Search

To observe the effect ofA total of 60 clean male Wistar rats were randomized into a normal group, a model group, a tripterygium wilfordii polyglycoside tablet (TWP) group and an acupuncture group, 15 rats in each group. Rats in the model group, the TWP group and the acupuncture group received intradermal injection of Freund's complete adjuvant (FCA) at right hind foot pad to induce the AA model. TWP suspension of 8 mg/kg was given by gavage in the TWP group. Acupuncture was applied at "Shenshu" (BL 23), "Pishu" (BL 20) and right "Housanli" (ST 36), "Sanyinjiao" (SP 6), "Yanglingquan" (GB 34) in the acupuncture group, 15 min a time, once a day. The intervention was given 15 days in both TWP group and acupuncture group. The foot-pad swelling degree before modeling, before and after intervention and the arthritis index (AI) score before and after intervention were calculated; the serum levels of interleukin (IL)-1β, IL-4, IL-10 and tumor necrosis factor-α (TNF-α) were detected by ELISA method; the ultrastructure and histomorphological changes of synovium issue were observed by transmission electron microscope and HE staining; the positive expression of matrix metalloproteinase (MMP)-3 and MMP-9 in synovium issue was detected by immunohistochemistry method.Before intervention, foot-pad swelling degree of the model group, the TWP group and the acupuncture group was increased compared with the normal group (

To explore the effect of moxibustion at "Zusanli"(ST36) and "Shenshu"(BL23) on synovitis, and expressions of miR-155, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), interlukine（IL-1） receptor-associated kinase (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), nuclear factor κB (NF-κB), IL-1β, tumor necrosis factor receptor (TNF)-α and IL-6 mRNA and protein of synovial membrane in rheumatoid arthritis (RA) rats, so as to explore its mechanism underlying improvement of RA.A total of 48 male Wistar rats were randomly divided into normal control, model, moxibustion and antagonist groups (Compared with the normal control group, the JSD and AI, and the expression levels of synovial miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein were significantly increased in the model group (Moxibustion at ST36 and BL23 can reduce the synovitis of RA rats, which is related to its effects in suppressing the expressions of miR-155, TLR4, MyD88, IRAK1, TRAF6, NF-κB, IL-1β, TNF-α and IL-6 mRNA and protein (i.e., inhibition of miR-155/TLR4/NF-κB signaling).

In this study, we report the synthesis and properties of new anion exchange membranes using m-polybenzimidazole (m-PBI) as polymer backbone attached with quaternary ammonium group and alkene group as side chains. These ionic m-PBIs were crosslinked by thermal thiol-ene reaction. The ion exchange capacity (IEC) values and crosslinking degrees were controlled independently by the amount of attached quaternary ammonium groups and alkene groups, respectively. m-PBI based AEMs with IEC from 1.51 to 2.50 mmol/g exhibit hydroxide conductivity of 14 to 58 mS/cm at 80 °C. With similar IEC values, crosslinked membranes absorb less water but show similar hydroxide conductivity and better dimension stability than uncrosslinked membranes. A crosslinked membrane with an IEC value of 2.46 mmol/g can retain 84% of its pristine hydroxide conductivity after being immersed in 1.0 M sodium hydroxide solution at 60 °C after 720 h. These membranes in hydrated condition also show mechanical robustness with tensile strength of 10.8 to 14.6 MPa. From the high hydroxide conductivity, enhanced alkaline stability and good mechanical properties, crosslinked ionic m-PBIs are promising candidate as anion exchange membranes for fuel cell application.

The ordered mesoporous silica functionalized with −NH2 groups was successfully synthesized using diatomite as silica source and used to adsorb Cd(II) ions from aqueous solution. The resultant adsorbent was characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption measurements, thermogravimetric analysis, the elemental analyzer and transmission electron microscopy. The effects of different concentrations of 3-aminopropyltrimethoxysilane, solution pH, adsorbent dose, contact time were thoroughly investigated. The adsorption kinetic studies were analyzed using pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and the adsorption isotherms were studied by Langmuir and Freundlich isotherm models. The results showed that the adsorption process was successfully fitted with the pseudo-first-order kinetics and Langmuir isotherm models. It was found that the maximum adsorption capacity of adsorbents obtained under optimum synthesis conditions reached 102.9 mg/g at 25 °C, indicating that this new sorbent could have a good potential for the removal of Cd(II) due to its low cost and eco-friendliness.

