Fever is an adaptive host response coordinated by the central nervous system (CNS) during systemic immune challenge. Recent research shed light on the mechanism of fever generation, particularly the underlying neura...Fever is an adaptive host response coordinated by the central nervous system (CNS) during systemic immune challenge. Recent research shed light on the mechanism of fever generation, particularly the underlying neural pathways. In this review, we first briefly summarize current views on the mechanism of sensing microbial infection by the nervous system, and the roles of prostaglandin E2 (PGE2) and its receptors in fever; then we focus on the neural circuits underlying fever generation, particularly their relationship with the distribution of PGE2 receptors within the CNS. At the end, an overall neurochemical model of fever generation is presented, pointing to the direction for future studies.展开更多
AIM: To investigate the acupuncture-modulated gastric motility and its underlying neural mechanism.METHODS: Intragastric pressure and/or waves of gastric contraction in rats were recorded by intrapyloric balloon and c...AIM: To investigate the acupuncture-modulated gastric motility and its underlying neural mechanism.METHODS: Intragastric pressure and/or waves of gastric contraction in rats were recorded by intrapyloric balloon and changes of gastric motility induced by acupuncture stimulation were compared with the background activity before any stimulation. Gastro-vagal or splanchnic-sympathetic nerves were recorded or cut respectively for investigating the involvement of autonomic nerve pathways. Spinalization experiment was also performed.RESULTS: Acupuncture-stimulation by exciting Aδ and/or C afferent fibers, could only modulate gastric motility. Acupuncture-stimulation on fore- and hind-limbs evoked a moderate gastric motility followed by increased vagus discharges with unchanged sympathetic activity, while the same stimulus to the acupoints in abdomen resulted in reversed effects on gastric motility and autonomic nervous activities. The inhibitory gastric response was completely abolished by splanchnic denervation, but the facilitative gastric response to stimulation of acupoints in limbs was not influenced, which was opposite to the effect when vagotomy was performed. The similar depressive effects were produced by the stimulation at the acupoints homo-segmental to the gastric innervation in the animals with or without spinalization. However, the facilitation induced by the stimulation at the acupoints hetero-segmental to the gastric innervation was not observed in the spinalized animals.CONCLUSION: Facilitative effects of stimulating hetero-segmental acupoints are involved in the intact preparation of vagal nerves and spinal cord, while the inhibitory response induced by stimulating homo-segmental acupoints is involved in the intact preparation of sympathetic nerves. Only the acupuncture-stimulation with intensity over the threshold of Aδ and/or C afferent fibers can markedly modulate gastrointestinal motility.展开更多
Objective: To elucidate the role of the autonomic nervous system (ANS) in acute mountain sickness (AMS) during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level residents rapidl...Objective: To elucidate the role of the autonomic nervous system (ANS) in acute mountain sickness (AMS) during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level residents rapidly ascended to Tibet plateau (3 675 m altitude) by airplane from Chengdu plain (560 m altitude). ANS function was tested in plain and day 2–4 in Tibet by heart rate variability (HRV), cold pressor test (CPT). AMS was evaluated by clinic symptomatic scores. All subjects were divided into non-AMS group (57, scores≤4) and AMS group (42, scores>4). Results: Compared with non-AMS group, AMS group had higher standard deviation of normal to normal intervals (SDNN), root mean square of delta RR (rMSSD), low-frequency (LF) power, and normalized low-frequency (LFnu) power in plain (P<0.05). After arrival at 3 675 m altitude, AMS group had greater reduction in percentage of delta RR>50 ms(PNN50), rMSSD (P<0.01) and SDNN, LF, total power (TP) (P<0.05). Although no significant differences in the increase of SP and DP during CPT were found between 2 groups in plain, the SP increase during CPT of AMS group was less than non-AMS group (P<0.05) at 3 675 m altitude. AMS symptomatic scores was not only positively correlated with SDNN, rMSSD, LF/HF in plain (P<0.05), but also negatively correlated with HFnu in plain (P<0.05). Conclusion: During the initial high altitude exposure, ANS modulation is generally blunted, but the relatively predominant sympathetic control is enhanced, and this characteristic change of ANS function is positively correlated with the development of AMS.展开更多
Sepsis and related syndromes are the major cause of multiple organ failure and death in patients with critical illnesses. Neuroendocrine dysfunction has long been thought to be an important event in sepsis. In clinic,...Sepsis and related syndromes are the major cause of multiple organ failure and death in patients with critical illnesses. Neuroendocrine dysfunction has long been thought to be an important event in sepsis. In clinic, optimal management of the hormones could alleviate severe complications in sepsis. In this article, we review the dysfunction ofneuroendocrine system as well as autonomic nervous system in sepsis, and summarize the respective therapy strategies.展开更多
