A growing number of studies have identified sex differences in response to general anesthesia;however,the underlying neural mechanisms are unclear.The medial preoptic area(MPA),an important sexually dimorphic structur...A growing number of studies have identified sex differences in response to general anesthesia;however,the underlying neural mechanisms are unclear.The medial preoptic area(MPA),an important sexually dimorphic structure and a critical hub for regulating consciousness transition,is enriched with estrogen receptor alpha(ERa),particularly in neuronal clusters that participate in regulating sleep.We found that male mice were more sensitive to sevoflurane.Pharmacological inhibition of ERαin the MPA abolished the sex differences in sevoflurane anesthesia,in particular by extending the induction time and facilitating emergence in males but not in females.Suppression of ERαin vitro inhibited GABAergic and glutamatergic neurons of the MPA in males but not in females.Furthermore,ERα.knockdown in GABAergic neurons of the male MPA was sufficient to eliminate sex differences during sevoflurane anesthesia.Collectively,MPA ERαpositively regulates the activity of MPA GABAergic neurons in males but not in females,which contributes to the sexdifference of mice in sevoflurane anesthesia.展开更多
BACKGROUND： Neurons expressing gamma-aminobutyric acid （GABA） play an important role in the regulation of wakefulness to sleep, as well as the maintenance of sleep. However, the role of GABAergic neurons in the tub...BACKGROUND： Neurons expressing gamma-aminobutyric acid （GABA） play an important role in the regulation of wakefulness to sleep, as well as the maintenance of sleep. However, the role of GABAergic neurons in the tuberomammillary nucleus （TMn）, with regard to the sleep-wakefulness cycle, is poorly understood. OBJECTIVE： To investigate the effects of GABAergic neurons in the TMn on the sleep-wakefulness cycle. DESIGN, TIME AND SETTING： Randomized controlled study, performed at the Laboratory of Neurobiology, Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Lanzhou University from July 2007 to February 2008. MATERIALS： Fifteen healthy, adult, male, Sprague Dawley rats were randomly divided into three groups（n = 5）： control, ventrolateral preoptic area （VLPO） lesion, and VLPO lesion plus GABAA receptor antagonist-treated. Ibotenic acid and bicuculline were provided by Sigma （St. Louis, USA）. METHODS： Four electroencephalogram screw electrodes were implanted into the skull at a frontal region （two） and parietal bones （two） on each side. Three flexible electromyogram wire electrodes were placed into the nuchal muscles. On day 8, a fine glass micropipette （10–20 mm tip diameter） containing ibotenic acid solution （10 nmol/L） was injected into the VLPO in both hemispheres following bone wax removal under anesthesia. One week after the second surgery, sleep-wakefulness states were recorded in rats from the VLPO lesion group. On day 10 after VLPO lesion, bicuculline （10 nmol/L）, a GABAA-receptor antagonist, was microinjected into the TMn and sleep-wakefulness states were recorded for 24 hours. MAIN OUTCOME MEASURES： Duration of the sleep-wakefulness cycle in each group using a Data acquisition unit （Micro1 401 mk2） and Data collection software （Spike Ⅱ）. RESULTS： VLPO lesion induced an increased duration of wakefulness （W, 13.17%） and light slow-wave sleep （SWS1, 28.9%）, respectively. Deep slow-wave sleep （SWS2, 43.74%） and paradoxical sleep （PS, 44.07%） were respectively decreased for 24 hours at day 9 post-lesion, compared with pre-lesion （P 〈 0.01）. Microinjection of bicuculline into the TMn following VLPO lesion at 10：00 am on the 10th day elicited a wake state for 40–55 minutes, with a latency of 15 minutes. However, 24-hour sleep-wake states demonstrated that the ratio of W and SWS1 were increased by 12.61% （P 〈 0.01） and 50.97% （P 〈 0.01）, respectively. In addition, SWS2 and PS were decreased by 68.08% （P 〈 0.01） and 39.92% （P 〈 0.05）, respectively, compared with prior to VLPO lesion. CONCLUSION： The evidence of decreased deep slow-wave sleep, which was induced by VLPO lesion, suggested that GABAergic neurons in the VLPO play an important role in maintaining sleep. Bicuculline microinjection into the TMn, following VLPO lesion, elicited wakefulness and sleep depression for 50 minutes, with contrary increased light slow-wave sleep for 24 hours, which suggested that GABAergic neurons in the TMn play a role in sleep drive （sleepiness） via local circuit to directly inhibit histaminergic neurons.展开更多