Present here is a new dual ratiometric luminescent probe D which is a trichromatic and white-light-emitting metal-organic framework (MOF) composite facilely obtained by incorporating red/green-emitting complex modules into a blue-emitting MOF. Probe D exhibits remarkable capabilities of sensing different volatile organic solvents (VOSs) via 2D code recognition of the two VOS-dependent MOF ligand-to-module ratios of the emission-peak intensities. For specific VOSs, the resultant luminescent color changes from the starting white color are sharp enough to be visible to the naked eye. Remarkably, D can differentiate solution-phase nitroaromatics and metal ions by recording the evolution of the two ratios during titration processes, enabling an unusual 3D code recognition using the titrant amount as the third dimension for the first time. D also can be used to detect dinoseb, Fe3+ and Al3+ ions quantitatively by analysis of the ratios with detection limits as low as 0.050, 0.41, and 0.12 ppm, respectively. Clearly, such a self-referencing trichromatic probe can maximize the output information and significantly enhance the detection selectivity and sensitivity via multi-dimensional sensing, and has great potentials for practical applications.

A square-planar bis(σ-acetylide) Pt(II) complex containing dual-recognition sites was designed, synthesized and used as a colorimetric/luminescent sensor for detecting the vapor of benzene compounds.

The square-planar diimine platinum(II) complex Pt(BpyC≡CSiMe3)(C≡CC6H5)2 (1, BpyC≡CSiMe3 = 4-[(2-trimethylsilyl)ethynyl]-2,2′-bipyridine) was prepared and characterized. In the solid state, 1 shows unusual reversible thermochromic and mechanochromic properties. When crystalline 1·2(CHCl3) is heated or ground, the bright yellow emission centered at ca. 544 (576, sh) nm changes to 722 nm, which corresponds to a thermo- and mechanochromic response redshift of ca. 146–178 nm. Once the heated or ground samples were exposed to organic vapors, they reverted to the original crystalline state, and the luminescence changed from red to yellow. The conversion between a triplet metal-to-ligand charge transfer/ligand-to-ligand charge transfer (3MLCT/3LLCT) emission state and a triplet metal–metal-to-ligand charge transfer (3MMLCT) state is the reason for the luminescence change.

The square-planar diimine-platinum(II) complex, Pt(4-Brbpy)(C≡CC6H5)2 (1) (4-Brbpy = 4-bromo-2,2'-bipyridine), was prepared and characterized. Solid-state 1 exhibits reversible thermo- and mechanical-grinding-triggered color and luminescence changes. When crystalline 1·2(CH2Cl2) or 1·2(CHCl3) are heated or ground, the original bright yellow-green emission centered at 525 (549, sh) nm changed to 637 and 690 nm, corresponding to thermo- and mechanochromic response shifts of approximately 88-112 nm and 141-165 nm, respectively. Meanwhile the crystalline state changes into an amorphous phase in both processes. Once the amorphous sample absorbs organic vapors, it can be reverted to the original crystalline state, along with red luminescence turning back to yellow-green emission. The reversibility of thermo- and mechanical-grinding-triggered chromic luminescence properties has been dynamically monitored by emission spectra and X-ray diffraction patterns. The dramatic thermo- and mechanical-grinding-triggered emission red shifts are most likely due to the conversion of the (3)MLCT/(3)LLCT emission state into the (3)MMLCT triplet state.

Discrete metal complexes, [MCl 2 (CEAP) 2 ] {M = Zn ( 1 ), Co ( 2 ) and Hg ( 3 ), CEAP = 4-[N,N-bis(2-cyanoethyl)amino]pyridine} and their hydrogen-bonded salts [CEAPH] 2 [MCl 4 ] {M = Zn ( 4 ), Co ( 5 ) and Hg ( 6 ), CEAPH = 4-[N,N-bis(2-cyanoethyl)amino]pyridium} were prepared using CEAP or CEAP·HCl ligands and metal chlorides (molar ratio = 2:1) by both solvent-thermal synthesis method and solvent-free method. The crystal structure and powder X-ray diffraction (PXDR) studies revealed that the discrete metal complexes 1 – 3 could be converted into their hydrogen-bonded salts 4 – 6 respectively by absorbing HCl vapor in solid-gas station and these salts except for 6 could be converted back to their corresponding discrete metal complexes by grinding with KOH in solid station.