Objective: To investigate the changes of autonomic nervous system (ANS) function during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level male residents were studied in Chengdu ...Objective: To investigate the changes of autonomic nervous system (ANS) function during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level male residents were studied in Chengdu plain and then Tibet plateau. Heart rate variability (HRV), cold pressor test (CPT), resting heart rate (HR) and blood pressure (BP) were measured at baseline (560 m altitude) and in 2 to 4 d after arriving at Tibet plateau (3 675 m altitude) to assess the ANS function. Results: Compared with baseline, on day 2 in Tibet the standard deviation of normal to normal intervals (SDNN), high-frequency (HF) power, total power (TP), root mean square of delta RR (rMSSD), percentage of delta RR>50 ms (PNN50), normalized high-frequency (HFnu) and fractal dimension (FD) decreased significantly (SDNN, HF, TP P<0.01, rMSSD, PNN50, HFnu, FD P<0.05), while the normalized low-frequency (LFnu) and LF/HF increased significantly (P<0.01). During day 3–4 in Tibet, SDNN, rMSSD, HF, TP and HFnu tended to rebound while LFnu and LF/HF decreased towards baseline day by day. In addition, in Tibet the increase in systolic pressure (SP) and diastolic pressure (DP) during CPT decreased significantly (P<0.01, 0.05), but resting HR increased compared with baseline (P<0.01). Conclusion: ANS modulation is generally blunted, and the relatively predominant sympathetic control is enhanced originally, then it reverts to the sea level states gradually during the initial days of acute high-altitude exposure.展开更多
Objectives: Heart rate variability (HRV) can be a simple, non-invasive method of gauging cardiac autonomic nervous system fluctuations across periodised training workloads and taper in elite athlete populations. Th...Objectives: Heart rate variability (HRV) can be a simple, non-invasive method of gauging cardiac autonomic nervous system fluctuations across periodised training workloads and taper in elite athlete populations. The purpose of these three case studies was to examine daily cardiac autonomic variations in Paralympic athletes leading in to the Paralympic games. Methods: Three Paralympie gold medallist swimmers were monitored daily for their resting HRV over a 17-week monitoring period leading up to the Paralympic games. Specific time- and frequency-domain measures, along with non-linear indices of HRV were calculated for all analyses. All HRV data were analysed individually using daily values, weekly average values, and average values for rest and training phases. Results: A significant difference in HRV was seen for all variables between athlete 1 and athletes 2 and 3 (amputee disabilities) during the entire monitoring period. Conclusion: Despite minimal long-term changes, both swimming classification and disability type significantly influence HRV during athlete monitoring. An increased understanding of individual responses to training, travel, and other outside influences affecting Paralympic athletes could potentially lead to improved management and monitoring of training workloads for enhanced nerformance.展开更多
Disturbance of the inflammatory response in the gut is important in several clinical diseases ranging from inflmmatory bowel disease to postoperative ileus. Several feedback mechanisms exist that control the inflammat...Disturbance of the inflammatory response in the gut is important in several clinical diseases ranging from inflmmatory bowel disease to postoperative ileus. Several feedback mechanisms exist that control the inflammatory cascade and avoid collateral damage. In the gast rointestinal tract, it is of particular importance tocontrol the immune response to maintain the balance that allows dietary up take and utilization of nutrientson one hand, while preventing invasion of bacteria and toxins on the other hand. The process of digestion and absorption of nutrients requires a relative hyporesponsiveness of the immune cells in the gut to luminacontents which is not yet fully understood. Recentlythe autonomic nervous system has been identifi ed asan important pathway to control local and systemic inflammation and gut barrier integrity. Activation of thepathway is possible via electrical or via pharm acological interventions, but is also achieved in a physiologicamanner by ingestion of dietary lipids. Administration of dietary lipids has been shown to be very effectivein reducing the inflammatory cascade and maintaining intestinal barrier integrity in several experimental studies. This beneficial effect of nutrition on the inflammatory response and intestinal barrier integrity opens new therapeutic opportunities for treatment of certain gastrointestinal disorders. Furthermore, this neural feedback mechanism provides more insight in the relative hyporesponsiveness of the immune cells in the gut. Here, we will discuss the regulatory function of the autonomic nervous system on the inflammatory response and gut barrier function and the potential benefit in a clinical setting.展开更多