Gonadotropin-releasing hormone （GnRH） neurons in the preoptic area may undergo morphological changes during the pubertal period when their activities are upregulated. To clarify the regulatory mechanism of puberty o...Gonadotropin-releasing hormone （GnRH） neurons in the preoptic area may undergo morphological changes during the pubertal period when their activities are upregulated. To clarify the regulatory mechanism of puberty onset, this study aimed to investigate the morphological changes of GnRH neurons in the preoptic area of GnRH-enhanced green fluorescent protein transgenic rats. Under confocal laser microscopy, pubertal GnRH neurons exhibited an inverted Y distribution pattern. Prepubertal GnRH neurons were generally unipolar and bipolar, and were distinguished as smooth type cells with few small processes or irregular type cells with many spine-like processes in the proximal dendrites. The number of GnRH neurons in the preoptic area and spine-like processes were increased during the course of reproductive maturation. There was no significant difference between male and female rats. Immunofluorescence staining revealed synaptophysin punctae close to the distal end of GnRH neurons, indicating that some presynaptic terminals may form a synaptic linkage with these neurons.展开更多
BACKGROUND： It has been shown that interleukin-1β（IL-1β） can induce fever by activating vascular endothelial cells and macrophages of the supraoptic crest to generate prostaglandin E2, which binds with receptors ...BACKGROUND： It has been shown that interleukin-1β（IL-1β） can induce fever by activating vascular endothelial cells and macrophages of the supraoptic crest to generate prostaglandin E2, which binds with receptors of the thermo-sensitive hypothalamic neurons. Lonicera japonica is one of the medicinal plants used widely in Asia for its antipyretic properties. However, these mechanisms have not yet been intensively studied. OBJECTIVE： To investigate the antipyretic effect and mechanisms of Lonicera japonica on IL-1β- induced febrile New Zealand rabbits by observing expression changes of E-type prostaglandin receptor-3 （EP3） mRNA in the preoptic anterior hypothalamus （POAH）. DESIGN： A randomized controlled study. SETTING： Electrophysiological Laboratory at the Department of Pathophysiology, Medical College of Jinan University; Department of Orthopaedics, First Hospital Affiliated to Medical College of Jinan University. MATERIALS： The experiment was performed from April to December 2005, using a total of 32 New Zealand white rabbits of both sexes, weighing 1.5 2.0 kg. All the animal experiments were performed according to the internationally accepted ethical guidelines. Lonicera japonica injection was purchased from Huanghe pharmaceutical factory of Xi＇an, China. IL-1βwas purchased from Sigma, USA. METHODS： A total of 32 rabbits were divided randomly into four groups： ① Normal saline （NS） control group;② Lonicerajaponica treatment group; ③ IL-1βtreatment group; and ④Lonicerajaponica plus IL-1βtreatment group. In the first 3 groups, the rabbits were given separate intravenous （i.v.） injections of l mL NS, l mL Lonicera japonica, and 100 ng IL-l β （dissolved in 0.9% NS without pyrogen）. In the Lonicerajaponica plus IL-1βgroup each rabbit was given i.v. injections of l mL NS and, 30 minutes later, 100 ng IL-1 β. MAIN OUTCOME MEASURES： Colonic temperature of each rabbit was measured at 0, 10, 20, 30, 40, 50, 60, and 70 minutes after injection and the maximum temperature rise （ A T） and the temperature response index after l hour （TRII） was calculated. Subsequently, in situ hybridization （ISH） was done with an ISH kit, EP3 mRNA expression in the POAH of all groups was measured （number of positive cells and average gray scale value）. RESULTS： A total of 32 rabbits were included in the result analysis, without any loss, （i） A T and