Prostate-derived IL-1β upregulates expression of NMDA receptor in the paraventricular nucleus and shortens ejaculation latency in rats with experimental autoimmune prostatitis / 亚洲男科学杂志(英文版)

Experimental autoimmune prostatitis (EAP)-induced persistent inflammatory immune response can significantly upregulate the expression of N-methyl-D-aspartic acid (NMDA) receptors in the paraventricular nucleus (PVN). However, the mechanism has not yet been elucidated. Herein, we screened out the target prostate-derived inflammation cytokines (PDICs) by comparing the inflammatory cytokine levels in peripheral blood and cerebrospinal fluid (CSF) between EAP rats and their controls. After identifying the target PDIC, qualified males in initial copulatory behavior testing (CBT) were subjected to implanting tubes onto bilateral PVN. Next, they were randomly divided into four subgroups (EAP-1, EAP-2, Control-1, and Control-2). After 1-week recovery, EAP-1 rats were microinjected with the target PDIC inhibitor, Control-1 rats were microinjected with the target PDIC, while the EAP-2 and Control-2 subgroups were only treated with the same amount of artificial CSF (aCSF). Results showed that only interleukin-1β(IL-1β) had significantly increased mRNA-expression in the prostate of EAP rats compared to the controls (P < 0.001) and significantly higher protein concentrations in both the serum (P = 0.001) and CSF (P < 0.001) of the EAP groups compared to the Control groups. Therefore, IL-1β was identified as the target PDIC which crosses the blood-brain barrier, thereby influencing the central nervous system. Moreover, the EAP-1 subgroup displayed a gradually prolonged ejaculation latency (EL) in the last three CBTs (all P < 0.01) and a significantly lower expression of NMDA NR1 subunit in the PVN (P = 0.043) compared to the respective control groups after a 10-day central administration of IL-1β inhibitors. However, the Control-1 subgroup showed a gradually shortened EL (P < 0.01) and a significantly higher NR1 expression (P = 0.004) after homochronous IL-1β administration. Therefore, we identified IL-1β as the primary PDIC which shortens EL in EAP rats. However, further studies should be conducted to elucidate the specific molecular mechanisms through which IL-1β upregulates NMDA expression.

Angiotensin Type 1 Receptors and Superoxide Anion Production in Hypothalamic Paraventricular Nucleus Contribute to Capsaicin-Induced Excitatory Renal Reflex and Sympathetic Activation / 神经科学通报·英文版

Chemical stimulation of the kidney increases sympathetic activity and blood pressure in rats. The hypothalamic paraventricular nucleus (PVN) is important in mediating the excitatory renal reflex (ERR). In this study, we examined the role of molecular signaling in the PVN in mediating the capsaicin-induced ERR and sympathetic activation. Bilateral PVN microinjections were performed in rats under anesthesia. The ERR was elicited by infusion of capsaicin into the cortico-medullary border of the right kidney. The reflex was evaluated as the capsaicin-induced changes in left renal sympathetic nerve activity and mean arterial pressure. Blockade of angiotensin type 1 receptors with losartan or inhibition of angiotensin-converting enzyme with captopril in the PVN abolished the capsaicin-induced ERR. Renal infusion of capsaicin significantly increased NAD(P)H oxidase activity and superoxide anion production in the PVN, which were prevented by ipsilateral renal denervation or microinjection of losartan into the PVN. Furthermore, either scavenging of superoxide anions or inhibition of NAD(P)H oxidase in the PVN abolished the capsaicin-induced ERR. We conclude that the ERR induced by renal infusion of capsaicin is mediated by angiotensin type 1 receptor-related NAD(P)H oxidase activation and superoxide anion production within the PVN.

Mu-opioid receptors in the paraventricular nucleus regulate ejaculatory behaviors via the sympathetic nerve system in male rats / 中华男科学杂志

Objective@#To explore the effects of the mu-opioid receptor (MOR) in the paraventricular nucleus (PVN) on the ejaculatory behaviors of male rats and its potential mechanisms.@*METHODS@#Male SD rats with normal ejaculation ability were mated with female ones in hormone-induced estrus. After bilateral PVN microinjection of D-Ala-2-Me-Phe-4-Gly-ol enkephalin (DAGO) or D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP) with an inserted catheter, the male animals were observed for mount latency (ML), mount frequency (MF), intromission latency (IL), intromission frequency (IF), ejaculation latency (EL), ejaculation frequency (EF), post-ejaculation interval (PEI), and intromission ratio (IR). The lumbar sympathetic nerve activity (LSNA) of the rats was recorded using the PowerLab data acquisition hardware device, and the levels of norepinephrine (NE) in the peripheral plasma were measured by ELISA following microinjection of saline or different doses of DAGO or CTAP.@*RESULTS@#Neither CTAP nor DGAO significantly affected the ML of the male rats (P > 0.05). DGAO remarkably increased IF (P < 0.01) and MF (P < 0.01), prolonged IL (P < 0.01), EL (P < 0.01) and PEI (P < 0.01), and reduced EF (P <0.01) and IR (P < 0.05). On the contrary, CTAP markedly decreased IF (P < 0.01) and MF (P < 0.01), shortened IL (P < 0.01), EL (P < 0.01) and PFI (P < 0.01), and elevated EF (P < 0.01) and IR (P < 0.01). Additionally, DAGO decreased LSNA in a dose-dependent manner and reduced the NE level in the peripheral plasma. CTAP, however, not only offset the effects of DAGO on LSNA, but also significantly increased LSNA.@*CONCLUSIONS@#MOR in PVN inhibits ejaculatory behaviors in male rats by weakening LSNA, which has provided some theoretical evidence for the use of highly selective opioids in the treatment of premature ejaculation.