Based on the principle of fuzzy matter-element analysis, the concept of information entropy is introduced to establish a fuzzy matter-element evaluation method. This method is utilized to comprehensively evaluate the degree of debris flow. The classifications of debris flow are regarded as the objects of matter-element and their indexes for evaluation as well as the corresponding fuzzy values are used to construct the composite fuzzy matter-elements. By calculating the relevancy the comprehensive evaluation of debris flow can be carried out. This model is applied to analyze the degree of debris flow in the practical application. The application shows that the model is effective and practical.

To explore the effect of Xinfeng Capsule (XC) on lipoprotein metabolism of rheumatoid arthritis (RA) patients.Totally 180 RA patients were assigned to the experimental group and the control group by random digit table, 90 in each group. Patients in the experimental group took XC (three pills each time, three times daily), while those in the control group took Methotrexate Tablet (four tablets each time, once per week). One month consisted of one therapeutic course and all patients were treated for two therapeutic courses. A healthy control group consisting of 60 patients was also set up. Changes of lipoprotein indices, clinical efficacy, lipid metabolism, joint symptoms and signs, activity indicators were observed, and correlation analyses were performed.Compared with the healthy control group, expression levels of prealbumin (PA), globulin (GLO), high-density lipoprotein (HDL), apolipoprotein Al (Apo-A1) were lowered in RA patients (P0. 05, P0. 01). Correlation analyses showed that PA was negatively correlated with joint tenderness, morning stiffness time, disease activity score (DAS-28), C-reactive protein (CRP), interleukin (IL)-6, respectively. Total protein (TP) was negatively correlated with joint tenderness. GLO was negatively correlated with joint tenderness and DAS-28. HDL was negatively correlated with erythrocyte sedimentation rate (ESR) and endothelin (ET)-1. Apo-Al was negatively correlated with joint pain; Apo-B was negatively correlated with CRP; LDL was negatively correlated with morning stiffness time (P0. 05, P0. 01). Compared with before treatment, expression levels of PA, HDL, Apo-A1 , Apo-B, and serum IL-10 contents increased, and expression levels of ESR, CRP, IL-6, ET-1 , joint pain, joint swelling, morning stiffness time, and DAS-28 decreased in the experimental group (P0. 05, P0. 01). PA increased more after treatment than before treatment in the control group (P0. 01). There was statistical difference in joint symptoms (except joint tenderness) and activity indices (except ET-1) in the control group (P0. 05, P0. 01). Compared with the control group after treatment, PA and HDL increased, ET-1 and duration of morning stiffness decreased in the experimental group (all P0. 05).Lipoprotein metabolic disorder exists in RA patients, and it is associated with disease activity. XC could obviously improve lipoprotein metabolism and joint symptoms.

Exposure to the group I metabotropic glutamate receptor (mGluR) agonist dihydroxyphenylglycine (DHPG) produces long-lasting changes in network excitability and epileptiform activity in the CA3 region of rat hippocampal slices that continues in the absence of the agonist and includes both interictal and more prolonged ictal-like activity. We evaluated the afterhyperpolarization (AHP) that follows repetitive neuronal firing in neurons exposed to DHPG and related the change in the AHP to the pattern of epileptiform activity. In contrast to neurons from control slices that had a robust AHP following neuronal depolarization and action potential generation, neurons that had been exposed to DHPG displayed a minimal AHP following depolarization. Whole-cell voltage-clamp recordings showed a small outward or transient inward current following a depolarizing pulse in neurons from slices that had been exposed to DHPG while control neurons had a long-lasting outward current. In slices that demonstrated ictal patterns after exposure to DHPG, bath application of 1-ethyl-2-benzimidazolinone (1-EBIO, 1 mM) or 5,6-dichloro-1-ethyl-1,3-dihydro-2H-benzimidazol-2-one (DCEBIO, 100 microM) which enhance the AHP, suppressed ictal discharges. Whole-cell voltage-clamp recordings demonstrated the return of the medium and slow AHP current in neurons that had transiently been exposed to DHPG when 1-EBIO or DCEBIO was bath-applied. Co-application of either 1-EBIO or DCEBIO with DHPG blocked the induction of epileptiform activity. Transient DHPG exposure caused a long-term suppression of the AHP and ictal patterns of epileptiform activity. 1-EBIO or DCEBIO which re-established both the medium and slow AHP suppressed ictal discharges. These results support the hypothesis that the loss of the AHP contributes to the generation of ictal activity after transient DHPG exposure.