A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural n...A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural network (GRNN) with incorporation of feature extraction method using principle component analysis. In the risk based security assessment formulation, the failure rate associated to weather condition of each line was used to compute the probability of line outage for a given weather condition and the extent of security violation was represented by a severity function. For low voltage and line overload, continuous severity function was considered due to its ability to zoom in into the effect of near violating contingency. New severity function for voltage collapse using the voltage collapse prediction index was proposed. To reduce the computational burden, a new contingency screening method was proposed using the risk factor so as to select the critical line outages. The risk based security assessment method using GRNN was implemented on a large scale 87-bus power system and the results show that the risk prediction results obtained using GRNN with the incorporation of principal component analysis give better performance in terms of accuracy.展开更多
Integrative Body-Mind Training(IBMT) originates from ancient Eastern tradition.The method stresses no effort to control thoughts,but instead a state of restful alertness that allows a high degree of awareness of the...Integrative Body-Mind Training(IBMT) originates from ancient Eastern tradition.The method stresses no effort to control thoughts,but instead a state of restful alertness that allows a high degree of awareness of the body,breathing,and external instructions.A series of studies indicates that IBMT improves attention and self-regulation through interaction between the central(brain) and the autonomic(body) nervous systems.The present review mainly summarizes the recent results of IBMT studies and proposes how it changes the state of brain and body to lead to positive outcomes.Future directions in this field are also discussed.展开更多
Mental states such as stress and anxiety can cause heart disease.On the other hand,meditation can improve cardiac performance.In this study,the heart rate variability,directed transfer function and corrected condition...Mental states such as stress and anxiety can cause heart disease.On the other hand,meditation can improve cardiac performance.In this study,the heart rate variability,directed transfer function and corrected conditional entropy were used to investigate the effects of mental tasks on cardiac performance,and the functional coupling between the cerebral cortex and the heart.When subjects tried to decrease their heart rate by volition,the sympathetic nervous system was inhibited and the heart rate decreased.When subjects tried to increase their heart rate by volition,the parasympathetic nervous system was inhibited and the sympathetic nervous system was stimulated,and the heart rate increased.When autonomic nervous system activity was regulated by mental tasks,the information flow from the post-central areas to the pre-central areas of the cerebral cortex increased,and there was greater coupling between the brain and the heart.Use of directed transfer function and corrected conditional entropy techniques enabled analysis of electroencephalographic recordings,and of the information flow causing functional coupling between the brain and the heart.展开更多
Objective: According to the theory of traditional Chinese medicine, the effect of cervical stimulation on autonomic nervous system activity in humans was investigated. Methods: Healthy young male volunteers were sel...Objective: According to the theory of traditional Chinese medicine, the effect of cervical stimulation on autonomic nervous system activity in humans was investigated. Methods: Healthy young male volunteers were selected as subjects of the trial. The upper cervical spine (C2-5) was stimulated bilaterally with spinal manipulation, and changes in heart rate and heart rate variability were calculated as measures of effects on autonomic nervous system tone. Results: Thirty healthy young male volunteers were tested. It was found that heart rate decreased (R-R interval prolonged) significantly. SDNN and total power spectrum increased significantly, indicating an increase in sympathetic tone. Conclusion: Cervical manipulation can regulate the autonomic nervous system tone in healthy young men, and it suggests a possibility of treating cardiovascular diseases such as arrhythmia with cervical manipulation.展开更多
文摘Fever is an adaptive host response coordinated by the central nervous system (CNS) during systemic immune challenge. Recent research shed light on the mechanism of fever generation, particularly the underlying neural pathways. In this review, we first briefly summarize current views on the mechanism of sensing microbial infection by the nervous system, and the roles of prostaglandin E2 (PGE2) and its receptors in fever; then we focus on the neural circuits underlying fever generation, particularly their relationship with the distribution of PGE2 receptors within the CNS. At the end, an overall neurochemical model of fever generation is presented, pointing to the direction for future studies.