Involvement of GABAergic projection from central amygdaloid nucleus to paraventricular nucleus of hypothalamus in electroacupuncture induced regulation of gastric function in GAD2-Cre mice / 针刺研究

OBJECTIVE: To explore the effect of γ-aminobutyric acid (GABA)ergic neuronal circuit of the central amygdaloid nucleus (CeA) and the paraventricular nucleus of hypothalamus (PVN) on electroacupuncture (EA)-induced regulation of gastric function by way of CeA-PVN projection. METHODS: The present study included 3 parts: 1) C57BL/6 mice were randomly divided into control and EA groups (n=6 in each group). EA was applied to right "Weishu"(BL21, Back-shu point) and "Zhongwan"(CV12, Front-mu point) for 20 min, followed by detecting the expression of c-fos in the CeA and PVN by using immunofluorescence staining; 2) Microinjection of anterograde tracer (rAAV-EF1α-DIO-mcherry-WPRE-pA) into the CeA was conducted in GAD2-Cre mice for confirming the projection of GABAergic neurons from CeA to PVN; 3) GAD2-Cre mice were randomly divided into rAAV-DIO-mcherry (intra-CeA injection of rAAV-EF1α-DIO-mcherry-WPRE-pA), rAAV-DIO-hM3D（Gq）-mcherry(intra-CeA injection of rAAV-EF1α-DIO-hM3D(Gq)-mcherry-WPRE-pA) and rAAV-DIO-hM3D（Gq）-mcherry+EA groups(n=6 in each group). The food intake and gastric empty were detected, and the concentration of GABA in the PVN was assayed by using high performance liquid chromatography on the 28th day after intra-CeA injection. RESULTS: 1) The expression of c-fos in the CeA and PVN was significantly increased in the EA group relevant to the control group(P<0.01), suggesting an activation of neurons in both CeA and PVN after EA. 2) Following CeA injection of rAAV-EF1α-DIO-mcherry-WPRE-pA, the densely expressed virus GABAergic neurons were found in CeA and large number of projection fibers found in the PVN, suggesting a direct connection between CeA and PVN. 3) After activating the GABAergic neurons of CeA, the concentration of GABA in the PVN was obviously increased (P<0.01), the food intake and the gastric empty were considerably decreased relevant to the rAAV-DIO-mcherry group(P<0.01). Following EA intervention，the concentration of GABA in the PVN was obviously decreased(P<0.01), the food intake and the gastric empty were significantly increased relevant to the rAAV-DIO-hM3D（Gq）-mcherry group (P<0.01). CONCLUSION: EA of BL21 and CV12 (Back-shu and Front-mu acupoints) can increase food intake and gastric empty in GAD2-Cre mice, which may be achieved by suppressing the release of GABA in PVN through CeA-PVN GABAergic neural circuit.

Intermedin in Paraventricular Nucleus Attenuates Sympathoexcitation and Decreases TLR4-Mediated Sympathetic Activation via Adrenomedullin Receptors in Rats with Obesity-Related Hypertension / 神经科学通报·英文版

Intermedin/adrenomedullin-2 (IMD/AM2), a member of the calcitonin gene-related peptide/AM family, plays an important role in protecting the cardiovascular system. However, its role in the enhanced sympathoexcitation in obesity-related hypertension is unknown. In this study, we investigated the effects of IMD in the paraventricular nucleus (PVN) of the hypothalamus on sympathetic nerve activity (SNA), and lipopolysaccharide (LPS)-induced sympathetic activation in obesity-related hypertensive (OH) rats induced by a high-fat diet for 12 weeks. Acute experiments were performed under anesthesia. The dynamic alterations of sympathetic outflow were evaluated as changes in renal SNA and mean arterial pressure (MAP) in response to specific drugs. Male rats were fed a control diet (12% kcal as fat) or a high-fat diet (42% kcal as fat) for 12 weeks to induce OH. The results showed that IMD protein in the PVN was downregulated, but Toll-like receptor 4 (TLR4) and plasma norepinephrine (NE, indicating sympathetic hyperactivity) levels, and systolic blood pressure were increased in OH rats. LPS (0.5 µg/50 nL)-induced enhancement of renal SNA and MAP was greater in OH rats than in obese or control rats. Bilateral PVN microinjection of IMD (50 pmol) caused greater decreases in renal SNA and MAP in OH rats than in control rats, and inhibited LPS-induced sympathetic activation, and these were effectively prevented in OH rats by pretreatment with the AM receptor antagonist AM22-52. The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) inhibitor U0126 in the PVN partially reversed the LPS-induced enhancement of SNA. However, IMD in the PVN decreased the LPS-induced ERK activation, which was also effectively prevented by AM22-52. Chronic IMD administration resulted in significant reductions in the plasma NE level and blood pressure in OH rats. Moreover, IMD lowered the TLR4 protein expression and ERK activation in the PVN, and decreased the LPS-induced sympathetic overactivity. These results indicate that IMD in the PVN attenuates SNA and hypertension, and decreases the ERK activation implicated in the LPS-induced enhancement of SNA in OH rats, and this is mediated by AM receptors.