Exposure to the group I metabotropic glutamate receptor (mGluR) agonist dihydroxy phenylglycine (DHPG) induces epileptiform activity in the CA3 region of the hippocampus that persists following washout of DHPG. DHPG also can cause long-term depression of synaptic transmission, and at some synapses this may be mediated by endocannabinoids. We evaluated whether the selective cannabinoid type 1 (CB1) receptor antagonists SR 141716 or AM 251 could modify induction of epileptiform activity produced by DHPG exposure. The induction of epileptiform activity by DHPG exposure was significantly reduced by CB1 receptor antagonists, SR 141716 or AM 251. Minimal effects on epileptiform activity were noted once the activity had been induced. In control slices, exposure to DHPG for 30 min produced long-term depression (LTD) of synaptic transmission, on average about a 70% reduction in slope of the field excitatory postsynaptic potential (EPSP). When slices were exposed to both DHPG and SR 141716 (3 microm), LTD did not occur and the population EPSP remained at control values or greater. These results suggest that CB1 receptors mediate some of DHPG effects that result in persistent epileptiform activity, and antagonism of CB1 receptors has antiepileptogenic properties. Paradoxically DHPG also caused LTD of excitatory synaptic transmission in the CA3 region and CB1 receptor antagonism prevents the depression. We hypothesize that the ictal activity induced by DHPG requires depression of synaptic strength and CB1 receptor antagonism prevents this depression and the induction of ictal activity.

Within glomeruli, the initial sites of synaptic integration in the olfactory pathway, olfactory sensory axons terminate on dendrites of projection and juxtaglomerular (JG) neurons. JG cells form at least two major circuits: the classic intraglomerular circuit consisting of external tufted (ET) and periglomerular (PG) cells and an interglomerular circuit comprised of the long-range connections of short axon (SA) cells. We examined the projections and the synaptic inputs of identified JG cell chemotypes using mice expressing green fluorescent protein (GFP) driven by the promoter for glutamic acid decarboxylase (GAD) 65 kDa, 67 kDa, or tyrosine hydroxylase (TH). Virtually all (97%) TH+ cells are also GAD67+ and are thus DAergic–GABAergic neurons. Using a combination of retrograde tracing, whole-cell patch-clamp recording, and single-cell three-dimensional reconstruction, we show that different JG cell chemotypes contribute to distinct microcircuits within or between glomeruli. GAD65+ GABAergic PG cells ramify principally within one glomerulus and participate in uniglomerular circuits. DAergic–GABAergic cells have extensive interglomerular projections. DAergic–GABAergic SA cells comprise two subgroups. One subpopulation contacts 5–12 glomeruli and is referred to as “oligoglomerular.” Approximately one-third of these oligoglomerular DAergic SA cells receive direct olfactory nerve (ON) synaptic input, and the remaining two-thirds receive input via a disynaptic ON→ET→SA circuit. The second population of DAergic–GABAergic SA cells also disynaptic ON input and connect tens to hundreds of glomeruli in an extensive “polyglomerular” network. Although DAergic JG cells have traditionally been considered PG cells, their interglomerular connections argue that they are more appropriately classified as SA cells.

Summary Swim stress regulates forebrain 5-hydroxytryptamine (5-HT) release in a complex manner and its effects are initiated in the serotonergic dorsal raphe nucleus (DRN). The purpose of this study was to examine the effects of swim stress on the physiology of DRN neurons in conjunction with 5-HT immunohistochemistry. Basic membrane properties, 5-HT 1A and 5-HT 1B receptor-mediated responses and glutamatergic excitatory postsynaptic currents (EPSCs) were measured using whole-cell patch clamp techniques. Rats were forced to swim for 15 min and 24 h later DRN brain slices were prepared for electrophysiology. Swim stress altered the resting membrane potential, input resistance and action potential duration of DRN neurons in a neurochemical-specific manner. Swim stress selectively elevated glutamate EPSC frequency in 5-HT DRN neurons. Swim stress non-selectively reduced EPSC amplitude in all DRN cells. Swim stress elevated the 5-HT 1B receptor-mediated inhibition of glutamatergic synaptic activity that selectively targeted 5-HT cells. Non-5-HT DRN neurons appeared to be particularly responsive to the effects of a milder handling stress. Handling elevated EPSC frequency, reduced EPSC decay time and enhanced a 5-HT 1B receptor-mediated inhibition of mEPSC frequency selectively in non-5-HT DRN cells. These results indicate that swim stress has both direct, i.e., changes in membrane characteristics, and indirect effects, i.e., via glutamatergic afferents, on DRN neurons. These results also indicate that there are distinct local glutamatergic afferents to neurochemically specific populations of DRN neurons, and furthermore that these distinct afferents are differentially regulated by swim stress. These cellular changes may contribute to the complex effects of swim stress on 5-HT neurotransmission and/or the behavioral changes underlying the forced swimming test model of depression.

