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Sample records for gabab receptors play

  1. GABAB Receptors, Schizophrenia and Sleep Dysfunction

    PubMed Central

    Kantrowitz, Joshua; Citrome, Leslie; Javitt, Daniel

    2016-01-01

    Evidence for an intrinsic relationship between sleep, cognition and the symptomatic manifestations of schizophrenia is accumulating. This review presents evidence for the possible utility of GABAB receptor agonists for the treatment of subjective and objective sleep abnormalities related to schizophrenia. At the phenotypic level, sleep disturbance occurs in 16–30% of patients with schizophrenia and is related to reduced quality of life and poor coping skills. On the neurophysiological level, studies suggest that sleep deficits reflect a core component of schizophrenia. Specifically, slow-wave sleep deficits, which are inversely correlated with cognition scores, are seen. Moreover, sleep plays an increasingly well documented role in memory consolidation in schizophrenia. Correlations of slow-wave sleep deficits with impaired reaction time and declarative memory have also been reported. Thus, both behavioural insomnia and sleep architecture are critical therapeutic targets in patients with schizophrenia. However, long-term treatment with antipsychotics often results in residual sleep dysfunction and does not improve slow-wave sleep, and adjunctive GABAA receptor modulators, such as benzodiazepines and zolpidem, can impair sleep architecture and cognition in schizophrenia. GABAB receptor agonists have therapeutic potential in schizophrenia. These agents have minimal effect on rapid eye movement sleep while increasing slow-wave sleep. Preclinical associations with increased expression of genes related to slow-wave sleep production and circadian rhythm function have also been reported. GABAB receptor deficits result in a sustained hyperdopaminergic state and can be reversed by a GABAB receptor agonist. Genetic, postmortem and electrophysiological studies also associate GABAB receptors with schizophrenia. While studies thus far have not shown significant effects, prior focus on the use of GABAB receptor agonists has been on the positive symptoms of schizophrenia, with

  2. GABA(B) receptors and synaptic modulation.

    PubMed

    Kornau, Hans-Christian

    2006-11-01

    GABA(B) receptors modulate transmitter release and postsynaptic membrane potential at various types of central synapses. They function as heterodimers of two related seven-transmembrane domain receptor subunits. Trafficking, activation and signalling of GABA(B) receptors are regulated both by allosteric interactions between the subunits and by the binding of additional proteins. Recent studies have shed light on the roles of GABA(B) receptors in plasticity processes at excitatory synapses. This review summarizes our knowledge of the localization, structure and function of GABA(B) receptors in the central nervous system and their use as drug targets for neurological and psychiatric disorders. PMID:16932937

  3. Chemistry and pharmacology of GABAB receptor ligands.

    PubMed

    Froestl, Wolfgang

    2010-01-01

    This chapter presents new clinical applications of the prototypic GABA(B) receptor agonist baclofen for the treatment of addiction by drugs of abuse, such as alcohol, cocaine, nicotine, morphine, and heroin, a novel baclofen prodrug Arbaclofen placarbil, the GABA(B) receptor agonist AZD3355 (Lesogabaran) currently in Phase 2 clinical trials for the treatment of gastroesophageal reflux disease, and four positive allosteric modulators of GABA(B) receptors (CGP7930, GS39783, NVP-BHF177, and BHFF), which have less propensity for the development of tolerance due to receptor desensitization than classical GABA(B) receptor agonists. All four compounds showed anxiolytic affects. In the presence of positive allosteric modulators the "classical" GABA(B) receptor antagonists CGP35348 and 2-hydroxy-saclofen showed properties of partial GABA(B) receptor agonists. Seven micromolar affinity GABA(B) receptor antagonists, phaclofen; 2-hydroxy-saclofen; CGP's 35348, 36742, 46381, 51176; and SCH50911, are discussed. CGP36742 (SGS742) showed statistically significant improvements of working memory and attention in a Phase 2 clinical trial in mild, but not in moderate Alzheimer patients. Eight nanomolar affinity GABA(B) receptor antagonists are presented (CGP's 52432, 54626, 55845, 56433, 56999, 61334, 62349, and 63360) that were used by pharmacologists for numerous in vitro and in vivo investigations. CGP's 36742, 51176, 55845, and 56433 showed antidepressant effects. Several compounds are also available as radioligands, such as [(3)H]CGP27492, [(3)H]CGP54626, [(3)H]CGP5699, and [(3)H]CGP62349. Three novel fluorescent and three GABA(B) receptor antagonists with very high specific radioactivity (>2,000 Ci/mmol) are presented. [(125)I]CGP64213 and the photoaffinity ligand [(125)I]CGP71872 allowed the identification of GABA(B1a) and GABA(B1b) receptors in the expression cloning work. PMID:20655477

  4. GABA(B) receptors play an essential role in maintaining sleep during the second half of the night in Drosophila melanogaster.

    PubMed

    Gmeiner, Florian; Kołodziejczyk, Agata; Yoshii, Taishi; Rieger, Dirk; Nässel, Dick R; Helfrich-Förster, Charlotte

    2013-10-15

    GABAergic signalling is important for normal sleep in humans and flies. Here we advance the current understanding of GABAergic modulation of daily sleep patterns by focusing on the role of slow metabotropic GABAB receptors in the fruit fly Drosophila melanogaster. We asked whether GABAB-R2 receptors are regulatory elements in sleep regulation in addition to the already identified fast ionotropic Rdl GABAA receptors. By immunocytochemical and reporter-based techniques we show that the pigment dispersing factor (PDF)-positive ventrolateral clock neurons (LNv) express GABAB-R2 receptors. Downregulation of GABAB-R2 receptors in the large PDF neurons (l-LNv) by RNAi reduced sleep maintenance in the second half of the night, whereas sleep latency at the beginning of the night that was previously shown to depend on ionotropic Rdl GABAA receptors remained unaltered. Our results confirm the role of the l-LNv neurons as an important part of the sleep circuit in D. melanogaster and also identify the GABAB-R2 receptors as the thus far missing component in GABA-signalling that is essential for sleep maintenance. Despite the significant effects on sleep, we did not observe any changes in circadian behaviour in flies with downregulated GABAB-R2 receptors, indicating that the regulation of sleep maintenance via l-LNv neurons is independent of their function in the circadian clock circuit. PMID:24068350

  5. Specific roles of GABAB(1) receptor isoforms in cognition

    PubMed Central

    Jacobson, Laura H.; Kelly, Peter H.; Bettler, Bernhard; Kaupmann, Klemens; Cryan, John F.

    2010-01-01

    The GABAB receptor is a heterodimer of GABAB(1) and GABAB(2) subunits. There are two isoforms of the GABAB(1) subunit: GABAB(1a) and GABAB(1b). Recent studies with mutant mice suggest a differential role for the two GABAB(1) isoforms in behavioural processes. As pharmacological and genetic studies have implicated GABAB receptors in cognition we investigated the behaviour of GABAB(1a) −/− and GABAB(1b) −/− mice in different types of cognitive paradigms. GABAB(1a) −/− and GABAB(1b) −/− mice were both impaired relative to wildtype controls in a continuous spontaneous alternation behaviour test of working spatial memory. In contrast to the reported phenotype of GABAB(1) −/− mice, however, neither GABAB(1a) −/− nor GABAB(1b) −/− mice were deficient in a passive avoidance task. On the other hand, GABAB(1a) −/− mice were impaired in familiar and novel object recognition. We conclude that GABAB(1) isoforms contribute differentially to GABAB receptor-mediated cognitive processes. PMID:17498817

  6. Regulating hippocampal hyperexcitability through GABAB Receptors

    PubMed Central

    Lang, Min; Moradi‐Chameh, Homeira; Zahid, Tariq; Gane, Jonathan; Wu, Chiping; Valiante, Taufik; Zhang, Liang

    2014-01-01

    Abstract Disturbances of GABAergic inhibition are a major cause of epileptic seizures. GABA exerts its actions via ionotropic GABAA receptors and metabotropic G protein‐coupled GABAB receptors. Malfunction of GABAA inhibition has long been recognized in seizure genesis but the role of GABAB receptors in controlling seizure activity is still not well understood. Here, we examined the anticonvulsive, or inhibitory effects, of GABAB receptors in a mouse model of hippocampal kindling as well as mouse hippocampal slices through the use of GS 39783, a positive allosteric GABAB receptor modulator, and CGP 55845, a selective GABAB receptor antagonist. When administered via intraperitoneal injections in kindled mice, GS 39783 (5 mg/kg) did not attenuate hippocampal EEG discharges, but did reduce aberrant hippocampal spikes, whereas CGP 55845 (10 mg/kg) prolonged hippocampal discharges and increased spike incidences. When examined in hippocampal slices, neither GS 39783 at 5 μmol/L nor the GABAB receptor agonist baclofen at 0.1 μmol/L alone significantly altered repetitive excitatory field potentials, but GS 39783 and baclofen together reversibly abolished these field potentials. In contrast, CGP 55845 at 1 μmol/L facilitated induction and incidence of these field potentials. In addition, CGP 55845 attenuated the paired pulse depression of CA3 population spikes and increased the frequency of EPSCs in individual CA3 pyramidal neurons. Collectively, these data suggest that GABABB receptors regulate hippocampal hyperexcitability by inhibiting CA3 glutamatergic synapses. We postulate that positive allosteric modulation of GABAB receptors may be effective in reducing seizure‐related hyperexcitability. PMID:24771688

  7. GABAB Receptor-Positive Modulators: Enhancement of GABAB Receptor Agonist Effects In Vivo

    PubMed Central

    France, Charles P.; Cheng, Kejun; Rice, Kenner C.

    2010-01-01

    In vivo effects of GABAB receptor-positive modulators suggest that they have therapeutic potential for treating central nervous system disorders such as anxiety, depression, and drug abuse. Although these effects generally are thought to be mediated by positive modulation of GABAB receptors, such modulation has been examined primarily in vitro. The present study was aimed at further examining the in vivo positive modulatory properties of the GABAB receptor-positive modulators, 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl) phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF). Both compounds enhanced loss of righting induced by baclofen in mice. However, CGP7930 was less effective and rac-BHFF was less potent for enhancing loss of righting induced by γ-hydroxybutyrate (GHB), which, like baclofen, has GABAB receptor agonist properties. In contrast with baclofen- and GHB-induced loss of righting, the hypothermic effects of baclofen and GHB were not enhanced by rac-BHFF but were enhanced by CGP7930 only at doses that produced hypothermia when given alone. CGP7930-induced hypothermia was not attenuated by the GABAB receptor antagonist 3-aminopropyl(diethoxymethyl)phosphinic acid (CGP35348), at doses that blocked baclofen-induced hypothermia, and was not increased by the nitric-oxide synthase inhibitor Nω-nitro-l-arginine methyl ester, at doses that increased the hypothermic effects of baclofen and GHB. The results provide evidence that CGP7930 and rac-BHFF act in vivo as positive modulators at GABAB receptors mediating loss of righting, but not at GABAB receptors mediating hypothermia. Conceivably, CGP7930, but not rac-BHFF, acts as an allosteric agonist at these latter receptors. Taken together, the results provide further evidence of pharmacologically distinct GABAB receptor subtypes, possibly allowing for a more selective therapeutic interference with the GABAB system. PMID:20628000

  8. GABAB(1) receptor subunit isoforms differentially regulate stress resilience.

    PubMed

    O'Leary, Olivia F; Felice, Daniela; Galimberti, Stefano; Savignac, Hélène M; Bravo, Javier A; Crowley, Tadhg; El Yacoubi, Malika; Vaugeois, Jean-Marie; Gassmann, Martin; Bettler, Bernhard; Dinan, Timothy G; Cryan, John F

    2014-10-21

    Stressful life events increase the susceptibility to developing psychiatric disorders such as depression; however, many individuals are resilient to such negative effects of stress. Determining the neurobiology underlying this resilience is instrumental to the development of novel and more effective treatments for stress-related psychiatric disorders. GABAB receptors are emerging therapeutic targets for the treatment of stress-related disorders such as depression. These receptors are predominantly expressed as heterodimers of a GABAB(2) subunit with either a GABAB(1a) or a GABAB(1b) subunit. Here we show that mice lacking the GABAB(1b) receptor isoform are more resilient to both early-life stress and chronic psychosocial stress in adulthood, whereas mice lacking GABAB(1a) receptors are more susceptible to stress-induced anhedonia and social avoidance compared with wild-type mice. In addition, increased hippocampal expression of the GABAB(1b) receptor subunit is associated with a depression-like phenotype in the helpless H/Rouen genetic mouse model of depression. Stress resilience in GABAB(1b)(-/-) mice is coupled with increased proliferation and survival of newly born cells in the adult ventral hippocampus and increased stress-induced c-Fos activation in the hippocampus following early-life stress. Taken together, the data suggest that GABAB(1) receptor subunit isoforms differentially regulate the deleterious effects of stress and, thus, may be important therapeutic targets for the treatment of depression. PMID:25288769

  9. Postnatal alterations in GABAB receptor tone produce sensorimotor gating deficits and protein level differences in adulthood.

    PubMed

    Bolton, Monica M; Heaney, Chelcie F; Murtishaw, Andrew S; Sabbagh, Jonathan J; Magcalas, Christy M; Kinney, Jefferson W

    2015-04-01

    The GABA transmitter system plays a vital role in modulating synaptic formation and activity during development. The GABAB receptor subtype in particular has been implicated in cell migration, promotion of neuronal differentiation, neurite outgrowth, and synapse formation but it's role in development is not well characterized. In order to investigate the effects of brief alterations in GABAB signaling in development, we administered to rats the GABAB agonist baclofen (2.0mg/kg) or antagonist phaclofen (0.3mg/kg) on postnatal days 7, 9, and 12, and evaluated sensorimotor gating in adulthood. We also examined tissue for changes in multiple proteins associated with GABAB receptor function and proteins associated with synapse formation. Our data indicate that early postnatal alterations to GABAB receptor-mediated signaling produced sex differences in sensorimotor gating in adulthood. Additionally, we found differences in GABAB receptor subunits and kalirin protein levels in the brain versus saline treated controls. Our data demonstrate that a subtle alteration in GABAB receptor function in early postnatal life induces changes that persist into adulthood. PMID:25314921

  10. Mouse hippocampal GABAB1 but not GABAB2 subunit-containing receptor complex levels are paralleling retrieval in the multiple-T-maze

    PubMed Central

    Falsafi, Soheil K.; Ghafari, Maryam; Miklósi, András G.; Engidawork, Ephrem; Gröger, Marion; Höger, Harald; Lubec, Gert

    2015-01-01

    GABAB receptors are heterodimeric G-protein coupled receptors known to be involved in learning and memory. Although a role for GABAB receptors in cognitive processes is evident, there is no information on hippocampal GABAB receptor complexes in a multiple T maze (MTM) task, a robust paradigm for evaluation of spatial learning. Trained or untrained (yoked control) C57BL/6J male mice (n = 10/group) were subjected to the MTM task and sacrificed 6 h following their performance. Hippocampi were taken, membrane proteins extracted and run on blue native PAGE followed by immunoblotting with specific antibodies against GABAB1, GABAB1a, and GABAB2. Immunoprecipitation with subsequent mass spectrometric identification of co-precipitates was carried out to show if GABAB1 and GABAB2 as well as other interacting proteins co-precipitate. An antibody shift assay (ASA) and a proximity ligation assay (PLA) were also used to see if the two GABAB subunits are present in the receptor complex. Single bands were observed on Western blots, each representing GABAB1, GABAB1a, or GABAB2 at an apparent molecular weight of approximately 100 kDa. Subsequently, densitometric analysis revealed that levels of GABAB1 and GABAB1a but not GABAB2- containing receptor complexes were significantly higher in trained than untrained groups. Immunoprecipitation followed by mass spectrometric studies confirmed the presence of GABAB1, GABAB2, calcium calmodulin kinases I and II, GluA1 and GluA2 as constituents of the complex. ASA and PLA also showed the presence of the two subunits of GABAB receptor within the complex. It is shown that increased levels of GABAB1 subunit-containing complexes are paralleling performance in a land maze. PMID:26539091

  11. Discriminative Stimulus Effects of the GABAB Receptor-Positive Modulator rac-BHFF: Comparison with GABAB Receptor Agonists and Drugs of Abuse

    PubMed Central

    Cheng, Kejun; Rice, Kenner C.

    2013-01-01

    GABAB receptor-positive modulators are thought to have advantages as potential medications for anxiety, depression, and drug addiction. They may have fewer side effects than GABAB receptor agonists, because selective enhancement of activated receptors could have effects different from nonselective activation of all receptors. To examine this, pigeons were trained to discriminate the GABAB receptor-positive modulator (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) from its vehicle. The discriminative stimulus effects of rac-BHFF were not mimicked by the GABAB receptor agonists baclofen and γ-hydroxybutyrate (GHB), not by diazepam, and not by alcohol, cocaine, and nicotine, whose self-administration has been reported to be attenuated by GABAB receptor-positive modulators. The discriminative stimulus effects of rac-BHFF were not antagonized by the GABAB receptor antagonist 3-aminopropyl (diethoxymethyl)phosphinic acid (CGP35348) but were attenuated by the less efficacious GABAB receptor-positive modulator 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl)phenol (CGP7930), suggesting the possibility that rac-BHFF produces its discriminative stimulus effects by directly activating GABAB2 subunits of GABAB receptors. At a dose 10-fold lower than the training dose, rac-BHFF enhanced the discriminative stimulus effects of baclofen, but not of GHB. This study provides evidence that the effects of GABAB receptor-positive modulators are not identical to those of GABAB receptor agonists. In addition, the results suggest that positive modulation of GABAB receptors does not produce discriminative stimulus effects similar to those of benzodiazepines, alcohol, cocaine, and nicotine. Finally, the finding that rac-BHFF enhanced effects of baclofen but not of GHB is consistent with converging evidence that the populations of GABAB receptors mediating the effects of baclofen and GHB are not identical. PMID:23275067

  12. CGP7930: a positive allosteric modulator of the GABAB receptor.

    PubMed

    Adams, C L; Lawrence, A J

    2007-01-01

    CGP7930 (3-(3',5'-Di-tert-butyl-4'-hydroxy)phenyl-2,2-dimethylpropanol) is a positive allosteric modulator of the metabotropic GABAB receptor. CGP7930 has been found to modulate the GABAB receptor in the open, or high affinity, state increasing agonist affinity for the receptor and signal transduction efficacy following agonist stimulation. The GABAB heteromeric subunit B2, involved in signal transduction but not ligand binding, seems to be the site of action of CGP7930 and similar allosteric modulators. When administered alone in naïve animals, CGP7930 acts as an anxiolytic in rodents without other overt behavioral effects and has also been demonstrated to reduce self-administration of nicotine, cocaine, or alcohol in rodents, suggesting that "fine tuning" of the GABAB receptor by positive allosteric modulators may be able to regulate abuse of these drugs. Baclofen, the GABAB agonist, is currently finding use in treating addiction and various other disorders, but this can result in off-target effects and tolerance. CGP7930 when co-administered with baclofen enhances its potency, which could in theory minimize deleterious effects. Further study of CGP7930 is required, but this compound, and others like it, holds potential in a clinical setting. PMID:17894647

  13. Behavioral Effects of γ-Hydroxybutyrate, Its Precursor γ-Butyrolactone, and GABAB Receptor Agonists: Time Course and Differential Antagonism by the GABAB Receptor Antagonist 3-Aminopropyl(diethoxymethyl)phosphinic Acid (CGP35348)

    PubMed Central

    Koek, Wouter; Mercer, Susan L.; Coop, Andrew; France, Charles P.

    2009-01-01

    γ-Hydroxybutyrate (GHB) is used therapeutically and recreationally. The mechanism by which GHB produces its therapeutic and recreational effects is not entirely clear, although GABAB receptors seem to play an important role. This role could be complex, because there are indications that different GABAB receptor mechanisms mediate the effects of GHB and the prototypical GABAB receptor agonist baclofen. To further explore possible differences in underlying GABAB receptor mechanisms, the present study examined the effects of GHB and baclofen on operant responding and their antagonism by the GABAB receptor antagonist 3-aminopropyl(diethoxymethyl)phosphinic acid (CGP35348). Pigeons were trained to peck a key for access to food during response periods that started at different times after the beginning of the session. In these pigeons, GHB, its precursor γ-butyrolactone (GBL), and the GABAB receptor agonists baclofen and 3-aminopropyl(methyl)phosphinic acid hydrochloride (SKF97541) decreased the rate of responding in a dose- and time-dependent manner. CGP35348 shifted the dose-response curve of each agonist to the right, but the magnitude of the shift differed among the agonists. Schild analysis yielded a pA2 value of CGP35348 to antagonize GHB and GBL [i.e., 3.9 (3.7–4.2)] that was different (P = 0.0011) from the pA2 value to antagonize baclofen and SKF97541 [i.e., 4.5 (4.4–4.7)]. This finding is further evidence that the GABAB receptor mechanisms mediating the effects of GHB and prototypical GABAB receptor agonists are not identical. A better understanding of the similarities and differences between these mechanisms, and their involvement in the therapeutic effects of GHB and baclofen, could lead to more effective medications with fewer adverse effects. PMID:19564487

  14. Swimming behavior regulation by GABAB receptors in Paramecium.

    PubMed

    Ramoino, Paola; Fronte, Paola; Beltrame, Francesco; Diaspro, Alberto; Fato, Marco; Raiteri, Luca; Stigliani, Sara; Usai, Cesare

    2003-12-10

    In Paramecium, internal Ca(2+) concentration increase coupled to membrane depolarization induces a reversal in the direction of ciliary beating and, consequently, a reversal in swimming direction. The ciliary reversal (CR) duration is correlated to Ca(2+) influx, and the addition of drugs that block the Ca(2+) current leads to a reduction in the backward swimming duration. In this study we have examined the possible function of GABA(B) receptors in P. primaurelia swimming control. The presence of GABA(B) immunoanalogue in Paramecium was evidenced using SDS-PAGE, Western blotting, and confocal laser scanning microscopy. By applying the specific GABA(B) receptor agonist baclofen, a dose-dependent inhibition of the membrane depolarization-induced CR duration was observed. This inhibition was antagonized by phaclofen, persisted when K(+) channel blockers were applied, and disappeared after treatment with nifedipine and verapamil. Moreover, the action of baclofen on depolarization-induced CR was suppressed by treatment with pertussis toxin. Therefore, these experiments suggest that baclofen modulates CR by a G protein (G(0) or G(1)) mediated inhibition of dihydropyridine-sensible calcium channels. Finally, synthesis and release of GABA in the environment by Paramecium have been demonstrated by HPLC. Possible correlations between GABA(B) receptor activation and the regulation of intracellular Ca(2+) levels are discussed. PMID:14644161

  15. Role of heteromer formation in GABAB receptor function.

    PubMed

    Kuner, R; Köhr, G; Grünewald, S; Eisenhardt, G; Bach, A; Kornau, H C

    1999-01-01

    Recently, GBR1, a seven-transmembrane domain protein with high affinity for gamma-aminobutyric acid (GABA)B receptor antagonists, was identified. Here, a GBR1-related protein, GBR2, was shown to be coexpressed with GBR1 in many brain regions and to interact with it through a short domain in the carboxyl-terminal cytoplasmic tail. Heterologously expressed GBR2 mediated inhibition of adenylyl cyclase; however, inwardly rectifying potassium channels were activated by GABAB receptor agonists only upon coexpression with GBR1 and GBR2. Thus, the interaction of these receptors appears to be crucial for important physiological effects of GABA and provides a mechanism in receptor signaling pathways that involve a heterotrimeric GTP-binding protein. PMID:9872744

  16. Inhibition of spontaneous EPSCs and IPSCs by presynaptic GABAB receptors on rat supraoptic magnocellular neurons.

    PubMed Central

    Kabashima, N; Shibuya, I; Ibrahim, N; Ueta, Y; Yamashita, H

    1997-01-01

    1. The function of presynaptic GABA receptors in the regulation of transmitter release in supraoptic nucleus (SON) magnocellular neurons was investigated by recording spontaneous postsynaptic currents from rat magnocellular SON neurons in a slice preparation (150 microns thick, 1.8 mm in diameter) using the whole-cell patch-clamp technique. 2. Both the spontaneous EPSCs and IPSCs were TTX resistant. The EPSCs were abolished by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), whereas the IPSCs were abolished by picrotoxin, suggesting that the EPSCs and IPSCs are synaptic inputs from glutamatergic and GABAergic neurons, respectively. 3. The selective GABAB agonist, baclofen, reduced the frequency of both the EPSCs and IPSCs without affecting the amplitude. The time constant of the decay phase of both the EPSCs and IPSCs remained unchanged after baclofen application. 4. The reduction of the frequency of the synaptic currents by baclofen was dose dependent (10 nM to 100 microM) and the EC50 values were 5.8 and 8.5 microM for the EPSCs and IPSCs, respectively. 5. The effect of baclofen (10 microM) was antagonized by the selective GABAB antagonist, 2-hydroxy-saclofen (2OH-saclofen), at 300 microM. 6. When given alone, 2OH-saclofen (100 microM) increased the frequency of both the EPSCs and IPSCs without affecting their amplitude, suggesting that endogenously released GABA in the slice acts on presynaptic GABAB receptors. 7. The GABAA agonist, muscimol, reduced the frequency of EPSCs, and picrotoxin increased the frequency of the EPSCs, suggesting that GABAA receptors also participate in the presynaptic inhibition of glutamate release. 8. Taken together, these data suggest that GABAB receptors are present on the presynaptic terminals of both GABA and glutamate neurons in the SON, and that these presynaptic GABAB receptors play an important role in the regulation of the neuronal activity in SON magnocellular neurons. Images Figure 1 PMID:9350623

  17. Activation but not blockade of GABAB receptors during early-life alters anxiety in adulthood in BALB/c mice.

    PubMed

    Sweeney, Fabian F; O'Leary, Olivia F; Cryan, John F

    2014-06-01

    Although the underlying pathophysiology of anxiety disorders is unknown it is clear that a combination of genetic and environmental factors in early life predispose to disease risk. Preclinical research increasingly suggests an important role for the GABAB receptor in modulating anxiety behaviour, with GABAB receptor deficient mice having increased anxiety behaviour. Previous studies have highlighted critical windows during development where adult anxiety behaviour is primed. However, little is known regarding the role played by the GABAB receptors in the developmental processes that underlie adult anxiety behaviour. To this end, we treated male BALB/c mouse pups with the either the selective GABAB receptor agonist, R-baclofen (2 mg/kg, s.c), the GABAB receptor antagonist CGP 52432 (10 mg/kg and 30 mg/kg) or vehicle from postnatal days (P) 14-28. The anxiety behaviour of these mice was then assessed in adulthood (P62 onwards) in a battery of behavioural tests comprising; the stress induced hyperthermia (SIH) test, defensive marble burying (DMB), elevated-plus maze (EPM) and the forced swim test (FST). Postnatal R-baclofen treatment resulted in increased anxiety-like behaviour in the EPM as shown by approach-avoidance and ethological measures. Other behavioural measures were not significantly altered. Interestingly, blockade of GABAB receptors with CGP52432 in early life caused no alterations in emotional behaviour. These data suggest that during early life GABAB receptor signalling can play a functional role in programing anxiety behaviour in adulthood. The underlying neurodevelopmental processes underlying these effects remain to be discovered. PMID:24050962

