Neural generators of brain potentials before rapid eye movements during human REM sleep: a study using sLORETA.
OBJECTIVE
Brain activity preceding rapid eye movements (REM) during human REM sleep has remained poorly understood. Slow negative brain potential (pre-REM negativity) appears before REMs. Current sources of this potential were investigated to identify brain activity immediately preceding REMs.


METHODS
In this study, 22 young healthy volunteers (20-25 years old) participated. Polysomnograms were recorded during normal nocturnal sleep. Brain potentials between 200ms before and 50ms after the onset of REMs and pseudo-triggers (3000ms before the onset of REMs) were averaged. Standardized low-resolution brain electromagnetic tomography (sLORETA) was used to estimate current sources of pre-REM negativity.


RESULTS
Pre-REM negativity appeared with the maximal amplitude at right prefrontal sites immediately before REMs. However, this negativity did not appear before pseudo-triggers. Current sources of the pre-REM negativity were estimated in the ventromedial prefrontal cortex, uncus, insula, anterior cingulated cortex, basal forebrain, parahippocampal gyrus, premotor cortex and frontal eye field.


CONCLUSIONS
The pre-REM negativity reflects brain activity coupled with the occurrence of REMs. Results of this study suggest that emotion, memory, and motor-related brain activity might occur before REMs.


CONCLUSIONS
Pre-REM negativity is expected to be a psychophysiological index for elucidating functions of REM sleep.
Abe
Takashi
T
Department of Behavioral Sciences, Graduate School of Biosphere Sciences, Hiroshima University, Higashi-Hiroshima, Japan.
Ogawa
Keiko
K
Nittono
Hiroshi
H
Hori
Tadao
T
D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D004569:Electroencephalography; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D017286:Polysomnography / Q000379:methods; D012895:Sleep, REM / Q000502:physiology*; D013997:Time Factors