Stimulation of the noradrenergic nucleus locus coeruleus (LC) releases norepinephrine in the spinal cord, which inhibits dorsal horn neurons and produces analgesia. Activation of this descending noradrenergic pathway also contributes to the analgesic action produced by systemic opioids. The δ-opioid receptors are present presynaptically in the LC. However, their functional role in the control of the activity of spinally projecting LC neurons remains uncertain. In this study, we tested the hypothesis that activation of presynaptic δ-opioid receptors excites spinally projecting LC neurons through inhibition of GABA release. Spinally projecting LC neurons were retrogradely labeled by a fluorescent dye, DiI, injected into the spinal dorsal horn of rats. Whole cell voltage- and current-clamp recordings were performed on DiI-labeled LC neurons in brain slices in vitro. Retrogradely labeled LC noradrenergic neurons were demonstrated by dopamine-β-hydroxylase immunofluorescence. [d-Pen2,d-Pen5]-enkephalin (DPDPE, 1 μM) significantly decreased the frequency of GABA-mediated miniature inhibitory postsynaptic currents (IPSCs) of nine DiI-labeled LC neurons from 2.1 ± 0.5 to 0.7 ± 0.2 Hz without altering their amplitude and the kinetics. On the other hand, the miniature excitatory postsynaptic currents (EPSC) of nine DiI-labeled LC neurons were not significantly altered by DPDPE. Furthermore, DPDPE significantly inhibited the amplitude of evoked IPSC but not EPSC in eight DiI-labeled LC neurons. Under the current-clamp condition, the firing activity in 9 of 11 DiI-labeled LC neurons was significantly increased by 1 μM DPDPE from 4.6 ± 0.7 to 6.2 ± 1.0 Hz. Bicuculline (20 μM) also significantly increased the firing frequency in 13 of 20 neurons from 1.8 ± 0.5 to 2.8 ± 0.6 Hz. Additionally, the excitatory effect of DPDPE on LC neurons was diminished in the presence of bicuculline. Collectively, these data strongly suggest that activation of presynaptic δ-opioid receptors by DPDPE excites a population of spinally projecting LC neurons by preferential inhibition of GABA release. Thus presynaptic δ-opioid receptors likely play an important role in the regulation of the excitability of spinally projecting LC neurons and the descending noradrenergic inhibitory system.

Activation of spinal α2-adrenergic receptors by the descending noradrenergic system and α2-adrenergic agonists produces analgesia. However, the sites and mechanisms of the analgesic action of spinally administered α2-adrenergic receptor agonists such as clonidine are not fully known. The dorsal horn neurons in the outer zone of lamina II (lamina IIo) are important for processing nociceptive information from C-fiber primary afferents. In the present study, we tested a hypothesis that activation of presynaptic α2-adrenergic receptors by clonidine inhibits the excitatory synaptic input to lamina IIoneurons. Whole cell voltage-clamp recordings were performed on visualized lamina IIoneurons in the spinal cord slice of rats. The miniature excitatory postsynaptic currents (mEPSCs) were recorded in the presence of tetrodotoxin, bicuculline, and strychnine. The evoked EPSCs were obtained by electrical stimulation of the dorsal root entry zone or the attached dorsal root. Both mEPSCs and evoked EPSCs were abolished by application of 6-cyano-7-nitroquinoxaline-2,3-dione. Clonidine (10 μM) significantly decreased the frequency of mEPSCs from 5.8 ± 0.9 to 2.7 ± 0.6 Hz (means ± SE) without altering the amplitude and the decay time constant of mEPSCs in 25 of 27 lamina IIoneurons. Yohimbine (2 μM, an α2-adrenergic receptor antagonist), but not prazosin (2 μM, an α1-adrenergic receptor antagonist), blocked the inhibitory effect of clonidine on the mEPSCs. Clonidine (1–20 μM, n = 8) also significantly attenuated the peak amplitude of evoked EPSCs in a concentration-dependent manner. The effect of clonidine on evoked EPSCs was abolished in the presence of yohimbine ( n = 5). These data suggest that clonidine inhibits the excitatory synaptic input to lamina IIoneurons through activation of α2-adrenergic receptors located on the glutamatergic afferent terminals. Presynaptic inhibition of glutamate release from primary afferents onto lamina IIoneurons likely plays an important role in the analgesic action produced by activation of the descending noradrenergic system and α2-adrenergic agonists.