TRII： there was no significant difference between the Lonicera japonica group and NS group （P 〉 0.05）. The IL-1β group was significantly greater compared to NS group （P 〈 0.01）. The Lonicera japonica plus IL-1β group was significantly less than the IL-1β group （P 〈 0.05）. ② In the NS and Lonicera japonica groups, the EP3 mRNA expression was negative （no coloration） or only weakly positive （only a few brown yellow particles in the cytoplasm cells could not be identified）. The number of positive cells and the average gray scale value were not significantly different between the two groups （P 〉 0.05）. In the IL-1β group, the number of positive cells was remarkably higher and the average gray scale value was lower than the NS group （P 〈 0.0 l）. In the Lonicera japonica plus IL-1β group, the number of positive cells was significantly less than the IL-1β group （P 〈 0.05）. However, the average gray scale value was greater than the IL-1β group （P 〈 0.05）. CONCLUSION： Lonicera japonica has obvious antipyretic effects on IL-1β-induced febrile rabbits and acts by inhibiting expression of EP3 mRNA in the POAH.展开更多
The preoptic area （POA） is located in the most anterior part of the hypothalamus and is bordered dorsally by the anterior commissure and anteroventrally by the nucleus of the diagonal band of Broca[1]. Accumulating ...The preoptic area （POA） is located in the most anterior part of the hypothalamus and is bordered dorsally by the anterior commissure and anteroventrally by the nucleus of the diagonal band of Broca[1]. Accumulating evidence from developmental neurobiology suggests, however, that the POA may be a separate entity from hypothalamus, and may actually be part of the basal telencephalon[2,3]. Both the hypothalamus and POA are highly complex and heterogeneous areas, containing multiple nuclei, each of which has specific fundamental functions for survival. Among these, the POA contains nuclei involved in the regulation of blood osmolality and temperature （the median preoptic nucleus）, sleep （the ventrolateral preoptic and suprachiasmatic nuclei）, ovulation （gonadotropin-releasing hormone neurons scattered mainly in the ventral part of the POA）, male sexual behavior （the medial preoptic nucleus）, and parental behavior （the central part of the medial POA, cMPOA）.展开更多
Objective： To investigate the effect of activation of angiotensin Ⅱ（AngⅡ） type 1 （AT1） receptors in the median preoptic nucleus （MnPO） of rats on renal sodium excretion. Methods： After anesthesia, the rats w...Objective： To investigate the effect of activation of angiotensin Ⅱ（AngⅡ） type 1 （AT1） receptors in the median preoptic nucleus （MnPO） of rats on renal sodium excretion. Methods： After anesthesia, the rats were injected into the MnPO via an implanted cannula. Urine samples were collected via a bladder cannula, and the urine sodium concentration was assayed with flame spectrophotometry. The serum level of endogenous digitalis-like factor （EDLF） and Na^＋,K^＋-ATPase activity in the renal cortex tissue were assayed respectively with a radioimmunoassay and with an ammonium molybdophosphate-based kit. Results： Both the urinary volume and the sodium excretion peaked 60 min after AngⅡ was administered into the MnPO. The responses were accompanied by an increase in serum EDLF and a decrease in Na^＋,K^＋-ATPase activity in the renal cortex. The responses of diuresis and natriuresis, as well as an increase in serum EDLF and a decrease in Na^＋,K^＋-ATPase activity in the renal cortex induced by MnPO adminstration with AngⅡ were inhibited by pior treatment with the AngⅡ receptor blocking agent losartan into the MnPO. Conclusion： These results suggest that activation of AT1 receptors in the MnPO of rat induces diuretic and natriuretic responses. The responses are associated with an increase release of EDLF and with the inhibition of Na^＋,K^＋-ATPase activity in renal cortex tissue.展开更多