Blockade of Endogenous Angiotensin-(1-7) in Hypothalamic Paraventricular Nucleus Attenuates High Salt-Induced Sympathoexcitation and Hypertension / 神经科学通报·英文版

Angiotensin (Ang)-(1-7) is an important biologically-active peptide of the renin-angiotensin system. This study was designed to determine whether inhibition of Ang-(1-7) in the hypothalamic paraventricular nucleus (PVN) attenuates sympathetic activity and elevates blood pressure by modulating pro-inflammatory cytokines (PICs) and oxidative stress in the PVN in salt-induced hypertension. Rats were fed either a high-salt (8% NaCl) or a normal salt diet (0.3% NaCl) for 10 weeks, followed by bilateral microinjections of the Ang-(1-7) antagonist A-779 or vehicle into the PVN. We found that the mean arterial pressure (MAP), renal sympathetic nerve activity (RSNA), and plasma norepinephrine (NE) were significantly increased in salt-induced hypertensive rats. The high-salt diet also resulted in higher levels of the PICs interleukin-6, interleukin-1beta, tumor necrosis factor alpha, and monocyte chemotactic protein-1, as well as higher gp91 expression and superoxide production in the PVN. Microinjection of A-779 (3 nmol/50 nL) into the bilateral PVN of hypertensive rats not only attenuated MAP, RSNA, and NE, but also decreased the PICs and oxidative stress in the PVN. These results suggest that the increased MAP and sympathetic activity in salt-induced hypertension can be suppressed by blockade of endogenous Ang-(1-7) in the PVN, through modulation of PICs and oxidative stress.

Chronic Intracerebroventricular Infusion of Metformin Inhibits Salt-Sensitive Hypertension via Attenuation of Oxidative Stress and Neurohormonal Excitation in Rat Paraventricular Nucleus / 神经科学通报·英文版

Metformin (MET), an antidiabetic agent, also has antioxidative effects in metabolic-related hypertension. This study was designed to determine whether MET has anti-hypertensive effects in salt-sensitive hypertensive rats by inhibiting oxidative stress in the hypothalamic paraventricular nucleus (PVN). Salt-sensitive rats received a high-salt (HS) diet to induce hypertension, or a normal-salt (NS) diet as control. At the same time, they received intracerebroventricular (ICV) infusion of MET or vehicle for 6 weeks. We found that HS rats had higher oxidative stress levels and mean arterial pressure (MAP) than NS rats. ICV infusion of MET attenuated MAP and reduced plasma norepinephrine levels in HS rats. It also decreased reactive oxygen species and the expression of subunits of NAD(P)H oxidase, improved the superoxide dismutase activity, reduced components of the renin-angiotensin system, and altered neurotransmitters in the PVN. Our findings suggest that central MET administration lowers MAP in salt-sensitive hypertension via attenuating oxidative stress, inhibiting the renin-angiotensin system, and restoring the balance between excitatory and inhibitory neurotransmitters in the PVN.

Impaired Hypothalamic Regulation of Sympathetic Outflow in Primary Hypertension / 神经科学通报·英文版

The hypothalamic paraventricular nucleus (PVN) is a crucial region involved in maintaining homeostasis through the regulation of cardiovascular, neuroendocrine, and other functions. The PVN provides a dominant source of excitatory drive to the sympathetic outflow through innervation of the brainstem and spinal cord in hypertension. We discuss current findings on the role of the PVN in the regulation of sympathetic output in both normotensive and hypertensive conditions. The PVN seems to play a major role in generating the elevated sympathetic vasomotor activity that is characteristic of multiple forms of hypertension, including primary hypertension in humans. Recent studies in the spontaneously hypertensive rat model have revealed an imbalance of inhibitory and excitatory synaptic inputs to PVN pre-sympathetic neurons as indicated by impaired inhibitory and enhanced excitatory synaptic inputs in hypertension. This imbalance of inhibitory and excitatory synaptic inputs in the PVN forms the basis for elevated sympathetic outflow in hypertension. In this review, we discuss the disruption of balance between glutamatergic and GABAergic inputs and the associated cellular and molecular alterations as mechanisms underlying the hyperactivity of PVN pre-sympathetic neurons in hypertension.