The planar platinum(II) complex [Pt(Me3SiC≡CbpyC≡CSiMe3)(C≡CC6H4Et-4)2] (1) with 5,5-bis(trimethylsilylethynyl)-2,2'-bipyridine was prepared and characterized. Solid-state 1 exhibits unusual, selective and reversible luminescence vapochromism to CH3CN and ClCH2CN vapors, which is useful for the detection of these hazardous vapors. A vapochromic cycle was monitored by dynamic variations in emission spectra and X-ray diffraction (XRD) patterns. Both X-ray crystallographic and density functional theory studies suggest that the vapochromic and vapoluminescent behavior of 1 are induced by the variation in the intermolecular Pt-Pt interactions.

The molecule of the title compound, C24H16BrN3OS3, contains three approximately planar fragments, viz. an oxadiazole ring plus two adjacent thiophene groups, and two phenothiazine benzene rings, with largest deviations from the least-squares planes of 0.051 (3), 0.019 (4) and 0.014 (3) Å, respectively. The phenothiazine unit adopts a butterfly conformation, with a dihedral angle of 38.06 (15)° between the terminal benzene rings. The dihedral angle between the 2,5-bis(thiophen-2-yl)oxadiazole unit and the attached benzene ring is 15.35 (11)°. In the crystal, molecules form stacks along the b-axis direction; neighboring molecules within the stack are related by inversion centers, with shortest intercentroid separations of 3.741 (2) and 3.767 (2) Å.

To investigate the effect of 2 mg/kg and 10 mg/kg losartan intraperitoneally (i.p) on arterial blood pressure (AP) and heart rate (HR) in rat and the involvement in the activity of habenulas neurons. Glass micropipette was used to record any changes of unit discharging of neurons in LHb and MHb before and after losartan was intraperitoneally injected.AP and HR were not significantly changed by 2 mg/kg losartan (i.p). However, AP was apparently decreased by 10 mg/kg losartan (i.p), but HR was unchanged. After 10 mg/kg losartan (i.p), 66.66% (12/18) unit discharging of neurons in LHb were increased in frequency, and 61.90% (13/21) in MHb were decreased.AP of rat was significantly decreased by 10 mg/kg losartan (i.p). Depressor effect of losartan (i.p) was involved in the excision of neurons in LHb and the inhibition in MHb.

The dorsal (DR) and median (MR) raphe nuclei contain 5-hydroxytryptamine (5-HT) cell bodies that give rise to the majority of the ascending 5-HT projections to the forebrain. The DR and MR have differential roles in mediating stress, anxiety and depression. Glutamate and GABA activity sculpt putative 5-HT neuronal firing and 5-HT release in a seemingly differential manner in the MR and DR, yet isolated glutamate and GABA activity within the DR and MR has not been systematically characterized. Visualized whole-cell voltage-clamp techniques were used to record excitatory and inhibitory postsynaptic currents (EPSC and IPSC) in 5-HT-containing neurons. There was a regional variation in action potential-dependent (spontaneous) and basal [miniature (m)] glutamate and GABAergic activity. mEPSC activity was greater than mIPSC activity in the DR, whereas in the MR the mIPSC activity was greater. These differences in EPSC and IPSC frequency indicate that glutamatergic and GABAergic input have distinct cytoarchitectures in the DR and MR. 5-HT(1B) receptor activation decreased mEPSC frequency in the DR and the MR, but selectively inhibited mIPSC activity only in the MR. This finding, in concert with its previously described function as an autoreceptor, suggests that 5-HT(1B) receptors influence the ascending 5-HT system through multiple mechanisms. The disparity in organization and integration of glutamatergic and GABAergic input to DR and MR neurons and their regulation by 5-HT(1B) receptors may contribute to the distinction in MR and DR regulation of forebrain regions and their differential function in the aetiology and pharmacological treatment of psychiatric disease states.