基金Supported by National Natural Science Foundation of China, No. C30100245 National Basic Research 973 Program, No. 2005CB523308
文摘AIM: To investigate the acupuncture-modulated gastric motility and its underlying neural mechanism.METHODS: Intragastric pressure and/or waves of gastric contraction in rats were recorded by intrapyloric balloon and changes of gastric motility induced by acupuncture stimulation were compared with the background activity before any stimulation. Gastro-vagal or splanchnic-sympathetic nerves were recorded or cut respectively for investigating the involvement of autonomic nerve pathways. Spinalization experiment was also performed.RESULTS: Acupuncture-stimulation by exciting Aδ and/or C afferent fibers, could only modulate gastric motility. Acupuncture-stimulation on fore- and hind-limbs evoked a moderate gastric motility followed by increased vagus discharges with unchanged sympathetic activity, while the same stimulus to the acupoints in abdomen resulted in reversed effects on gastric motility and autonomic nervous activities. The inhibitory gastric response was completely abolished by splanchnic denervation, but the facilitative gastric response to stimulation of acupoints in limbs was not influenced, which was opposite to the effect when vagotomy was performed. The similar depressive effects were produced by the stimulation at the acupoints homo-segmental to the gastric innervation in the animals with or without spinalization. However, the facilitation induced by the stimulation at the acupoints hetero-segmental to the gastric innervation was not observed in the spinalized animals.CONCLUSION: Facilitative effects of stimulating hetero-segmental acupoints are involved in the intact preparation of vagal nerves and spinal cord, while the inhibitory response induced by stimulating homo-segmental acupoints is involved in the intact preparation of sympathetic nerves. Only the acupuncture-stimulation with intensity over the threshold of Aδ and/or C afferent fibers can markedly modulate gastrointestinal motility.
文摘Objective: To elucidate the role of the autonomic nervous system (ANS) in acute mountain sickness (AMS) during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level residents rapidly ascended to Tibet plateau (3 675 m altitude) by airplane from Chengdu plain (560 m altitude). ANS function was tested in plain and day 2–4 in Tibet by heart rate variability (HRV), cold pressor test (CPT). AMS was evaluated by clinic symptomatic scores. All subjects were divided into non-AMS group (57, scores≤4) and AMS group (42, scores>4). Results: Compared with non-AMS group, AMS group had higher standard deviation of normal to normal intervals (SDNN), root mean square of delta RR (rMSSD), low-frequency (LF) power, and normalized low-frequency (LFnu) power in plain (P<0.05). After arrival at 3 675 m altitude, AMS group had greater reduction in percentage of delta RR>50 ms(PNN50), rMSSD (P<0.01) and SDNN, LF, total power (TP) (P<0.05). Although no significant differences in the increase of SP and DP during CPT were found between 2 groups in plain, the SP increase during CPT of AMS group was less than non-AMS group (P<0.05) at 3 675 m altitude. AMS symptomatic scores was not only positively correlated with SDNN, rMSSD, LF/HF in plain (P<0.05), but also negatively correlated with HFnu in plain (P<0.05). Conclusion: During the initial high altitude exposure, ANS modulation is generally blunted, but the relatively predominant sympathetic control is enhanced, and this characteristic change of ANS function is positively correlated with the development of AMS.