  18. Role of GABA(B) receptors in learning and memory and neurological disorders.

    PubMed

    Heaney, Chelcie F; Kinney, Jefferson W

    2016-04-01

    Although it is evident from the literature that altered GABAB receptor function does affect behavior, these results often do not correspond well. These differences could be due to the task protocol, animal strain, ligand concentration, or timing of administration utilized. Because several clinical populations exhibit learning and memory deficits in addition to altered markers of GABA and the GABAB receptor, it is important to determine whether altered GABAB receptor function is capable of contributing to the deficits. The aim of this review is to examine the effect of altered GABAB receptor function on synaptic plasticity as demonstrated by in vitro data, as well as the effects on performance in learning and memory tasks. Finally, data regarding altered GABA and GABAB receptor markers within clinical populations will be reviewed. Together, the data agree that proper functioning of GABAB receptors is crucial for numerous learning and memory tasks and that targeting this system via pharmaceuticals may benefit several clinical populations. PMID:26814961

  19. GABAB Receptor-Positive Modulators: Brain Region-Dependent Effects

    PubMed Central

    Advani, Tushar; Burke, Teresa F.; Cheng, Kejun; Rice, Kenner C.; Koek, Wouter

    2012-01-01

    This study examined the positive modulatory properties of 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethyl-propyl)-phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) at γ-aminobutyric acid B (GABAB) receptors in different brain regions. Using quantitative autoradiography, we measured GABAB receptor-stimulated binding of guanosine 5′-O-(3-[35S]thiotriphosphate) ([35S]GTPγS) to G proteins in medial prefrontal cortex (mPFC), hippocampus, and cerebellum. CGP7930 and rac-BHFF enhanced baclofen-stimulated [35S]GTPγS binding similarly in mPFC and hippocampus, but were more effective in cerebellum. CGP7930 (100 μM) increased [35S]GTPγS binding stimulated by baclofen (30 μM) from 29 to 241% above basal in mPFC and from 13 to 1530% above basal in cerebellum. Likewise, rac-BHFF (10 μM) increased baclofen-stimulated [35S]GTPγS binding more in cerebellum (from 13 to 1778% above basal) than in mPFC (from 29 to 514% above basal). rac-BHFF (10 μM) in combination with γ-hydroxybutyrate (20 mM) increased [35S]GTPγS binding in cerebellum but not in mPFC. rac-BHFF also enhanced the effects of 3-aminopropyl(diethoxymethyl)phosphinic acid (CGP35348). Consistent with its partial agonist properties, CGP35348 stimulated [35S]GTPγS binding in mPFC when given alone (to 18% above basal), but less extensively than baclofen (140% above basal), and antagonized baclofen when given together. CGP35348 (1 mM) in combination with rac-BHFF (100 μM) produced an increase in [35S]GTPγS binding that was larger in cerebellum (from 61 to 1260% above basal) than in mPFC (from 18 to 118% above basal). Taken together, the results show that GABAB receptor-positive modulators enhance [35S]GTPγS binding stimulated by GABAB receptor agonists in a brain region-dependent manner. This regionally selective enhancement is further evidence of pharmacologically distinct GABAB receptor populations, possibly allowing for more selective therapeutic targeting

  20. GABAB Receptor Constituents Revealed by Tandem Affinity Purification from Transgenic Mice*

    PubMed Central

    Bartoi, Tudor; Rigbolt, Kristoffer T. G.; Du, Dan; Köhr, Georg; Blagoev, Blagoy; Kornau, Hans-Christian

    2010-01-01

    GABAB receptors function as heterodimeric G-protein-coupled receptors for the neurotransmitter γ-aminobutyric acid (GABA). Receptor subtypes, based on isoforms of the ligand-binding subunit GABAB1, are thought to involve a differential set of associated proteins. Here, we describe two mouse lines that allow a straightforward biochemical isolation of GABAB receptors. The transgenic mice express GABAB1 isoforms that contain sequences for a two-step affinity purification, in addition to their endogenous subunit repertoire. Comparative analyses of purified samples from the transgenic mice and wild-type control animals revealed two novel components of the GABAB1 complex. One of the identified proteins, potassium channel tetramerization domain-containing protein 12, associates with heterodimeric GABAB receptors via the GABAB2 subunit. In transfected hippocampal neurons, potassium channel tetramerization domain-containing protein 12 augmented axonal surface targeting of GABAB2. The mice equipped with tags on GABAB1 facilitate validation and identification of native binding partners of GABAB receptors, providing insight into the molecular mechanisms of synaptic modulation. PMID:20406808

  1. GABAB receptor constituents revealed by tandem affinity purification from transgenic mice.

    PubMed

    Bartoi, Tudor; Rigbolt, Kristoffer T G; Du, Dan; Köhr, Georg; Blagoev, Blagoy; Kornau, Hans-Christian

    2010-07-01

    GABA(B) receptors function as heterodimeric G-protein-coupled receptors for the neurotransmitter gamma-aminobutyric acid (GABA). Receptor subtypes, based on isoforms of the ligand-binding subunit GABA(B1), are thought to involve a differential set of associated proteins. Here, we describe two mouse lines that allow a straightforward biochemical isolation of GABA(B) receptors. The transgenic mice express GABA(B1) isoforms that contain sequences for a two-step affinity purification, in addition to their endogenous subunit repertoire. Comparative analyses of purified samples from the transgenic mice and wild-type control animals revealed two novel components of the GABA(B1) complex. One of the identified proteins, potassium channel tetramerization domain-containing protein 12, associates with heterodimeric GABA(B) receptors via the GABA(B2) subunit. In transfected hippocampal neurons, potassium channel tetramerization domain-containing protein 12 augmented axonal surface targeting of GABA(B2). The mice equipped with tags on GABA(B1) facilitate validation and identification of native binding partners of GABA(B) receptors, providing insight into the molecular mechanisms of synaptic modulation. PMID:20406808

  2. Discriminative stimulus effects of the GABAB receptor-positive modulator rac-BHFF: comparison with GABAB receptor agonists and drugs of abuse.

    PubMed

    Koek, Wouter; Cheng, Kejun; Rice, Kenner C

    2013-03-01

    GABA(B) receptor-positive modulators are thought to have advantages as potential medications for anxiety, depression, and drug addiction. They may have fewer side effects than GABA(B) receptor agonists, because selective enhancement of activated receptors could have effects different from nonselective activation of all receptors. To examine this, pigeons were trained to discriminate the GABA(B) receptor-positive modulator (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) from its vehicle. The discriminative stimulus effects of rac-BHFF were not mimicked by the GABA(B) receptor agonists baclofen and γ-hydroxybutyrate (GHB), not by diazepam, and not by alcohol, cocaine, and nicotine, whose self-administration has been reported to be attenuated by GABA(B) receptor-positive modulators. The discriminative stimulus effects of rac-BHFF were not antagonized by the GABA(B) receptor antagonist 3-aminopropyl (diethoxymethyl)phosphinic acid (CGP35348) but were attenuated by the less efficacious GABA(B) receptor-positive modulator 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl)phenol (CGP7930), suggesting the possibility that rac-BHFF produces its discriminative stimulus effects by directly activating GABA(B2) subunits of GABA(B) receptors. At a dose 10-fold lower than the training dose, rac-BHFF enhanced the discriminative stimulus effects of baclofen, but not of GHB. This study provides evidence that the effects of GABA(B) receptor-positive modulators are not identical to those of GABA(B) receptor agonists. In addition, the results suggest that positive modulation of GABA(B) receptors does not produce discriminative stimulus effects similar to those of benzodiazepines, alcohol, cocaine, and nicotine. Finally, the finding that rac-BHFF enhanced effects of baclofen but not of GHB is consistent with converging evidence that the populations of GABA(B) receptors mediating the effects of baclofen and GHB are not identical. PMID:23275067

  3. Presynaptic Excitation via GABAB Receptors in Habenula Cholinergic Neurons Regulates Fear Memory Expression.

    PubMed

    Zhang, Juen; Tan, Lubin; Ren, Yuqi; Liang, Jingwen; Lin, Rui; Feng, Qiru; Zhou, Jingfeng; Hu, Fei; Ren, Jing; Wei, Chao; Yu, Tao; Zhuang, Yinghua; Bettler, Bernhard; Wang, Fengchao; Luo, Minmin

    2016-07-28

    Fear behaviors are regulated by adaptive mechanisms that dampen their expression in the absence of danger. By studying circuits and the molecular mechanisms underlying this adaptive response, we show that cholinergic neurons of the medial habenula reduce fear memory expression through GABAB presynaptic excitation. Ablating these neurons or inactivating their GABAB receptors impairs fear extinction in mice, whereas activating the neurons or their axonal GABAB receptors reduces conditioned fear. Although considered exclusively inhibitory, here, GABAB mediates excitation by amplifying presynaptic Ca(2+) entry through Cav2.3 channels and potentiating co-release of glutamate, acetylcholine, and neurokinin B to excite interpeduncular neurons. Activating the receptors for these neurotransmitters or enhancing neurotransmission with a phosphodiesterase inhibitor reduces fear responses of both wild-type and GABAB mutant mice. We identify the role of an extra-amygdalar circuit and presynaptic GABAB receptors in fear control, suggesting that boosting neurotransmission in this pathway might ameliorate some fear disorders. PMID:27426949

  4. GABA(B) receptor subunit 1 binds to proteins affected in 22q11 deletion syndrome.

    PubMed

    Zunner, Dagmar; Deschermeier, Christina; Kornau, Hans-Christian

    2010-03-01

    GABA(B) receptors mediate slow inhibitory effects of the neurotransmitter gamma-aminobutyric acid (GABA) on synaptic transmission in the central nervous system. They function as heterodimeric G-protein-coupled receptors composed of the seven-transmembrane domain proteins GABA(B1) and GABA(B2), which are linked through a coiled-coil interaction. The ligand-binding subunit GABA(B1) is at first retained in the endoplasmic reticulum and is transported to the cell surface only upon assembly with GABA(B2). Here, we report that GABA(B1), via the coiled-coil domain, can also bind to soluble proteins of unknown function, that are affected in 22q11 deletion/DiGeorge syndrome and are therefore referred to as DiGeorge critical region 6 (DGCR6). In transfected neurons the GABA(B1)-DGCR6 association resulted in a redistribution of both proteins into intracellular clusters. Furthermore, the C-terminus of GABA(B2) interfered with the novel interaction, consistent with heterodimer formation overriding transient DGCR6-binding to GABA(B1). Thus, sequential coiled-coil interactions may direct GABA(B1) into functional receptors. PMID:20036641

  5. The role of GABAB receptors in human reinforcement learning.

    PubMed

    Ort, Andres; Kometer, Michael; Rohde, Judith; Seifritz, Erich; Vollenweider, Franz X

    2014-10-01

    Behavioral evidence from human studies suggests that the γ-aminobutyric acid type B receptor (GABAB receptor) agonist baclofen modulates reinforcement learning and reduces craving in patients with addiction spectrum disorders. However, in contrast to the well established role of dopamine in reinforcement learning, the mechanisms by which the GABAB receptor influences reinforcement learning in humans remain completely unknown. To further elucidate this issue, a cross-over, double-blind, placebo-controlled study was performed in healthy human subjects (N=15) to test the effects of baclofen (20 and 50mg p.o.) on probabilistic reinforcement learning. Outcomes were the feedback-induced P2 component of the event-related potential, the feedback-related negativity, and the P300 component of the event-related potential. Baclofen produced a reduction of P2 amplitude over the course of the experiment, but did not modulate the feedback-related negativity. Furthermore, there was a trend towards increased learning after baclofen administration relative to placebo over the course of the experiment. The present results extend previous theories of reinforcement learning, which focus on the importance of mesolimbic dopamine signaling, and indicate that stimulation of cortical GABAB receptors in a fronto-parietal network leads to better attentional allocation in reinforcement learning. This observation is a first step in our understanding of how baclofen may improve reinforcement learning in healthy subjects. Further studies with bigger sample sizes are needed to corroborate this conclusion and furthermore, test this effect in patients with addiction spectrum disorder. PMID:25194227

  6. Presynaptic GABAB Receptors Regulate Hippocampal Synapses during Associative Learning in Behaving Mice

    PubMed Central

    Jurado-Parras, M. Teresa; Delgado-García, José M.; Sánchez-Campusano, Raudel; Gassmann, Martin; Bettler, Bernhard; Gruart, Agnès

    2016-01-01

    GABAB receptors are the G-protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the central nervous system. Pharmacological activation of GABAB receptors regulates neurotransmission and neuronal excitability at pre- and postsynaptic sites. Electrophysiological activation of GABAB receptors in brain slices generally requires strong stimulus intensities. This raises the question as to whether behavioral stimuli are strong enough to activate GABAB receptors. Here we show that GABAB1a-/- mice, which constitutively lack presynaptic GABAB receptors at glutamatergic synapses, are impaired in their ability to acquire an operant learning task. In vivo recordings during the operant conditioning reveal a deficit in learning-dependent increases in synaptic strength at CA3-CA1 synapses. Moreover, GABAB1a-/- mice fail to synchronize neuronal activity in the CA1 area during the acquisition process. Our results support that activation of presynaptic hippocampal GABAB receptors is important for acquisition of a learning task and for learning-associated synaptic changes and network dynamics. PMID:26848590

  7. Presynaptic GABAB Receptors Regulate Hippocampal Synapses during Associative Learning in Behaving Mice.

    PubMed

    Jurado-Parras, M Teresa; Delgado-García, José M; Sánchez-Campusano, Raudel; Gassmann, Martin; Bettler, Bernhard; Gruart, Agnès

    2016-01-01

    GABAB receptors are the G-protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the central nervous system. Pharmacological activation of GABAB receptors regulates neurotransmission and neuronal excitability at pre- and postsynaptic sites. Electrophysiological activation of GABAB receptors in brain slices generally requires strong stimulus intensities. This raises the question as to whether behavioral stimuli are strong enough to activate GABAB receptors. Here we show that GABAB1a-/- mice, which constitutively lack presynaptic GABAB receptors at glutamatergic synapses, are impaired in their ability to acquire an operant learning task. In vivo recordings during the operant conditioning reveal a deficit in learning-dependent increases in synaptic strength at CA3-CA1 synapses. Moreover, GABAB1a-/- mice fail to synchronize neuronal activity in the CA1 area during the acquisition process. Our results support that activation of presynaptic hippocampal GABAB receptors is important for acquisition of a learning task and for learning-associated synaptic changes and network dynamics. PMID:26848590

  8. Cockroach GABAB receptor subtypes: molecular characterization, pharmacological properties and tissue distribution.

    PubMed

    Blankenburg, S; Balfanz, S; Hayashi, Y; Shigenobu, S; Miura, T; Baumann, O; Baumann, A; Blenau, W

    2015-01-01

    γ-aminobutyric acid (GABA) is the predominant inhibitory neurotransmitter in the central nervous system (CNS). Its effects are mediated by either ionotropic GABAA receptors or metabotropic GABAB receptors. GABAB receptors regulate, via Gi/o G-proteins, ion channels, and adenylyl cyclases. In humans, GABAB receptor subtypes are involved in the etiology of neurologic and psychiatric disorders. In arthropods, however, these members of the G-protein-coupled receptor family are only inadequately characterized. Interestingly, physiological data have revealed important functions of GABAB receptors in the American cockroach, Periplaneta americana. We have cloned cDNAs coding for putative GABAB receptor subtypes 1 and 2 of P. americana (PeaGB1 and PeaGB2). When both receptor proteins are co-expressed in mammalian cells, activation of the receptor heteromer with GABA leads to a dose-dependent decrease in cAMP production. The pharmacological profile differs from that of mammalian and Drosophila GABAB receptors. Western blot analyses with polyclonal antibodies have revealed the expression of PeaGB1 and PeaGB2 in the CNS of the American cockroach. In addition to the widespread distribution in the brain, PeaGB1 is expressed in salivary glands and male accessory glands. Notably, PeaGB1-like immunoreactivity has been detected in the GABAergic salivary neuron 2, suggesting that GABAB receptors act as autoreceptors in this neuron. PMID:25242738

  9. Alterations in cortical GABAB receptors in neonatal rats exposed to hypoxic stress: role of glucose, oxygen, and epinephrine resuscitation.

    PubMed

    Anju, T R; Abraham, Pretty Mary; Antony, Sherin; Paulose, C S

    2010-10-01

    Hypoxia in neonates can cause permanent brain damage by gene and receptor level alterations mediated through changes in neurotransmitters. The present study evaluated GABA(B) receptor alterations, gene expression changes in glutamate decarboxylase and hypoxia-inducible factor 1A in the cerebral cortex of hypoxic neonatal rats and the resuscitation groups with glucose, oxygen, and epinephrine. Under hypoxic stress, a significant decrease in total GABA and GABA(B) receptors, GABA(B) and GAD gene expression was observed in the cerebral cortex, which accounts for the respiratory inhibition. Hypoxia-inducible factor 1A was upregulated under hypoxia to maintain body homeostasis. Hypoxic rats supplemented with glucose alone and with oxygen showed a reversal of the receptor alterations and changes in GAD and HIF-1A to near control. Being a source of immediate energy, glucose can reduce the ATP-depletion-induced changes in GABA and oxygenation, which helps in encountering hypoxia. Resuscitation with oxygen alone and epinephrine was less effective in reversing the receptor alterations. Thus, our study suggests that reduction in the GABA(B) receptors functional regulation during hypoxia plays an important role in cortical damage. Resuscitation with glucose alone and glucose and oxygen to hypoxic neonatal rats helps in protecting the brain from severe hypoxic damage. PMID:20473556

  10. Regulation of muscarinic acetylcholine receptor-mediated synaptic responses by GABAB receptors in the rat hippocampus

    PubMed Central

    Morton, Robin A; Manuel, Nick A; Bulters, Diederick O; Cobb, Stuart R; Davies, Ceri H

    2001-01-01

    Both GABAB and muscarinic acetylcholine receptors (mAChRs) influence hippocampal-dependent mnemonic processing. Here the possibility of a direct interaction between GABAB receptors and mAChR-mediated synaptic responses has been studied using intracellular recording in rat hippocampal slices. The GABAB receptor agonist(−)-baclofen (5–10 μm) depressed an atropine-sensitive slow EPSP (EPSPM) and occluded the GABAB-receptor-mediated IPSP (IPSPB) which preceded it. These inhibitory effects were accompanied by postsynaptic hyperpolarization (9 ± 2 mV) and a reduction in cell input resistance (12 ± 3 %). The selective GABAB receptor antagonist CGP 55845A (1 μm) fully reversed the depressant effects of (−)-baclofen (5–10 μm) such that in the combined presence of (−)-baclofen and CGP 55845A the EPSPM was 134 ± 21 % of control. (−)-Baclofen (5–10 μm) caused a small (28 ± 11 %) inhibition of carbachol-induced (3.0 μm) postsynaptic depolarizations and increases in input resistance. CGP 55845A (1 μm) alone caused an increase in the amplitude of the EPSPM (253 ± 74 % of control) and blocked the IPSPB that preceded it. In contrast, the selective GABA uptake inhibitor NNC 05–0711 (10 μm) increased the amplitude of the IPSPB by 141 ± 38 % and depressed the amplitude of the EPSPM by 58 ± 10 %. This inhibition was abolished by CGP 55845A (1 μm). Taken together these data provide good evidence that synaptically released GABA activates GABAB receptors that inhibit mAChR-mediated EPSPs in hippocampal CA1 pyramidal neurones. The mechanism of inhibition may involve both pre- and postsynaptic elements. PMID:11559773

  11. Modular composition and dynamics of native GABAB receptors identified by high-resolution proteomics.

    PubMed

    Schwenk, Jochen; Pérez-Garci, Enrique; Schneider, Andy; Kollewe, Astrid; Gauthier-Kemper, Anne; Fritzius, Thorsten; Raveh, Adi; Dinamarca, Margarita C; Hanuschkin, Alexander; Bildl, Wolfgang; Klingauf, Jürgen; Gassmann, Martin; Schulte, Uwe; Bettler, Bernhard; Fakler, Bernd

    2016-02-01

    GABAB receptors, the most abundant inhibitory G protein-coupled receptors in the mammalian brain, display pronounced diversity in functional properties, cellular signaling and subcellular distribution. We used high-resolution functional proteomics to identify the building blocks of these receptors in the rodent brain. Our analyses revealed that native GABAB receptors are macromolecular complexes with defined architecture, but marked diversity in subunit composition: the receptor core is assembled from GABAB1a/b, GABAB2, four KCTD proteins and a distinct set of G-protein subunits, whereas the receptor's periphery is mostly formed by transmembrane proteins of different classes. In particular, the periphery-forming constituents include signaling effectors, such as Cav2 and HCN channels, and the proteins AJAP1 and amyloid-β A4, both of which tightly associate with the sushi domains of GABAB1a. Our results unravel the molecular diversity of GABAB receptors and their postnatal assembly dynamics and provide a roadmap for studying the cellular signaling of this inhibitory neurotransmitter receptor. PMID:26691831

  12. The effects of agonists of ionotropic GABA(A) and metabotropic GABA(B) receptors on learning.

    PubMed

    Zyablitseva, Evgeniya A; Kositsyn, Nikolay S; Shul'gina, Galina I

    2009-05-01

    The research described here investigates the role played by inhibitory processes in the discriminations made by the nervous system of humans and animals between familiar and unfamiliar and significant and nonsignificant events. This research compared the effects of two inhibitory mediators of gamma-aminobutyric acid (GABA): 1) phenibut, a nonselective agonist of ionotropic GABA(A) and metabotropic GABA(B) receptors and 2) gaboxadol a selective agonist of ionotropic GABA(A) receptors on the process of developing active defensive and inhibitory conditioned reflexes in alert non-immobilized rabbits. It was found that phenibut, but not gaboxadol, accelerates the development of defensive reflexes at an early stage of conditioning. Both phenibut and gaboxadol facilitate the development of conditioned inhibition, but the effect of gaboxadol occurs at later stages of conditioning and is less stable than that of phenibut. The earlier and more stable effects of phenibut, as compared to gaboxadol, on storage in memory of the inhibitory significance of a stimulus may occur because GABA(B) receptors play the dominant role in the development of internal inhibition during an early stage of conditioning. On the other hand this may occur because the participation of both GABA(A) and GABA(B) receptors are essential to the process. We discuss the polyfunctionality of GABA receptors as a function of their structure and the positions of the relevant neurons in the brain as this factor can affect regulation of various types of psychological processes. PMID:19476215

  13. Marlin-1 and conventional kinesin link GABAB receptors to the cytoskeleton and regulate receptor transport.

    PubMed

    Vidal, René L; Ramírez, Omar A; Sandoval, Lisette; Koenig-Robert, Roger; Härtel, Steffen; Couve, Andrés

    2007-07-01

    The cytoskeleton and cytoskeletal motors play a fundamental role in neurotransmitter receptor trafficking, but proteins that link GABA(B) receptors (GABA(B)Rs) to the cytoskeleton have not been described. We recently identified Marlin-1, a protein that interacts with GABA(B)R1. Here, we explore the association of GABA(B)Rs and Marlin-1 to the cytoskeleton using a combination of biochemistry, microscopy and live cell imaging. Our results indicate that Marlin-1 is associated to microtubules and the molecular motor kinesin-I. We demonstrate that a fraction of Marlin-1 is mobile in dendrites of cultured hippocampal neurons and that mobility is microtubule-dependent. We also show that GABA(B)Rs interact robustly with kinesin-I and that intracellular membranes containing GABA(B)Rs are sensitive to treatments that disrupt a protein complex containing Marlin-1, kinesin-I and tubulin. Finally, we report that a kinesin-I mutant severely impairs receptor transport. We conclude that Marlin-1 and kinesin-1 link GABA(B)Rs to the tubulin cytoskeleton in neurons. PMID:17532644

  14. A negative allosteric modulator modulates GABAB-receptor signalling through GB2 subunits.

    PubMed

    Sun, Bing; Chen, Linhai; Liu, Lei; Xia, Zhixiong; Pin, Jean-Philippe; Nan, Fajun; Liu, Jianfeng

    2016-03-15

    An γ-aminobutyric acid type B (GABAB)-receptor mediates slow and prolonged synaptic inhibition in the central nervous system, which represents an interesting target for the treatment of various diseases and disorders of the central nervous system. To date, only one activator of the GABAB-receptor, baclofen, is on the market for the treatment of spasticity. Inhibitors of the GABAB-receptor, such as antagonists, show anti-absence seizure activity and pro-cognitive properties. In a search for allosteric compounds of the GABAB-receptor, although several positive allosteric modulators have been developed, it is only recently that the first negative allosteric modulator (NAM), CLH304a (also named Compound 14), has been reported. In the present study, we provide further information on the mechanism of action of CLH304a, and also show the possibility of designing more NAMs, such as CLH391 and CLH393, based on the structure of CLH304a. First we show that CLH304a inhibits native GABAB-receptor activity in cultured cerebellar granular neurons. We then show that CLH304a has inverse agonist properties and non-competitively inhibits the effect of agonists, indicating that it binds at a different site to GABA. The GABAB-receptor is a mandatory heterodimer made of GB1 subunits, in which agonists bind, and GB2 subunits, which activate G-proteins. By using various combinations made up of wild-type and/or mutated GB1 and GB2 subunits, we show that CLH304a acts on the heptahelical domain of GB2 subunits. These data revealed the possibility of designing innovative NAMs acting in the heptahelical domain of the GB2 subunits, offering novel possibilities for therapeutic intervention based on GABAB-receptor inhibition. PMID:26772870

