TY - JOUR A1 - Perlitz, Volker A1 - Lambertz, Manfred A1 - Cotuk, Birol A1 - Grebe, Reinhard A1 - Vandenhouten, Ralf A1 - Flatten, Guido A1 - Petzold, Ernst Richard A1 - Schmid-Schönbein, Holger A1 - Langhorst, Peter T1 - Cardiovascular rhythms in the 0.15-Hz band: common origin of identical phenomena in man and dog in the reticular formation of the brain stem? JF - Pflügers Archiv: European Journal of Physiology N2 - Selected examples from experiments in humans and dogs with time series of reticular neurons, respiration, arterial blood pressure and cutaneous forehead blood content fluctuations were analysed using multiscaled time-frequency distribution, post-event-scan and pointwise transinformation. We found in both experiments a “0.15-Hz rhythm” exhibiting periods of spindle waves (increasing and decreasing amplitudes), phase synchronized with respiration at 1:2 and 1:1 integer number ratios. At times of wave-epochs and n:m phase synchronization, the 0.15-Hz rhythm appeared in heart rate and arterial blood pressure. As phase synchronization of the 0.15-Hz rhythm with respiration was established at a 1:1 integer number ratio, all cardiovascular-respiratory oscillations were synchronized at 0.15 Hz. Analysis of a canine experiment supplied evidence that the emergence of the 0.15-Hz rhythm and n:m phase synchronization appears to result from a decline in the level of the general activity of the organism associated with a decline in the level of activity of reticular neurons in the lower brainstem network. These findings corroborate the notion of the 0.15-Hz rhythm as a marker of the “trophotropic mode of operation” first introduced by W.R. Hess. KW - vegetative rhythm KW - cardiovascular-respiratory coordination KW - n:m phase synchronization KW - autogenic training KW - lower brainstem dynamics KW - non-linear analysis Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9348 SN - 1432-2013 VL - 448 IS - 6 ER - TY - JOUR A1 - Vandenhouten, Ralf A1 - Lambertz, Manfred A1 - Langhorst, Peter A1 - Grebe, Reinhard T1 - Nonstationary time-series analysis applied to investigation of brainstem system dynamics JF - IEEE Transactions on Biomedical Engineering (T-BME) N2 - Previous investigations of the dynamic organization of the lower brainstem and its relation to peripheral and other central nervous systems were predominantly performed by linear methods. These are based on time-averaging algorithms, which merely can be applied to stationary signal intervals. Thus, the current concept of the common brainstem system (CBS) in the reticular formation (RF) of the lower brainstem and basic types of its functional organization have been developed. Here, the authors present experiments where neuronal activities of the RF and the nucleus tractus solitarii (NTS, first relay station of baroreceptor afferents) were recorded together with related parameters of electroencephalogram (EEG), respiration, and cardiovascular system. The RF neurons are part of the CBS, which participates in regulation and coordination of cardiovascular, respiratory, and motor systems, and vigilance. The physiological time series, thus acquired, yield information about the internal dynamic coordination of the participating regulation processes. The major problem in evaluating these data is the nonlinearity and nonstationarity of the signals. The authors used a set of especially designed time resolving methods to evaluate nonlinear dynamic couplings in the interaction between CBS neurons and cardiovascular signals, respiration and the EEG, and between NTS neurons (influenced by baroreceptor afferents) and CBS neurons. KW - time series analysis KW - neuron KW - radio frequency KW - electroencephalography KW - cardiology KW - central nervous system KW - relay KW - cardiovascular system KW - nonlinear dynamical system KW - design methodology Y1 - 2000 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-9337 SN - 1558-2531 VL - 47 IS - 6 SP - 729 EP - 737 ER -