基金This study was supported by grants from the National Basic Research Program of China (No. 2005CB522602) and the National Natural Science Foundation of China (No. 30973120, No. 30672178, No. 30872683).
文摘Sepsis and related syndromes are the major cause of multiple organ failure and death in patients with critical illnesses. Neuroendocrine dysfunction has long been thought to be an important event in sepsis. In clinic, optimal management of the hormones could alleviate severe complications in sepsis. In this article, we review the dysfunction ofneuroendocrine system as well as autonomic nervous system in sepsis, and summarize the respective therapy strategies.
文摘Objective: To investigate the changes of autonomic nervous system (ANS) function during the initial phase at acute high-altitude exposure. Methods: Ninety-nine healthy sea-level male residents were studied in Chengdu plain and then Tibet plateau. Heart rate variability (HRV), cold pressor test (CPT), resting heart rate (HR) and blood pressure (BP) were measured at baseline (560 m altitude) and in 2 to 4 d after arriving at Tibet plateau (3 675 m altitude) to assess the ANS function. Results: Compared with baseline, on day 2 in Tibet the standard deviation of normal to normal intervals (SDNN), high-frequency (HF) power, total power (TP), root mean square of delta RR (rMSSD), percentage of delta RR>50 ms (PNN50), normalized high-frequency (HFnu) and fractal dimension (FD) decreased significantly (SDNN, HF, TP P<0.01, rMSSD, PNN50, HFnu, FD P<0.05), while the normalized low-frequency (LFnu) and LF/HF increased significantly (P<0.01). During day 3–4 in Tibet, SDNN, rMSSD, HF, TP and HFnu tended to rebound while LFnu and LF/HF decreased towards baseline day by day. In addition, in Tibet the increase in systolic pressure (SP) and diastolic pressure (DP) during CPT decreased significantly (P<0.01, 0.05), but resting HR increased compared with baseline (P<0.01). Conclusion: ANS modulation is generally blunted, and the relatively predominant sympathetic control is enhanced originally, then it reverts to the sea level states gradually during the initial days of acute high-altitude exposure.
文摘Objectives: Heart rate variability (HRV) can be a simple, non-invasive method of gauging cardiac autonomic nervous system fluctuations across periodised training workloads and taper in elite athlete populations. The purpose of these three case studies was to examine daily cardiac autonomic variations in Paralympic athletes leading in to the Paralympic games. Methods: Three Paralympie gold medallist swimmers were monitored daily for their resting HRV over a 17-week monitoring period leading up to the Paralympic games. Specific time- and frequency-domain measures, along with non-linear indices of HRV were calculated for all analyses. All HRV data were analysed individually using daily values, weekly average values, and average values for rest and training phases. Results: A significant difference in HRV was seen for all variables between athlete 1 and athletes 2 and 3 (amputee disabilities) during the entire monitoring period. Conclusion: Despite minimal long-term changes, both swimming classification and disability type significantly influence HRV during athlete monitoring. An increased understanding of individual responses to training, travel, and other outside influences affecting Paralympic athletes could potentially lead to improved management and monitoring of training workloads for enhanced nerformance.