  15. Binding characteristics of gamma-hydroxybutyric acid as a weak but selective GABAB receptor agonist.

    PubMed

    Mathivet, P; Bernasconi, R; De Barry, J; Marescaux, C; Bittiger, H

    1997-02-19

    The aim of this study was to reexamine the concept that gamma-hydroxybutyric acid (GHB) is a weak but selective agonist at gamma-aminobutyric acidB (GABAB) receptors, using binding experiments with several radioligands. Ki values of GHB were similar (approximately equal to 100 microM) in three agonist radioligand assays for GABAB receptors, [3H]baclofen (beta-para-chlorophenyl-gamma-aminobutyric acid), [3H]CGP 27492 (3-aminopropyl-phosphinic acid) and [3H]GABA, in the presence of the GABAA receptor agonist isoguvacine with rat cortical, cerebellar and hippocampal membranes. In competition experiments between GHB and the GABAB receptor antagonist, [3H]CGP 54626 (3-N [1-{(S)-3,4-dichlorophenyl}-ethylamino]-2-(S)-hydroxypropyl cyclo-hexylmethyl phosphinic acid), the IC50 values were significantly increased with 300 microM of 5'-guanyl-imidodiphosphate (Gpp(NH)p), which suggested that guanine nucleotide binding proteins (G-proteins) modulate GHB binding on GABAB receptors. The inhibition by GHB of [3H]CGP 27492 binding in cortical membranes was not altered in the presence of 0.3 or 3 mM of the two GHB dehydrogenase inhibitors, valproate and ethosuximide. Thus, GHB is not reconverted into GABA by GHB dehydrogenase. Taken together, the results of this study demonstrated that GHB is an endogenous weak but selective agonist at GABAB receptors. PMID:9083788

  16. Experimental absence seizures: potential role of gamma-hydroxybutyric acid and GABAB receptors.

    PubMed

    Bernasconi, R; Lauber, J; Marescaux, C; Vergnes, M; Martin, P; Rubio, V; Leonhardt, T; Reymann, N; Bittiger, H

    1992-01-01

    We have investigated whether the pathogenesis of spontaneous generalized non-convulsive seizures in rats with genetic absence epilepsy is due to an increase in the brain levels of gamma-hydroxybutyric acid (GHB) or in the rate of its synthesis. Concentrations of GHB or of its precursor gamma-butyrolactone (GBL) were measured with a new GC/MS technique which allows the simultaneous assessment of GHB and GBL. The rate of GHB synthesis was estimated from the increase in GHB levels after inhibition of its catabolism with valproate. The results of this study do not indicate significant differences in GHB or GBL levels, or in their rates of synthesis in rats showing spike-and-wave discharges (SWD) as compared to rats without SWD. Binding data indicate that GHB, but not GBL, has a selective, although weak affinity for GABAB receptors (IC50 = 150 microM). Similar IC50 values were observed in membranes prepared from rats showing SWD and from control rats. The average GHB brain levels of 2.12 +/- 0.23 nmol/g measured in the cortex and of 4.28 +/- 0.90 nmol/g in the thalamus are much lower than the concentrations necessary to occupy a major part of the GABAB receptors. It is unlikely that local accumulations of GHB reach concentrations 30-70-fold higher than the average brain levels. After injection of 3.5 mmol/kg GBL, a dose sufficient to induce SWD, brain concentrations reach 240 +/- 31 nmol/g (Snead, 1991) and GHB could thus stimulate the GABAB receptor. Like the selective and potent GABAB receptor agonist R(-)-baclofen, GHB causes a dose-related decrease in cerebellar cGMP. This decrease and the increase in SWD caused by R(-)-baclofen were completely blocked by the selective and potent GABAB receptor antagonist CGP 35348, whereas only the increase in the duration of SWD induced by GHB was totally antagonized by CGP 35348. The decrease in cerebellar cGMP levels elicited by GHB was only partially antagonized by CGP 35348. These findings suggest that all effects of R

  17. Spinal GABA-B receptor modulates neutrophil recruitment to the knee joint in zymosan-induced arthritis.

    PubMed

    Bassi, Gabriel S; do C Malvar, David; Cunha, Thiago M; Cunha, Fernando Q; Kanashiro, Alexandre

    2016-08-01

    Recent studies have demonstrated that the central nervous system controls inflammatory responses by activating complex efferent neuroimmune pathways. The present study was designed to evaluate the role that central gamma-aminobutyric acid type B (GABA-B) receptor plays in neutrophil migration in a murine model of zymosan-induced arthritis by using different pharmacological tools. We observed that intrathecal administration of baclofen, a selective GABA-B agonist, exacerbated the inflammatory response in the knee after zymosan administration characterized by an increase in the neutrophil recruitment and knee joint edema, whereas saclofen, a GABA-B antagonist, exerted the opposite effect. Intrathecal pretreatment of the animals with SB203580 (an inhibitor of p38 mitogen-activated protein kinase) blocked the pro-inflammatory effect of baclofen. On the other hand, systemic administration of guanethidine, a sympatholytic drug that inhibits catecholamine release, and nadolol, a beta-adrenergic receptor antagonist, reversed the effect of saclofen. Moreover, saclofen suppressed the release of the pro-inflammatory cytokines into the knee joint (ELISA) and pain-related behaviors (open field test). Since the anti-inflammatory effect of saclofen depends on the sympathetic nervous system integrity, we observed that isoproterenol, a beta-adrenergic receptor agonist, mimics the central GABA-B blockade decreasing knee joint neutrophil recruitment. Together, these results demonstrate that the pharmacological manipulation of spinal GABAergic transmission aids control of neutrophil migration to the inflamed joint by modulating the activation of the knee joint-innervating sympathetic terminal fibers through a mechanism dependent on peripheral beta-adrenergic receptors and central components, such as p38 MAPK. PMID:27106212

  18. Effects of repeated cocaine on medial prefrontal cortical GABAB receptor modulation of neurotransmission in the mesocorticolimbic dopamine system.

    PubMed

    Jayaram, Prathiba; Steketee, Jeffery D

    2004-08-01

    Increased excitatory output from medial prefrontal cortex is an important component in the development of cocaine sensitization. Activation of GABAergic systems in the prefrontal cortex can decrease glutamatergic activity. A recent study suggested that sensitization might be associated with a decrease in GABAB receptor responsiveness in the medial prefrontal cortex. Therefore, the present study examined whether repeated exposure to cocaine-modified neurochemical changes in the mesocorticolimbic dopamine system induced by infusion of baclofen into the medial prefrontal cortex. In vivo microdialysis studies were conducted to monitor dopamine, glutamate and GABA levels in the medial prefrontal cortex and glutamate levels in the ipsilateral nucleus accumbens and ventral tegmental area during the infusion of baclofen into medial prefrontal cortex. Baclofen minimally affected glutamate levels in the medial prefrontal cortex, nucleus accumbens or ventral tegmental area of control animals, but dose-dependently increased glutamate levels in each of these regions in animals sensitized to cocaine. This effect was not the result of changes in GABAB receptor-mediated modulation of dopamine or GABA in the medial prefrontal cortex. The data suggest that alterations in GABAB receptor modulation of medial prefrontal cortical excitatory output may play an important role in the development of sensitization to cocaine. PMID:15287889

  19. [GABAB receptor as therapeutic target for drug addiction: from baclofen to positive allosteric modulators].

    PubMed

    Agabio, Roberta; Colombo, Giancarlo

    2015-01-01

    The present paper summarizes experimental and clinical data indicating the therapeutic potential of the GABAB receptor agonist, baclofen, in the treatment of alcohol use disorder (AUD) and substance use disorder (SUD). Multiple preclinical studies have demonstrated the ability of baclofen to suppress alcohol drinking (including binge- and relapse-like drinking), oral alcohol self-administration, and intravenous self-administration of cocaine, nicotine, amphetamine, methamphetamine, morphine, and heroin in rodents. Some randomized, controlled trials (RCTs) and case reports support the efficacy of baclofen in suppressing alcohol consumption, craving for alcohol, and alcohol withdrawal symptomatology in alcohol-dependent patients. Data from RCTs and open studies investigating baclofen efficacy on SUD are currently less conclusive. Interest in testing high doses of baclofen in AUD and SUD treatment has recently emerged. Preclinical research has extended the anti-addictive properties of baclofen to positive allosteric modulators of the GABAB receptor (GABAB PAMs). In light of their more favourable side effect profile (compared to baclofen), GABAB PAMs may represent a major step forward in a GABAB receptor-based pharmacotherapy of AUD and SUD. PMID:26093587

  20. Developing oligodendrocytes express functional GABA(B) receptors that stimulate cell proliferation and migration.

    PubMed

    Luyt, Karen; Slade, Timothy P; Dorward, Jienchi J; Durant, Claire F; Wu, Yue; Shigemoto, Ryuichi; Mundell, Stuart J; Váradi, Anikó; Molnár, Elek

    2007-02-01

    GABA(B) receptors (GABA(B)Rs) are involved in early events during neuronal development. The presence of GABA(B)Rs in developing oligodendrocytes has not been established. Using immunofluorescent co-localization, we have identified GABA(B)R proteins in O4 marker-positive oligodendrocyte precursor cells (OPCs) in 4-day-old mouse brain periventricular white matter. In culture, OPCs, differentiated oligodendrocytes (DOs) and type 2 astrocytes (ASTs) express both the GABA(B1abcdf) and GABA(B2) subunits of the GABA(B)R. Using semiquantitative PCR analysis with GABA(B)R isoform-selective primers we found that the expression level of GABA(B1abd) was substantially higher in OPCs or ASTs than in DOs. In contrast, the GABA(B2) isoform showed a similar level of expression in OPCs and DOs, and a significantly higher level in ASTs. This indicates that the expression of GABA(B1) and GABA(B2) subunits are under independent control during oligodendroglial development. Activation of GABA(B)Rs using the selective agonist baclofen demonstrated that these receptors are functionally active and negatively coupled to adenylyl cyclase. Manipulation of GABA(B)R activity had no effect on OPC migration in a conventional agarose drop assay, whereas baclofen significantly increased OPC migration in a more sensitive transwell microchamber-based assay. Exposure of cultured OPCs to baclofen increased their proliferation, providing evidence for a functional role of GABA(B)Rs in oligodendrocyte development. The presence of GABA(B)Rs in developing oligodendrocytes provides a new mechanism for neuronal-glial interactions during development and may offer a novel target for promoting remyelination following white matter injury. PMID:17144904

  1. Diminished Presynaptic GABAB Receptor Function in the Neocortex of a Genetic Model of Absence Epilepsy

    PubMed Central

    Inaba, Yugi; D’Antuono, Margherita; Bertazzoni, Giuliano; Biagini, Giuseppe; Avoli, Massimo

    2016-01-01

    Changes in GABAB receptor subunit expression have been recently reported in the neocortex of epileptic WAG/Rij rats that are genetically prone to experience absence seizures. These alterations may lead to hyperexcitability by down-regulating the function of presynaptic GABAB receptors in neocortical networks as suggested by a reduction in paired-pulse depression. Here, we tested further this hypothesis by analyzing the effects induced by the GABAB receptor agonist baclofen (0.1–10 μM) on the inhibitory events recorded in vitro from neocortical slices obtained from epileptic (>180 day-old) WAG/Rij and age-matched, non-epileptic control (NEC) rats. We found that higher doses of baclofen were required to depress pharmacologically isolated, stimulus-induced IPSPs generated by WAG/Rij neurons as compared to NEC. We also obtained similar evidence by comparing the effects of baclofen on the rate of occurrence of synchronous GABAergic events recorded by WAG/Rij and NEC neocortical slices treated with 4-aminopyridine + glutamatergic receptor antagonists. In conclusion, these data highlight a decreased function of presynaptic GABAB receptors in the WAG/Rij rat neocortex. We propose that this alteration may contribute to neocortical hyperexcitability and thus to absence seizures. PMID:19176980

  2. Structure and functional interaction of the extracellular domain of human GABAB receptor GBR2

    PubMed Central

    Geng, Yong; Xiong, Dazhi; Mosyak, Lidia; Malito, David L.; Kniazeff, Julie; Chen, Yan; Burmakina, Svetlana; Quick, Matthias; Bush, Martin; Javitch, Jonathan A.; Pin, Jean-Philippe; Fan, Qing R.

    2012-01-01

    Inhibitory neurotransmission is mediated primarily by GABA. Metabotropic GABAB receptor is a G protein coupled receptor central to mammalian brain function. Malfunction of GABAB receptor has been implicated in a number of neurological disorders. GABAB receptor functions as a heterodimeric assembly of GBR1 and GBR2 subunits, where GBR1 is responsible for ligand-binding and GBR2 is responsible for G protein coupling. Here we demonstrate that the GBR2 ectodomain directly interacts with the GBR1 ectodomain to increase agonist affinity by selectively stabilizing the agonist-bound conformation of GBR1. We present the crystal structure of the GBR2 ectodomain, which reveals a polar heterodimeric interface. We also identify specific heterodimer contacts from both subunits, and GBR1 residues involved in ligand recognition. Lastly, our structural and functional data indicate that the GBR2 ectodomain adopts a constitutively open conformation, suggesting a structural asymmetry in the active state of GABAB receptor that is unique to the GABAergic system. PMID:22660477

  3. Effect of GABA(B) receptor agonist SKF97541 on cortical and hippocampal epileptic afterdischarges.

    PubMed

    Fábera, P; Mareš, P

    2014-01-01

    Activation of GABA(B) receptors leads to longer inhibitory postsynaptic potentials than activation of GABA(A) receptors. Therefore GABA(B) receptors may be a target for anticonvulsant therapy. The present study examined possible effects of GABA(B) receptor agonist SKF97541 on cortical and hippocampal epileptic afterdischarges (ADs). Epileptic ADs elicited by electrical stimulation of sensorimotor cortex or dorsal hippocampus were studied in adult male Wistar rats. Stimulation series were applied 6 times with 10- or 20-min interval. Either interval was efficient for reliable elicitation of cortical ADs but stimulation at 10-min intervals did not reliably elicit hippocampal ADs, many stimulations were without effect. SKF97541 in dose 1 mg/kg significantly prolonged cortical ADs. Duration of hippocampal ADs was not significantly changed by either dose of SKF97541 in spite of a marked myorelaxant effect of the higher dose. Our present data demonstrated that neither cortical nor hippocampal ADs in adult rats were suppressed by GABA(B) receptor agonist SKF97541. Proconvulsant effect on cortical ADs indicates a different role in these two brain structures. In addition, duration of refractory period for electrically-induced ADs in these two structures in adult rats is different. PMID:24702499

  4. Opposite Effects of KCTD Subunit Domains on GABAB Receptor-mediated Desensitization*

    PubMed Central

    Seddik, Riad; Jungblut, Stefan P.; Silander, Olin K.; Rajalu, Mathieu; Fritzius, Thorsten; Besseyrias, Valérie; Jacquier, Valérie; Fakler, Bernd; Gassmann, Martin; Bettler, Bernhard

    2012-01-01

    GABAB receptors assemble from principle and auxiliary subunits. The principle subunits GABAB1 and GABAB2 form functional heteromeric GABAB(1,2) receptors that associate with homotetramers of auxiliary KCTD8, -12, -12b, or -16 (named after their K+ channel tetramerization domain) subunits. These auxiliary subunits constitute receptor subtypes with distinct functional properties. KCTD12 and -12b generate desensitizing receptor responses while KCTD8 and -16 generate largely non-desensitizing receptor responses. The structural elements of the KCTDs underlying these differences in desensitization are unknown. KCTDs are modular proteins comprising a T1 tetramerization domain, which binds to GABAB2, and a H1 homology domain. KCTD8 and -16 contain an additional C-terminal H2 homology domain that is not sequence-related to the H1 domains. No functions are known for the H1 and H2 domains. Here we addressed which domains and sequence motifs in KCTD proteins regulate desensitization of the receptor response. We found that the H1 domains in KCTD12 and -12b mediate desensitization through a particular sequence motif, T/NFLEQ, which is not present in the H1 domains of KCTD8 and -16. In addition, the H2 domains in KCTD8 and -16 inhibit desensitization when expressed C-terminal to the H1 domains but not when expressed as a separate protein in trans. Intriguingly, the inhibitory effect of the H2 domain is sequence-independent, suggesting that the H2 domain sterically hinders desensitization by the H1 domain. Evolutionary analysis supports that KCTD12 and -12b evolved desensitizing properties by liberating their H1 domains from antagonistic H2 domains and acquisition of the T/NFLEQ motif. PMID:23035119

  5. Role of GABAB Receptor and L-Arg in GABA-Induced Vasorelaxation in Non-diabetic and Streptozotocin-Induced Diabetic Rat Vessels

    PubMed Central

    Kharazmi, Fatemah; Soltani, Nepton; Rezaei, Sana; Keshavarz, Mansoor; Farsi, Leila

    2015-01-01

    Background: Hypertension is considered an independent risk factor for cardiovascular mortality in diabetic patients. The present study was designed to determine the role of gamma amino butyric acid B (GABAB) receptor and L-arginine (L-Arg) in GABA-induced vasorelaxation in normal and streptozotocin-induced diabetic rat vessels. Methods: Diabetes was induced by a single i.p. injection of streptozotocin (STZ, 60 mg/kg). Eight weeks later, superior mesenteric arteries of all groups were isolated and perfused according to the McGregor method. Results: Baseline perfusion pressure of STZ diabetic rats was significantly higher than non-diabetic rats in both intact and denuded endothelium. In the presence of faclofen, a selective GABAB receptor blocker, GABA-induced relaxation in intact and denuded endothelium mesenteric beds of STZ diabetic rats was suppressed, but this response in non-diabetic rats was not suppressed. Our results showed that in the presence of L-Arg, a nitric oxide precursor, GABA induced vasorelaxation in both diabetic and non-diabetic vessels. Conclusion: From the results of this study, it may be concluded that the vasorelaxatory effect of GABA in diabetic vessel is mediated by the GABAB receptor and nitric oxide, but it seems that in non-diabetic vessel GABAB receptor does not play any role in GABA-induced vasorelaxation, but nitric oxide induced GABA relaxation in non-diabetic vessel. PMID:25864813

  6. Inhibition of mechanosensitivity in visceral primary afferents by GABAB receptors involves calcium and potassium channels.

    PubMed

    Page, A J; O'Donnell, T A; Blackshaw, L A

    2006-01-01

    GABA(B) receptors inhibit mechanosensitivity of visceral afferents. This is associated with reduced triggering of events that lead to gastro-esophageal reflux, with important therapeutic consequences. In other neuronal systems, GABA(B) receptor activation may be linked via G-proteins to reduced N-type Ca(2+) channel opening, increased inward rectifier K(+) channel opening, plus effects on a number of intracellular messengers. Here we aimed to determine the role of Ca(2+) and K(+) channels in the inhibition of vagal afferent mechanoreceptor function by the GABA(B) receptor agonist baclofen. The responses of three types of ferret gastro-esophageal vagal afferents (mucosal, tension and tension mucosal receptors) to graded mechanical stimuli were investigated in vitro. The effects of baclofen (200 microM) alone on these responses were quantified, and the effects of baclofen in the presence of the G-protein-coupled inward rectifier potassium channel blocker Rb(+) (4.7 mM) and/or the N-type calcium channel blocker omega-conotoxin GVIA (0.1 microM). Baclofen inhibition of mucosal receptor mechanosensitivity was abolished by both blockers. Its inhibitory effect on tension mucosal receptors was partly reduced by both. The inhibitory effect of baclofen on tension receptors was unaffected. The data indicate that the inhibitory action of GABA(B) receptors is mediated via different pathways in mucosal, tension and tension mucosal receptors via mechanisms involving both N-type Ca(2+) channels and inwardly rectifying K(+) channels and others. PMID:16289839

  7. Resequencing of the auxiliary GABAB receptor subunit gene KCTD12 in chronic tinnitus

    PubMed Central

    Sand, P. G.; Langguth, B.; Itzhacki, J.; Bauer, A.; Geis, S.; Cárdenas-Conejo, Z. E.; Pimentel, V.; Kleinjung, T.

    2012-01-01

    Tinnitus is a common and often incapacitating hearing disorder marked by the perception of phantom sounds. Susceptibility factors remain largely unknown but GABAB receptor signaling has long been implicated in the response to treatment and, putatively, in the etiology of the disorder. We hypothesized that variation in KCTD12, the gene encoding an auxiliary subunit of GABAB receptors, could help to predict the risk of developing tinnitus. Ninety-five Caucasian outpatients with a diagnosis of chronic tinnitus were systematically screened for mutations in the KCTD12 open reading frame and the adjacent 3′ untranslated region by Sanger sequencing. Allele frequencies were determined for 14 known variants of which three (rs73237446, rs34544607, and rs41287030) were polymorphic. When allele frequencies were compared to data from a large reference population of European ancestry, rs34544607 was associated with tinnitus (p = 0.04). However, KCTD12 genotype did not predict tinnitus severity (p = 0.52) and the association with rs34544607 was weakened after screening 50 additional cases (p = 0.07). Pending replication in a larger cohort, KCTD12 may act as a risk modifier in chronic tinnitus. Issues that are yet to be addressed include the effects of neighboring variants, e.g., in the KCTD12 gene regulatory region, plus interactions with variants of GABAB1 and GABAB2. PMID:22654739

  8. CGP 36,742, an orally active GABAB receptor antagonist, facilitates memory in a social recognition test in rats.

    PubMed

    Mondadori, C; Moebius, H J; Zingg, M

    1996-05-01

    CGP 36,742, an orally active GABAB receptor antagonist, improves the retention performance of rats in a social recognition test. This effect is detectable over a very wide range of doses (0.03 to 300 mg/kg, p.o.). Considering its binding (32 mumol affinity for the GABAB site) the surprisingly potent activity of CGP 36,742 makes it appear quite possible that the effect is mediated by an as yet unknown receptor subtype. PMID:8762176

  9. Association of Rgs7/Gβ5 complexes with Girk channels and GABAB receptors in hippocampal CA1 pyramidal neurons.

    PubMed

    Fajardo-Serrano, Ana; Wydeven, Nicole; Young, Daniele; Watanabe, Masahiko; Shigemoto, Ryuichi; Martemyanov, Kirill A; Wickman, Kevin; Luján, Rafael

    2013-12-01

    In the hippocampus, signaling through G protein-coupled receptors is modulated by Regulators of G protein signaling (Rgs) proteins, which act to stimulate the rate of GTP hydrolysis, and consequently, G protein inactivation. The R7-Rgs subfamily selectively deactivates the G(i/o)-class of Gα subunits that mediate the action of several GPCRs. Here, we used co-immunoprecipitation, electrophysiology and immunoelectron microscopy techniques to investigate the formation of macromolecular complexes and spatial relationship of Rgs7/Gβ5 complexes and its prototypical signaling partners, the GABAB receptor and Girk channel. Co-expression of recombinant GABAB receptors and Girk channels in combination with co-immunoprecipitation experiments established that the Rgs7/Gβ5 forms complexes with GABAB receptors or Girk channels. Using electrophysiological experiments, we found that GABAB -Girk current deactivation kinetics was markedly faster in cells coexpressing Rgs7/Gβ5. At the electron microscopic level, immunolabeling for Rgs7 and Gβ5 proteins was found primarily in the dendritic layers of the hippocampus and showed similar distribution patterns. Immunoreactivity was mostly localized along the extrasynaptic plasma membrane of dendritic shafts and spines of pyramidal cells and, to a lesser extent, to that of presynaptic terminals. Quantitative analysis of immunogold particles for Rgs7 and Gβ5 revealed an enrichment of the two proteins around excitatory synapses on dendritic spines, virtually identical to that of Girk2 and GABAB1 . These data support the existence of macromolecular complexes composed of GABAB receptor-G protein-Rgs7-Girk channels in which Rgs7 and Gβ5 proteins may preferentialy modulate GABAB receptor signaling through the deactivation of Girk channels on dendritic spines. In contrast, Rgs7 and Girk2 were associated but mainly segregated from GABAB1 in dendritic shafts, where Rgs7/Gβ5 signaling complexes might modulate Girk-dependent signaling via a

  10. Association of Rgs7/Gβ5 complexes with Girk channels and GABAB receptors in hippocampal CA1 pyramidal neurons

    PubMed Central

    Fajardo-Serrano, Ana; Wydeven, Nicole; Young, Daniele; Watanabe, Masahiko; Shigemoto, Ryuichi; Martemyanov, Kirill A.; Wickman, Kevin; Luján, Rafael

    2013-01-01

    In the hippocampus, signalling through G protein-coupled receptors is modulated by Regulators of G protein Signalling (Rgs) proteins, which act to stimulate the rate of GTP hydrolysis, and consequently, G protein inactivation. The R7-Rgs subfamily selectively deactivates the Gi/o-class of Gα subunits that mediate the action of several GPCRs. Here, we used co-immunoprecipitation, electrophysiology and immunoelectron microscopy techniques to investigate the formation of macromolecular complexes and spatial relationship of Rgs7/Gβ5 complexes and its prototypical signalling partners, the GABAB receptor and Girk channel. Co-expression of recombinant GABAB receptors and Girk channels in combination with co-immunoprecipitation experiments established that the Rgs7/Gβ5 forms complexes with GABAB receptors or Girk channels. Using electrophysiological experiments, we found that GABAB-Girk current deactivation kinetics was markedly faster in cells co-expressing Rgs7/Gβ5. At the electron microscopic level, immunolabelling for Rgs7 and Gβ5 proteins was found primarily in the dendritic layers of the hippocampus and showed similar distribution patterns. Immunoreactivity was mostly localized along the extrasynaptic plasma membrane of dendritic shafts and spines of pyramidal cells and, to a lesser extent, to that of presynaptic terminals. Quantitative analysis of immunogold particles for Rgs7 and Gβ5 revealed an enrichment of the two proteins around excitatory synapses on dendritic spines, virtually identical to that of Girk2 and GABAB1. These data support the existence of macromolecular complexes composed of GABAB receptor-G protein-Rgs7-Girk channels, in which Rgs7 and Gβ5 proteins may preferentially modulate GABAB receptor signalling through the deactivation of Girk channels on dendritic spines. In contrast, Rgs7 and Girk2 were associated but mainly segregated from GABAB1 in dendritic shafts, where Rgs7/Gβ5 signalling complexes might modulate Girk-dependent signalling

