title: Autonomic mediation in the interdependences between cardiocortical activity time variations and between cardiorespiratory activity time variations in the lizard, Gallotia galloti.
abstract: Multivariate nonlinear analysis methods were applied to variability time series extracted from electrocardiographic, electrocorticographic and respiratory activities of Gallotia galloti lizards, to study interdependences between cardio-cortical activity time variations, and between cardio-respiratory activity time variations. Autonomic nervous system involvement in the mediation of such interdependences was investigated through pharmacological blockade. Cardiac variability was evaluated from the R-R intervals of the electrocardiogram (RRIv). Cortical (CORTv) and respiratory (RESPv) activity time variations were evaluated from power-data signals derived from both electrocorticogram and respiratory signal segments obtained within each R-R interval, respectively. A nonlinear index N to measure interdependence between the signals, and a surrogate data test to measure the significance and nature of the interdependences were used. A nonlinear dependence of RRIv vs. CORTv and of RRIv vs. RESPv was found. Both dependences seem to be unconnected with the functioning of both alpha(1)-adrenoceptor and cholinoceptor systems, but appear to be mediated by beta-adrenoceptor mechanisms. A linear dependence of CORTv vs. RRIv and of RESPv vs. RRIv was also found. Both dependences seem to be unconnected with the operation of alpha(1)-adrenoceptor, beta-adrenoceptor and cholinoceptor systems. It is suggested that both the cardiocortical and cardiorespiratory synchronizations studied seem to be mediated by beta-adrenoceptor mechanisms.
authors.affiliation: Laboratory of Biophysics, Department of Physiology, Faculty of Medicine, University of La Laguna, 38071-La Laguna, Tenerife, Canary Islands, Spain. lvera@ull.es
authors.forename: Luis
authors.initials: L
authors.lastname: De Vera
authors.forename: Alejandro
authors.initials: A
authors.lastname: Santana
authors.forename: Ernesto
authors.initials: E
authors.lastname: Pereda
authors.forename: Julian J
authors.initials: JJ
authors.lastname: Gonzalez
mesh_terms: D000818:Animals; D004562:Electrocardiography; D006321:Heart / Q000502:physiology*; D008116:Lizards / Q000502:physiology*; D012119:Respiration; D013997:Time Factors