Spinal lamina II (substantia gelatinosa) neurons play an important role in processing of nociceptive information from primary afferent nerves. Anatomical studies suggest that neurons in the outer (lamina IIo) and inner (lamina IIi) zone of lamina II receive distinct afferent inputs. The functional significance of this preferential afferent termination in lamina II remains unclear. In this study, we examined the differential synaptic inputs to neurons in lamina IIo and IIi in response to primary afferent stimulation. Whole cell voltage-clamp recordings were performed on neurons in lamina IIo and IIi of the rat spinal cord slice under visual guidance. Capsaicin (1 μM) significantly increased the frequency of glutamatergic miniature excitatory postsynaptic currents (mEPSCs) in all 27 lamina IIo neurons and significantly increased the amplitude of mEPSCs in 12 of 27 lamina IIo neurons. However, capsaicin only significantly increased the frequency of mEPSCs in 9 of 22 (40.9%) lamina IIi neurons and increased the amplitude of mEPSCs in 6 of these 9 neurons. Furthermore, the peak amplitude of EPSCs, evoked by electrical stimulation of the attached dorsal root, in 40 lamina IIo neurons was significantly greater than that [160.5 ± 16.7 vs. 87.0 ± 10.4 (SE) pA] in 37 lamina IIi neurons. On the other hand, the peak amplitude of evoked inhibitory postsynaptic currents (IPSCs) in 40 lamina IIo neurons was significantly smaller than that (103.1 ± 11.6 vs. 258.4 ± 24.4 pA) in 37 lamina IIi neurons. In addition, the peak amplitudes of both EPSCs and IPSCs, evoked by direct stimulation of lamina II, were similar in lamina IIo and IIi neurons. This study provides new information that stimulation of primary afferents differentially potentiates synaptic inputs to neurons in lamina IIo and IIi. The quantitative difference in excitatory and inhibitory synaptic inputs to lamina IIo and IIi neurons may be important for integration of sensory information from primary afferent nerves.

The nucleus locus coeruleus (LC) plays an important role in analgesia produced by opioids and by modulation of the descending noradrenergic pathway. The functional role of micro-opioid receptors (muOR) in regulation of the excitability of spinally projecting LC neurons has not been investigated. In the present study, we tested the hypothesis that activation of presynaptic mu-opioid receptors excites a population of spinally projecting LC neurons through attenuation of gamma-aminobutyric acid (GABA)-ergic synaptic inputs. Spinally projecting LC neurons were retrogradely labeled by a fluorescent dye injected into the spinal dorsal horn of rats. Whole-cell current- and voltage-clamp recordings were performed on labeled LC neurons in brain slices. All labeled LC noradrenergic neurons were demonstrated by dopamine-beta-hydroxylase (DbetaH) immunofluorescence. In 37 labeled LC neurons, (D-Ala(2),N-Me-Phe(4),Gly-ol(5))-enkephalin (DAMGO) significantly increased the discharge activity of 17 (45.9%) neurons, but significantly inhibited the firing activity of another 15 (40.5%) cells. The excitatory effect of DAMGO on seven labeled LC neurons was diminished in the presence of bicuculline. DAMGO significantly decreased the frequency of GABA-mediated miniature inhibitory postsynaptic currents (mIPSCs) in all nine labeled LC neurons. However, DAMGO had no effect on glutamate-mediated miniature excitatory postsynaptic currents (mEPSCs) in 12 of 15 neurons. Furthermore, DAMGO significantly inhibited the peak amplitude of evoked inhibitory postsynaptic currents (eIPSCs) in all 11 labeled neurons, but had no significant effect on the evoked excitatory postsynaptic currents (eEPSCs) in 10 of these 11 neurons. Thus, data from this study suggest that activation of micro-opioid receptors excites a population of spinally projecting LC neurons by preferential inhibition of GABAergic synaptic inputs. These findings provide important new information about the descending noradrenergic modulation and analgesic mechanisms of opioids.

The dorsal (DR) and median raphe (MR) nuclei contain 5-hydroxytryptamine (serotonin, 5-HT) cell bodies that give rise to the majority of the ascending 5-HT projections to the forebrain limbic areas that control emotional behavior. In the past, the electrophysiological identification of neurochemically identified 5-HT neurons has been limited. Recent technical developments have made it possible to re-examine the electrophysiological characteristics of identified 5-HT- and non-5-HT-containing neurons. Visualized whole cell electrophysiological techniques in combination with fluorescence immunohistochemistry for 5-HT were used. In the DR, both 5-HT- and non-5-HT-containing neurons exhibited similar characteristics that have historically been attributed to putative 5-HT neurons. In contrast, in the MR, the 5-HT-and non-5-HT-containing neurons had very different characteristics. Interestingly, the MR 5-HT-containing neurons had a shorter time constant and larger afterhyperpolarization (AHP) amplitude than DR 5-HT-containing neurons. The 5-HT1A receptor-mediated response was also measured. The efficacy of the response elicited by 5-HT1A receptor activation was greater in 5-HT-containing neurons in the DR than the MR, whereas the potency was similar, implicating greater autoinhibition in the DR. Non-5-HT-containing neurons in the DR were responsive to 5-HT1A receptor activation, whereas the non-5-HT-containing neurons in the MR were not. These differences in the cellular characteristics and 5-HT1A receptor-mediated responses between the MR and DR neurons may be extremely important in understanding the role of these two 5-HT circuits in normal physiological processes and in the etiology and treatment of pathophysiological states.