  11. Sodium salicylate reduces the level of GABAB receptors in the rat's inferior colliculus.

    PubMed

    Butt, S; Ashraf, F; Porter, L A; Zhang, H

    2016-03-01

    Previous studies have indicated that sodium salicylate (SS) can cause hearing abnormalities through affecting the central auditory system. In order to understand central effects of the drug, we examined how a single intraperitoneal injection of the drug changed the level of subunits of the type-B γ-aminobutyric acid receptor (GABAB receptor) in the rat's inferior colliculus (IC). Immunohistochemical and western blotting experiments were conducted three hours following a drug injection, as previous studies indicated that a tinnitus-like behavior could be reliably induced in rats within this time period. Results revealed that both subunits of the receptor, GABABR1 and GABABR2, reduced their level over the entire area of the IC. Such a reduction was observed in both cell body and neuropil regions. In contrast, no changes were observed in other brain structures such as the cerebellum. Thus, a coincidence existed between a structure-specific reduction in the level of GABAB receptor subunits in the IC and the presence of a tinnitus-like behavior. This coincidence likely suggests that a reduction in the level of GABAB receptor subunits was involved in the generation of a tinnitus-like behavior and/or used by the nervous system to restore normal hearing following application of SS. PMID:26705739

  12. Expression of GABAB receptors in magnocellular neurosecretory cells of male, virgin female and lactating rats.

    PubMed

    Richards, D S; Villalba, R M; Alvarez, F J; Stern, J E

    2005-07-01

    GABA is one of the key neurotransmitters that regulate the firing activity of neurones in the supraoptic (SON) and paraventricular (PVN) nuclei. In the present study, we used immunohistochemical techniques to study the distribution and subcellular localisation of metabotropic GABA(B) receptors in magnocellular neurones in the SON and PVN. Robust GABA(B) receptor immunoreactivity (GABA(B)R; both subunit 1 and subunit 2 of the heterodimer), was observed in the SON and PVN. At the light microcope level, GABA(B)R immonoreactivity displayed a clustered pattern localised both intracytoplasmically and at the plasma membrane. Densitometry analysis indicated that GABA(B)R immunoreactivity was significantly more intense in vasopressin cells than in oxytocin cells, both in male, virgin female and lactating rats, and was denser in males than in virgin females. Light and electron microscope studies indicated that cytoplasmic GABA(B)R was localised in various organelles, including the Golgi, early endosomes and lysosomes, suggesting the cycling of the receptor within the endocytic and trafficking pathways. Some smaller clusters at the level of the cell plasma membrane were apposed to glutamic acid decarboxylase 67 immunoreactive boutons, and appeared to be colocalised with gephyrin, a constituent protein of the postsynaptic density at inhibitory synapses. The presence of GABA(B)R immunoreactivity at synaptic and extrasynaptic sites was supported by electron microscopy. These results provide anatomical evidence for the expression of postsynaptic GABA(B) receptors in magnocellular neurosecretory cells. PMID:15946159

  13. Gamma-hydroxybutyrate (GHB) induces cognitive deficits and affects GABAB receptors and IGF-1 receptors in male rats.

    PubMed

    Johansson, Jenny; Grönbladh, Alfhild; Hallberg, Mathias

    2014-08-01

    In recent years, the abuse of the club drug gamma-hydroxybutyrate (GHB) has become increasingly popular among adolescents. The drug induces euphoria but can also result in sedation, anaesthesia as well as short-term amnesia. In addition, the abuse of GHB causes cognitive impairments and the mechanism by which GHB induces these impairments is not clarified. The present study investigates the impact of GHB treatment on spatial learning and memory using a water maze (WM) test in rats. Furthermore, the behavioural data is combined with an autoradiographic analysis of the GABAB and the IGF-1 receptor systems. The results demonstrate that the animals administered with GHB display an impaired performance in the WM test as compared to controls. In addition, significant alterations in GABAB and IGF-1 receptor density as well as GABAB receptor functionality, were observed in several brain regions associated with cognitive functions e.g. hippocampus. To conclude, our findings suggest that GHB treatment can affect spatial learning and memory, and that this outcome at least to some extent is likely to involve both GABAB and IGF-1 receptors. PMID:24786330

  14. Evidence of a pathogenic role for CD8+ T cells in anti-GABAB receptor limbic encephalitis

    PubMed Central

    Golombeck, Kristin S.; Bönte, Kathrin; Mönig, Constanze; van Loo, Karen M.; Hartwig, Marvin; Schwindt, Wolfram; Widman, Guido; Lindenau, Matthias; Becker, Albert J.; Glatzel, Markus; Elger, Christian E.; Wiendl, Heinz; Meuth, Sven G.; Lohmann, Hubertus; Gross, Catharina C.

    2016-01-01

    Objectives: To characterize the cellular autoimmune response in patients with γ-aminobutyric acid (GABA)B receptor antibody–associated limbic encephalitis (GABAB-R LE). Methods: Patients underwent MRI, extensive neuropsychological assessment, and multiparameter flow cytometry of peripheral blood and CSF. Results: We identified a series of 3 cases of nonparaneoplastic GABAB-R LE and one case of paraneoplastic GABAB-R LE associated with small cell lung cancer. All patients exhibited temporal lobe epilepsy, neuropsychological deficits, and MRI findings typical of LE. Absolute numbers of CD19+ B cells, CD138+ CD19+ plasma cells, CD4+ T cells, activated HLADR+ CD4+ T cells, as well as CD8+ T cells and HLADR+ CD8+ T cells did not differ in peripheral blood but were elevated in CSF of patients with GABAB-R LE compared to controls. Augmented absolute numbers of CD138+ CD19+ plasma cells and activated HLADR+ CD8+ T cells in CSF corresponded to higher overall neuropsychological and memory deficits in patients with GABAB-R LE. A histologic specimen of one patient following selective amygdalohippocampectomy revealed perivascular infiltrates of CD138+ plasma cells and CD4+ T cells, whereas cytotoxic CD8+ T cells were detected within the brain parenchyma in close contact to neurons. Conclusion: Our data suggest a pathogenic role for CD8+ T cells in addition to the established role of plasma cell–derived autoantibodies in GABAB-R LE. PMID:27213174

  15. Human brain somatostatin release from isolated cortical nerve endings and its modulation through GABAB receptors.

    PubMed Central

    Bonanno, G.; Gemignani, A.; Schmid, G.; Severi, P.; Cavazzani, P.; Raiteri, M.

    1996-01-01

    1. The release of somatostatin-like immunoreactivity (SRIF-LI) in the human brain was studied in synaptosomal preparations from fresh neocortical specimens obtained from patients undergoing neurosurgery to remove deeply sited tumours. 2. The basal outflow of SRIF-LI from superfused synaptosomes was increased about 3 fold during exposure to a depolarizing medium containing 15 mM KCl. The K(+)-evoked overflow of SRIF-LI was almost totally dependent on the presence of Ca2+ in the superfusion medium. 3. The GABAB receptor agonist, (-)-baclofen (0.3 - 100 microM), inhibited the overflow of SRIF-LI in a concentration-dependent manner (EC50 = 1.84 +/- 0.20 microM; maximal effect: about 50%). The novel GABAB receptor ligand, 3-aminopropyl(difluoromethyl)phosphinic acid (CGP 47656) mimicked (-)-baclofen in inhibiting the SRIF-LI overflow (EC50 = 3.06 +/- 0.52 microM; maximal effect: about 50%), whereas the GABAA receptor agonist, muscimol, was ineffective up to 100 microM. 4. The inhibition by 10 microM (-)-baclofen of the K(+)-evoked SRIF-LI overflow was concentration-dependently prevented by two selective GABAB receptor antagonists, 3-amino-propyl (diethoxymethyl)-phosphinic acid (CGP 35348) (IC50 = 24.40 +/- 2.52 microM) and [3-[[(3,4-dichlorophenyl) methyl]amino]propyl] (diethoxymethyl) phosphinic acid (CGP 52432) (IC50 = 0.06 +/- 0.005 microM). 5. The inhibition of SRIF-LI overflow caused by 10 microM CGP 47656 was abolished by 1 microM CGP 52432. 6. When human synaptosomes were labelled with [3H]-GABA and depolarized in superfusion with 15 mM KCl, the inhibition by 10 microM (-)-baclofen of the depolarization-evoked [3H]-GABA overflow was largely prevented by 10 microM CGP 47656 which therefore behaved as an autoreceptor antagonist. 7. In conclusion: (a) the characteristics of SRIF-LI release from synaptosomal preparations of human neocortex are compatible with a neuronal origin; (b) the nerve terminals releasing the neuropeptide possess inhibitory receptors of the

  16. Prolonged activation of NMDA receptors promotes dephosphorylation and alters postendocytic sorting of GABAB receptors

    PubMed Central

    Terunuma, Miho; Vargas, Karina J.; Wilkins, Megan E.; Ramírez, Omar A.; Jaureguiberry-Bravo, Matías; Pangalos, Menelas N.; Smart, Trevor G.; Moss, Stephen J.; Couve, Andrés

    2010-01-01

    Slow and persistent synaptic inhibition is mediated by metabotropic GABAB receptors (GABABRs). GABABRs are responsible for the modulation of neurotransmitter release from presynaptic terminals and for hyperpolarization at postsynaptic sites. Postsynaptic GABABRs are predominantly found on dendritic spines, adjacent to excitatory synapses, but the control of their plasma membrane availability is still controversial. Here, we explore the role of glutamate receptor activation in regulating the function and surface availability of GABABRs in central neurons. We demonstrate that prolonged activation of NMDA receptors (NMDA-Rs) leads to endocytosis, a diversion from a recycling route, and subsequent lysosomal degradation of GABABRs. These sorting events are paralleled by a reduction in GABABR-dependent activation of inwardly rectifying K+ channel currents. Postendocytic sorting is critically dependent on phosphorylation of serine 783 (S783) within the GABABR2 subunit, an established substrate of AMP-dependent protein kinase (AMPK). NMDA-R activation leads to a rapid increase in phosphorylation of S783, followed by a slower dephosphorylation, which results from the activity of AMPK and protein phosphatase 2A, respectively. Agonist activation of GABABRs counters the effects of NMDA. Thus, NMDA-R activation alters the phosphorylation state of S783 and acts as a molecular switch to decrease the abundance of GABABRs at the neuronal plasma membrane. Such a mechanism may be of significance during synaptic plasticity or pathological conditions, such as ischemia or epilepsy, which lead to prolonged activation of glutamate receptors. PMID:20643948

  17. Presynaptic GABAB receptors reduce transmission at parabrachial synapses in the lateral central amygdala by inhibiting N-type calcium channels

    PubMed Central

    Delaney, A.J.; Crane, J.W.

    2016-01-01

    The nocioceptive information carried by neurons of the pontine parabrachial nucleus to neurons of the lateral division of the central amydala (CeA-L) is thought to contribute to the affective components of pain and is required for the formation of conditioned-fear memories. Importantly, excitatory transmission between parabrachial axon terminals and CeA-L neurons can be inhibited by a number of presynaptic receptors linked to Gi/o-type G-proteins, including α2-adrenoceptors and GABAB receptors. While the intracellular signalling pathway responsible for α2-adrenoceptor inhibition of synaptic transmission at this synapse is known, the mechanism by which GABAB receptors inhibits transmission has not been determined. The present study demonstrates that activation of presynaptic GABAB receptors reduces excitatory transmission between parabrachial axon terminals and CeA-L neurons by inhibiting N-type calcium channels. While the involvement of Gβγ subunits in mediating the inhibitory effects of GABAB receptors on N-type calcium channels is unclear, this inhibition does not involve Gβγ-independent activation of pp60C-src tyrosine kinase. The results of this study further enhance our understanding of the modulation of the excitatory input from parabrachial axon terminals to CeA-L neurons and indicate that presynaptic GABAB receptors at this synapse could be valuable therapeutic targets for the treatment of fear- and pain-related disorders. PMID:26755335

  18. Presynaptic GABAB receptors reduce transmission at parabrachial synapses in the lateral central amygdala by inhibiting N-type calcium channels.

    PubMed

    Delaney, A J; Crane, J W

    2016-01-01

    The nocioceptive information carried by neurons of the pontine parabrachial nucleus to neurons of the lateral division of the central amydala (CeA-L) is thought to contribute to the affective components of pain and is required for the formation of conditioned-fear memories. Importantly, excitatory transmission between parabrachial axon terminals and CeA-L neurons can be inhibited by a number of presynaptic receptors linked to Gi/o-type G-proteins, including α2-adrenoceptors and GABAB receptors. While the intracellular signalling pathway responsible for α2-adrenoceptor inhibition of synaptic transmission at this synapse is known, the mechanism by which GABAB receptors inhibits transmission has not been determined. The present study demonstrates that activation of presynaptic GABAB receptors reduces excitatory transmission between parabrachial axon terminals and CeA-L neurons by inhibiting N-type calcium channels. While the involvement of Gβγ subunits in mediating the inhibitory effects of GABAB receptors on N-type calcium channels is unclear, this inhibition does not involve Gβγ-independent activation of pp60C-src tyrosine kinase. The results of this study further enhance our understanding of the modulation of the excitatory input from parabrachial axon terminals to CeA-L neurons and indicate that presynaptic GABAB receptors at this synapse could be valuable therapeutic targets for the treatment of fear- and pain-related disorders. PMID:26755335

  19. The interactive role of CB(1) and GABA(B) receptors in hippocampal synaptic plasticity in rats.

    PubMed

    Nazari, Masoumeh; Komaki, Alireza; Karamian, Ruhollah; Shahidi, Siamak; Sarihi, Abdolrahman; Asadbegi, Masoumeh

    2016-01-01

    Long-term potentiation (LTP) of synaptic transmission is a cellular process underlying learning and memory. Cannabinoids are known to be powerful modulators of this kind of synaptic plasticity. Changes in GABAergic inhibition have also been shown to affect synaptic plasticity in the hippocampus. GABA receptor type B (GABAB) and cannabinoid receptor type 1 (CB1) exhibit overlapping anatomical localization in some brain areas including the hippocampus. CB1 and GABAB are also localized to the same cells and share a common signaling pathway in some brain areas. In this study, we examined the hippocampal effects of co-administrating AM251 and CGP55845, which are CB1 and GABAB antagonists, respectively, on LTP induction in the dentate gyrus (DG) of rats. LTP in the hippocampal area was induced by high-frequency stimulation (HFS) of the perforant path. Our results showed that HFS coupled with administration of the CB1 antagonist increased both the population spike (PS) amplitude and field excitatory post-synaptic potential (fEPSP). Conversely, the GABAB antagonist decreased these parameters along with decreased LTP induction. We also demonstrated that the co-administration of CB1 and GABAB antagonists had different effects on the PS amplitude and fEPSP slope. It is likely that GABAB receptor antagonists modulate cannabinoid outputs that cause a decrease in synaptic plastisity, while in the simultaneous consumption of two antagonists, CB1 antagonists can alter the release of GABA which in turn results in enhancement of LTP induction. These findings suggest that there are functional interactions between the CB1 and GABAB receptor in the hippocampus. PMID:26611204

  20. Suppression of ATP-induced excitability in rat small-diameter trigeminal ganglion neurons by activation of GABAB receptor.

    PubMed

    Takeda, Mamoru; Ikeda, Mizuho; Takahashi, Masayuki; Kanazawa, Takuya; Nasu, Masanori; Matsumoto, Shigeji

    2013-09-01

    The aim of the present study was to investigate whether a GABAB receptor agonist could modulate ATP-activated neuronal excitability of nociceptive TRG neurons using perforated whole-cell patch-clamp and immunohistochemical techniques. Immunohistochemical analysis revealed that 86% of P2X3 receptor-immunoreactive, small-diameter TRG neurons co-expressed GABAB receptor. Under voltage-clamp conditions (Vh=-60mV), application of ATP activated the inward current in acutely isolated rat TRG neurons in a dose-dependent manner (10-50 μM) and this current could be blocked by pyridoxal-phosphate-6-azophenyl-27,47-disulfonic acid (PPADS) (10 μM), a selective P2 purinoreceptor antagonist. The peak amplitude of ATP-activated currents was significantly inhibited after application of GABAB receptor agonist, baclofen (10-50 μM), in a concentration-dependent and reversible manner. The baclofen-induced inhibition of ATP-activated current was abolished by co-application of 3-amino-2 (4-chlorophenyl)-2hydroxypropysufonic acid) saclofen, a GABAB receptor antagonist (50 μM). Under current-clamp conditions, application of 20 μM ATP significantly depolarized the membrane potential resulting in increased mean action potential frequencies, and these ATP-induced effects were significantly inhibited by baclofen and these effects were antagonized by co-application of saclofen. Together, the results suggested that GABAB receptor activation could inhibit the ATP-induced excitability of small-diameter TRG neurons activated through the P2X3 receptor. Thus, the interaction between P2X3 and GABAB receptors of small-diameter TRG neuronal cell bodies is a potential therapeutic target for the treatment of trigeminal nociception. PMID:24004472

  1. Evaluation of peripheral versus central effects of GABAB receptor activation using a novel, positive allosteric modulator of the GABAB receptor ADX71943, a pharmacological tool compound with a fully peripheral activity profile

    PubMed Central

    Kalinichev, M; Donovan-Rodriguez, T; Girard, F; Riguet, E; Rouillier, M; Bournique, B; Haddouk, H; Mutel, V; Poli, S

    2014-01-01

    Background and Purpose The GABAB receptor agonist, baclofen, has shown promising effects in patients suffering from pain, post-traumatic stress disorder, alcoholism, overactive bladder and gastroesophageal reflux disease. However, baclofen's short duration of action and side effects limit its wider use. Here we characterized a novel, GABAB receptor positive allosteric modulator (PAM) ADX71943. Experimental Approach In vitro, ADX71943 was assessed for pharmacological activity and selectivity using recombinant and native GABAB receptors. In vivo ADX71943 was assessed in the acetic acid-induced writhing (AAW) test in mice and formalin tests (FTs) in mice and rats. Marble burying (MB) and elevated plus maze (EPM) tests, rotarod, spontaneous locomotor activity (sLMA) and body temperature (BT) tests in mice and rats were used to investigate centrally-mediated effects. Key Results In vitro, in the presence of GABA, ADX71943 increased the potency and efficacy of agonists and showed selectivity at the GABAB receptor. ADX71943 reduced pain-associated behaviours in AAW; an effect blocked by GABAB receptor antagonist CGP63360. ADX71943 reduced pain in the FT in mice and rats, but was inactive in the MB and EPM despite reaching high concentrations in plasma. ADX71943 had no effect on BT, rotarod and sLMA. Conclusions and Implications ADX71943 showed consistent and target-related efficacy in tests of disorders that have a significant peripheral component (acute and chronic pain), while having no effect in those associated with centrally-mediated anxiety-like reactivity and side effects. Thus, ADX71943 is a useful pharmacological tool for delineation of peripherally- versus centrally-mediated effects of GABAB receptor activation. PMID:24923436

  2. The positive allosteric GABAB receptor modulator rac-BHFF enhances baclofen-mediated analgesia in neuropathic mice.

    PubMed

    Zemoura, Khaled; Ralvenius, William T; Malherbe, Pari; Benke, Dietmar

    2016-09-01

    Neuropathic pain is associated with impaired inhibitory control of spinal dorsal horn neurons, which are involved in processing pain signals. The metabotropic GABAB receptor is an important component of the inhibitory system and is highly expressed in primary nociceptors and intrinsic dorsal horn neurons to control their excitability. Activation of GABAB receptors with the orthosteric agonist baclofen effectively reliefs neuropathic pain but is associated with severe side effects that prevent its widespread application. The recently developed positive allosteric GABAB receptor modulators lack most of these side effects and are therefore promising drugs for the treatment of pain. Here we tested the high affinity positive allosteric modulator rac-BHFF for its ability to relief neuropathic pain induced by chronic constriction of the sciatic nerve in mice. rac-BHFF significantly increased the paw withdrawal threshold to mechanical stimulation in healthy mice, indicating an endogenous GABABergic tone regulating the sensitivity to mechanical stimuli. Surprisingly, rac-BHFF displayed no analgesic activity in neuropathic mice although GABAB receptor expression was not affected in the dorsal horn as shown by quantitative receptor autoradiography. However, activation of spinal GABAB receptors by intrathecal injection of baclofen reduced hyperalgesia and its analgesic effect was considerably potentiated by co-application of rac-BHFF. These results indicate that under conditions of neuropathic pain the GABAergic tone is too low to provide a basis for allosteric modulation of GABAB receptors. However, allosteric modulators would be well suited as an add-on to reduce the dose of baclofen required to achieve analgesia. PMID:27108932

  3. GABAB receptor-mediated contractile effects resistant to tetrodotoxin in isolated cat ileum.

    PubMed

    Pencheva, N; Venkova, K; Radomirov, R

    1990-06-21

    The effects of gamma-aminobutyric acid (GABA) and GABAergic drugs were studied on longitudinal strips from cat terminal ileum prepared after removing the myenteric plexus. GABA and baclofen exerted concentration-dependent contractile effects. Muscimol was ineffective, and bicuculline did not antagonize the effect of GABA. The complete elimination of the neural input to the smooth muscle cells by tetrodotoxin failed to prevent the action of GABA and baclofen. Pharmacological analyses of the effects indicated the existence of GABAB receptors on the smooth muscle cells in the longitudinal layer of cat terminal ileum. PMID:2169425

  4. Adaptation in sound localization: from GABA(B) receptor-mediated synaptic modulation to perception.

    PubMed

    Stange, Annette; Myoga, Michael H; Lingner, Andrea; Ford, Marc C; Alexandrova, Olga; Felmy, Felix; Pecka, Michael; Siveke, Ida; Grothe, Benedikt

    2013-12-01

    Across all sensory modalities, the effect of context-dependent neural adaptation can be observed at every level, from receptors to perception. Nonetheless, it has long been assumed that the processing of interaural time differences, which is the primary cue for sound localization, is nonadaptive, as its outputs are mapped directly onto a hard-wired representation of space. Here we present evidence derived from in vitro and in vivo experiments in gerbils indicating that the coincidence-detector neurons in the medial superior olive modulate their sensitivity to interaural time differences through a rapid, GABA(B) receptor-mediated feedback mechanism. We show that this mechanism provides a gain control in the form of output normalization, which influences the neuronal population code of auditory space. Furthermore, psychophysical tests showed that the paradigm used to evoke neuronal GABA(B) receptor-mediated adaptation causes the perceptual shift in sound localization in humans that was expected on the basis of our physiological results in gerbils. PMID:24141311

  5. GABAergic Afferents activate both GABAA and GABAB receptors in mouse substantia nigra dopaminergic neurons in vivo

    PubMed Central

    Brazhnik, Elena; Shah, Fulva; Tepper, James M.

    2008-01-01

    Most in vivo electrophysiological studies of substantia nigra have employed rats. With the recent proliferation of the use of mice for in vitro neurophysiological studies due to the availability of various genetically modified strains to identify the roles of various channels and proteins in neuronal function, it is crucial to obtain data on in vivo responses in mice to verify that the in vitro results reflect functioning of systems comparable to those that have been well studied in rat. Inhibitory responses of rat nigral dopaminergic neurons by stimulation of afferents from striatum, globus pallidus or pars reticulata have been shown to be mediated predominantly or exclusively by GABAA receptors. This is puzzling given the substantial expression of GABAB receptors and the ubiquitous appearance of GABAB synaptic responses in rat dopaminergic neurons in vitro. In the present study we studied electrically evoked GABAergic inhibition in nigral dopaminergic neurons in C57BL/6J mice. Stimulation of the three major GABAergic inputs elicited stronger and longer lasting inhibitory responses than those seen in rats. The early inhibition was GABAA mediated, whereas the later component, absent in rats, was GABAB mediated and selectively enhanced by GABA uptake inhibition. Striatal-evoked inhibition exhibited a slower onset and a weaker initial component compared to inhibition from globus pallidus or substantia nigra pars reticulata. These results are discussed with respect to differences in the size and neuronal density of the rat and mouse brain, and the different sites of synaptic contact of the synapses from the three GABAergic afferents. PMID:18842898

  6. GABAB receptor modulation of serotonin neurons in the dorsal raphé nucleus and escalation of aggression in mice

    PubMed Central

    Takahashi, Aki; Shimamoto, Akiko; Boyson, Christopher O.; DeBold, Joseph F.; Miczek, Klaus A.