Objective:To examine the effect of an neurokinin 3 receptor(NK3R)agonist,senktide,on neuronal nitric oxide synthase(nNOS)activation in the median eminence-arcuate nucleus(ME-ARC)and preoptic area(POA)regions of the hy...Objective:To examine the effect of an neurokinin 3 receptor(NK3R)agonist,senktide,on neuronal nitric oxide synthase(nNOS)activation in the median eminence-arcuate nucleus(ME-ARC)and preoptic area(POA)regions of the hypothalamus across proestrus,diestrus,and ovariectomized states in female rats and its correlation with luteinizing hormone(LH)secretion.Methods:Adult female Sprague-Dawley rats were examined for proestrus and diestrus phases of the estrous cycle.Female rats were categorized into proestrus and diestrus groups,and each was further divided into four subgroups(n=4).In both the diestrus and proestrus categories,Group 1 was the control group.Groups 2,3,and 4 received senktide(100μg/kg-1),NK3R antagonist SB222200(10 mg/kg-1),and SB222200 followed by senktide,respectively.To evaluate the effect of sex steroids on NK3R agonist-induced nNOS activation,female rats underwent bilateral ovariectomy and were divided into four groups(n=3).Group 1 served as the control.Group 2 received a subcutaneous injection of 17β-estradiol 3-benzoate(E2,3μg/rat).Group 3 received E2 and progesterone(30μg/rat).Group 4 was administered senktide(100μg/kg).Female rats from each group were sacrificed,blood was collected for LH ELISA,and hypothalamic tissues were collected for Western blotting.Results:Senktide increased nNOS phosphorylation in the ME-ARC during both the proestrus and diestrus phases.In the POA,senktide increased nNOS phosphorylation only during the diestrus phase.In ovariectomized rats,senktide activated nNOS independent of sex steroid levels.Senktide also increased serum LH concentration in diestrus and ovariectomized female rats.Conclusions:Senktide,an NK3R agonist,activates nNOS in the POA and ME-ARC regions of the hypothalamus in a phase dependent manner.The activation of nNOS by senktide suggests a potential mechanism by which neurokinin B triggers nNOS activation in the ARC and POA regions and regulates GnRH/LH secretion.展开更多
Many research works through out the world show that the preoptic area(POA) is a region concerned with analgesia. Electric stimulation to this region could enhance markedly pain threshold and exert an analgesic effect....Many research works through out the world show that the preoptic area(POA) is a region concerned with analgesia. Electric stimulation to this region could enhance markedly pain threshold and exert an analgesic effect. Central 5-hydroxytryptamine (5-HT) plays an important role in pain mediation. Acupuncture could accelerate the synthe-展开更多
Several studies showed that sex hormone receptors are in close relationship with classical neurotransmitter neurons especially catecholaminergic(CA) neurons. There are many gonadotrophin releasing hormone (GnRH) neuro...Several studies showed that sex hormone receptors are in close relationship with classical neurotransmitter neurons especially catecholaminergic(CA) neurons. There are many gonadotrophin releasing hormone (GnRH) neurons in hypothalamus and the medial preoptic area (MPO). Electrical stimulation of MPO can cause a rise in secretion展开更多
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
基金This workwas supported by,the National Natural Science Foundation of China(82071554 and 81620108012).
文摘A growing number of studies have identified sex differences in response to general anesthesia;however,the underlying neural mechanisms are unclear.The medial preoptic area(MPA),an important sexually dimorphic structure and a critical hub for regulating consciousness transition,is enriched with estrogen receptor alpha(ERa),particularly in neuronal clusters that participate in regulating sleep.We found that male mice were more sensitive to sevoflurane.Pharmacological inhibition of ERαin the MPA abolished the sex differences in sevoflurane anesthesia,in particular by extending the induction time and facilitating emergence in males but not in females.Suppression of ERαin vitro inhibited GABAergic and glutamatergic neurons of the MPA in males but not in females.Furthermore,ERα.knockdown in GABAergic neurons of the male MPA was sufficient to eliminate sex differences during sevoflurane anesthesia.Collectively,MPA ERαpositively regulates the activity of MPA GABAergic neurons in males but not in females,which contributes to the sexdifference of mice in sevoflurane anesthesia.