Spinally administered muscarinic receptor agonists or acetylcholinesterase inhibitors can produce effective pain relief. However, the analgesic mechanisms and the site of actions of cholinergic agents in the spinal cord are not fully understood. In this study, we investigated the mechanisms underlying cholinergic presynaptic regulation of glutamate release onto spinal dorsal horn neurons. The role of spinal GABA(B) receptors in the antinociceptive action of muscarine was also determined. Whole-cell voltage-clamp recordings were performed on visualized dorsal horn neurons in the lamina II in the spinal cord slice preparation of rats. The miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) were recorded in the presence of tetrodotoxin. The evoked EPSCs (eEPSCs) were obtained by electrical stimulation of the dorsal root entry zone or the attached dorsal root. Nociception in rats was measured using a radiant heat stimulus and the effect of intrathecal administration of drugs tested. Acetylcholine (10-100 microM) reduced the amplitude of monosynaptic eEPSCs in a concentration-dependent manner. Acetylcholine also significantly decreased the frequency of non-NMDA receptor-mediated mEPSCs, which was antagonized by atropine but not mecamylamine. The frequency of GABA(A) receptor-mediated mIPSCs was significantly increased by acetylcholine and this excitatory effect was abolished by atropine. Existence of presynaptic M(2) muscarinic receptors in the spinal dorsal horn was further demonstrated by immunocytochemistry staining and dorsal rhizotomy. CGP55845, a GABA(B) receptor antagonist, significantly attenuated the inhibitory effect of acetylcholine on the frequency of mEPSCs and the amplitude of monosynaptic eEPSCs in lamina II neurons. Furthermore, the antinociceptive action produced by intrathecal muscarine was significantly reduced by CGP55845 pretreatment in rats. Therefore, data from this integrated study provide new information that acetylcholine inhibits the glutamatergic synaptic input to lamina II neurons through presynaptic muscarinic receptors. Inhibition of glutamate release onto lamina II neurons by presynaptic muscarinic and GABA(B) heteroreceptors in the spinal cord probably contributes to the antinociceptive action of cholinergic agents.

Both inhibitory GABAergic and excitatory glutamatergic inputs to supraoptic nucleus (SON) neurons can influence the release of vasopressin and oxytocin. Acetylcholine is known to excite SON neurons and to increase vasopressin release. The functional significance of cholinergic receptors, located at the presynaptic nerve terminals, in the regulation of the excitability of SON neurons is not fully known. In this study, we determined the role of presynaptic cholinergic receptors in regulation of the inhibitory GABAergic inputs to the SON neurons. The magnocellular neurons in the rat hypothalamic slice were identified microscopically, and the spontaneous miniature inhibitory postsynaptic currents (mIPSCs) were recorded using the whole-cell voltage-clamp technique. The mIPSCs were abolished by the GABA(A) receptor antagonist, bicuculline (10 microM). Acetylcholine (100 microM) significantly reduced the frequency of mIPSCs of SON neurons from 3.59+/-0.36 to 1.62+/-0.20 Hz (n=37), but did not alter the amplitude and the decay time constant of mIPSCs. Furthermore, the nicotinic receptor antagonist, mecamylamine (10 microM, n=13), eliminated the inhibitory effect of acetylcholine on mIPSCs of SON neurons. The muscarinic receptor antagonist, atropine (100 microM), did not alter significantly the effect of acetylcholine on mIPSCs in most of the 17 SON neurons studied. These results suggest that the excitatory effect of acetylcholine on the SON neurons is mediated, at least in part, by inhibition of presynaptic GABA release. Activation of presynaptic nicotinic receptors located in the GABAergic terminals plays a major role in the cholinergic regulation of the inhibitory GABAergic input to SON neurons.

In the title compound, C17H15N3OS, the phenothiazine ring system is slightly bent, with a dihedral angle of 13.68 (7)° between the benzene rings. The dihedral angle between the oxadiazole ring and the adjacent benzene ring is 7.72 (7)°. In the crystal, a π–π interaction with a centroid–centroid distance of 3.752 (2) Å is observed between the benzene rings of neighbouring molecules.