    2010-01-01

    The serotonin (5-HT) system in the brain has been studied more than any other neurotransmitter for its role in the neurobiological basis of aggression. However, which mechanisms modulate the 5-HT system to promote escalated aggression is not clear. We here explore the role of GABAergic modulation in the raphé nuclei, from where most 5-HT in the forebrain originates, on escalated aggression in male mice. Pharmacological activation of GABAB, but not GABAA, receptors in the dorsal raphé nucleus (DRN) escalated aggressive behaviors. In contrast, GABA agonists did not escalate aggressive behaviors after microinjection into the median raphé nucleus (MRN). The aggression-heightening effect of the GABAB agonist baclofen depended on the activation of 5-HT neurons in the DRN because it was blocked by co-administration of the 5-HT1A agonist 8-OH-DPAT, which acts on autoreceptors and inhibits 5-HT neural activity. In vivo microdialysis showed that GABAB activation in the DRN increased extracellular 5-HT level in the medial prefrontal cortex (mPFC). This may be due to an indirect action via presynaptic GABAB receptors. The presynaptic GABAB receptors suppress Ca2+ channel activity and inhibit neurotransmission, and the co-administration of N-type Ca2+ channel blocker facilitated the effect of baclofen. These findings suggest that the indirect disinhibition of 5-HT neuron activity by presynaptic GABAB receptors on non-5-HT neurons in the DRN is one of the neurobiological mechanisms of escalated aggression. PMID:20810897

  7. GABAB receptor deficiency causes failure of neuronal homeostasis in hippocampal networks.

    PubMed

    Vertkin, Irena; Styr, Boaz; Slomowitz, Edden; Ofir, Nir; Shapira, Ilana; Berner, David; Fedorova, Tatiana; Laviv, Tal; Barak-Broner, Noa; Greitzer-Antes, Dafna; Gassmann, Martin; Bettler, Bernhard; Lotan, Ilana; Slutsky, Inna

    2015-06-23

    Stabilization of neuronal activity by homeostatic control systems is fundamental for proper functioning of neural circuits. Failure in neuronal homeostasis has been hypothesized to underlie common pathophysiological mechanisms in a variety of brain disorders. However, the key molecules regulating homeostasis in central mammalian neural circuits remain obscure. Here, we show that selective inactivation of GABAB, but not GABA(A), receptors impairs firing rate homeostasis by disrupting synaptic homeostatic plasticity in hippocampal networks. Pharmacological GABA(B) receptor (GABA(B)R) blockade or genetic deletion of the GB(1a) receptor subunit disrupts homeostatic regulation of synaptic vesicle release. GABA(B)Rs mediate adaptive presynaptic enhancement to neuronal inactivity by two principle mechanisms: First, neuronal silencing promotes syntaxin-1 switch from a closed to an open conformation to accelerate soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex assembly, and second, it boosts spike-evoked presynaptic calcium flux. In both cases, neuronal inactivity removes tonic block imposed by the presynaptic, GB(1a)-containing receptors on syntaxin-1 opening and calcium entry to enhance probability of vesicle fusion. We identified the GB(1a) intracellular domain essential for the presynaptic homeostatic response by tuning intermolecular interactions among the receptor, syntaxin-1, and the Ca(V)2.2 channel. The presynaptic adaptations were accompanied by scaling of excitatory quantal amplitude via the postsynaptic, GB(1b)-containing receptors. Thus, GABA(B)Rs sense chronic perturbations in GABA levels and transduce it to homeostatic changes in synaptic strength. Our results reveal a novel role for GABA(B)R as a key regulator of population firing stability and propose that disruption of homeostatic synaptic plasticity may underlie seizure's persistence in the absence of functional GABA(B)Rs. PMID:26056260

  8. GABAB receptor deficiency causes failure of neuronal homeostasis in hippocampal networks

    PubMed Central

    Vertkin, Irena; Styr, Boaz; Slomowitz, Edden; Ofir, Nir; Shapira, Ilana; Berner, David; Fedorova, Tatiana; Laviv, Tal; Barak-Broner, Noa; Greitzer-Antes, Dafna; Gassmann, Martin; Bettler, Bernhard; Lotan, Ilana; Slutsky, Inna

    2015-01-01

    Stabilization of neuronal activity by homeostatic control systems is fundamental for proper functioning of neural circuits. Failure in neuronal homeostasis has been hypothesized to underlie common pathophysiological mechanisms in a variety of brain disorders. However, the key molecules regulating homeostasis in central mammalian neural circuits remain obscure. Here, we show that selective inactivation of GABAB, but not GABAA, receptors impairs firing rate homeostasis by disrupting synaptic homeostatic plasticity in hippocampal networks. Pharmacological GABAB receptor (GABABR) blockade or genetic deletion of the GB1a receptor subunit disrupts homeostatic regulation of synaptic vesicle release. GABABRs mediate adaptive presynaptic enhancement to neuronal inactivity by two principle mechanisms: First, neuronal silencing promotes syntaxin-1 switch from a closed to an open conformation to accelerate soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex assembly, and second, it boosts spike-evoked presynaptic calcium flux. In both cases, neuronal inactivity removes tonic block imposed by the presynaptic, GB1a-containing receptors on syntaxin-1 opening and calcium entry to enhance probability of vesicle fusion. We identified the GB1a intracellular domain essential for the presynaptic homeostatic response by tuning intermolecular interactions among the receptor, syntaxin-1, and the CaV2.2 channel. The presynaptic adaptations were accompanied by scaling of excitatory quantal amplitude via the postsynaptic, GB1b-containing receptors. Thus, GABABRs sense chronic perturbations in GABA levels and transduce it to homeostatic changes in synaptic strength. Our results reveal a novel role for GABABR as a key regulator of population firing stability and propose that disruption of homeostatic synaptic plasticity may underlie seizure's persistence in the absence of functional GABABRs. PMID:26056260

  9. Presynaptic GABAB Receptors Regulate Experience-Dependent Development of Inhibitory Short-Term Plasticity

    PubMed Central

    Kotak, Vibhakar C.; Sanes, Dan H.

    2010-01-01

    Short-term changes in synaptic gain support information processing throughout the CNS, yet we know little about the developmental regulation of such plasticity. Here we report that auditory experience is necessary for the normal maturation of synaptic inhibitory short-term plasticity (iSTP) in the auditory cortex, and that presynaptic GABAB receptors regulate this development. Moderate or severe hearing loss was induced in gerbils, and iSTP was characterized by measuring inhibitory synaptic current amplitudes in response to repetitive stimuli. We reveal a profound developmental shift of iSTP from depressing to facilitating after the onset of hearing. Even moderate hearing loss prevented this shift. This iSTP change was mediated by a specific class of inhibitory interneurons, the low-threshold spiking cells. Further, using paired recordings, we reveal that presynaptic GABAB receptors at interneuron-pyramidal connections regulate iSTP in an experience-dependent manner. This novel synaptic mechanism may support the emergence of mature temporal processing in the auditory cortex. PMID:20164356

  10. The role of GABAB receptors in the vestibular oculomotor system in mice.

    PubMed

    Shimizu, Naoki; Wood, Scott; Kushiro, Keisuke; Perachio, Adrian; Makishima, Tomoko

    2016-04-01

    Systemic administration of a gamma-amino butyric acid type B (GABAB) receptor agonist, baclofen, affects various physiological and psychological processes. To date, the effects on oculomotor system have been well characterized in primates, however those in mice have not been explored. In this study, we investigated the effects of baclofen focusing on vestibular-related eye movements. Two rotational paradigms, i.e. sinusoidal rotation and counter rotation were employed to stimulate semicircular canals and otolith organs in the inner ear. Experimental conditions (dosage, routes and onset of recording) were determined based on the prior studies exploring the behavioral effects of baclofen in mice. With an increase in dosage, both canal and otolith induced ocular responses were gradually affected. There was a clear distinction in the drug sensitivity showing that eye movements derived from direct vestibulo-ocular reflex pathways were relatively unaltered, while the responses through higher-order neural networks in the vestibular system were substantially decreased. These findings were consistent with those observed in primates suggesting a well-conserved role of GABAB receptors in the oculomotor system across frontal-eyed and lateral-eyed animals. We showed here a previously unrecognized effect of baclofen on the vestibular oculomotor function in mice. When interpreting general animal performance under the drug, the potential contribution of altered balance system should be taken into consideration. PMID:26778789

  11. LACK OF FUNCTIONAL GABAB RECEPTORS ALTERS Kiss1, Gnrh1 AND Gad1 mRNA EXPRESSION IN THE MEDIAL BASAL HYPOTHALAMUS AT POSTNATAL DAY 4

    PubMed Central

    Di Giorgio, Noelia P.; Catalano, Paolo N.; López, Paula V.; González, Betina; Semaan, Sheila J.; López, Gabriela C.; Kauffman, Alexander S.; Rulli, Susana B.; Somoza, Gustavo M.; Bettler, Bernhard; Libertun, Carlos; Lux-Lantos, Victoria A.

    2013-01-01

    Background/Aims Adult mice lacking functional GABAB receptors (GABAB1KO) show altered Gnrh1 and Gad1 expressions in the preoptic area-anterior hypothalamus (POA-AH) and females display disruption of cyclicity and fertility. Here we addressed whether sexual differentiation of the brain and the proper wiring of the GnRH and kisspeptin systems were already disturbed in postnatal day 4 (PND4) GABAB1KO mice. Methods PND4 wild type (WT) and GABAB1KO mice of both sexes were sacrificed; tissues were collected to determine mRNA expression (qPCR), amino acids (HPLC), and hormones (RIA and/or IHC). Results GnRH neuron number (IHC) did not differ among groups in olfactory bulbs or OVLT-POA. Gnrh1 mRNA (qPCR) in POA-AH was similar among groups. Gnrh1 mRNA in medial basal hypothalamus (MBH) was similar in WTs but was increased in GABAB1KO females compared to GABAB1KO males. Hypothalamic GnRH (RIA) was sexually different in WTs (males > females) but this sex difference was lost in GABAB1KOs; the same pattern was observed when analyzing only the MBH, but not in the POA-AH. Arcuate nucleus Kiss1 mRNA (micropunch-qPCR) was higher in WT females than in WT males and GABAB1KO females. Gad1 mRNA in MBH was increased in GABAB1KO females compared to GABAB1KO males. Serum LH and gonadal estradiol content were also increased in GABAB1KOs. Conclusion We demonstrate that GABABRs participate in the sexual differentiation of the ARC/MBH, because sex differences in several reproductive genes, such as Gad1, Kiss1 and Gnrh1, are critically disturbed in GABAB1KO mice at PND4, probably altering the organization and development of neural circuits governing the reproductive axis. PMID:24080944

  12. The GABA(B) receptor positive modulator BHF177 attenuated anxiety, but not conditioned fear, in rats.

    PubMed

    Li, Xia; Kaczanowska, Katarzyna; Finn, M G; Markou, Athina; Risbrough, Victoria B

    2015-10-01

    GABAB (γ-aminobutyric acid B) receptors may be a therapeutic target for anxiety disorders. Here we characterized the effects of the GABAB receptor positive allosteric modulator (PAM) BHF177 on conditioned and unconditioned physiological responses to threat in the light-enhanced startle (LES), stress-induced hyperthermia, and fear-potentiated startle (FPS) procedures in rats. The effects of BHF177 on LES were compared with those of the GABAB receptor agonists baclofen and CGP44532, and the positive control buspirone, a 5-HT1A receptor partial agonist with anxiolytic activity in humans. Baclofen (0.4, 0.9 and 1.25 mg/kg) and CGP44532 (0.065, 0.125 and 0.25 mg/kg) administration had significant sedative, but not anxiolytic, activity reflected in overall decrease in the startle response in the LES tests. BHF177 (10, 20 and 40 mg/kg) had no effect on LES, nor did it produce an overall sedative effect. Interesting, however, when rats were grouped by high and low LES responses, BHF177 had anxiolytic-like effects only on LES in high, but not low, LES responding rats. BHF177 also blocked stress-induced hyperthermia, but had no effect on conditioned fear responses in the FPS test. Buspirone (1 and 3 mg/kg) had an anxiolytic-like profile in both LES and FPS tests. These results indicate that BHF177 may specifically attenuate unconditioned anxiety in individuals that exhibit a high anxiety state, and has fewer sedative effects than direct agonists. Thus, BHF177 or other GABAB receptor PAMs may be promising compounds for alleviating increased anxiety seen in various psychiatric disorders with a superior side-effect profile compared to GABAB receptor agonists. PMID:26002628

  13. Presynaptic GABAB Autoreceptor Regulation of Nicotinic Acetylcholine Receptor Mediated [3H]-GABA Release from Mouse Synaptosomes

    PubMed Central

    McClure-Begley, Tristan D.; Grady, Sharon R.; Marks, Michael J.; Collins, Allan C.; Stitzel, Jerry A.

    2014-01-01

    Activation of nicotinic acetylcholine receptors (nAChRs) can elicit neurotransmitter release from presynaptic nerve terminals. Mechanisms contributing to cell-and-terminal specific regulation of nAChR-mediated neurotransmitter exocytosis are not fully understood. The experiments discussed here examine how activation of GABAB auto- and hetero-receptors suppress nAChR-mediated release of [3H]-GABA and [3H]-dopamine (3H-DA) from mouse striatal synaptosomes. Activation of presynaptic GABAB receptors with (R)-baclofen decreased both [3H]-GABA and [3H]-DA release evoked by potassium depolarization. However, when nAChRs were activated with ACh to evoke neurotransmitter release, (R)-baclofen had no effect on [3H]-DA release, but potently inhibited ACh-evoked [3H]-GABA release. Inhibition of nAChR-evoked [3H]-GABA release by (R)-baclofen was time sensitive and the effect was lost after prolonged exposure to the GABAB agonist. The early inhibitory effect of GABA activation on ACh-evoked [3H]-GABA release was partially attenuated by antagonists of the phosphatase, calcineurin. Furthermore, antagonists of protein kinase C (PKC) prevented the time-dependent loss of the inhibitory (R)-baclofen effect on [3H]-GABA release. These results suggest that α4β2*-nAChRs present on GABAergic nerve terminals in the striatum are subject to functional regulation by GABAB autoreceptors that is apparently cell-type specific, since it is absent from DAergic striatal nerve terminals. In addition, the functional modulation of α4β2*-type nAChRs on striatal GABAergic nerve terminals by GABAB autoreceptor activation is time-sensitive and appears to involve opposing actions of calcineurin and PKC. PMID:24953818

  14. Embryonic GABA(B) receptor blockade alters cell migration, adult hypothalamic structure, and anxiety- and depression-like behaviors sex specifically in mice.

    PubMed

    Stratton, Matthew S; Staros, Michelle; Budefeld, Tomaz; Searcy, Brian T; Nash, Connor; Eitel, Chad; Carbone, David; Handa, Robert J; Majdic, Gregor; Tobet, Stuart A

    2014-01-01

    Neurons of the paraventricular nucleus of the hypothalamus (PVN) regulate the hypothalamic- pituitary-adrenal (HPA) axis and the autonomic nervous system. Females lacking functional GABA(B) receptors because of a genetic disruption of the R1 subunit have altered cellular characteristics in and around the PVN at birth. The genetic disruption precluded appropriate assessments of physiology or behavior in adulthood. The current study was conducted to test the long term impact of a temporally restricting pharmacological blockade of the GABA(B) receptor to a 7-day critical period (E11-E17) during embryonic development. Experiments tested the role of GABA(B) receptor signaling in fetal development of the PVN and later adult capacities for adult stress related behaviors and physiology. In organotypic slices containing fetal PVN, there was a female specific, 52% increase in cell movement speeds with GABA(B) receptor antagonist treatment that was consistent with a sex-dependent lateral displacement of cells in vivo following 7 days of fetal exposure to GABA(B) receptor antagonist. Anxiety-like and depression-like behaviors, open-field activity, and HPA mediated responses to restraint stress were measured in adult offspring of mothers treated with GABA(B) receptor antagonist. Embryonic exposure to GABA(B) receptor antagonist resulted in reduced HPA axis activation following restraint stress and reduced depression-like behaviors. There was also increased anxiety-like behavior selectively in females and hyperactivity in males. A sex dependent response to disruptions of GABA(B) receptor signaling was identified for PVN formation and key aspects of physiology and behavior. These changes correspond to sex specific prevalence in similar human disorders, namely anxiety disorders and hyperactivity. PMID:25162235

  15. Embryonic GABAB Receptor Blockade Alters Cell Migration, Adult Hypothalamic Structure, and Anxiety- and Depression-Like Behaviors Sex Specifically in Mice

    PubMed Central

    Stratton, Matthew S.; Staros, Michelle; Budefeld, Tomaz; Searcy, Brian T.; Nash, Connor; Eitel, Chad; Carbone, David; Handa, Robert J.; Majdic, Gregor; Tobet, Stuart A.

    2014-01-01

    Neurons of the paraventricular nucleus of the hypothalamus (PVN) regulate the hypothalamic- pituitary-adrenal (HPA) axis and the autonomic nervous system. Females lacking functional GABAB receptors because of a genetic disruption of the R1 subunit have altered cellular characteristics in and around the PVN at birth. The genetic disruption precluded appropriate assessments of physiology or behavior in adulthood. The current study was conducted to test the long term impact of a temporally restricting pharmacological blockade of the GABAB receptor to a 7-day critical period (E11–E17) during embryonic development. Experiments tested the role of GABAB receptor signaling in fetal development of the PVN and later adult capacities for adult stress related behaviors and physiology. In organotypic slices containing fetal PVN, there was a female specific, 52% increase in cell movement speeds with GABAB receptor antagonist treatment that was consistent with a sex-dependent lateral displacement of cells in vivo following 7 days of fetal exposure to GABAB receptor antagonist. Anxiety-like and depression-like behaviors, open-field activity, and HPA mediated responses to restraint stress were measured in adult offspring of mothers treated with GABAB receptor antagonist. Embryonic exposure to GABAB receptor antagonist resulted in reduced HPA axis activation following restraint stress and reduced depression-like behaviors. There was also increased anxiety-like behavior selectively in females and hyperactivity in males. A sex dependent response to disruptions of GABAB receptor signaling was identified for PVN formation and key aspects of physiology and behavior. These changes correspond to sex specific prevalence in similar human disorders, namely anxiety disorders and hyperactivity. PMID:25162235

  16. Effects of the GABAB Receptor-Positive Modulators CGP7930 and rac-BHFF in Baclofen- and γ-Hydroxybutyrate-Discriminating Pigeons

    PubMed Central

    France, Charles P.; Cheng, Kejun; Rice, Kenner C.

    2012-01-01

    In vivo effects of GABAB receptor-positive modulators suggest them to have therapeutic potential to treat central nervous system disorders such as anxiety and drug abuse. Although these effects are thought to be mediated by positive modulation of GABAB receptors, such modulation has been examined primarily in vitro. This study further examined the in vivo properties of the GABAB receptor-positive modulators 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl) phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF). In pigeons discriminating baclofen from saline, γ-hydroxybutyrate (GHB) produced 100% baclofen-appropriate responding, and the GABAB antagonist 3-aminopropyl(dimethoxymethyl) phosphinic acid (CGP35348) blocked the effects of both drugs. CGP7930 and rac-BHFF produced at most 41 and 74% baclofen-appropriate responding, respectively, and enhanced the discriminative stimulus effects of baclofen, but not of GHB. In pigeons discriminating GHB from saline, CGP7930 and rac-BHFF produced at most 1 and 49% GHB-appropriate responding, respectively, and enhanced the effects of baclofen, but not of GHB. Enhancement of the discriminative stimulus effects of baclofen by rac-BHFF and CGP7930 is further evidence of their effectiveness as GABAB receptor-positive modulators in vivo. Furthermore, lack of complete substitution of the positive modulators rac-BHFF and CGP7930 for baclofen and GHB suggests that their discriminative stimulus effects differ from those of GABAB receptor agonists. Finally, together with converging evidence that the GABAB receptor populations mediating the effects of baclofen and GHB are not identical, the present findings suggest that these populations differ in their susceptibility to positive modulatory effects. Such differences could allow for more selective therapeutic targeting of the GABAB system. PMID:22319197

  17. Effects of the GABAB receptor-positive modulators CGP7930 and rac-BHFF in baclofen- and γ-hydroxybutyrate-discriminating pigeons.

    PubMed

    Koek, Wouter; France, Charles P; Cheng, Kejun; Rice, Kenner C

    2012-05-01

    In vivo effects of GABA(B) receptor-positive modulators suggest them to have therapeutic potential to treat central nervous system disorders such as anxiety and drug abuse. Although these effects are thought to be mediated by positive modulation of GABA(B) receptors, such modulation has been examined primarily in vitro. This study further examined the in vivo properties of the GABA(B) receptor-positive modulators 2,6-di-tert-butyl-4-(3-hydroxy-2,2-dimethylpropyl) phenol (CGP7930) and (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF). In pigeons discriminating baclofen from saline, γ-hydroxybutyrate (GHB) produced 100% baclofen-appropriate responding, and the GABA(B) antagonist 3-aminopropyl(dimethoxymethyl) phosphinic acid (CGP35348) blocked the effects of both drugs. CGP7930 and rac-BHFF produced at most 41 and 74% baclofen-appropriate responding, respectively, and enhanced the discriminative stimulus effects of baclofen, but not of GHB. In pigeons discriminating GHB from saline, CGP7930 and rac-BHFF produced at most 1 and 49% GHB-appropriate responding, respectively, and enhanced the effects of baclofen, but not of GHB. Enhancement of the discriminative stimulus effects of baclofen by rac-BHFF and CGP7930 is further evidence of their effectiveness as GABA(B) receptor-positive modulators in vivo. Furthermore, lack of complete substitution of the positive modulators rac-BHFF and CGP7930 for baclofen and GHB suggests that their discriminative stimulus effects differ from those of GABA(B) receptor agonists. Finally, together with converging evidence that the GABA(B) receptor populations mediating the effects of baclofen and GHB are not identical, the present findings suggest that these populations differ in their susceptibility to positive modulatory effects. Such differences could allow for more selective therapeutic targeting of the GABA(B) system. PMID:22319197

  18. Transport along the dendritic endoplasmic reticulum mediates the trafficking of GABAB receptors

    PubMed Central

    Valenzuela, José I.; Jaureguiberry-Bravo, Matías; Salas, Daniela A.; Ramírez, Omar A.; Cornejo, Víctor H.; Lu, Hsiangmin E.; Blanpied, Thomas A.; Couve, Andrés

    2014-01-01

    ABSTRACT In neurons, secretory organelles within the cell body are complemented by the dendritic endoplasmic reticulum (ER) and Golgi outposts (GOPs), whose role in neurotransmitter receptor trafficking is poorly understood. γ-aminobutyric acid (GABA) type B metabotropic receptors (GABABRs) regulate the efficacy of synaptic transmission throughout the brain. Their plasma membrane availability is controlled by mechanisms involving an ER retention motif and assembly-dependent ER export. Thus, they constitute an ideal molecular model to study ER trafficking, but the extent to which the dendritic ER participates in GABABR biosynthesis has not been thoroughly explored. Here, we show that GABAB1 localizes preferentially to the ER in dendrites and moves long distances within this compartment. Not only diffusion but also microtubule and dynein-dependent mechanisms control dendritic ER transport. GABABRs insert throughout the somatodendritic plasma membrane but dendritic post-ER carriers containing GABABRs do not fuse selectively with GOPs. This study furthers our understanding of the spatial selectivity of neurotransmitter receptors for dendritic organelles. PMID:24895402

  19. Modulation of non-adrenergic, non-cholinergic neural bronchoconstriction in guinea-pig airways via GABAB-receptors.

    PubMed

    Belvisi, M G; Ichinose, M; Barnes, P J

    1989-08-01

    via an action at GABAB receptors and that GABA might play a role in the regulation of neurogenic responses in the airways. PMID:2477104

  20. GABAA and GABAB receptor-mediated effects in guinea-pig ileum.

    PubMed

    Giotti, A; Luzzi, S; Spagnesi, S; Zilletti, L

    1983-03-01

    -pig ileum: a bicuculline-sensitive GABA(A) receptor, which elicits contraction through an excitatory action on cholinergic post-ganglionic neurones; and a bicuculline-insensitive GABA(B) receptor which causes relaxation through an inhibitory presynaptic action on cholinergic post-ganglionic neurones. We confirm that GABA, homotaurine and muscimol are GABA(A) agonists, while GABA and (-)-baclofen are GABA(B) agonists. PMID:6301600

  1. The GABAB receptor agonist, baclofen, contributes to three distinct varieties of amnesia in the human brain - A detailed case report.

    PubMed

    Zeman, Adam; Hoefeijzers, Serge; Milton, Fraser; Dewar, Michaela; Carr, Melanie; Streatfield, Claire

    2016-01-01

    We describe a patient in whom long-term, therapeutic infusion of the selective gamma-amino-butyric acid type B (GABAB) receptor agonist, baclofen, into the cerebrospinal fluid (CSF) gave rise to three distinct varieties of memory impairment: i) repeated, short periods of severe global amnesia, ii) accelerated long-term forgetting (ALF), evident over intervals of days and iii) a loss of established autobiographical memories. This pattern of impairment has been reported in patients with temporal lobe epilepsy (TLE), in particular the subtype of Transient Epileptic Amnesia (TEA). The amnesic episodes and accelerated forgetting remitted on withdrawal of baclofen, while the autobiographical amnesia (AbA) persisted. This exceptional case highlights the occurrence of 'non-standard' forms of human amnesia, reflecting the biological complexity of memory processes. It suggests a role for GABAB signalling in the modulation of human memory over multiple time-scales and hints at its involvement in 'epileptic amnesia'. PMID:26599496

  2. Effects of GABA(B) receptor agents on cocaine priming, discrete contextual cue and food induced relapses.

    PubMed

    Filip, Małgorzata; Frankowska, Małgorzata

    2007-10-01

    In the present study we investigated the effects of the GABA(B) receptor antagonist (2S)-(+)-5,5-dimethyl-2-morpholineacetic acid (SCH 50911), the agonists baclofen and 3-aminopropyl(methyl)phosphinic acid (SKF 97541), and the allosteric positive modulator 3,5-bis(1,1-dimethylethyl)-4-hydroxy-beta,beta-dimethylbenzenepropanol (CGP 7930) on cocaine seeking behavior. The effects of the above drugs on the reinstatement of responding induced by natural reinforcer (food) were also studied. Male Wistar rats were trained to self-administer either cocaine (0.5 mg/kg/infusion) or food (sweet milk) and responding on the reinforcer-paired lever was extinguished. Reinstatement of responding was induced by a noncontingent presentation of the self-administered reinforcer (10 mg/kg cocaine, i.p.), a discrete contextual cue, or a contingent presentation of food. SCH 50911 (3-10 mg/kg) dose-dependently attenuated responding on the previously cocaine-paired lever during both reinstatement conditions, with slightly greater efficacy at reducing conditioned cue reinstatement. At the same time, it failed to alter reinstatement of food-seeking behavior. Baclofen (1.25-5 mg/kg) and SKF 97541 (0.03-0.3 mg/kg) attenuated cocaine- or food-seeking behavior; the effect of the drug appeared more effective for cocaine-seeking than food-seeking. CGP 7930 (10-30 mg/kg) reduced cocaine seeking without affecting food-induced reinstatement on reward seeking. Our results indicate that tonic activation of GABA(B) receptors is required for cocaine seeking behavior in rats. Moreover, the GABA(B) receptor antagonist SCH 50911 was effective in reducing relapse to cocaine at doses that failed to alter reinstatement of food-seeking behavior (present study), basal locomotor activity, cocaine and food self-administration (Filip et al., submitted for publication), suggesting its selective effects on motivated drug-seeking behavior. The potent inhibitory responses on cocaine seeking behavior were also seen

  3. Positive Modulation of GABAB Receptors Decreased Nicotine Self-administration and Counteracted Nicotine-induced Enhancement of Brain Reward Function in Rats

    PubMed Central

    Paterson, Neil E.; Vlachou, Styliani; Guery, Sebastien; Kaupmann, Klemens; Froestl, Wolfgang; Markou, Athina

    2008-01-01

    Acute administration of γ-aminobutyric acid (GABA)-B receptor agonists decreases nicotine, cocaine, ethanol, and heroin self-administration, and also decreases food-maintained responding and suppresses locomotor activity at high doses. GABAB receptor positive modulators may represent potentially improved therapeutic compounds because of their fewer side-effects than receptor agonists. The present study investigated the effects of administration of the GABAB receptor positive modulators 2,6-Di-tert-butyl-4-(3-hydroxy-2,2-dimethyl-propyl)-phenol (CGP7930) and N-[(1R,2R,4S)-bicyclo[2.2.1]hept-2-yl]-2-methyl-5-[4-(trifluoromethyl)phenyl]-4-pyrimidinamine (BHF177), and co-administration of the GABAB receptor positive modulator N,N'-dicyclopentyl-2-methylsulfanyl-5-nitro-pyrimidine-4,6-diamine (GS39783) with the GABAB receptor agonist (3-amino-2[S]-hydroxypropyl)-methylphosphinic acid (CGP44532) on nicotine- and food-maintained responding under fixed-ratio 5 (FR5) and progressive-ratio schedules of reinforcement. Furthermore, the effects of BHF177 and CGP44532 on nicotine-induced enhancement of brain reward function were evaluated. The results indicated that administration of CGP7930 decreased nicotine self-administration under an FR5 schedule. Administration of either GS39783 or CGP44532 selectively decreased nicotine self-administration, while co-administration of these compounds had additive effects. BHF177 administration selectively decreased nicotine-, but not food-, maintained responding under FR5 and progressive-ratio schedules. The nicotine-induced enhancement of brain reward function was blocked by BHF177 or CGP44532, although the highest doses of both compounds, particularly CGP44532, decreased brain reward function when administered alone, suggesting an additive, rather than interactive, effect. Overall, the present results indicate that GABAB receptor positive modulators, similarly to GABAB receptor agonists, attenuated the reinforcing and reward