基金the National Natural Science Foundation of China, No. 30670677
文摘BACKGROUND： Neurons expressing gamma-aminobutyric acid （GABA） play an important role in the regulation of wakefulness to sleep, as well as the maintenance of sleep. However, the role of GABAergic neurons in the tuberomammillary nucleus （TMn）, with regard to the sleep-wakefulness cycle, is poorly understood. OBJECTIVE： To investigate the effects of GABAergic neurons in the TMn on the sleep-wakefulness cycle. DESIGN, TIME AND SETTING： Randomized controlled study, performed at the Laboratory of Neurobiology, Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Lanzhou University from July 2007 to February 2008. MATERIALS： Fifteen healthy, adult, male, Sprague Dawley rats were randomly divided into three groups（n = 5）： control, ventrolateral preoptic area （VLPO） lesion, and VLPO lesion plus GABAA receptor antagonist-treated. Ibotenic acid and bicuculline were provided by Sigma （St. Louis, USA）. METHODS： Four electroencephalogram screw electrodes were implanted into the skull at a frontal region （two） and parietal bones （two） on each side. Three flexible electromyogram wire electrodes were placed into the nuchal muscles. On day 8, a fine glass micropipette （10–20 mm tip diameter） containing ibotenic acid solution （10 nmol/L） was injected into the VLPO in both hemispheres following bone wax removal under anesthesia. One week after the second surgery, sleep-wakefulness states were recorded in rats from the VLPO lesion group. On day 10 after VLPO lesion, bicuculline （10 nmol/L）, a GABAA-receptor antagonist, was microinjected into the TMn and sleep-wakefulness states were recorded for 24 hours. MAIN OUTCOME MEASURES： Duration of the sleep-wakefulness cycle in each group using a Data acquisition unit （Micro1 401 mk2） and Data collection software （Spike Ⅱ）. RESULTS： VLPO lesion induced an increased duration of wakefulness （W, 13.17%） and light slow-wave sleep （SWS1, 28.9%）, respectively. Deep slow-wave sleep （SWS2, 43.74%） and paradoxical sleep （PS, 44.07%） were respectively decreased for 24 hours at day 9 post-lesion, compared with pre-lesion （P 〈 0.01）. Microinjection of bicuculline into the TMn following VLPO lesion at 10：00 am on the 10th day elicited a wake state for 40–55 minutes, with a latency of 15 minutes. However, 24-hour sleep-wake states demonstrated that the ratio of W and SWS1 were increased by 12.61% （P 〈 0.01） and 50.97% （P 〈 0.01）, respectively. In addition, SWS2 and PS were decreased by 68.08% （P 〈 0.01） and 39.92% （P 〈 0.05）, respectively, compared with prior to VLPO lesion. CONCLUSION： The evidence of decreased deep slow-wave sleep, which was induced by VLPO lesion, suggested that GABAergic neurons in the VLPO play an important role in maintaining sleep. Bicuculline microinjection into the TMn, following VLPO lesion, elicited wakefulness and sleep depression for 50 minutes, with contrary increased light slow-wave sleep for 24 hours, which suggested that GABAergic neurons in the TMn play a role in sleep drive （sleepiness） via local circuit to directly inhibit histaminergic neurons.
文摘Gonadotropin-releasing hormone （GnRH） neurons in the preoptic area may undergo morphological changes during the pubertal period when their activities are upregulated. To clarify the regulatory mechanism of puberty onset, this study aimed to investigate the morphological changes of GnRH neurons in the preoptic area of GnRH-enhanced green fluorescent protein transgenic rats. Under confocal laser microscopy, pubertal GnRH neurons exhibited an inverted Y distribution pattern. Prepubertal GnRH neurons were generally unipolar and bipolar, and were distinguished as smooth type cells with few small processes or irregular type cells with many spine-like processes in the proximal dendrites. The number of GnRH neurons in the preoptic area and spine-like processes were increased during the course of reproductive maturation. There was no significant difference between male and female rats. Immunofluorescence staining revealed synaptophysin punctae close to the distal end of GnRH neurons, indicating that some presynaptic terminals may form a synaptic linkage with these neurons.
