Electrodermal activity (EDA) was recorded as skin potential responses
(SPRs), on the hindpaws of cats during waking and sleep. SPRs recorded
on both paws showed an overall parallelism during all stages of vigil
ance. SPRs on both paws significantly decreased in amplitude and in fr
equency from wakefulness to sleep. Most SPRs were synchronous but show
ed bilateral differences larger than 0.1 mV. However, this asymmetry d
id not show any significant variation as a function of sleep stages. E
lectrical stimulation of the reticular central tegmental field at leve
ls below the thresholds for behavioral and cortical arousal thresholds
evoked SPRs during wakefulness and all stages of sleep. Bilateral dif
ferences between evoked SPR amplitudes did not show significant variat
ions as a function of the stages of vigilance. Moreover, the bilateral
asymmetry of the evoked SPRs was significantly lower than that of the
spontaneous SPRs. These results are discussed in relation to the vari
ations in bilateral EDA recorded in humans during waking and sleep; th
e influence of central and peripheral factors on EDA laterality is als
o discussed.