The effect of state on sensory gating: comparison of waking, REM and non-REM sleep

Objectives: Auditory sensory gating is an electrophysiological assay that h as been employed in clinical and basic research to clarify the neurobiologi cal basis of perceptual and attentional impairments associated with schizop hrenia and other diseases. In addition to genetically linked characteristic s, this measure also exhibits potentially confounding sensitivity to behavi oral stare, most notably acute stress. The goal of the present study is to determine if auditory sensory gating of evoked potential component P59 ('P1 ') could be measured during rapid eye movement (REM) sleep, as an alternati ve to the waking state. Methods: The suppression of vertex-recorded auditory evoked potential compo nents, P30. P50 and N100, was measured as a function of stimulus redundancy using the paired-click paradigm during all-night sleep in 10 control subje cts. Average evoked responses were computed separately for 30 min periods o f waking, REM sleep, and non-REM (stage 2) sleep. Results: Evoked response component P50 exhibited suppression to the paired- click stimulus during REM sleep, not significantly different than waking. S uppression of wave N100 was significantly poorer during both sleep stages t han waking. Component P30 was not suppressed in response to repetitive stim uli under any state of vigilance. Conclusions: In addition to waking, response suppression of evoked potentia l component P50 can be measured during REM sleep, thus allowing the separat ion of trait- and state-dependent effects in future investigations of audit ory sensory gating. published by Elsevier Science Ireland Ltd.