Drive dependent neural functional of the self-organisation of global drive reduction: an interspecies comparison

Abstract

Introduction: We have repeatedly demonstrated the practical significance of a 0.15 Hz rhythm band in the cutaneous perfusion patterns (e.g. 1). In order to study the origin of this rhythm, we studied and analysed a set of physiological systems in the frequency domain in dog and in man by modifying the level of activation. In dog this was achieved using anesthetics and in man using relaxation techniques. Methods: An adult male mongrel dog (BW18kg) was administered additional chloralose-urethane after fading of the initial anesthesia. Invasively recorded were blood pressure, intrapleural pressure, and extracellular neural activity of reticular neurons in the brainstem. In man, an expert (female, 56 yrs.) practiced autogenic training while non-invasively recording blood pressure, thoracic excursions, and forehead skin perfusion. Analysis used non-linear routines: Morlet-Wavelet time frequency spectra, Pointwise transinformation. Results: In both species, non-linear analysis unveiled identical dynamics in response to the experimental maneuvers as the 0.15 Hz emerged first in unspecific neurons to appear in all other cardiovascular time series. Discussion: The reticular formation (RF) in the lower brainstem was shown to be responsible for the generation of cardio-vascular-respiratory rhythms in mammals in a frequency band at 0.15 Hz. This rhythm emerged in unspecific reticular neurons of the RF not associated with any specific nuclei. This rhythm was therefore referred to as the reticular rhythm (retR) which was not identical with the respiratory rhythm, but both were coordinated exhibiting temporarily phase- and frequency-coupling (2,3).