基金Grants from the National Natural Science Foundation of China, No. 39600061National Administration of Traditional Chinese Medicine, No.2003LHR13+3 种基金Medical Science Foundation of Guangdong Province, No. A2004327, A2006334the Natural Science Foundation of Guangdong, No. 04010443, 06105246 Administration Bureau of Traditional Chinese Medicine of Guangdong Province, No.1040074Technology Bureau of Guangzhou, No. 2007J1-C0041
文摘BACKGROUND： It has been shown that interleukin-1β（IL-1β） can induce fever by activating vascular endothelial cells and macrophages of the supraoptic crest to generate prostaglandin E2, which binds with receptors of the thermo-sensitive hypothalamic neurons. Lonicera japonica is one of the medicinal plants used widely in Asia for its antipyretic properties. However, these mechanisms have not yet been intensively studied. OBJECTIVE： To investigate the antipyretic effect and mechanisms of Lonicera japonica on IL-1β- induced febrile New Zealand rabbits by observing expression changes of E-type prostaglandin receptor-3 （EP3） mRNA in the preoptic anterior hypothalamus （POAH）. DESIGN： A randomized controlled study. SETTING： Electrophysiological Laboratory at the Department of Pathophysiology, Medical College of Jinan University; Department of Orthopaedics, First Hospital Affiliated to Medical College of Jinan University. MATERIALS： The experiment was performed from April to December 2005, using a total of 32 New Zealand white rabbits of both sexes, weighing 1.5 2.0 kg. All the animal experiments were performed according to the internationally accepted ethical guidelines. Lonicera japonica injection was purchased from Huanghe pharmaceutical factory of Xi＇an, China. IL-1βwas purchased from Sigma, USA. METHODS： A total of 32 rabbits were divided randomly into four groups： ① Normal saline （NS） control group;② Lonicerajaponica treatment group; ③ IL-1βtreatment group; and ④Lonicerajaponica plus IL-1βtreatment group. In the first 3 groups, the rabbits were given separate intravenous （i.v.） injections of l mL NS, l mL Lonicera japonica, and 100 ng IL-l β （dissolved in 0.9% NS without pyrogen）. In the Lonicerajaponica plus IL-1βgroup each rabbit was given i.v. injections of l mL NS and, 30 minutes later, 100 ng IL-1 β. MAIN OUTCOME MEASURES： Colonic temperature of each rabbit was measured at 0, 10, 20, 30, 40, 50, 60, and 70 minutes after injection and the maximum temperature rise （ A T） and the temperature response index after l hour （TRII） was calculated. Subsequently, in situ hybridization （ISH） was done with an ISH kit, EP3 mRNA expression in the POAH of all groups was measured （number of positive cells and average gray scale value）. RESULTS： A total of 32 rabbits were included in the result analysis, without any loss, （i） A T and TRII： there was no significant difference between the Lonicera japonica group and NS group （P 〉 0.05）. The IL-1β group was significantly greater compared to NS group （P 〈 0.01）. The Lonicera japonica plus IL-1β group was significantly less than the IL-1β group （P 〈 0.05）. ② In the NS and Lonicera japonica groups, the EP3 mRNA expression was negative （no coloration） or only weakly positive （only a few brown yellow particles in the cytoplasm cells could not be identified）. The number of positive cells and the average gray scale value were not significantly different between the two groups （P 〉 0.05）. In the IL-1β group, the number of positive cells was remarkably higher and the average gray scale value was lower than the NS group （P 〈 0.0 l）. In the Lonicera japonica plus IL-1β group, the number of positive cells was significantly less than the IL-1β group （P 〈 0.05）. However, the average gray scale value was greater than the IL-1β group （P 〈 0.05）. CONCLUSION： Lonicera japonica has obvious antipyretic effects on IL-1β-induced febrile rabbits and acts by inhibiting expression of EP3 mRNA in the POAH.
文摘The preoptic area （POA） is located in the most anterior part of the hypothalamus and is bordered dorsally by the anterior commissure and anteroventrally by the nucleus of the diagonal band of Broca[1]. Accumulating evidence from developmental neurobiology suggests, however, that the POA may be a separate entity from hypothalamus, and may actually be part of the basal telencephalon[2,3]. Both the hypothalamus and POA are highly complex and heterogeneous areas, containing multiple nuclei, each of which has specific fundamental functions for survival. Among these, the POA contains nuclei involved in the regulation of blood osmolality and temperature （the median preoptic nucleus）, sleep （the ventrolateral preoptic and suprachiasmatic nuclei）, ovulation （gonadotropin-releasing hormone neurons scattered mainly in the ventral part of the POA）, male sexual behavior （the medial preoptic nucleus）, and parental behavior （the central part of the medial POA, cMPOA）.
