title: Weakened long-range correlation of renal sympathetic nerve activity in Wistar rats after anaesthesia.
abstract: In this study we employed multiscale entropy (MSE) measurement to assess the long-range temporal correlation (LRTC) of multifibre renal sympathetic nerve activity (RSNA) signals in conscious and anaesthetized Wistar rats. It was found that both groups presented more complex MSE profiles than an uncorrelated process. Moreover, the results of MSE analysis of RSNA demonstrated that the entropy values, derived from the conscious group, increased on small time scales and then stabilized to a relatively constant value, however, the entropy measure, derived from animals with anaesthesia, almost monotonically decreased. The present study shows that while LRTC in the temporal dynamics of energy fluctuations of RSNA does not implicate a unique mechanism, the data for the first time provide evidence of much less temporal correlation in anaesthetized condition. This suggests the fractal properties of underlying dynamical system have been effectively eliminated by anaesthesia. These results demonstrate that apparently random fluctuations in multifibre RSNA are dictated by a complex deterministic process that imparts "long-term" memory to the dynamic system. However, this memory is significantly weakened by anaesthesia.
authors.affiliation: Key Laboratory of Bioactive Materials, Ministry of Education and the College of Life Sciences, Nankai University, Tianjin 300071, PR China.
authors.forename: Yatang
authors.initials: Y
authors.lastname: Li
authors.forename: Jiaheng
authors.initials: J
authors.lastname: Qiu
authors.forename: Rui
authors.initials: R
authors.lastname: Yan
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Yang
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
mesh_terms: D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D002698:Chloralose / Q000494:pharmacology; D003243:Consciousness / Q000502:physiology; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004737:Enflurane; D019277:Entropy; D017709:Fractals; D007668:Kidney / Q000294:innervation* / Q000502:physiology; D008297:Male; D017711:Nonlinear Dynamics; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012077:Renal Artery / Q000294:innervation / Q000502:physiology; D017779:Sympathetic Fibers, Postganglionic / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D014520:Urethane / Q000494:pharmacology
chemical_list: D000777:Anesthetics; D002698:Chloralose; D014520:Urethane; D004737:Enflurane