  4. GABAB receptor-mediated activation of astrocytes by gamma-hydroxybutyric acid

    PubMed Central

    Gould, Timothy; Chen, Lixin; Emri, Zsuzsa; Pirttimaki, Tiina; Errington, Adam C.; Crunelli, Vincenzo; Parri, H. Rheinallt

    2014-01-01

    The gamma-aminobutyric acid (GABA) metabolite gamma-hydroxybutyric acid (GHB) shows a variety of behavioural effects when administered to animals and humans, including reward/addiction properties and absence seizures. At the cellular level, these actions of GHB are mediated by activation of neuronal GABAB receptors (GABABRs) where it acts as a weak agonist. Because astrocytes respond to endogenous and exogenously applied GABA by activation of both GABAA and GABABRs, here we investigated the action of GHB on astrocytes on the ventral tegmental area (VTA) and the ventrobasal (VB) thalamic nucleus, two brain areas involved in the reward and proepileptic action of GHB, respectively, and compared it with that of the potent GABABR agonist baclofen. We found that GHB and baclofen elicited dose-dependent (ED50: 1.6 mM and 1.3 µM, respectively) transient increases in intracellular Ca2+ in VTA and VB astrocytes of young mice and rats, which were accounted for by activation of their GABABRs and mediated by Ca2+ release from intracellular store release. In contrast, prolonged GHB and baclofen exposure caused a reduction in spontaneous astrocyte activity and glutamate release from VTA astrocytes. These findings have key (patho)physiological implications for our understanding of the addictive and proepileptic actions of GHB. PMID:25225100

  5. Characterization of (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one as a positive allosteric modulator of GABAB receptors

    PubMed Central

    Malherbe, P; Masciadri, R; Norcross, R D; Knoflach, F; Kratzeisen, C; Zenner, M-T; Kolb, Y; Marcuz, A; Huwyler, J; Nakagawa, T; Porter, R H P; Thomas, A W; Wettstein, J G; Sleight, A J; Spooren, W; Prinssen, E P

    2008-01-01

    Background and purpose: As baclofen is active in patients with anxiety disorders, GABAB receptors have been implicated in the modulation of anxiety. To avoid the side effects of baclofen, allosteric enhancers of GABAB receptors have been studied to provide an alternative therapeutic avenue for modulation of GABAB receptors. The aim of this study was to characterize derivatives of (R,S)-5,7-di-tert-butyl-3-hydroxy-3-trifluoromethyl-3H-benzofuran-2-one (rac-BHFF) as enhancers of GABAB receptors. Experimental approach: Enhancing properties of rac-BHFF were assessed in the Chinese hamster ovary (CHO)-Gα16-hGABAB(1a,2a) cells by Fluorometric Imaging Plate Reader and GTPγ[35S]-binding assays, and in rat hippocampal slices by population spike (PS) recordings. In vivo activities of rac-BHFF were assessed using the loss of righting reflex (LRR) and stress-induced hyperthermia (SIH) models. Key results: In GTPγ[35S]-binding assays, 0.3 μM rac-BHFF or its pure enantiomer (+)-BHFF shifted the GABA concentration–response curve to the left, an effect that resulted in a large increase in both GABA potency (by 15.3- and 87.3-fold) and efficacy (149% and 181%), respectively. In hippocampal slices, rac-BHFF enhanced baclofen-induced inhibition of PS of CA1 pyramidal cells. In an in vivo mechanism-based model in mice, rac-BHFF increased dose-dependently the LRR induced by baclofen with a minimum effective dose of 3 mg kg−1 p.o. rac-BHFF (100 mg kg−1 p.o.) tested alone had no effect on LRR nor on spontaneous locomotor activity, but exhibited anxiolytic-like activity in the SIH model in mice. Conclusions and implications: rac-BHFF derivatives may serve as valuable pharmacological tools to elucidate the pathophysiological roles played by GABAB receptors in the central and peripheral nervous systems. PMID:18536733

  6. GABAB and group I metabotropic glutamate receptors in the striatopallidal complex in primates

    PubMed Central

    SMITH, YOLAND; CHARARA, ALI; HANSON, JESSE E.; PAQUET, MARYSE; LEVEY, ALLAN I.

    2000-01-01

    Glutamate and GABA neurotransmission is mediated through various types of ionotropic and metabotropic receptors. In this review, we summarise some of our recent findings on the subcellular and subsynaptic localisation of GABAB and group I metabotropic glutamate receptors in the striatopallidal complex of monkeys. Polyclonal antibodies that specifically recognise GABABR1, mGluR1a and mGluR5 receptor subtypes were used for immunoperoxidase and pre-embedding immunogold techniques at the light and electron microscope levels. Both subtypes of group I mGluRs were expressed postsynaptically in striatal projection neurons and interneurons where they aggregate perisynaptically at asymmetric glutamatergic synapses and symmetric dopaminergic synaptic junctions. Moreover, they are also strongly expressed in the main body of symmetric synapses established by putative intrastriatal GABAergic terminals. In the globus pallidus, both receptor subtypes are found postsynaptically in the core of striatopallidal GABAergic synapses and perisynaptically at subthalamopallidal glutamatergic synapses. Finally, extrasynaptic labelling was commonly seen in the globus pallidus and the striatum. Moderate to intense GABABR1 immunoreactivity was observed in the striatopallidal complex. At the electron microscope level, GABABR1 immunostaining was commonly found in neuronal cell bodies and dendrites. Many striatal dendritic spines also displayed GABABR1 immunoreactivity. Moreover, GABABR1-immunoreactive axons and axon terminals were frequently encountered. In the striatum, GABABR1-immunoreactive boutons resembled terminals of cortical origin, while in the globus pallidus, subthalamic-like terminals were labelled. Pre-embedding immunogold data showed that postsynaptic GABABR1 receptors are concentrated at extrasynaptic sites on dendrites, spines and somata in the striatopallidal complex, perisynaptically at asymmetric synapses and in the main body of symmetric striatopallidal synapses in the GPe and

  7. Altered emotionality and neuronal excitability in mice lacking KCTD12, an auxiliary subunit of GABAB receptors associated with mood disorders

    PubMed Central

    Cathomas, F; Stegen, M; Sigrist, H; Schmid, L; Seifritz, E; Gassmann, M; Bettler, B; Pryce, C R

    2015-01-01

    Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the brain, is fundamental to brain function and implicated in the pathophysiology of several neuropsychiatric disorders. GABA activates G-protein-coupled GABAB receptors comprising principal GABAB1 and GABAB2 subunits as well as auxiliary KCTD8, 12, 12b and 16 subunits. The KCTD12 gene has been associated with bipolar disorder, major depressive disorder and schizophrenia. Here we compare Kctd12 null mutant (Kctd12−/−) and heterozygous (Kctd12+/−) with wild-type (WT) littermate mice to determine whether lack of or reduced KCTD12 expression leads to phenotypes that, extrapolating to human, could constitute endophenotypes for neuropsychiatric disorders with which KCTD12 is associated. Kctd12−/− mice exhibited increased fear learning but not increased memory of a discrete auditory-conditioned stimulus. Kctd12+/− mice showed increased activity during the inactive (light) phase of the circadian cycle relative to WT and Kctd12−/− mice. Electrophysiological recordings from hippocampal slices, a region of high Kctd12 expression, revealed an increased intrinsic excitability of pyramidal neurons in Kctd12−/− and Kctd12+/− mice. This is the first direct evidence for involvement of KCTD12 in determining phenotypes of emotionality, behavioral activity and neuronal excitability. This study provides empirical support for the polymorphism and expression evidence that KCTD12 confers risk for and is associated with neuropsychiatric disorders. PMID:25689571

  8. Subcellular compartment-specific molecular diversity of pre- and postsynaptic GABAB-activated GIRK channels in Purkinje cells

    PubMed Central

    Fernández-Alacid, Laura; Aguado, Carolina; Ciruela, Francisco; Martín, Ricardo; Colón, José; Cabañero, María José; Gassmann, Martin; Watanabe, Masahiko; Shigemoto, Ryuichi; Wickman, Kevin; Bettler, Bernhard; Sánchez-Prieto, José; Luján, Rafael

    2009-01-01

    Activation of G protein-gated inwardly-rectifying K+ (GIRK or Kir3) channels by metabotropic gamma-aminobutyric acid (B) (GABAB) receptors is an essential signalling pathway controlling neuronal excitability and synaptic transmission in the brain. To investigate the relationship between GIRK channel subunits and GABAB receptors in cerebellar Purkinje cells at post- and pre-synaptic sites, we used biochemical, functional and immunohistochemical techniques. Co-immunoprecipitation analysis demonstrated that GIRK subunits are co-assembled with GABAB receptors in the cerebellum. Immunoelectron microscopy showed that the subunit composition of GIRK channels in Purkinje cell spines is compartment-dependent. Thus, at extrasynaptic sites GIRK channels are formed by GIRK1/GIRK2/GIRK3, postsynaptic densities contain GIRK2/GIRK3 and dendritic shafts contain GIRK1/GIRK3. The postsynaptic association of GIRK subunits with GABAB receptors in Purkinje cells is supported by the subcellular regulation of the ion channel and the receptor in mutant mice. At presynaptic sites, GIRK channels localized to parallel fibre terminals are formed by GIRK1/GIRK2/GIRK3 and co-localize with GABAB receptors. Consistent with this morphological evidence we demonstrate their functional interaction at axon terminals in the cerebellum by showing that GIRK channels play a role in the inhibition of glutamate release by GABAB receptors. The association of GIRK channels and GABAB receptors with excitatory synapses at both post- and presynaptic sites indicates their intimate involvement in the modulation of glutamatergic neurotransmission in the cerebellum. PMID:19558451

  9. Characterization of the antiabsence effects of SCH 50911, a GABA-B receptor antagonist, in the lethargic mouse, gamma-hydroxybutyrate, and pentylenetetrazole models.

    PubMed

    Hosford, D A; Wang, Y; Liu, C C; Snead, O C

    1995-09-01

    Recent studies have shown that gamma-aminobutyric acidB (GABAB) receptor antagonists suppress absence seizures in animal models. (+)-5,5-Dimethyl-2-morpholineacetic acid, hydrochloride (SCH 50911) is a new GABAB antagonist that is structurally dissimilar to previously studied GABAB antagonists such as 3-aminopropyl-diethoxymethyl-phosphinic acid (CGP 35348), 3-aminopropyl-n-butyl-phosphinic acid (CGP 36742) or 3-aminopropyl-cyclohexylmethyl-phosphinic acid (CGP 46381). In this study we measured the antiabsence effects of SCH 50911 in three animal models: the lethargic (lh/lh) mutant mouse, which has spontaneous absence seizures; and two rat models in which absence seizures were induced by administration of either gamma-hydroxybutyrate or pentylenetetrazole. SCH 50911 abolished seizures in all three models in a dose-dependent fashion (ID100 = 8-170 mumol/kg). In each model SCH 50911 was more potent (ID50 = 2-22 mumol/kg) than the following antiabsence compounds: the GABAB antagonist CGP 35348 (ID50 = 210-890 mumol/kg); ethosuximide (ID50 < or = 142-1240 mumol/kg); trimethadione (ID50 = 520-1100 mumol/kg); and valproic acid (ID50 = 900-2360 mumol/kg). SCH 50911 was equipotent with the GABAB antagonist CGP 46381 (ID50 = 20 mumol/kg) in the lh/lh mouse model. These findings suggest that antiabsence activity may be a defining feature of GABAB receptor antagonists and provide a rationale for pursuing clinical trials of GABAB receptor antagonists in human patients with absence seizures. PMID:7562514

  10. GABAA and GABAB receptor-mediated effects on the spontaneous activity of the longitudinal layer in cat terminal ileum.

    PubMed

    Pencheva, N; Radomirov, R; Venkova, K

    1991-01-01

    1. GABA and GABAergic agonists-muscimol and (+/-)baclofen changed the spontaneous mechanical activity in isolated cat terminal ileum. 2. GABA at doses ranging from 5 microM to 2 mM produced concentration-dependent biphasic responses consisting of a transient relaxation followed by contractions with a tonic and a phasic components. 3. The GABA-induced relaxation was sensitive to bicuculline and picrotoxinin and was mimicked by muscimol, while the GABA-induced contractions were insensitive to bicuculline and picrotoxinin and were mimicked by (+/-)baclofen. Specific cross desensitization occurred between GABA and muscimol or GABA and (+/-)baclofen. 4. The bicuculline-sensitive relaxation induced by GABA and muscimol was abolished by atropine or tetrodotoxin (TTX), while the bicuculline-insensitive contractions induced by GABA and (+/-)baclofen were not antagonized by atropine or TTX, though they were slightly suppressed. 5. The GABA effects in the longitudinal layer of cat terminal ileum were mediated by the following receptors: -GABAA prejunctional receptors whose activation causes relaxation, probably through an inhibitory action on cholinergic neurons; -GABAB prejunctional receptors whose activation cause contractions; -GABAB postjunctional receptors located on the smooth muscle membrane whose activation induces tonic and phasic contractions. PMID:1646745

  11. [The pharmacological differences between kynurenine- and korazol-induced seizures (the participation of GABA-B receptors and dopamine)].

    PubMed

    Lapin, I P

    1998-01-01

    In experiments of male SHR (nonbred) and C57B1/6 mice [correction of rats] bicucullin intensified corasole-induced convulsions but had no effect on kynurenine convulsions, removed the anticonvulsive effect of phenibut against kynurenine and did not affect the anticonvulsive effect of diazepam against corasole. Phenibut and baclofen reduced the anticonvulsive effect of diazepam against corasole and caffeine. Haloperidol increased kynurenine-induced convulsions and had no effect on those caused by corasole. Dopamine removed the effect of haloperidol. Haloperidol and 6-oxydopamine weakened the sedative effect of phenibut. Blockade of GAMAB-receptors and weakening of dopaminergic activity are important in the mechanisms of kynurenine convulsions, and blockage of GABAA-receptors unrelated to it is important in the mechanisms of corasole convulsions. A functional antagonism in anticonvulsive activity may exist between these receptors. Bicucullin may probably have an effect both on GABAA- and GABAB-receptors. PMID:9621167

  12. GABAB Receptor Agonist R-Baclofen Reverses Social Deficits and Reduces Repetitive Behavior in Two Mouse Models of Autism.

    PubMed

    Silverman, J L; Pride, M C; Hayes, J E; Puhger, K R; Butler-Struben, H M; Baker, S; Crawley, J N

    2015-08-01

    Autism spectrum disorder (ASD) is diagnosed by two core behavioral criteria, unusual reciprocal social interactions and communication, and stereotyped, repetitive behaviors with restricted interests. Excitatory/inhibitory imbalance is a prominent hypothesis for the etiology of autism. The selective GABAB receptor agonist R-baclofen previously reversed social deficits and reduced repetitive behaviors in a mouse model of Fragile X syndrome, and Arbaclofen improved some clinical symptoms in some Fragile X and ASD patients. To evaluate R-baclofen in a broader range of mouse models of ASD, we tested both the R-baclofen enantiomer and the less potent S-baclofen enantiomer in two inbred strains of mice that display low sociability and/or high repetitive or stereotyped behaviors. R-baclofen treatment reversed social approach deficits in BTBR T+ Itpr3tf/J (BTBR), reduced repetitive self-grooming and high marble burying scores in BTBR, and reduced stereotyped jumping in C58/J (C58), at nonsedating doses. S-baclofen produced minimal effects at the same doses. These findings encourage investigations of R-baclofen in other preclinical model systems. Additional clinical studies may be warranted to further evaluate the hypothesis that the GABAB receptor represents a promising pharmacological target for treating appropriately stratified subsets of individuals with ASD. PMID:25754761

  13. GABAB receptors as a common target for hypothermia and spike and wave seizures: intersecting mechanisms of thermoregulation and absence epilepsy.

    PubMed

    Ostojić, Z S; Ilić, T V; Vesković, S M; Andjus, P R

    2013-05-15

    In the current study the link among the γ-hydroxybutyrate (GHB)/pentylenetetrazole (PTZ)-induced absence-like seizures and concomitant decreases in the core temperature, as well as electroencephalographic (EEG) activity during rewarming from deep hypothermia produced by a drug-free protocol were investigated. During the rewarming period after deep cooling, most Wistar rats suffered from bilaterally synchronous spike and waves with no or mild behavioral correlates. Spike and wave seizures were temperature-dependent and were initially registered when body temperature (Tb) reached 25-27°C, but mostly during the mild hypothermia of 0.3-1.3°C (Tb of 36.3-37.3°C). In chemical absence models, spike and wave discharges were also closely accompanied by mild systemic hypothermia, as both PTZ- and GHB-induced temperature decreases ranged from about 1-1.4°C respectively, together with EEG markers of absence activity. Thus, throughout the different experimental designs, the occurrence of spike and wave discharges was always related to a mild (0.3-1.4°C) decrease of Tb. Benzodiazepine diazepam as the GABAA-positive allosteric modulator and CGP 62349 as the selective antagonist of GABAB receptors were used to determine if their well-known anticonvulsant properties also affect hypothermia elicited by these drugs. Finally, during the course of spontaneous rewarming from deep hypothermia, another selective GABAB-blocking agent, CGP 35348, was used to elucidate if GABAB inhibitory system could be critically implicated in the generation of hypothermia-dependent spike and waves. Diazepam prevented both the PTZ-induced hypothermia and electrographic absence seizures, but these two beneficial effects did not occur in the GHB model. Even though diazepam delayed GHB-induced maximal temperature decrease, the GHB effects remained highly significant. The GABAB antagonist CGP 62349 completely prevented hypothermia as well as absence seizures in both chemical models. Likewise, spike and

  14. Different in vitro and in vivo profiles of substituted 3-aminopropylphosphinate and 3-aminopropyl(methyl)phosphinate GABAB receptor agonists as inhibitors of transient lower oesophageal sphincter relaxation

    PubMed Central

    Lehmann, A; Antonsson, M; Aurell-Holmberg, A; Blackshaw, LA; Brändén, L; Elebring, T; Jensen, J; Kärrberg, L; Mattsson, JP; Nilsson, K; Oja, SS; Saransaari, P; von Unge, S

    2012-01-01

    BACKGROUND AND PURPOSE Gastro-oesophageal reflux is predominantly caused by transient lower oesophageal sphincter relaxation (TLOSR) and GABAB receptor stimulation inhibits TLOSR. Lesogaberan produces fewer CNS side effects than baclofen, which has been attributed to its affinity for the GABA transporter (GAT), the action of which limits stimulation of central GABAB receptors. To understand the structure–activity relationship for analogues of lesogaberan (3-aminopropylphosphinic acids), and corresponding 3-aminopropyl(methyl)phosphinic acids, we have compared representatives of these classes in different in vitro and in vivo models. EXPERIMENTAL APPROACH The compounds were characterized in terms of GABAB agonism in vitro. Binding to GATs and cellular uptake was done using rat brain membranes and slices respectively. TLOSR was measured in dogs, and CNS side effects were evaluated as hypothermia in mice and rats. KEY RESULTS 3-Aminopropylphosphinic acids inhibited TLOSR with a superior therapeutic index compared to 3-aminopropyl(methyl)phosphinic acids. This difference was most likely due to differential GAT-mediated uptake into brain cells of the former but not latter. In agreement, 3-aminopropyl(methyl)phosphinic acids were much more potent in producing hypothermia in rats even when administered i.c.v. CONCLUSIONS AND IMPLICATIONS An enhanced therapeutic window for 3-aminopropylphosphinic acids compared with 3-aminopropyl(methyl)phosphinic acids with respect to inhibition of TLOSR was observed and is probably mechanistically linked to neural cell uptake of the former but not latter group of compounds. These findings offer a platform for discovery of new GABAB receptor agonists for the treatment of reflux disease and other conditions where selective peripheral GABAB receptor agonism may afford therapeutic effects. PMID:21950457

  15. Effects of GABA agonists on body temperature regulation in GABAB(1)−/− mice

    PubMed Central

    Quéva, Christophe; Bremner-Danielsen, Marianne; Edlund, Anders; Jonas Ekstrand, A; Elg, Susanne; Erickson, Sven; Johansson, Thore; Lehmann, Anders; Mattsson, Jan P

    2003-01-01

    Activation of GABAB receptors evokes hypothermia in wildtype (GABAB(1)+/+) but not in GABAB receptor knockout (GABAB(1)−/−) mice. The aim of the present study was to determine the hypothermic and behavioural effects of the putative GABAB receptor agonist γ-hydroxybutyrate (GHB), and of the GABAA receptor agonist muscimol. In addition, basal body temperature was determined in GABAB(1)+/+, GABAB(1)+/− and GABAB(1)−/− mice. GABAB(1)−/− mice were generated by homologous recombination in embryonic stem cells. Correct gene targeting was assessed by Southern blotting, PCR and Western blotting. GABAB receptor-binding sites were quantified with radioligand binding. Measurement of body temperature was done using subcutaneous temperature-sensitive chips, and behavioural changes after drug administration were scored according to a semiquantitative scale. GABAB(1)−/− mice had a short lifespan, probably caused by generalised seizure activity. No histopathological or blood chemistry changes were seen, but the expression of GABAB(2) receptor protein was below the detection limit in brains from GABAB(1)−/− mice, in the absence of changes in mRNA levels. GABAB receptor-binding sites were absent in brain membranes from GABAB(1)−/− mice. GABAB(1)−/− mice were hypothermic by approximately 1°C compared to GABAB(1)+/+ and GABAB(1)+/− mice. Injection of baclofen (9.6 mg kg−1) produced a large reduction in body temperature and behavioural effects in GABAB(1)+/+ and in GABAB(1)+/− mice, but GABAB(1)−/− mice were unaffected. The same pattern was seen after administration of GHB (400 mg kg−1). The GABAA receptor agonist muscimol (2 mg kg−1), on the other hand, produced a more pronounced hypothermia in GABAB(1)−/−mice. In GABAB(1)+/+ and GABAB(1)+/− mice, muscimol induced sedation and reduced locomotor activity. However, when given to GABAB(1)−/− mice, muscimol triggered periods of intense jumping and wild running. It is concluded that

  16. Blockade of presynaptic 4-aminopyridine-sensitive potassium channels increases initial neurotransmitter release probability, reinstates synaptic transmission altered by GABAB receptor activation in rat midbrain periaqueductal gray.

    PubMed

    Li, Guangying; Liu, Zhi-Liang; Zhang, Wei-Ning; Yang, Kun

    2016-01-01

    The activation of γ-aminobutyric acid receptor subtype B (GABAB) receptors in the midbrain ventrolateral periaqueductal gray (vlPAG) induces both postsynaptic and presynaptic inhibition. Whereas the postsynaptic inhibition is mediated by G protein-coupled inwardly rectifying K channels, the presynaptic inhibition of neurotransmitter release is primarily mediated by voltage-gated calcium channels. Using whole-cell recordings from acute rat PAG slices, we report here that the bath application of 4-aminopyridine, a voltage-gated K channel blocker, increases the initial GABA and glutamate release probability (P) and reinstates P depressed by presynaptic GABAB receptor activation at inhibitory and excitatory synapses, respectively. However, Ba, which blocks G protein-coupled inwardly rectifying K channels, does not produce similar effects. Our data suggest that the blockade of presynaptic 4-aminopyridine-sensitive K channels in vlPAG facilitates neurotransmitter release and reinstates synaptic transmission that has been altered by presynaptic GABAB receptor activation. Because vlPAG is involved in the descending pain control system, the present results may have potential therapeutic applications. PMID:26575285

  17. New effects of GABAB receptor allosteric modulator rac-BHFF on ambient GABA, uptake/release, Em and synaptic vesicle acidification in nerve terminals.

    PubMed

    Pozdnyakova, N; Dudarenko, M; Borisova, T

    2015-09-24

    Positive allosteric modulators of GABAB receptors have great therapeutic potential for medications of anxiety, depression, etc. The effects of recently discovered modulator rac-BHFF on the key characteristics of GABAergic neurotransmission were investigated in cortical and hippocampal presynaptic nerve terminals of rats (synaptosomes). The ambient level of [(3)H]GABA that is a balance between release and uptake of the neurotransmitter increased significantly in the presence of rac-BHFF (at concentrations 10-30μM). The initial velocity of synaptosomal [(3)H]GABA uptake was suppressed by the modulator. In the presence of GABA transporter blocker NO-711, it was shown that rac-BHFF increased tonic release of [(3)H]GABA from synaptosomes (at concentrations 3-30μM). Rac-BHFF within the concentration range of 0.3-30μM did not enhance inhibiting effect of (±)-baclofen on depolarization-induced exocytotic release of [(3)H]GABA. Rac-BHFF (0.3-30μM) caused dose-dependent depolarization of the plasma membrane and dissipation of the proton gradient of synaptic vesicles in synaptosomes that was shown in the absence/presence of GABAB receptor antagonist saclofen using fluorescent dyes rhodamine 6G and acridine orange, respectively, and so, the above effects of rac-BHFF were not associated with the modulation of presynaptic GABAB receptors. Therefore, drug development strategy of positive allosteric modulation of GABAB receptors is to eliminate the above side effects of rac-BHFF in presynapse, and vice versa, these new properties of rac-BHFF may be exploited appropriately. PMID:26197223

  18. Reducing effect of saikosaponin A, an active ingredient of Bupleurum falcatum, on alcohol self-administration in rats: Possible involvement of the GABAB receptor.