基金supported by the Science Foundation of Zhuhai Municipality (PC20052031)
文摘Objective： To investigate the effect of activation of angiotensin Ⅱ（AngⅡ） type 1 （AT1） receptors in the median preoptic nucleus （MnPO） of rats on renal sodium excretion. Methods： After anesthesia, the rats were injected into the MnPO via an implanted cannula. Urine samples were collected via a bladder cannula, and the urine sodium concentration was assayed with flame spectrophotometry. The serum level of endogenous digitalis-like factor （EDLF） and Na^＋,K^＋-ATPase activity in the renal cortex tissue were assayed respectively with a radioimmunoassay and with an ammonium molybdophosphate-based kit. Results： Both the urinary volume and the sodium excretion peaked 60 min after AngⅡ was administered into the MnPO. The responses were accompanied by an increase in serum EDLF and a decrease in Na^＋,K^＋-ATPase activity in the renal cortex. The responses of diuresis and natriuresis, as well as an increase in serum EDLF and a decrease in Na^＋,K^＋-ATPase activity in the renal cortex induced by MnPO adminstration with AngⅡ were inhibited by pior treatment with the AngⅡ receptor blocking agent losartan into the MnPO. Conclusion： These results suggest that activation of AT1 receptors in the MnPO of rat induces diuretic and natriuretic responses. The responses are associated with an increase release of EDLF and with the inhibition of Na^＋,K^＋-ATPase activity in renal cortex tissue.
基金supported by DST-Science and Engineering Research Board(SERB)Early carrier research grant ECR/2015/000240Core research grant CRG/2020/003257,the University Grants Commission(UGC start-up grant F.30-318/2016)the Central University of Punjab RSM grant-CUPB/CC/16/00/13.
文摘Objective:To examine the effect of an neurokinin 3 receptor(NK3R)agonist,senktide,on neuronal nitric oxide synthase(nNOS)activation in the median eminence-arcuate nucleus(ME-ARC)and preoptic area(POA)regions of the hypothalamus across proestrus,diestrus,and ovariectomized states in female rats and its correlation with luteinizing hormone(LH)secretion.Methods:Adult female Sprague-Dawley rats were examined for proestrus and diestrus phases of the estrous cycle.Female rats were categorized into proestrus and diestrus groups,and each was further divided into four subgroups(n=4).In both the diestrus and proestrus categories,Group 1 was the control group.Groups 2,3,and 4 received senktide(100μg/kg-1),NK3R antagonist SB222200(10 mg/kg-1),and SB222200 followed by senktide,respectively.To evaluate the effect of sex steroids on NK3R agonist-induced nNOS activation,female rats underwent bilateral ovariectomy and were divided into four groups(n=3).Group 1 served as the control.Group 2 received a subcutaneous injection of 17β-estradiol 3-benzoate(E2,3μg/rat).Group 3 received E2 and progesterone(30μg/rat).Group 4 was administered senktide(100μg/kg).Female rats from each group were sacrificed,blood was collected for LH ELISA,and hypothalamic tissues were collected for Western blotting.Results:Senktide increased nNOS phosphorylation in the ME-ARC during both the proestrus and diestrus phases.In the POA,senktide increased nNOS phosphorylation only during the diestrus phase.In ovariectomized rats,senktide activated nNOS independent of sex steroid levels.Senktide also increased serum LH concentration in diestrus and ovariectomized female rats.Conclusions:Senktide,an NK3R agonist,activates nNOS in the POA and ME-ARC regions of the hypothalamus in a phase dependent manner.The activation of nNOS by senktide suggests a potential mechanism by which neurokinin B triggers nNOS activation in the ARC and POA regions and regulates GnRH/LH secretion.
文摘Many research works through out the world show that the preoptic area(POA) is a region concerned with analgesia. Electric stimulation to this region could enhance markedly pain threshold and exert an analgesic effect. Central 5-hydroxytryptamine (5-HT) plays an important role in pain mediation. Acupuncture could accelerate the synthe-
文摘Several studies showed that sex hormone receptors are in close relationship with classical neurotransmitter neurons especially catecholaminergic(CA) neurons. There are many gonadotrophin releasing hormone (GnRH) neurons in hypothalamus and the medial preoptic area (MPO). Electrical stimulation of MPO can cause a rise in secretion
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.