Effects and mechanism of injection of glutamate into hypothalamic paraventricular nucleus on visceral pain in chronic visceral hypersensitivity rats / 中华行为医学与脑科学杂志

Objective@#To investigate the effects of glutamate (Glu) injected into hypothalamic paraventricular nucleus (PVN) on visceral pain of chronic visceral hypersensitivity (CVH) rats and its possible mechanism.@*Methods@#Newborn SD rats were given CVH rat model by colorectal distension (CRD) on the 8th, 10th and 12th day after birth. Thirty rats with successful CVH model were randomly divided into CVH model group (CVH group), CVH + injection of saline into PVN group (NS group), CVH+ injection of Glu into PVN (3, 6, and 12 μg Glu, namely G3, G6, and G12, respectively), 6 rats in each group, and 6 SD rats with matching body mass were taken as sham operation group (Sham group). The pain behavior of the rats was evaluated by pain threshold, abdominal withdrawal reflex (AWR) score, and abdominal external oblique muscle electromyography (EMG). The expression of arginine vasopressin (AVP) and the proliferation of colon tissue were detected by immunohistochemical staining. The apoptosis of colon tissue was detected by TUNEL.@*Results@#Compared with the NS group, the pain thresholds of the G3, G6 and G12 groups increased, and the AWR scores and EMG amplitudes decreased. The differences were statistically significant(Pain threshold: t=7.65, 16.31, 24.78, both P<0.05; AWR scores: t=-2.98, -4.77, -7.29, both P<0.05; EMG amplitudes: t=-3.06, -5.75, -8.92, both P<0.05). Compared with the Sham group, the expression of AVP in PVN of the CVH group and NS group decreased ((42.63±5.20) %, (18.67±2.94) %, (17.53±2.47) %; t=6.95, t=7.56, both P<0.05). The expression of AVP was increased after different doses of Glu into PVN, and the AVP level in G12 group ((18.15±6.49)%) was higher than that of NS group, the difference was statistically significant (t=-4.21, P<0.05). Compared with the Sham group, the expression of PCNA in colonic mucosal cells of the CVH group and NS group decreased ((65.48±1.68) %, (18.39±1.67) %, (17.69±1.68) %; t=34.35, t=34.80, both P<0.05). The expression of PCNA was increased after different doses of Glu injected into PVN, and the PCNA level in G12 group ((59.91±5.63)%) was higher than that of NS group, the difference was statistically significant (t=-12.44, P<0.05). Compared with the Sham group, the expression of apoptotic cells in colonic mucosal cells of the CVH group and NS group increased ((23.38±11.40)%, (83.79±3.57)%, (80.91±2.47)%; t=-8.77, t=-8.54, both P<0.05). The expression of apoptotic cells was decreased after different doses of Glu into PVN, and the G12 group was ((18.15±6.49) %). Compared with NS group, the difference was statistically significant (t=15.65, P<0.05).@*Conclusion@#Injection of Glu into hypothalamic PVN can alleviate the visceral pain behaviors in CVH rats, and its mechanism may be related to arginine vasopressin.

Effects and mechanism of injection of glutamate into hypothalamic paraventricular nucleus on viscer-al pain in chronic visceral hypersensitivity rats / 中华行为医学与脑科学杂志

Objective To investigate the effects of glutamate (Glu) injected into hypothalamic pa-raventricular nucleus (PVN) on visceral pain of chronic visceral hypersensitivity (CVH) rats and its possi-ble mechanism. Methods Newborn SD rats were given CVH rat model by colorectal distension (CRD) on the 8th,10th and 12th day after birth. Thirty rats with successful CVH model were randomly divided into CVH model group (CVH group),CVH + injection of saline into PVN group (NS group),CVH+ injection of Glu into PVN (3,6,and 12 μg Glu,namely G3,G6,and G12,respectively),6 rats in each group,and 6 SD rats with matching body mass were taken as sham operation group (Sham group). The pain behavior of the rats was evaluated by pain threshold,abdominal withdrawal reflex (AWR) score,and abdominal external ob-lique muscle electromyography (EMG). The expression of arginine vasopressin (AVP) and the proliferation of colon tissue were detected by immunohistochemical staining. The apoptosis of colon tissue was detected by TUNEL. Results Compared with the NS group, the pain thresholds of the G3, G6 and G12 groups in-creased,and the AWR scores and EMG amplitudes decreased. The differences were statistically significant (Pain threshold:t=7. 65,16. 31,24. 78,both P<0. 05;AWR scores:t=-2. 98,-4. 77,-7. 29,both P<0. 05;EMG amplitudes:t=-3. 06,-5. 75,-8. 92,both P<0. 05). Compared with the Sham group,the expression of AVP in PVN of the CVH group and NS group decreased ((42. 63±5. 20) %,(18. 67±2. 94) %,(17. 53± 2. 47) %; t=6. 95,t=7. 56,both P<0. 05). The expression of AVP was increased after different doses of Glu into PVN,and the AVP level in G12 group ((18. 15±6. 49)%) was higher than that of NS group,the difference was statistically significant (t=-4. 21,P<0. 05). Compared with the Sham group,the expression of PCNA in colonic mucosal cells of the CVH group and NS group decreased ((65. 48±1. 68) %,(18. 39± 1. 67) %,(17. 69±1. 68) %;t=34. 35,t=34. 80,both P<0. 05). The expression of PCNA was increased after different doses of Glu injected into PVN,and the PCNA level in G12 group ((59. 91±5. 63)%) was higher than that of NS group,the difference was statistically significant (t=-12. 44,P<0. 05). Compared with the Sham group,the expression of apoptotic cells in colonic mucosal cells of the CVH group and NS group increased ((23. 38±11. 40)%,(83. 79± 3. 57)%,(80. 91± 2. 47)%;t=-8. 77,t=-8. 54,both P<0. 05). The expression of apoptotic cells was decreased after different doses of Glu into PVN,and the G12 group was ((18. 15±6. 49) %). Compared with NS group,the difference was statistically significant ( t=15. 65,P<0. 05). Conclusion Injection of Glu into hypothalamic PVN can alleviate the visceral pain be-haviors in CVH rats,and its mechanism may be related to arginine vasopressin.