    PubMed

    Maccioni, Paola; Lorrai, Irene; Carai, Mauro A M; Riva, Antonella; Morazzoni, Paolo; Mugnaini, Claudia; Corelli, Federico; Gessa, Gian Luigi; Colombo, Giancarlo

    2016-05-16

    Recent studies demonstrated that treatment with saikosaponin A (SSA) - an active ingredient of the medicinal herb, Bupleurum falcatum L. - selectively suppressed, likely via a GABAB receptor-mediated mechanism, intravenous self-administration of morphine and cocaine in rats [Yoon et al., 2012; 2013]. The present study was designed to investigate whether the capacity of SSA to suppress morphine and cocaine self-administration extends to oral alcohol self-administration. To this end, selectively bred Sardinian alcohol-preferring (sP) rats were trained to lever-respond on a Fixed Ratio (FR) 4 (FR4) schedule of reinforcement for alcohol (15%, v/v) in daily 30-min sessions. Once responding had stabilized, rats were tested under the FR4 (measure of alcohol reinforcing properties) and Progressive Ratio (PR; measure of alcohol motivational properties) schedules of reinforcement. The possible involvement of the GABAB receptor system was investigated testing the effect of (a) pretreatment with the GABAB receptor antagonist, SCH50911, and (b) combined treatment with the positive allosteric modulator of the GABAB receptor, GS39783. Treatment with SSA (0, 0.25, 0.5, and 1mg/kg, i.p.) markedly reduced lever-responding for alcohol, amount of self-administered alcohol, and breakpoint for alcohol (defined as the lowest response requirement not achieved in the PR experiment). Pretreatment with 2mg/kg SCH50911 (i.p.) resulted in a partial blockade of the reducing effect of 0.5mg/kg SSA on lever-responding for alcohol and amount of self-administered alcohol. Combination of per se ineffective doses of GS39783 (5mg/kg, i.g.) and SSA (0.1mg/kg, i.p.) reduced lever-responding for alcohol and amount of self-administered alcohol. These results (a) extend to alcohol self-administration the capacity of SSA to suppress morphine and cocaine self-administration in rats and (b) suggest that the GABAB receptor system is likely part of the neural substrate underlying the reducing effect of SSA on

  19. GABAB receptor-mediated, layer-specific synaptic plasticity reorganizes gamma-frequency neocortical response to stimulation.

    PubMed

    Ainsworth, Matthew; Lee, Shane; Kaiser, Marcus; Simonotto, Jennifer; Kopell, Nancy J; Whittington, Miles A

    2016-05-10

    Repeated presentations of sensory stimuli generate transient gamma-frequency (30-80 Hz) responses in neocortex that show plasticity in a task-dependent manner. Complex relationships between individual neuronal outputs and the mean, local field potential (population activity) accompany these changes, but little is known about the underlying mechanisms responsible. Here we show that transient stimulation of input layer 4 sufficient to generate gamma oscillations induced two different, lamina-specific plastic processes that correlated with lamina-specific changes in responses to further, repeated stimulation: Unit rates and recruitment showed overall enhancement in supragranular layers and suppression in infragranular layers associated with excitatory or inhibitory synaptic potentiation onto principal cells, respectively. Both synaptic processes were critically dependent on activation of GABAB receptors and, together, appeared to temporally segregate the cortical representation. These data suggest that adaptation to repetitive sensory input dramatically alters the spatiotemporal properties of the neocortical response in a manner that may both refine and minimize cortical output simultaneously. PMID:27118845

  20. GABAB receptor-mediated, layer-specific synaptic plasticity reorganizes gamma-frequency neocortical response to stimulation

    PubMed Central

    Ainsworth, Matthew; Lee, Shane; Kaiser, Marcus; Simonotto, Jennifer; Kopell, Nancy J.

    2016-01-01

    Repeated presentations of sensory stimuli generate transient gamma-frequency (30–80 Hz) responses in neocortex that show plasticity in a task-dependent manner. Complex relationships between individual neuronal outputs and the mean, local field potential (population activity) accompany these changes, but little is known about the underlying mechanisms responsible. Here we show that transient stimulation of input layer 4 sufficient to generate gamma oscillations induced two different, lamina-specific plastic processes that correlated with lamina-specific changes in responses to further, repeated stimulation: Unit rates and recruitment showed overall enhancement in supragranular layers and suppression in infragranular layers associated with excitatory or inhibitory synaptic potentiation onto principal cells, respectively. Both synaptic processes were critically dependent on activation of GABAB receptors and, together, appeared to temporally segregate the cortical representation. These data suggest that adaptation to repetitive sensory input dramatically alters the spatiotemporal properties of the neocortical response in a manner that may both refine and minimize cortical output simultaneously. PMID:27118845

  1. Modulation of TLR3/TLR4 inflammatory signaling by the GABAB receptor agonist baclofen in glia and immune cells: relevance to therapeutic effects in multiple sclerosis

    PubMed Central

    Crowley, Tadhg; Fitzpatrick, John-Mark; Kuijper, Teun; Cryan, John F.; O’Toole, Orna; O’Leary, Olivia F.; Downer, Eric J.

    2015-01-01

    The GABAB receptor agonist, baclofen, is used to treat muscle tightness and cramping caused by spasticity in a number of disorders including multiple sclerosis (MS), but its precise mechanism of action is unknown. Neuroinflammation drives the central pathology in MS and is mediated by both immunoreactive glial cells and invading lymphocytes. Furthermore, a body of data indicates that the Toll-like receptor (TLR) family of innate immune receptors is implicated in MS progression. In the present study we investigated whether modulation of GABAB receptors using baclofen can exert anti-inflammatory effects by targeting TLR3 and(or) TLR4-induced inflammatory signaling in murine glial cells and human peripheral blood mononuclear cells (PBMCs) isolated from healthy control individuals and patients with the relapse-remitting (RR) form of MS. TLR3 and TLR4 stimulation promoted the nuclear sequestration of NF-κB and pro-inflammatory cytokine expression in murine glia, while TLR4, but not TLR3, promoted pro-inflammatory cytokine expression in PBMCs isolated from both healthy donors and RR-MS patients. Importantly, this effect was exacerbated in RR-MS patient immune cells. We present further evidence that baclofen dose-dependently attenuated TLR3- and TLR4-induced inflammatory signaling in primary glial cells. Pre-exposure of PBMCs isolated from healthy donors to baclofen attenuated TLR4-induced TNF-α expression, but did not affect TLR4-induced TNF-α expression in RR-MS patient PBMCs. Interestingly, mRNA expression of the GABAB receptor was reduced in PBMCs from RR-MS donors when compared to healthy controls, an effect that might contribute to the differential sensitivity to baclofen seen in healthy and RR-MS patient cells. Overall these findings indicate that baclofen differentially regulates TLR3 and TLR4 signaling in glia and immune cells, and offers insight on the role of baclofen in the treatment of neuroinflammatory disease states including MS. PMID:26283920

  2. Attenuation of the stimulant response to ethanol is associated with enhanced ataxia for a GABAA, but not a GABAB, receptor agonist

    PubMed Central

    Holstein, Sarah E.; Dobbs, Lauren; Phillips, Tamara J.

    2008-01-01

    Background The γ-aminobutyric acid (GABA) system is implicated in the neurobiological actions of ethanol, and pharmacological agents that increase the activity of this system have been proposed as potential treatments for alcohol use disorders. As ethanol has its own GABA mimetic properties, it is critical to determine the mechanism by which GABAergic drugs may reduce the response to ethanol (i.e. via an inhibition or an accentuation of the neurobiological effects of ethanol). Methods In the present study, we examined the ability of three different types of GABAergic compounds, the GABA reuptake inhibitor NO-711, the GABAA receptor agonist muscimol, and the GABAB receptor agonist baclofen, to attenuate the locomotor stimulant response to ethanol in FAST mice, which were selectively bred for extreme sensitivity to ethanol-induced locomotor stimulation. In order to determine whether these compounds produced a specific reduction in stimulation, their effects on ethanol-induced motor incoordination were also examined. Results NO-711, muscimol, and baclofen were all found to potently attenuate the locomotor stimulant response to ethanol in FAST mice. However, both NO-711 and muscimol produced a marked increase in ethanol-induced ataxia, whereas baclofen did not accentuate this response. Conclusions These results suggest that pharmacological agents that increase extracellular concentrations of GABA and GABAA receptor activity may attenuate the stimulant effects of ethanol by accentuating its intoxicating and sedative properties. However, selective activation of the GABAB receptor appears to produce a specific attenuation of ethanol-induced stimulation, suggesting that GABAB receptor agonists may hold greater promise as potential pharmacotherapies for alcohol use disorders. PMID:18945218

  3. Inhibition of presynaptic calcium transients in cortical inputs to the dorsolateral striatum by metabotropic GABAB and mGlu2/3 receptors

    PubMed Central

    Kupferschmidt, David A; Lovinger, David M

    2015-01-01

    Cortical inputs to the dorsolateral striatum (DLS) are dynamically regulated during skill learning and habit formation, and are dysregulated in disorders characterized by impaired action control. Therefore, a mechanistic investigation of the processes regulating corticostriatal transmission is key to understanding DLS-associated circuit function, behaviour and pathology. Presynaptic GABAB and group II metabotropic glutamate (mGlu2/3) receptors exert marked inhibitory control over corticostriatal glutamate release in the DLS, yet the signalling pathways through which they do so are unclear. We developed a novel approach using the genetically encoded calcium (Ca2+) indicator GCaMP6 to assess presynaptic Ca2+ in corticostriatal projections to the DLS. Using simultaneous photometric presynaptic Ca2+ and striatal field potential recordings, we report that relative to P/Q-type Ca2+ channels, N-type channels preferentially contributed to evoked presynaptic Ca2+ influx in motor cortex projections to, and excitatory transmission in, the DLS. Activation of GABAB or mGlu2/3 receptors inhibited both evoked presynaptic Ca2+ transients and striatal field potentials. mGlu2/3 receptor-mediated depression did not require functional N-type Ca2+ channels, but was attenuated by blockade of P/Q-type channels. These findings reveal presynaptic mechanisms of inhibitory modulation of corticostriatal function that probably contribute to the selection and shaping of behavioural repertoires. Key points Plastic changes at cortical inputs to the dorsolateral striatum (DLS) underlie skill learning and habit formation, so characterizing the mechanisms by which these inputs are regulated is important for understanding the neural basis of action control. We developed a novel approach using the genetically encoded calcium (Ca2+) indicator GCaMP6 and brain slice photometry to assess evoked presynaptic Ca2+ transients in cortical inputs to the DLS and study their regulation by GABAB and mGlu2

  4. Regulator of G Protein Signaling 6 (RGS6) Protein Ensures Coordination of Motor Movement by Modulating GABAB Receptor Signaling*

    PubMed Central

    Maity, Biswanath; Stewart, Adele; Yang, Jianqi; Loo, Lipin; Sheff, David; Shepherd, Andrew J.; Mohapatra, Durga P.; Fisher, Rory A.

    2012-01-01

    γ-Aminobutyric acid (GABA) release from inhibitory interneurons located within the cerebellar cortex limits the extent of neuronal excitation in part through activation of metabotropic GABAB receptors. Stimulation of these receptors triggers a number of downstream signaling events, including activation of GIRK channels by the Gβγ dimer resulting in membrane hyperpolarization and inhibition of neurotransmitter release from presynaptic sites. Here, we identify RGS6, a member of the R7 subfamily of RGS proteins, as a key regulator of GABABR signaling in cerebellum. RGS6 is enriched in the granule cell layer of the cerebellum along with neuronal GIRK channel subunits 1 and 2 where RGS6 forms a complex with known binding partners Gβ5 and R7BP. Mice lacking RGS6 exhibit abnormal gait and ataxia characterized by impaired rotarod performance improved by treatment with a GABABR antagonist. RGS6−/− mice administered baclofen also showed exaggerated motor coordination deficits compared with their wild-type counterparts. Isolated cerebellar neurons natively expressed RGS6, GABABR, and GIRK channel subunits, and cerebellar granule neurons from RGS6−/− mice showed a significant delay in the deactivation kinetics of baclofen-induced GIRK channel currents. These results establish RGS6 as a key component of GABABR signaling and represent the first demonstration of an essential role for modulatory actions of RGS proteins in adult cerebellum. Dysregulation of RGS6 expression in human patients could potentially contribute to loss of motor coordination and, thus, pharmacological manipulation of RGS6 levels might represent a viable means to treat patients with ataxias of cerebellar origin. PMID:22179605

  5. Regulator of G protein signaling 6 (RGS6) protein ensures coordination of motor movement by modulating GABAB receptor signaling.

    PubMed

    Maity, Biswanath; Stewart, Adele; Yang, Jianqi; Loo, Lipin; Sheff, David; Shepherd, Andrew J; Mohapatra, Durga P; Fisher, Rory A

    2012-02-10

    γ-Aminobutyric acid (GABA) release from inhibitory interneurons located within the cerebellar cortex limits the extent of neuronal excitation in part through activation of metabotropic GABA(B) receptors. Stimulation of these receptors triggers a number of downstream signaling events, including activation of GIRK channels by the Gβγ dimer resulting in membrane hyperpolarization and inhibition of neurotransmitter release from presynaptic sites. Here, we identify RGS6, a member of the R7 subfamily of RGS proteins, as a key regulator of GABA(B)R signaling in cerebellum. RGS6 is enriched in the granule cell layer of the cerebellum along with neuronal GIRK channel subunits 1 and 2 where RGS6 forms a complex with known binding partners Gβ(5) and R7BP. Mice lacking RGS6 exhibit abnormal gait and ataxia characterized by impaired rotarod performance improved by treatment with a GABA(B)R antagonist. RGS6(-/-) mice administered baclofen also showed exaggerated motor coordination deficits compared with their wild-type counterparts. Isolated cerebellar neurons natively expressed RGS6, GABA(B)R, and GIRK channel subunits, and cerebellar granule neurons from RGS6(-/-) mice showed a significant delay in the deactivation kinetics of baclofen-induced GIRK channel currents. These results establish RGS6 as a key component of GABA(B)R signaling and represent the first demonstration of an essential role for modulatory actions of RGS proteins in adult cerebellum. Dysregulation of RGS6 expression in human patients could potentially contribute to loss of motor coordination and, thus, pharmacological manipulation of RGS6 levels might represent a viable means to treat patients with ataxias of cerebellar origin. PMID:22179605

  6. GABAB receptors inhibit low-voltage activated and high-voltage activated Ca(2+) channels in sensory neurons via distinct mechanisms.

    PubMed

    Huang, Dongyang; Huang, Sha; Peers, Chris; Du, Xiaona; Zhang, Hailin; Gamper, Nikita

    2015-09-18

    Growing evidence suggests that mammalian peripheral somatosensory neurons express functional receptors for gamma-aminobutyric acid, GABAA and GABAB. Moreover, local release of GABA by pain-sensing (nociceptive) nerve fibres has also been suggested. Yet, the functional significance of GABA receptor triggering in nociceptive neurons is not fully understood. Here we used patch-clamp recordings from small-diameter cultured DRG neurons to investigate effects of GABAB receptor agonist baclofen on voltage-gated Ca(2+) currents. We found that baclofen inhibited both low-voltage activated (LVA, T-type) and high-voltage activated (HVA) Ca(2+) currents in a proportion of DRG neurons by 22% and 32% respectively; both effects were sensitive to Gi/o inhibitor pertussis toxin. Inhibitory effect of baclofen on both current types was about twice less efficacious as compared to that of the μ-opioid receptor agonist DAMGO. Surprisingly, only HVA but not LVA current modulation by baclofen was partially prevented by G protein inhibitor GDP-β-S. In contrast, only LVA but not HVA current modulation was reversed by the application of a reducing agent dithiothreitol (DTT). Inhibition of T-type Ca(2+) current by baclofen and the recovery of such inhibition by DTT were successfully reconstituted in the expression system. Our data suggest that inhibition of LVA current in DRG neurons by baclofen is partially mediated by an unconventional signaling pathway that involves a redox mechanism. These findings reinforce the idea of targeting peripheral GABA receptors for pain relief. PMID:26239659

  7. Bidirectional enantioselective effects of the GABAB receptor agonist baclofen in two mouse models of excessive ethanol consumption

    PubMed Central

    Kasten, Chelsea R.; Blasingame, Shelby N.; Boehm, Stephen L.

    2014-01-01

    The GABAB receptor agonist baclofen has been studied extensively in preclinical models of alcohol use disorders, yet results on its efficacy have been uncertain. Racemic baclofen, which is used clinically, can be broken down into separate enantiomers of the drug. Baclofen has been shown to produce enantioselective effects in behavioral assays including those modeling reflexive and sexual behavior. The current studies sought to characterize the enantioselective effects of baclofen in two separate models of ethanol consumption. The first was a Drinking-in-the-Dark procedure that provides “binge-like” ethanol access to mice by restricting access to a two hour period, three hours into the dark cycle. The second was a two-bottle choice procedure that utilized selectively bred High Alcohol Preferring 1 (HAP1) mice to model chronic ethanol access. HAP1 mice are selectively bred to consume pharmacologically relevant amounts of ethanol in a 24-hour two-bottle choice paradigm. The results showed that baclofen yields enantioselective effects on ethanol intake in both models, and that these effects are bidirectional. Total ethanol intake was decreased by R(+)- baclofen, while total intake was increased by S(-)-baclofen in the binge-like and chronic drinking models. Whereas overall binge-like saccharin intake was significantly reduced by R(+)- baclofen, chronic intake was not significantly altered. S(-)- baclofen did not significantly alter saccharin intake. Neither enantiomer significantly affected locomotion during binge-like reinforcer consumption. Collectively, these results demonstrate that baclofen produces enantioselective effects on ethanol consumption. More importantly, the modulation of consumption is bidirectional. The opposing enantioselective effects may explain some of the variance seen in published baclofen literature. PMID:25557834

  8. Differential effects of K+ channel blockers on antinociception induced by alpha 2-adrenoceptor, GABAB and kappa-opioid receptor agonists.

    PubMed Central

    Ocaña, M.; Baeyens, J. M.

    1993-01-01

    1. The effects of several K+ channel blockers (sulphonylureas, 4-aminopyridine and tetraethylammonium) on the antinociception induced by clonidine, baclofen and U50,488H were evaluated by use of a tail flick test in mice. 2. Clonidine (0.125-2 mg kg-1, s.c.) induced a dose-dependent antinociceptive effect. The ATP-dependent K+ (KATP) channel blocker gliquidone (4-8 micrograms/mouse, i.c.v.) produced a dose-dependent displacement to the right of the clonidine dose-response line, but neither 4-aminopyridine (4-AP) (25-250 ng/mouse, i.c.v.) nor tetraethylammonium (TEA) (10-20 micrograms/mouse, i.c.v.) significantly modified clonidine-induced antinociception. 3. The order of potency of sulphonylureas in antagonizing clonidine-induced antinociception was gliquidone > glipizide > glibenclamide > tolbutamide, which is the same order of potency as these drugs block KATP channels in neurones of the CNS. 4. Baclofen (2-16 mg kg-1, s.c.) also induced a dose-dependent antinociceptive effect. Both 4-AP (2.5-25 ng/mouse, i.c.v.) and TEA (10-20 micrograms/mouse, i.c.v.) dose-dependently antagonized baclofen antinociception, producing a displacement to the right of the baclofen dose-response line. However, gliquidone (8-16 micrograms/mouse, i.c.v.) did not significantly modify the baclofen effect. 5. None of the K+ channel blockers tested (gliquidone, 8-16 micrograms/mouse; 4-AP, 25-250 ng/mouse and TEA, 10-20 micrograms/mouse, i.c.v.), significantly modified the antinociception induced by U50,488H (8 mg kg-1, s.c.). 6. These results suggest that the opening of K+ channels is involved in the antinociceptive effect of alpha 2 and GABAB, but not kappa-opioid, receptor agonists.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7905339

  9. Visual experience prevents dysregulation of GABAB receptor-dependent short-term depression in adult superior colliculus

    PubMed Central

    Balmer, Timothy S.

    2015-01-01

    Progressive loss of plasticity during development prevents refined circuits from regressing to an immature state and is thought to depend on maturation of GABAergic inhibition. For example, a gradual reduction in size of visual receptive fields (RFs) occurs in the superior colliculus (SC) during development. Maintenance of the refined state throughout adulthood requires early light exposure. Here we investigate the potential role of changes in long- or short-term plasticity in experience-dependent maintenance of refined RFs. Using an acute SC slice preparation, we found that long-term plasticity was not affected by visual deprivation, indicating that it does not underlie deprivation-induced RF enlargement. In contrast, visual deprivation altered short-term plasticity in an unexpected way. Specifically, GABAB receptor (GABABR)-mediated paired pulse depression was increased in slices from dark-reared animals. This increase was mimicked by GABAAR blockade in slices from normally reared animals, suggesting that experience-dependent maintenance of GABAAR function prevents an increase in probability of neurotransmitter release. GABABR-mediated short-term depression in response to strong stimulation (such as occurs during vision) was reduced in slices from dark-reared animals. This change was mimicked in slices from normal animals by reducing GABA release. These results are consistent with the hypothesis that early visual experience maintains GABAergic inhibition and prevents later deprivation-induced alterations of short-term depression in SC. Identifying how plasticity is restricted in mature circuits could guide therapies to enhance recovery of function in adults. PMID:25568162

  10. Bidirectional enantioselective effects of the GABAB receptor agonist baclofen in two mouse models of excessive ethanol consumption.

    PubMed

    Kasten, Chelsea R; Blasingame, Shelby N; Boehm, Stephen L

    2015-02-01

    The GABAB receptor agonist baclofen has been studied extensively in preclinical models of alcohol-use disorders, yet results on its efficacy have been uncertain. Racemic baclofen, which is used clinically, can be broken down into separate enantiomers of the drug. Baclofen has been shown to produce enantioselective effects in behavioral assays, including those modeling reflexive and sexual behavior. The current studies sought to characterize the enantioselective effects of baclofen in two separate models of ethanol consumption. The first was a Drinking-in-the-Dark procedure that provides "binge-like" ethanol access to mice by restricting access to a 2-h period, 3 h into the dark cycle. The second was a two-bottle choice procedure that utilized selectively bred High Alcohol Preferring 1 (HAP1) mice to model chronic ethanol access. HAP1 mice are selectively bred to consume pharmacologically relevant amounts of ethanol in a 24-h two-bottle choice paradigm. The results showed that baclofen yields enantioselective effects on ethanol intake in both models, and that these effects are bidirectional. Total ethanol intake was decreased by R(+)-baclofen, while total intake was increased by S(-)-baclofen in the binge-like and chronic drinking models. Whereas overall binge-like saccharin intake was significantly reduced by R(+)-baclofen, chronic intake was not significantly altered. S(-)-baclofen did not significantly alter saccharin intake. Neither enantiomer significantly affected locomotion during binge-like reinforcer consumption. Collectively, these results demonstrate that baclofen produces enantioselective effects on ethanol consumption. More importantly, the modulation of consumption is bidirectional. The opposing enantioselective effects may explain some of the variance seen in published baclofen literature. PMID:25557834

  11. Endoplasmic Reticulum Sorting and Kinesin-1 Command the Targeting of Axonal GABAB Receptors

    PubMed Central

    Valdés, Viviana; Valenzuela, José Ignacio; Salas, Daniela A.; Jaureguiberry-Bravo, Matías; Otero, Carolina; Thiede, Christina; Schmidt, Christoph F.; Couve, Andrés

    2012-01-01

    In neuronal cells the intracellular trafficking machinery controls the availability of neurotransmitter receptors at the plasma membrane, which is a critical determinant of synaptic strength. Metabotropic γ amino-butyric acid (GABA) type B receptors (GABABRs) are neurotransmitter receptors that modulate synaptic transmission by mediating the slow and prolonged responses to GABA. GABABRs are obligatory heteromers constituted by two subunits, GABABR1 and GABABR2. GABABR1a and GABABR1b are the most abundant subunit variants. GABABR1b is located in the somatodendritic domain whereas GABABR1a is additionally targeted to the axon. Sushi domains located at the N-terminus of GABABR1a constitute the only difference between both variants and are necessary and sufficient for axonal targeting. The precise targeting machinery and the organelles involved in sorting and transport have not been described. Here we demonstrate that GABABRs require the Golgi apparatus for plasma membrane delivery but that axonal sorting and targeting of GABABR1a operate in a pre-Golgi compartment. In the axon GABABR1a subunits are enriched in the endoplasmic reticulum (ER), and their dynamic behavior and colocalization with other secretory organelles like the ER-to-Golgi intermediate compartment (ERGIC) suggest that they employ a local secretory route. The transport of axonal GABABR1a is microtubule-dependent and kinesin-1, a molecular motor of the kinesin family, determines axonal localization. Considering that progression of GABABRs through the secretory pathway is regulated by an ER retention motif our data contribute to understand the role of the axonal ER in non-canonical sorting and targeting of neurotransmitter receptors. PMID:22952914

  12. Thymoquinone and vitamin C attenuates pentylenetetrazole-induced seizures via activation of GABAB1 receptor in adult rats cortex and hippocampus.

