fluctuation. Both excitability changes in the brainstem preceded the spindle oscillation, and the phase was reversed during the emerging period of spindle oscillation. The results suggest a primary triggering mechanism of the brainstem for the spindle oscillation, which is independent of preceding cortical drives (K-complexes) upon the thalamus. The difference of the excitability change between the spindle oscillation and the paroxysmal discharge (spike-and-wave complex) was also discussed.
authors.affiliation: Department of Pediatrics, Hokkaido University School of Medicine, N-15 W-7, Kita-ku, 060, Sapporo, Japan. shinobu-masako@mm.neweb.ne.jp
authors.forename: S
authors.initials: S
authors.lastname: Kohsaka
authors.forename: T
authors.initials: T
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Kohsaka
authors.forename: N
authors.initials: N
authors.lastname: Fukuda
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D001683:Biological Clocks / Q000502:physiology*; D001933:Brain Stem / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D012890:Sleep / Q000502:physiology*