Alpha-adrenergic receptors in PVT neurons promote recovery from propofol anesthesia / 医学研究生学报

Objective The locus coeruleus noradrenergic system regulates the recovery process of general anesthesia, but its mechanism remains unclear. The locus coeruleus has a large amount of projection to the paraventricular nucleus of the thalamus (PVT). This study was to investigate the effect of the α-noradrenergic receptor in PVT neurons in propofol anesthesia. Methods The immunofluorescence technique was used for comparison of the c-fos expression in the PVT neurons collected from male SD rats under propofol anesthesia (the PA group, n = 4) or no anesthesia (the non-PA group, n = 4) and observation of the activity of PVT neurons. PVT microinjection models were established in 40 rats and randomized into four groups of equal number: noradrenaline, phentolamine, propranolol, and isotonic saline. Under propofol anesthesia, the animals received microinjection of noradrenaline, phentolamine, propranolol, and isotonic saline at 1 μL into the PVT, respectively, and were observed for the time of recovery of righting reflex (RORR) and the δ (1-4 Hz), θ (4-8 Hz), α (8-12 Hz), β (12-25 Hz) and γ waves (25-60 Hz) on EEG before and after microinjection. Results The expression of c-fos was significantly reduced in the PA group compared with that in the non-PA control. The Ca2+ signals in the PVT were significantly increased during the propofol induction of the loss of righting reflex (LORR), but decreased in the early stage of and during propofol anesthesia (P < 0.05), and remarkably increased at the emergence of and during RORR (P < 0.05). In comparison with the isotonic saline control, the noradrenaline group showed markedly shortened time of RORR (837.8 s vs 647.7 s, P < 0.05), reduced rate of δ waves (P < 0.05) and elevated rate of β waves (P < 0.05), while the phentolamine group exhibited prolonged time of RORR (837.8 s vs 1045.1 s, P < 0.05) and increased rate of δ waves after microinjection (P < 0.05). Conclusion The α-noradrenergic receptors in PVT neurons play a critical role in promoting recovery from propofol anesthesia.

Effect of electroacupuncture at "Shenmen"(HT7) and "Sanyinjiao"(SP6) on energy metabolism in paraventricular nucleus of hypothalamus of insomnia rats / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture(EA) at "Shenmen"(HT7) and "Sanyinjiao"(SP6)on energy metabolism in paraventricular nucleus (PVN) of hypothalamus in insomnia rats, so as to explore its mechanism underlying improvement of insomnia. METHODS: A total of 66 SD rats (half male and half female) were randomized into 3 groups：normal control, model and EA groups(n＝22 per group). The insomnia model was established by binding the rat for at least 4 h (step increase of 30 min per day), once daily for 15 days. EA (5 Hz /25 Hz, 0.5－1.0 mA) was applied to unilateral HT7 and SP6 for 15 min, once daily for 5 days. The rats' spontaneous activities during day and night were recorded by using the ClockLab Data Collection and Analysis System, and the duration of exhausted swimming was detected by using load-bearing endurance swimming test. The expression of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) of PVN tissue was assayed by Western blot, and the contents of acetyl coenzyme A (Ac-CoA) and Na＋-K＋adenosine triphosphatase (Na＋-K＋-ATPase) in the PVN tissue, and corticosterone (CORT) in plasma were assayed by ELISA. Changes of the ultrastructure of PVN cells were observed by transmission electron microscope. RESULTS: After modeling, the rats' daytime and nocturnal locomotor activities were significantly increased and decreased, respectively (P<0.05), and the duration of exhausted swimming was considerably shortened in the model group compared with that of the normal control group (P<0.05). The expression level of AMPK protein in the PVN was obviously up-regulated (P<0.05), and the contents of Ac-CoA and Na＋-K＋-ATPase in PVN and CORT in plasma were markedly decreased in the model control group relevant to the normal group (P<0.05). After EA intervention, the increased daytime locomotion and the decreased nocturnal activities, the shortened duration of exhausted swimming, the up-regulated expression of AMPK, and the decreased Ac-CoA, Na＋-K＋-ATPase and CORT contents were all reversed in the EA treated rats relevant to those of the insomnia rats (all P<0.05). Moreover, ultrastructural observation showed mitochondrial swelling and disappearance of partial ribosomes in the plasma of PVN cells in the model group, while in the EA group, only mild swelling of some mitochondria was found, being with basically normal nuclear membrane, mitochondria, rough endoplasmic reticulum, Golgi complex and ribosomes. CONCLUSION: EA at HT7 and SP6 has a positive effect in improving insomnia and insomnia-induced fatigue in insomnia rats, which may be associated with its effects in restraining the expression of AMPK protein, and up-regulating the contents of Ac-CoA and Na＋-K＋-ATPase in PVN and CORT in plasma.