文摘Disturbance of the inflammatory response in the gut is important in several clinical diseases ranging from inflmmatory bowel disease to postoperative ileus. Several feedback mechanisms exist that control the inflammatory cascade and avoid collateral damage. In the gast rointestinal tract, it is of particular importance tocontrol the immune response to maintain the balance that allows dietary up take and utilization of nutrientson one hand, while preventing invasion of bacteria and toxins on the other hand. The process of digestion and absorption of nutrients requires a relative hyporesponsiveness of the immune cells in the gut to luminacontents which is not yet fully understood. Recentlythe autonomic nervous system has been identifi ed asan important pathway to control local and systemic inflammation and gut barrier integrity. Activation of thepathway is possible via electrical or via pharm acological interventions, but is also achieved in a physiologicamanner by ingestion of dietary lipids. Administration of dietary lipids has been shown to be very effectivein reducing the inflammatory cascade and maintaining intestinal barrier integrity in several experimental studies. This beneficial effect of nutrition on the inflammatory response and intestinal barrier integrity opens new therapeutic opportunities for treatment of certain gastrointestinal disorders. Furthermore, this neural feedback mechanism provides more insight in the relative hyporesponsiveness of the immune cells in the gut. Here, we will discuss the regulatory function of the autonomic nervous system on the inflammatory response and gut barrier function and the potential benefit in a clinical setting.
文摘A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural network (GRNN) with incorporation of feature extraction method using principle component analysis. In the risk based security assessment formulation, the failure rate associated to weather condition of each line was used to compute the probability of line outage for a given weather condition and the extent of security violation was represented by a severity function. For low voltage and line overload, continuous severity function was considered due to its ability to zoom in into the effect of near violating contingency. New severity function for voltage collapse using the voltage collapse prediction index was proposed. To reduce the computational burden, a new contingency screening method was proposed using the risk factor so as to select the critical line outages. The risk based security assessment method using GRNN was implemented on a large scale 87-bus power system and the results show that the risk prediction results obtained using GRNN with the incorporation of principal component analysis give better performance in terms of accuracy.
基金supported by the National Natural Science Foundation of China (60971096)National Basic Research Development Program of China (973 Program,2012CB518200)
文摘Integrative Body-Mind Training(IBMT) originates from ancient Eastern tradition.The method stresses no effort to control thoughts,but instead a state of restful alertness that allows a high degree of awareness of the body,breathing,and external instructions.A series of studies indicates that IBMT improves attention and self-regulation through interaction between the central(brain) and the autonomic(body) nervous systems.The present review mainly summarizes the recent results of IBMT studies and proposes how it changes the state of brain and body to lead to positive outcomes.Future directions in this field are also discussed.
基金supported by the National Natural Science Foundation of China(61302011)
文摘Mental states such as stress and anxiety can cause heart disease.On the other hand,meditation can improve cardiac performance.In this study,the heart rate variability,directed transfer function and corrected conditional entropy were used to investigate the effects of mental tasks on cardiac performance,and the functional coupling between the cerebral cortex and the heart.When subjects tried to decrease their heart rate by volition,the sympathetic nervous system was inhibited and the heart rate decreased.When subjects tried to increase their heart rate by volition,the parasympathetic nervous system was inhibited and the sympathetic nervous system was stimulated,and the heart rate increased.When autonomic nervous system activity was regulated by mental tasks,the information flow from the post-central areas to the pre-central areas of the cerebral cortex increased,and there was greater coupling between the brain and the heart.Use of directed transfer function and corrected conditional entropy techniques enabled analysis of electroencephalographic recordings,and of the information flow causing functional coupling between the brain and the heart.
文摘Objective: According to the theory of traditional Chinese medicine, the effect of cervical stimulation on autonomic nervous system activity in humans was investigated. Methods: Healthy young male volunteers were selected as subjects of the trial. The upper cervical spine (C2-5) was stimulated bilaterally with spinal manipulation, and changes in heart rate and heart rate variability were calculated as measures of effects on autonomic nervous system tone. Results: Thirty healthy young male volunteers were tested. It was found that heart rate decreased (R-R interval prolonged) significantly. SDNN and total power spectrum increased significantly, indicating an increase in sympathetic tone. Conclusion: Cervical manipulation can regulate the autonomic nervous system tone in healthy young men, and it suggests a possibility of treating cardiovascular diseases such as arrhythmia with cervical manipulation.