[Heart rate in cats during sleep after coagulation of the locus coeruleus].

The relationship between heart rate (HR) modulation and sleep mechanisms were analysed in 14 unrestrained cats with implanted electrodes and additional tripolar electrodes in the lateral geniculate nucleus and the abducens nucleus for recording the ponto--geniculo--occipital spikes. Anterior lesion of the locus coeruleus (LC) reduced the heart rate by about 18%, and a severe arrhythmia with augmented dispersion of R--R intervals occurred during paradoxical sleep (PS). Cats with posterior lesion had the heart rate increased by 20% and the spontaneous fluctuations of the R--R interval totally disappeared in them. The obtained data show that anterior and posterior LC exert different influences upon the heart rate fluctuations in sleep.