Korean red ginseng excitation of paraventricular nucleus neurons via non-N-methyl-D-aspartate glutamate receptor activation in mice

It has been reported that Korean red ginseng (KRG), a valuable and important traditional medicine, has varied effects on the central nervous system, suggesting its activities are complicated. The paraventricular nucleus (PVN) neurons of the hypothalamus has a critical role in stress responses and hormone secretions. Although the action mechanisms of KRG on various cells and systems have been reported, the direct membrane effects of KRG on PVN neurons have not been fully described. In this study, the direct membrane effects of KRG on PVN neuronal activity were investigated by using a perforated patch-clamp in ICR mice. In gramicidin perforated patch-clamp mode, KRG extract (KRGE) induced repeatable depolarization followed by hyperpolarization of PVN neurons. The KRGE-induced responses were concentration-dependent and persisted in the presence of tetrodotoxin, a voltage sensitive Na+ channel blocker. The KRGE-induced responses were suppressed by 6-cyano-7-nitroquinoxaline-2,3-dione (10 µM), a non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist, but not by picrotoxin, a type A gamma-aminobutyric acid receptor antagonist. The results indicate that KRG activates non-NMDA glutamate receptors of PVN neurons in mice, suggesting that KRG may be a candidate for use in regulation of stress responses by controlling autonomic nervous system and hormone secretion.

Differences in sympathetic nervous system activity and NMDA receptor levels within the hypothalamic paraventricular nucleus in rats with differential ejaculatory behavior / 亚洲男科学杂志(英文版)

Differences in intravaginal ejaculation latency reflect normal biological variation, but the causes are poorly understood. Here, we investigated whether variation in ejaculation latency in an experimental rat model is related to altered sympathetic nervous system (SNS) activity and expression of N-methyl-D-aspartic acid (NMDA) receptors in the paraventricular nucleus of the hypothalamus (PVN). Male rats were classified as "sluggish," "normal," and "rapid" ejaculators on the basis of ejaculation frequency during copulatory behavioral testing. The lumbar splanchnic nerve activity baselines in these groups were not significantly different at 1460 ± 480 mV, 1660 ± 600 mV, and 1680 ± 490 mV, respectively (P = 0.71). However, SNS sensitivity was remarkably different between the groups (P < 0.01), being 28.9% ± 8.1% in "sluggish," 48.4% ± 7.5% in "normal," and 88.7% ± 7.4% in "rapid" groups. Compared with "normal" ejaculators, the percentage of neurons expressing NMDA receptors in the PVN of "rapid" ejaculators was significantly higher, whereas it was significantly lower in "sluggish" ejaculators (P = 0.01). In addition, there was a positive correlation between the expression of NMDA receptors in the PVN and SNS sensitivity (r = 0.876, P = 0.02). This study shows that intravaginal ejaculatory latency is associated with SNS activity and is mediated by NMDA receptors in the PVN.

Role and mechanism of Epac protein in regulation of inflammatory pain in paraventricular nucleus of hypothalamus / 中国药理学通报

Aim To investigate the role and mecha-nism of exchange protein directly activated by cAMP (Epac) protein in the paraventricular nucleus(PVN) of the hypothalamus in the development of inflammatory pain in rats. Methods Adult SD male rats were cho-sen to establish the model of inflammatory pain through subcutaneous injection of complete Freund's adjuvant(CFA) on the center of left hind foot. Western blot was used to detect the changes of the expression of Ep-ac protein. Thermal withdrawal latency(TWL) was ob-served after the PVN injecting 8p-CPT-2′-O-Me-cAMP (8p-CPT),the agonist of Epac. Then activated down-stream MEK1/2 protein of Epac in PVN was detected using Western blot when the potency was the strongest.Results ① Compared with normal saline(control group),TWL decreased significantly on d 1, d 3, d 5, d 7,d 9 on the ipsilateral foot of CFA group rats(P<0.01),whereas it returned to normal level in d 13;the paw mechanical withdrawal threshold(PMWT) de-creased significantly on d 6,d 8,d 10,d 12 and d 14 (P<0.05);②Compared with the control,the Epac1 protein in CFA group rats began to decrease from d 3, and significantly decreased on d 3 and d 9(P<0.05), however the expression of Epac2 had no significant change, meanwhile p-MEK1/2 protein decreased sig-nificantly on d 3(P<0.05);③Compared with micro-injection of saline into the PVN(Saline group), the heat hyperalgesia of 20 min and 1h decreased signifi-cantly and TWL increased significantly after PVN ad-ministration of 8p-CPT(8p-CPT group)(P <0.05);paraventricular nucleus p-MEK1/2 protein expression increased significantly in 30 min(P <0.05) and re-covered to normal level 2 h after administration. Con-clusion The Epac1-MEK1/2 signaling pathway in the paraventricular nucleus of the hypothalamus may be in-volved in the development of chronic inflammatory pain induced by CFA.

