| Popis: |
The dynamics of a rhythm band observed first in the ear skin microcirculation of awake human subjects were scrutinized using a naturalistic study design and nonlinear frequency and phase analysis. Since this frequency band with its centre between 0.12 and 0.18 Hz was slower than the respiratory rhythm but faster than the 0.1 Hz sympathetic dominated rhythm, this rhythm band is referred to as intermediary rhythm. Using nonlinear frequency and phase detection methods pronounced differences between episodes exhibiting amplitude modulated intermediary rhythm activity and episodes void of it were identified. Varying coherence, the modulation of peak to peak distances and fluctuations of energy transfer (modulation of the dV/dt in the protosystolic and the diastolic phase of cardiac driven pulsations) and, most importantly, the objective documentation of phase jumps relate the intermediary rhythm to the principles of ‘synergetic self-organization’ as discussed by Haken. The emergence of the intermediary rhythm is suggested to originate in non-equilibrium phase transitions in the network of lower brainstem neurons and is further linked to parasympathetic neuronal effectors, e.g. parasympathetic innervations of facial skin microcirculation. Thus, the intermediary rhythm comprises oscillations of a dynamic equipoise allowing either deceleration to slower sympathetic rhythms or acceleration to faster vagal and respiratory related rhythms. |
