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Role of forebrain in blood pressure control during paradoxical sleep
WS6-B2-1-10 ROLE OF FOREBRAIN IN BLOOD PRESSURE CONTROL DURING PARADOXICAL SLEEP. H. Sei 1, N. Kanamori 2, K. Sakai 3, M. Yamamoto 4, Y. Morita 1, M. Jouvet 3. 1) Dept. Physiol., Sch. Med., The Univ. Tokushima, Tokushima, Japan. 2) Dept. Physiol., Sch. Dent., The Univ. Tokushima, Tokushima, Japan. 3) Dept. Exp. Med., Univ. Claude Bernard, Lyon, France. 4) Dept. Inform. Eng., Fac. Eng., Tohoku Univ. Sendai, Japan. We have investigated the role of forebrain structures in the control of blood pressure (BP) during sleep, especially paradoxical sleep (PS). Using a new telemetric system for BP recordings, we have investigated long-term postoperative changes in BP during sleep in freely moving cats. In the initial postoperative stage lasting 2 to 5 days, the BP decreased during the transition from slowwave sleep (SWS) to PS and maintained its lower level until the end of PS. In contrast, in the latter chronic stage, the BP increased tonically during the transition from SWS to PS and maintained its higher level throughout PS on which several phasic rises in BP were superimposed. A significant increase in BP during the transition period began shortly after the first appearance of PGO waves. Significant phasic rises in BP during PS shortly preceded the onset of PGO wave bursts. Furthermore, we made the cats transected at the pontomesencephalic border of brainstem. The transected cats exhibited periodically PS-like phases with muscle atonia and PGO waves. BP showed consistently a sustained fall without vivid phasic increases during PS-like throughout the survival periods of one month or more. These results indicate that the cats exhibit both tonic and phasic increases in BP during PS just as in other animal species and human and that forebrain structures are responsible for these alterations.
W S 6 - B 2 - 1 - 11 M U L T I S T A T E A N D M U L T I V A R I A T E A N A L Y S I S OF C A R D I O V A S C U L A R D Y N A M I C S M. Nakao 1, Y. Mizutani 1, M. Yamamoto 1, M. Munakata 2, Y. Imai 2, and K. Abe 2 1) Graduate School of Information Sciences 2) 2nd Department of Medicine, School of Medicine Tohoku University, Sendal 980-77, JAPAN Cardiovascular system has many physiological variables such as heart rate and blood pressure which are mutually interacting. Besides, its dynamics is known to change associated with the physiological states including sleep, posture, and exercise. Therefore, firstly, the cardiovascular dynamics multivariate analysis and modeling are essential. Secondly, the relationship among state-dependent dynamics could be important aspect to characterize the cardiovascular dynamics from the synthetic point of view in addition to understanding the dynamics in each state. According to this concept, we have been investigating the state-dependent dynamics of cardiovascular variables during sleep and wakefulness. Subjetcs were 9 normal males (aged 21-24). Four biological signals, electrocardiogram, systolic blood pressure (BP), thoracic impeadance change (dZ/dt) and respiration rhythm (RSP) were recorded simultaneously as to four physiological states including standing (STD), supine (SUP), slow wave sleep (SWS), rapid eye movement sleep (REM). For the analysis, four cardiovascular variables, RR (R-R intervals), BP, SV (stroke volume calculated from recorded dZ/dt), and RSP. Recordings have been made several times for each subject. These four variables were sampled beat by beat and subject to the four-dimensional multivariate autoregressive (MAR) modeling. The Kullback-Leibler divergence between cardiovascular variables is calculated in terms of the power spectral density estimated by the MAR parameters. Using this "distance" measure, the mutual relationship between cariovascular dynamics during two states can be defined as a matrix (K-L matrix). Firstly, the state-dependency of the relationship between the corresponding variables was studied based on the above distance measure. Since the distances between the dynamics in the different records during SWS were within a small range, the remarkably constant dynamics were shown during SWS in spite that the records were obtained from the different episodes, on the different days, and from the different subjects. From those results, the state-dependency was described in reference to the dynamics of the corresponding variables during SWS. For REM and SUP, the dynamics of RR and BP during REM were shown to tend to deviate slightly from those during SWS. For STD, on the contrary to the previous states, the dynamics of RR during STD were shown to tend to deviate from that during SWS. In addition, almost state-independent dynamics of SV was pronounced. Next, the state-dependency of the relationship between the different variables was studied based on the distance between their dynamics within the same state. Common features worth noting were the consistent relationship between the different variables through the records in SWS. Besides, the consistent relationship between different variables in STD and its deviation from that of SWS were also remarked. Shortly, the important findings were the consistency of the cardiovascular dynamics during SWS. The relationship between the corresponding variables was found to be highly constant through the records of SWS. Concerning the different variables, almost the consistent relationship through the records was observed in SWS. Actually, data should be accumulated to verify those observations and to obtain more detail perspectives concerning the state-dependency of the cardiovascular dynamics. However, the consistency of the cardiovascular dynamics during SWS is worth investigating further as a possible candidate of a basis of characterization.