Role of central PGE2 on sympathetic excitation in chronic heart failure / 中国病理生理杂志

AIM:To observe the effect of central prostaglandin E2(PGE2) on sympathetic activation in chronic heart failure (CHF) and to explore the underlying mechanism. METHODS:Male SD rats were subjected to coronary ar-tery ligation to induce heart failure (HF), and the intracerebroventricular infusion was performed by osmotic pump continu-ously. The rats in sham group and HF group were given artificial cerebrospinal fluid (0. 25 μL/h). The rats in HF plus treatment group was given celecoxib (CLB; 20 mg/h). After 4 weeks, the levels of PGE2 in cerebrospinal fluid ( CSF), the sympathetic nerve excitability and cardiac function were measured, and the changes of corticotropin-hormone releasing hormone ( CRH)-containing neurons activation and neurotransmitter contents in the hypothalamic paraventricular nucleus ( PVN) were also determined. RESULTS:Compared with the sham-operated rats, the HF rats had raised level of PGE2 in CSF, up-regulated renal sympathetic nerve activity and plasma norepinephrine, increased left ventricular end diastolic pres-sure, lung-to-body weight and right ventricular-to-body weight ratios, and decreased maximal increase and decreased rate of left ventricular pressure (P<0.05). In addition, the number of CRH positive neurons in PVN and the level of plasma ad-renocorticotropic hormone were higher in HF rats than those in sham-operated rats (P<0.05). After administration of CLB into the lateral ventricle of HF rats, the contents of PGE2 in CSF were significantly reduced, the number of activation CRH neurons in PVN was decreased, the excitability of sympathetic nerves was down-regulated and cardiac function was im-proved (P<0.05). Compared with the sham-operated rats, the content of glutamic acid in PVN of HF rats was increased, the content of γ-aminobutyric acid and the number of glutamate decarboxylase 67-positive neurons were decreased ( P<0.05). After the CLB was given, the above indexes were reversed (P<0.05). CONCLUSION:These findings indicate that in CHF, the increased central PGE2 may activate CRH-containing PVN neurons and contribute to the augmented sym-pathetic drive possibly by modulating the neurotransmitters within the PVN.

Upregulated FAAH expression in PVN contributes to sympathoexcitation in rat with chronic heart failure / 中国病理生理杂志

AIM:To investigate the expression of fatty-acid amide hydrolase(FAAH)in paraventricular nu-cleus(PVN)and its contribution to renal sympathetic nerve activity in rats with chronic heart failure(CHF).METH-ODS:A rat model of CHF was established by ligation of the left coronary artery to induce acute myocardial infarction. Eight weeks after ischemia,the rat model of CHF was identified by echocardiogram and histopathological observation.The plasma level of norepinephrine(NE)was detected by ELISA.The protein expression levels of FAAH in the PVN were de-termined by Western blot.The N-arachidonoylethanolamide(AEA)generation in PVN was analyzed by high-performance liquid chromatography.After microinjection of AEA,PF3845(an FAAH inhibitor)or rAAV2-FAAH shRNA virus in PVN, the sympathetic drive indexes were recorded in different experiment groups.RESULTS: Compared with the rats in sham group,the cardiac function and AEA concentration in PVN were significantly reduced, while the plasma NE level and FAAH expression in PVN were obviously increased in the CHF rats(P<0.05).After microinjecion of PF3845, AEA or rAAV2-FAAH shRNA virus in PVN, the sympathetic drive indexes were decreased significantly and the cardiac function were improved in the CHF rats.CONCLUSION:Upregulated FAAH expression in PVN may result in sympathoexcitation in the rat with CHF.

Role of microglia in paraventricular nucleus in susceptibility to depression in rats with chronic vis-ceral pain / 中华麻醉学杂志

Objective To evaluate the role of microglia in paraventricular nucleus (PVN) in sus-ceptibility to depression in rats with chronic visceral pain. Methods Ninety-six pathogen-free healthy male Sprague-Dawley rats, aged 8 days, were divided into 6 groups (n= 16 each) using a random number table: sham operation group (S group), chronic visceral pain group (CHVP group), sham operation plus colorectal distension group (S+C group), chronic visceral pain plus colorectal distension group (CHVP+C group), chronic visceral pain plus phosphate buffer solution plus colorectal distension group (CHVP+P+C group) and chronic visceral pain plus minocycline plus colorectal distension group (CHVP+M+C group). Colorectal distension was not performed in S group. In CHVP group, chronic visceral pain was induced by performing colorectal distension twice daily on postnatal days 8, 10, and 12. Phosphate buffer solution 0. 5μl was injected into PVN by stereotaxic method at 8th week after birth in CHVP+P+C group, and 2％ mi-nocycline 0. 5 μl was injected into PVN at 8th week after birth in CHVP+M+C group. Eight rats in each group were selected 2 h later for measurement of visceral pain threshold. In S+C, CHVP+C, CHVP+P+C and CHVP+M+C groups, colorectal distension was performed for 2 times, open field test and sucrose preference test were then performed, the rats were sacrificed and PVN was removed for determination of micro-glial activation by immunofluorescence. Results The pain threshold was significantly decreased in CHVP, CHVP+C, CHVP+P+C and CHVP+M+C groups as compared with S and S+C groups (P<0. 05). The pain threshold was significantly increased in CHVP+M+C group when compared with CHVP +P +C group (P<0. 05). Compared with S, CHVP and S+C groups, the total locomotor distance, the number of rea-ring and sucrose consumption were significantly reduced, and the proportion of activated microglia in PVN was increased in CHVP+C, CHVP+P+C and CHVP+M+C groups (P<0. 05). Compared with CHVP+P+C group, the total locomotor distance, the number of rearing and sucrose consumption were significantly in-creased, and the proportion of activated microglia in PVN was decreased in CHVP+M+C group (P<0. 05). Conclusion Microglia in PVN is involved in regulation of susceptibility to depression in rats with chronic visceral pain.

