Coordination dynamics of circulatory and respiratory rhythms during psychomotor drive reduction

Effects of a facial nerve lesion on responses in forehead microvessels to conjunctival irritation and paced breathing

“…Increased flow was accompanied by an increase in the frequency of the dominant vascular waveform on the intact side of the forehead. Although activation of parasympathetic vasodilator fibres in the facial nerve may result in slow-wave changes in the forehead microvasculature, this did not produce the 0.15 Hz waveform anticipated by Perlitz et al (2004aPerlitz et al ( , 2004b or others (Silverman et al, 2001;Silverman and Stout, 2002).…”

“…Moreover, Perlitz et al (2004a) reported that an independent 0.15 Hz rhythm in forehead blood flow emerged during deep relaxation. To maximize respiratory influences on the 0.15 Hz rhythm in the present study, participants breathed at a controlled rate of 0.15 Hz.…”

“…On the basis of experiments in animal models and humans, Perlitz et al (2004aPerlitz et al ( , 2004b) attributed a distinctive 0.15 Hz rhythm of blood flow through forehead vessels to a source in the brainstem that relayed periodic bursts of activity through parasympathetic vasomotor fibres distributed with the facial nerve to blood vessels in the forehead. To explore this possibility, we previously investigated whether a facial nerve lesion interrupted vascular rhythms in the forehead microvasculature (Drummond and O'Brien, 2011).…”

“…It was hypothesized that conjunctival irritation would induce increases in blood flow on the intact side of the forehead, mediated by reflex activation of parasympathetic vasodilator fibres in the facial nerve (Drummond, 1992(Drummond, , 1995a(Drummond, , 1995b. If rhythmic excitation of parasympathetic neurons induce vascular waves at 0.15 Hz (Perlitz et al, 2004a(Perlitz et al, , 2004b, the waves might strengthen on the intact side of the forehead during trigeminal-parasympathetic vasodilatation.…”

“…To investigate whether parasympathetic nerves also regulate rhythmic waves of dilatation and constriction in these vessels (Perlitz et al, 2004a(Perlitz et al, , 2004b, forehead blood flow was monitored in participants with a facial nerve lesion during relaxation, respiratory biofeedback and while they watched a sad documentary (Drummond and O'Brien, 2011). Both before and during relaxation and the sad documentary, a psychomotor rhythm at 0.15 Hz was more prominent in vascular waveforms on the denervated than intact side of the forehead.…”