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W S 6 - B 2 - 1 - 11 M U L T I S T A T E A N D M U L T I V A R I A T E A N A L Y S I S OF C A R D I O V A S C U L A R D Y N A M I C S M. Nakao 1, Y. Mizutani 1, M. Yamamoto 1, M. Munakata 2, Y. Imai 2, and K. Abe 2 1) Graduate School of Information Sciences 2) 2nd Department of Medicine, School of Medicine Tohoku University, Sendal 980-77, JAPAN Cardiovascular system has many physiological variables such as heart rate and blood pressure which are mutually interacting. Besides, its dynamics is known to change associated with the physiological states including sleep, posture, and exercise. Therefore, firstly, the cardiovascular dynamics multivariate analysis and modeling are essential. Secondly, the relationship among state-dependent dynamics could be important aspect to characterize the cardiovascular dynamics from the synthetic point of view in addition to understanding the dynamics in each state. According to this concept, we have been investigating the state-dependent dynamics of cardiovascular variables during sleep and wakefulness. Subjetcs were 9 normal males (aged 21-24). Four biological signals, electrocardiogram, systolic blood pressure (BP), thoracic impeadance change (dZ/dt) and respiration rhythm (RSP) were recorded simultaneously as to four physiological states including standing (STD), supine (SUP), slow wave sleep (SWS), rapid eye movement sleep (REM). For the analysis, four cardiovascular variables, RR (R-R intervals), BP, SV (stroke volume calculated from recorded dZ/dt), and RSP. Recordings have been made several times for each subject. These four variables were sampled beat by beat and subject to the four-dimensional multivariate autoregressive (MAR) modeling. The Kullback-Leibler divergence between cardiovascular variables is calculated in terms of the power spectral density estimated by the MAR parameters. Using this "distance" measure, the mutual relationship between cariovascular dynamics during two states can be defined as a matrix (K-L matrix). Firstly, the state-dependency of the relationship between the corresponding variables was studied based on the above distance measure. Since the distances between the dynamics in the different records during SWS were within a small range, the remarkably constant dynamics were shown during SWS in spite that the records were obtained from the different episodes, on the different days, and from the different subjects. From those results, the state-dependency was described in reference to the dynamics of the corresponding variables during SWS. For REM and SUP, the dynamics of RR and BP during REM were shown to tend to deviate slightly from those during SWS. For STD, on the contrary to the previous states, the dynamics of RR during STD were shown to tend to deviate from that during SWS. In addition, almost state-independent dynamics of SV was pronounced. Next, the state-dependency of the relationship between the different variables was studied based on the distance between their dynamics within the same state. Common features worth noting were the consistent relationship between the different variables through the records in SWS. Besides, the consistent relationship between different variables in STD and its deviation from that of SWS were also remarked. Shortly, the important findings were the consistency of the cardiovascular dynamics during SWS. The relationship between the corresponding variables was found to be highly constant through the records of SWS. Concerning the different variables, almost the consistent relationship through the records was observed in SWS. Actually, data should be accumulated to verify those observations and to obtain more detail perspectives concerning the state-dependency of the cardiovascular dynamics. However, the consistency of the cardiovascular dynamics during SWS is worth investigating further as a possible candidate of a basis of characterization.
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