Effect of Electroacupuncture at "Shenmen" (HT 7)- "Tongli" (HT 5) of Heart Meridian on Neuronal Activities in Paraventricular Nucleus of Hypothalamus in Myocardial Ischemia Rats / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) stimulation of "Shenmen" (HT 7) - "Tongli" (HT 5) segment of the Heart Meridian on neuronal electrical activities of hypothalamic paraventricular nucleus (PVN) in rats with myocardial ischemia (MI), so as to investigate its possible mechanism underlying improvement of MI. METHODS: Thirty-two SD rats were randomly divided into sham control, model, HT 7-HT 5 and "Taiyuan" (LU 9)- "Lieque" (LU 7) groups (n=8 in each group). EA preconditioning (2 Hz, 1 V, 20 min) was applied to bilateral HT 7-HT 5 and bilateral LU 9-LU 7, respectively, once everyday for 7 days. The electrical activities of the right PVN region were recorded by the implanted microelectrode array(2×4)and Plexon multi-channel acquisition system. Cluster analysis of neuronal signals was carried out by Offline Sorter software. The discharge waveforms, autocorrelation and cross-correlation of neuronal activities were analyzed by using Neuro Explorer software. RESULTS: Cluster analysis of neuronal signals showed that 2, 2, 1 and 1 interneuron in the sham, model, HT 7-HT 5, and LU 9-LU 7 groups, and 3 pyramidal neurons in the HT 7-HT 5 were acquired. Cross correlation analysis showed that the SPK 02 a and SPK 02 b neurons of the HT 7-HT 5 group had an inhibitory relationship. The total discharge frequency was significantly increased in the model group relevant to the sham group (P<0.01), and was markedly lower in the HT 7-HT 5 group than in the model group and LU 9-LU 7 group (P<0.01). Real-time spectrum analysis showed that the local field potential spectrum energy of the HT 7-HT 5 group was significantly lower than that of the model group and the LU 9-LU 7 group. CONCLUSION: EA of HT 7-HT 5 segment of the Heart Meridian can inhibit the electrical activity of interneuron and activate the electrical activity of pyramidal neuron in PVN region, and an inhibitory relationship exists between the interneuron and pyramidal neuron in MI rats, which may be a mechanism of EA in regulating activities of the ischemic heart.

Efecto hipofágico de la urocortina en ratas adrenalectomizadas: un análisis de la secuencia de saciedad conductual / Hypophagic effect of urocortin in adrenalectomized rats: An analysis of the behavioral satiety sequence

El objetivo de la presente investigación fue evaluar el efecto de la estimulación de los receptores CRH2 del núcleo paraventricular hipotalámico sobre la ingesta de alimento y la expresión de la secuencia de saciedad conductual (SSC) en ratas adrenalectomizadas. Se trabajó con ocho grupos independientes de ratas Wistar, cuatro grupos adrenalectomizados (ADX) y cuatro con falsa cirugía. A todos los sujetos se les implantó una cánula en el núcleo paraventricular hipotalámico, y se les administró uno de cuatro tratamientos: vehículo, urocortina 2 (UCN2, agonista de CRH2), antisauvagina 30 (antagonista de CRH2), y antisauvagina-30 + UCN2 (pretratamiento). La administración de UCN2 redujo la ingesta de hidratos de carbono y de grasas en las ratas ADX, debido a la interrupción de la SSC; mientras que en las ratas con falsa cirugía, la UCN2 solo disminuyó la ingesta de grasas, debido al adelanto de la SSC. El pretratamiento previno los efectos inducidos en las ratas ADX, pero no en las ratas con falsa cirugía. Estos resultados indican que los receptores CRH2 modularon la ingesta y la SSC en las ratas ADX, lo que constituye un aporte importante en la comprensión de la etiología de la anorexia y del patrón conductual asociado a esta.

The objective of this research was to evaluate the effect of stimulation of receptors CRH2 in the paraventricular nucleus of the hypothalamus on food intake and expression of behavioral satiety sequence (BSS) in adrenalectomized rats. Eight independent groups of Wistar rats were utilized; four adrenalectomized groups (ADX) and four were false surgery. All subjects were implanted with a cannula in the paraventricular nucleus of the hypothalamus and were administered with one of the four treatments: vehicle, urocortin-2 (UCN2, CRH2 agonist), antisauvagine-30 (CRH2 antagonist) or antisauvagine-30 + UCN2 (pretreatment). UCN2 administration reduced intake of carbohydrates and fats in ADX rats due to the interruption of the BSS. In rats with false surgery it decreased fat intake due to the advancement of the BSS. Pretreatment prevented the effects induced by UCN2 in ADX rats but not in rats with false surgery. These results suggest that receptors CRH2 modulated intake and BSS in ADX rats, contributing with relevant information for the understanding of the anorexic ethiology and the behavioral pattern associated to it.