    PubMed

    Ullah, Ikram; Badshah, Haroon; Naseer, Muhammad Imran; Lee, Hae Young; Kim, Myeong Ok

    2015-03-01

    Epilepsy is a common neurological disorder that leads to neuronal excitability and provoke various forms of cellular reorganization in the brain. In this study, we investigate the anti-convulsant and neuroprotective effects of thymoquinone (TQ) and vitamin C against pentylenetetrazole (PTZ)-induced generalized seizures. Epileptic seizures were induced in adult rats using systemic intraperitoneal injections of PTZ (50 mg/kg) for 7 days. Animals pretreated with either TQ or vitamin C or in combination attenuated PTZ-induced seizures and mortality in rats as well neurodegeneration in the cells. Compared to PTZ, TQ and vitamin C significantly prolonged the onset of seizures (p > 0.05) as well decrease the high-grade seizures. Analysis of electroencephalogram (EEG) recordings revealed that TQ or vitamin C supplementation significantly reduced polyspike and epileptiform discharges. Epileptic seizures caused a decline in expression of gamma-aminobutyric acid B1 receptor (GABAB1R) (p > 0.05), unchanged expression of protein kinase A (PKA), decreased calcium/calmodulin-dependent protein kinase II (CaMKII) (p > 0.05) and inhibit the phosphorylation of cAMP response element-binding protein (CREB) (p > 0.05) in cortex and hippocampus, respectively, compared with control. Changes in expression of GABAB1R, CaMKII and CREB by PTZ were reversed by TQ and vitamin C supplementation. Moreover, PTZ significantly increased Bax, decreased Bcl-2 expression and finally the activation of caspase-3. TQ and vitamin C pretreatment reversed all these deleterious effects induced by PTZ. TQ and vitamin C showed anticonvulsant effects via activation of GABAB1R/CaMKII/CREB pathway and suggest a potential therapeutic role in epilepsy. PMID:25429759

  13. ADX71441, a novel, potent and selective positive allosteric modulator of the GABAB receptor, shows efficacy in rodent models of overactive bladder

    PubMed Central

    Kalinichev, M; Palea, S; Haddouk, H; Royer-Urios, I; Guilloteau, V; Lluel, P; Schneider, M; Saporito, M; Poli, S

    2014-01-01

    Background and Purpose The GABAB receptor agonist baclofen reduces urethral resistance and detrusor overactivity in patients with spasticity. However, baclofen's side effects limit its use for the treatment of overactive bladder (OAB). Here, we tested a novel GABAB positive allosteric modulator (PAM) ADX71441 in models of OAB in mice and guinea pigs. Experimental Approach Mice were left untreated or given (p.o.) vehicle (1= CMC), ADX71441 (1, 3, 10 mg kg−1) or oxybutynin (100 mg kg−1; Experiment 1) or vehicle (1= CMC), baclofen (1, 3, 6 mg kg−1) or oxybutynin (Experiment 2). Treated mice were then overhydrated with water, challenged with furosemide, before being placed into micturition chambers and monitored for urinary parameters. In anaesthetized guinea pigs, intravesical infusion of acetic acid was used to induce OAB and the effects of ADX71441 (1, 3 mg kg−1) or baclofen (1 mg kg−1), administered i.v., on cystometric parameters were monitored. Key Results In mice, 10 mg kg−1 ADX71441 increased urinary latencies, reduced the number of urinary events and the total and average urinary volumes. In guinea pigs, ADX71441 (1 and 3 mg kg−1) increased the intercontraction interval (ICI) and bladder capacity (BC), and reduced micturition frequency (MF) compared to vehicle. At 3 mg kg−1 ADX71441 completely inhibited the micturition reflex and induced overflow incontinence in five out of 10 animals. Baclofen slightly increased ICI and BC and reduced MF. Conclusion and Implications Our findings demonstrate, for the first time, that a GABAB PAM has potential as a novel approach for the treatment of OAB. PMID:24224799

  14. Cloning and characterization of GABAA α subunits and GABAB subunits in Xenopus laevis during development

    PubMed Central

    Kaeser, Gwendolyn E.; Rabe, Brian A.; Saha, Margaret S.

    2011-01-01

    Gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the adult nervous system, acts via two classes of receptors, the ionotropic GABAA and metabotropic GABAB receptors. During the development of the nervous system GABA acts in a depolarizing, excitatory manner and plays an important role in various neural developmental processes including cell proliferation, migration, synapse formation and activity-dependent differentiation. Here we describe the spatial and temporal expression patterns of the GABAA and GABAB receptors during early development of Xenopus laevis. Using in situ hybridization and qRT-PCR, GABAA α2 was detected as a maternal mRNA. All other α-subunits were first detected by tailbud through hatching stages. Expression of the various subunits was seen in the brain, spinal cord, cranial ganglia, olfactory epithelium, pineal, and pituitary gland. Each receptor subunit showed a distinctive, unique expression pattern suggesting these receptors have specific functions and are regulated in a precise spatial and temporal manner. PMID:21384470

  15. The GABAB receptor antagonist CGP 36,742 and the nootropic oxiracetam facilitate the formation of long-term memory.

    PubMed

    Mondadori, C; Möbius, H J; Borkowski, J

    1996-05-01

    The memory-enhancing effects of a single treatment with the GABAB antagonist CGP 36,742 (10 mg/kg) or the nootropic agent oxiracetam (100 mg/kg) given immediately after a learning experience ('post-trial') remain detectable for at least 4 months thereafter. This indicates that in all probability these substances facilitate the formation of the long-term memory trace. PMID:8762175

  16. A novel GABAergic action mediated by functional coupling between GABAB-like receptor and two different high-conductance K+ channels in cricket Kenyon cells.

    PubMed

    Nakamura, Atsunao; Yoshino, Masami

    2013-04-01

    The γ-aminobutyric acid type B (GABA(B)) receptor has been shown to attenuate high-voltage-activated Ca(2+) currents and enhance voltage-dependent or inwardly rectifying K(+) currents in a variety of neurons. In this study, we report a novel coupling of GABA(B)-like receptor with two different high-conductance K(+) channels, Na(+)-activated K(+) (K(Na)) channel and Ca(2+)-activated K(+) (K(Ca)) channel, in Kenyon cells isolated from the mushroom body of the cricket brain. Single-channel activities of K(Na) and K(Ca) channels in response to bath applications of GABA and the GABA(B)-specific agonist SKF97541 were recorded with the cell-attached patch configuration. The open probability (P(o)) of both K(Na) and K(Ca) channels was found to be increased by bath application of GABA, and this increase in Po was antagonized by coapplication of the GABAB antagonist CGP54626, suggesting that GABA(B)-like receptors mediate these actions. Similarly, GABA(B)-specific agonist SKF97541 increased the Po of both K(Na) and K(Ca) channels. Perforated-patch recordings using β-escin further revealed that SKF97541 increased the amplitude of the outward currents elicited by step depolarizations. Under current-clamp conditions, SKF97541 decreased the firing frequency of spontaneous action potential (AP) and changed the AP waveform. The amplitude and duration of AP were decreased, whereas the afterhyperpolarization of AP was increased. Resting membrane potential, however, was not significantly altered by SKF97541. Taken together, these results suggest that GABA(B)-like receptor is functionally coupled with both K(Na) and K(Ca) channels and this coupling mechanism may serve to prevent AP formation and limit excitatory synaptic input. PMID:23303861

  17. Involvement of PKC and PKA in the enhancement of L-type calcium current by GABAB receptor activation in neonatal hippocampus

    PubMed Central

    Bray, Jennifer G.; Mynlieff, Michelle

    2011-01-01

    In the early neonatal period activation of GABAB receptors attenuates calcium current through N-type calcium channels while enhancing current through L-type calcium channels in rat hippocampal neurons. The attenuation of N-type calcium current has been previously demonstrated to occur through direct interactions of the βγ subunits of Gi/o G-proteins, but the signal transduction pathway for the enhancement of L-type calcium channels in mammalian neurons remains unknown. In the present study, calcium currents were elicited in acute cultures from postnatal day 6–8 rat hippocampi in the presence of various modulators of protein kinase A (PKA) and protein kinase C (PKC) pathways. Overnight treatment with an inhibitor of Gi/o (pertussis toxin, 200 ng/ml) abolished the attenuation of calcium current by the GABAB agonist, baclofen (10 μM) with no effect on the enhancement of calcium current. These data indicate that while the attenuation of N-type calcium current is mediated by the Gi/o subtype of G-protein, the enhancement of L-type calcium current requires activation of a different G-protein. The enhancement of the sustained component of calcium current by baclofen was blocked by PKC inhibitors, GF-109203X (500 nM), chelerythrine chloride (5 μM), and PKC fragment 19–36 (2 μM) and mimicked by the PKC activator phorbol-12-myristate-13-acetate (1 μM). The enhancement of the sustained component of calcium current was blocked by PKA inhibitors H-89 (1 μM) and PKA fragment 6–22 (500 nM) but not Rp-cAMPS (30 μM) and it was not mimicked by the PKA activator, 8-Br-cAMP (500 μM – 1 mM). The data suggest that activation of PKC alone is sufficient to enhance L-type calcium current but that PKA may also be involved in the GABAB receptor mediated effect. PMID:21277353

  18. General, kappa, delta and mu opioid receptor antagonists mediate feeding elicited by the GABA-B agonist baclofen in the ventral tegmental area and nucleus accumbens shell in rats: reciprocal and regional interactions.

    PubMed

    Miner, Patricia; Shimonova, Lyudmila; Khaimov, Arthur; Borukhova, Yaffa; Ilyayeva, Ester; Ranaldi, Robert; Bodnar, Richard J

    2012-03-14

    Food intake is significantly increased following administration of agonists of GABA and opioid receptors into the nucleus accumbens shell (NACs) and ventral tegmental area (VTA). GABA-A or GABA-B receptor antagonist pretreatment within the VTA or NACs differentially affects mu-opioid agonist-induced feeding elicited from the same site. Correspondingly, general or selective opioid receptor antagonist pretreatment within the VTA or NACs differentially affects GABA agonist-induced feeding elicited from the same site. Regional interactions have been evaluated in feeding studies by administering antagonists in one site prior to agonist administration in a second site. Thus, opioid antagonist-opioid agonist and GABA antagonist-GABA agonist feeding interactions have been identified between the VTA and NACs. However, pretreatment with GABA-A or GABA-B receptor antagonists in the VTA failed to affect mu opioid agonist-induced feeding elicited from the NACs, and correspondingly, these antagonists administered in the NACs failed to affect mu opioid-induced feeding elicited from the VTA. To evaluate whether regional and reciprocal VTA and NACs feeding interactions occur for opioid receptor modulation of GABA agonist-mediated feeding, the present study examined whether feeding elicited by the GABA-B agonist, baclofen microinjected into the NACs was dose-dependently blocked by pretreatment with general (naltrexone: NTX), mu (beta-funaltrexamine: BFNA), kappa (nor-binaltorphamine: NBNI) or delta (naltrindole: NTI) opioid antagonists in the VTA, and correspondingly, whether VTA baclofen-induced feeding was dose-dependently blocked by NACs pretreatment with NTX, BFNA, NBNI or NTI in rats. Bilateral pairs of cannulae aimed at the VTA and NACs were stereotaxically implanted in rats, and their food intakes were assessed following vehicle and baclofen (200 ng) in each site. Baclofen produced similar magnitudes of increased food intake following VTA and NACs treatment. Baclofen

  19. GABAB receptor-mediated tonic inhibition regulates the spontaneous firing of locus coeruleus neurons in developing rats and in citalopram-treated rats

    PubMed Central

    Wang, Han-Ying; Kuo, Zhao-Chen; Fu, Yu-Show; Chen, Ruei-Feng; Min, Ming-Yuan; Yang, Hsiu-Wen

    2015-01-01

    Noradrenaline (NA)-releasing neurons in the locus coeruleus (LC) provide NA to the forebrain. Their activity is believed to be a key factor regulating the wakefulness/arousal level of the brain. In this study, we found that the activity of NA-releasing neurons in the LC (LC neurons) was subject to γ-aminobutyric acid (GABA) tonic inhibition through GABAB receptors (GABABRs), but not GABAA receptors. The intensity of GABABR tonic inhibition was found to depend on ambient GABA levels, as it was dramatically increased by blockade of GABA reuptake. It also varied with the function of GABABRs. The GABABR activity on LC neurons was found to increase with postnatal age up to postnatal days 8–10, resulting in increased tonic inhibition. Interestingly, there was no significant difference in the spontaneous activity of LC neurons at different postnatal ages unless GABABR tonic inhibition was blocked. These results show that, during postnatal development, there is a continuous increase in GABABR tonic inhibition that maintains the activity of LC neurons at a proper level. In male, but not female, rats, chronic perinatal treatment with citalopram, a selective serotonin reuptake inhibitor, reduced GABABR activity and tonic inhibition, which might result in the significantly higher spontaneous activity of LC neurons seen in these animals. In conclusion, our results show that GABABR-mediated tonic inhibition has a direct impact on the spontaneous activity of LC neurons and that the extent of the effect varies with ambient GABA levels and functionality of GABABR signalling. PMID:25556794

  20. [The influence of the GABA-B receptor antagonists 2-hydoxysaclofen and faclofen on the sedative effect of fenibut and baclofen].

    PubMed

    Lapin, I P

    1995-01-01

    Pretreatment of NIH-Swiss mice with HYS (8 mg/kg) is shown to reduce the inhibiting effect (namely, the reduction of the locomotion rate and the number of horizontal movements) of PHE (80 mg/kg) and do not affect the action of an equipotent dose (4 mg/kg) of BAC. BAC induced shortening of the locomotion period is reduced by HYS. HYS appeared to be inactive with respect to inhibiting effect of PHE. PHE and BAC shortening of the distance covered was insensitive to HYS administration. HYS reduces decrease in the rate and duration of rearings induced by PHE. PHA (8 mg/kg) do not change the sedative effect of PHE and BAC on locomotion, attenuated the PHE-induced inhibition of rearings and increase the effect of BAC. It is suggested that GABA-B receptors affect the inhibitory action of PHE rather strong than that of BAC and differ in the inhibition of horizontal and vertical components of the locomotor activity of mice. PMID:8704585

  1. G(o) transduces GABAB-receptor modulation of N-type calcium channels in cultured dorsal root ganglion neurons.

    PubMed

    Menon-Johansson, A S; Berrow, N; Dolphin, A C

    1993-11-01

    High-voltage-activated (HVA) calcium channel currents (IBa) were recorded from acutely replated cultured dorsal root ganglion (DRG) neurons. IBa was irreversibly inhibited by 56.9 +/- 2.7% by 1 microM omega-conotoxin-GVIA (omega-CTx-GVIA), whereas the 1,4-dihydropyridine antagonist nicardipine was ineffective. The selective gamma-aminobutyric acidB (GABAB) agonist, (-)-baclofen (50 microM), inhibited the HVA IBa by 30.7 +/- 5.4%. Prior application of omega-CTx-GVIA completely occluded inhibition of the HVA IBa by (-)-baclofen, indicating that in this preparation (-)-baclofen inhibits N-type current. To investigate which G protein subtype was involved, cells were replated in the presence of anti-G protein antisera. Under these conditions the antibodies were shown to enter the cells through transient pores created during the replating procedure. Replating DRGs in the presence of anti-G(o) antiserum, raised against the C-terminal decapeptide of the G alpha o subunit, reduced (-)-baclofen inhibition of the HVA IBa, whereas replating DRGs in the presence of the anti-Gi antiserum did not. Using anti-G alpha o antisera (1:2000) and confocal laser microscopy, G alpha o localisation was investigated in both unreplated and replated neurons. G alpha o immunoreactivity was observed at the plasma membrane, neurites, attachment plaques and perinuclear region, and was particularly pronounced at points of cell-to-cell contact. The plasma membrane G alpha o immunoreactivity was completely blocked by preincubation with the immunising G alpha o undecapeptide (1 microgram.ml-1) for 1 h at 37 degrees C. A similar treatment also blocked recognition of G alpha o in brain membranes on immunoblots.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8309795

  2. Noise-induced hearing loss is correlated with alterations in the expression of GABAB receptors and PKC gamma in the murine cochlear nucleus complex

    PubMed Central

    Kou, Zhen-Zhen; Qu, Juan; Zhang, Dong-Liang; Li, Hui; Li, Yun-Qing

    2013-01-01

    Noise overexposure may induce permanent noise-induced hearing loss (NIHL). The cochlear nucleus complex (CNC) is the entry point for sensory information in the central auditory system. Impairments in gamma-aminobutyric acid (GABA)—mediated synaptic transmission in the CNC have been implicated in the pathogenesis of auditory disorders. However, the role of protein kinase C (PKC) signaling pathway in GABAergic inhibition in the CNC in NIHL remains elusive. Thus, we investigated the alterations of glutamic acid decarboxylase 67 (GAD67, the chemical marker for GABA-containing neurons), PKC γ subunit (PKCγ) and GABAB receptor (GABABR) expression in the CNC using transgenic GAD67-green fluorescent protein (GFP) knock-in mice, BALB/c mice and C57 mice. Immunohistochemical results indicate that the GFP-labeled GABAergic neurons were distributed in the molecular layer (ML) and fusiform cell layer (FCL) of the dorsal cochlear nucleus (DCN). We found that 69.91% of the GFP-positive neurons in the DCN were immunopositive for both PKCγ and GABABR1. The GAD67-positive terminals made contacts with PKCγ/GABABR1 colocalized neurons. Then we measured the changes of auditory thresholds in mice after noise exposure for 2 weeks, and detected the GAD67, PKCγ, and GABABR expression at mRNA and protein levels in the CNC. With noise over-exposure, there was a reduction in GABABR accompanied by an increase in PKCγ expression, but no significant change in GAD67 expression. In summary, our results demonstrate that alterations in the expression of PKCγ and GABABRs may be involved in impairments in GABAergic inhibition within the CNC and the development of NIHL. PMID:23908607

  3. GABAB Encephalitis: A Fifty-Two-Year-Old Man with Seizures, Dysautonomia, and Acute Heart Failure

    PubMed Central

    Loftspring, Matthew C.; Landsness, Eric; Wooliscroft, Lindsey; Rudock, Robert; Jo, Sally; Patel, Kevin R.

    2015-01-01

    Autoantibodies to the γ-aminobutyric acid receptor, subtype B (GABAB), are a known cause of limbic encephalitis. The spectrum of clinical manifestations attributable to this antibody is not well defined at the present time. Here we present a case of GABAB encephalitis presenting with encephalopathy, status epilepticus, dysautonomia, and acute heart failure. To our knowledge, heart failure and dysautonomia have not yet been reported with this syndrome. PMID:26609456

  4. Structure-Activity Studies of Cysteine-Rich α-Conotoxins that Inhibit High-Voltage-Activated Calcium Channels via GABA(B) Receptor Activation Reveal a Minimal Functional Motif.

    PubMed

    Carstens, Bodil B; Berecki, Géza; Daniel, James T; Lee, Han Siean; Jackson, Kathryn A V; Tae, Han-Shen; Sadeghi, Mahsa; Castro, Joel; O'Donnell, Tracy; Deiteren, Annemie; Brierley, Stuart M; Craik, David J; Adams, David J; Clark, Richard J

    2016-04-01

    α-Conotoxins are disulfide-rich peptides that target nicotinic acetylcholine receptors. Recently we identified several α-conotoxins that also modulate voltage-gated calcium channels by acting as G protein-coupled GABA(B) receptor (GABA(B)R) agonists. These α-conotoxins are promising drug leads for the treatment of chronic pain. To elucidate the diversity of α-conotoxins that act through this mechanism, we synthesized and characterized a set of peptides with homology to α-conotoxins known to inhibit high voltage-activated calcium channels via GABA(B)R activation. Remarkably, all disulfide isomers of the active α-conotoxins Pu1.2 and Pn1.2, and the previously studied Vc1.1 showed similar levels of biological activity. Structure determination by NMR spectroscopy helped us identify a simplified biologically active eight residue peptide motif containing a single disulfide bond that is an excellent lead molecule for developing a new generation of analgesic peptide drugs. PMID:26948522

  5. Upregulation of genes related to bone formation by γ-amino butyric acid and γ-oryzanol in germinated brown rice is via the activation of GABAB-receptors and reduction of serum IL-6 in rats

    PubMed Central

    Muhammad, Sani Ismaila; Maznah, Ismail; Mahmud, Rozi; Zuki, Abu Bakar Zakaria; Imam, Mustapha Umar

    2013-01-01

    -treated groups. Conclusion GABA and ORZ from GBR stimulates osteoblastogenesis by upregulation of bone formation genes, possibly via the activation of GABAB receptors and by inhibiting the activity of inflammatory cytokines and reactive oxygen species. Therefore, it could be used effectively in the management of osteoporosis. PMID:24098073

  6. L-baclofen-sensitive GABAB binding sites in the medial vestibular nucleus localized by immunocytochemistry

    NASA Technical Reports Server (NTRS)

    Holstein, G. R.; Martinelli, G. P.; Cohen, B.

    1992-01-01

    L-Baclofen-sensitive GABAB binding sites in the medial vestibular nucleus (MVN) were identified immunocytochemically and visualized ultrastructurally in L-baclofen-preinjected rats and monkeys, using a mouse monoclonal antibody with specificity for the p-chlorophenyl moiety of baclofen. Saline-preinjected animals showed no immunostain. In drug-injected animals, there was evidence for both pre- and postsynaptic GABAergic inhibition in MVN mediated by GABAB receptors. These neural elements could be utilized in control of velocity storage in the vestibulo-ocular reflex.

  7. Play.

    ERIC Educational Resources Information Center

    Rogers, Fred; Sharapan, Hedda

    1993-01-01

    Contends that, in childhood, work and play seem to come together. Says that for young children their play is their work, and the more adults encourage children to play, the more they emphasize important lifelong resource. Examines some uses of children's play, making and building, artwork, dramatic play, monsters and superheroes, gun play, and…

  8. gamma-Hydroxybutyrate conversion into GABA induces displacement of GABAB binding that is blocked by valproate and ethosuximide.

    PubMed

    Hechler, V; Ratomponirina, C; Maitre, M

    1997-05-01

    gamma-Hydroxybutyrate (GHB) has been reported to be a ligand for GABAB receptor(s), although with low or very low affinity (IC50 = 150-796 microM). In addition, several reports argue for a role of GHB via GABAB receptors in both in vivo and in vitro electro-physiological experiments. In the present study, we demonstrate that the inhibition of GHB's conversion into GABA by rat brain membranes blocks the ability of GHB to interfere with GABAB binding. In particular, the inhibition of GHB dehydrogenase by valproate or ethosuximide and the blockade of GABA-T by aminooxyacetic acid induce the disappearance of the GABA-like effect of GHB at GABAB, but also at GABAA, receptors. This finding could explain the misinterpretation of in vitro or in vivo experiments where GHB possesses a GABA-like effect. But in addition, it is postulated that the normal metabolism of GHB in brain induces GABAB mechanisms that could be blocked by the administration of valproate or ethosuximide. PMID:9152382

  9. Rapid antidepressants stimulate the decoupling of GABAB receptors from GIRK/Kir3 channels through increased protein stability of 14-3-3η

    PubMed Central

    Workman, E R; Haddick, P C G; Bush, K; Dilly, G A; Niere, F; Zemelman, B V; Raab-Graham, K F

    2015-01-01

    A single injection of N-methyl-D-aspartate receptor (NMDAR) antagonists produces a rapid antidepressant response. Lasting changes in the synapse structure and composition underlie the effectiveness of these drugs. We recently discovered that rapid antidepressants cause a shift in the γ-aminobutyric acid receptor (GABABR) signaling pathway, such that GABABR activation shifts from opening inwardly rectifiying potassium channels (Kir/GIRK) to increasing resting dendritic calcium signal and mammalian Target of Rapamycin activity. However, little is known about the molecular and biochemical mechanisms that initiate this shift. Herein, we show that GABABR signaling to Kir3 (GIRK) channels decreases with NMDAR blockade. Blocking NMDAR signaling stabilizes the adaptor protein 14-3-3η, which decouples GABABR signaling from Kir3 and is required for the rapid antidepressant efficacy. Consistent with these results, we find that key proteins involved in GABABR signaling bidirectionally change in a depression model and with rapid antidepressants. In socially defeated rodents, a model for depression, GABABR and 14-3-3η levels decrease in the hippocampus. The NMDAR antagonists AP5 and Ro-25-6981, acting as rapid antidepressants, increase GABABR and 14-3-3η expression and decrease Kir3.2. Taken together, these data suggest that the shift in GABABR function requires a loss of GABABR-Kir3 channel activity mediated by 14-3-3η. Our findings support a central role for 14-3-3η in the efficacy of rapid antidepressants and define a critical molecular mechanism for activity-dependent alterations in GABABR signaling. PMID:25560757

  10. Electrophysiological study of SR 42641, a novel aminopyridazine derivative of GABA: antagonist properties and receptor selectivity of GABAA versus GABAB responses.

    PubMed Central

    Desarmenien, M.; Desaulles, E.; Feltz, P.; Hamann, M.

    1987-01-01

    A new arylamino-pyridazine gamma-aminobutyric acid (GABA) derivative, SR 42641, has been tested for its ability to antagonize the actions of GABA on mammalian sensory neurones. SR 42641 and bicuculline reversibly decreased GABAA-induced depolarizations and currents recorded intracellularly from dorsal root ganglion neurons (DRG). Dose-response curves were shifted to the right in a parallel fashion. KB values (determined under voltage clamp conditions) were respectively 0.12 +/- 0.05 and 0.38 +/- 0.08 microM. Similar values were obtained with current clamp recording conditions. The study of the GABA-induced Cl- current under voltage-clamp conditions did not show any voltage-dependency of the antagonist effect of SR 42641. In nodose ganglion neurones, SR 42641 (0.4-4.5 microM) did not alter the (-)-baclofen-induced shortening of the calcium component of action potentials. At concentrations higher than 10 microM, SR 42641 itself prolonged calcium-dependent action potentials. Patch-clamp recordings from DRG cultured neurones indicated that SR 42641 did not affect the calcium current responsible for sustained calcium entry into cells. We conclude that SR 42641 is a potent competitive GABA antagonist, specific for the GABAA receptor. It does not act at the level of the chloride ionophore. PMID:2435350

  11. Globus pallidus neurons dynamically regulate the activity pattern of subthalamic nucleus neurons through the frequency-dependent activation of postsynaptic GABAA and GABAB receptors.

    PubMed

    Hallworth, Nicholas E; Bevan, Mark D

    2005-07-01

    Reciprocally connected GABAergic neurons of the globus pallidus (GP) and glutamatergic neurons of the subthalamic nucleus (STN) are a putative generator of pathological rhythmic burst firing in Parkinson's disease (PD). Burst firing of STN neurons may be driven by rebound depolarization after barrages of GABA(A) receptor (GABA(A)R)-mediated IPSPs arising from pallidal fibers. To determine the conditions under which pallidosubthalamic transmission activates these and other postsynaptic GABARs, a parasagittal mouse brain slice preparation was developed in which pallidosubthalamic connections were preserved. Intact connectivity was first confirmed through the injection of a neuronal tracer into the GP. Voltage-clamp and gramicidin-based perforated-patch current-clamp recordings were then used to study the relative influences of GABA(A)R- and GABA(B)R-mediated pallidosubthalamic transmission on STN neurons. Spontaneous phasic, but not tonic, activation of postsynaptic GABA(A)Rs reduced the frequency and disrupted the rhythmicity of autonomous firing in STN neurons. However, postsynaptic GABA(B)Rs were only sufficiently activated to impact STN firing when pallidosubthalamic transmission was elevated or pallidal fibers were synchronously activated by electrical stimulation. In a subset of neurons, rebound burst depolarizations followed high-frequency, synchronous stimulation of pallidosubthalamic fibers. Although GABA(B)R-mediated hyperpolarization was itself sufficient to generate rebound bursts, coincident activation of postsynaptic GABA(A)Rs produced longer and more intense burst firing. These findings elucidate a novel route through which burst activity can be generated in the STN, and suggest that GABARs on STN neurons could act in a synergistic manner to generate abnormal burst activity in PD. PMID:16000620

  12. GABAB agonism promotes sleep and reduces cataplexy in murine narcolepsy.

    PubMed

    Black, Sarah Wurts; Morairty, Stephen R; Chen, Tsui-Ming; Leung, Andrew K; Wisor, Jonathan P; Yamanaka, Akihiro; Kilduff, Thomas S

    2014-05-01

    γ-Hydroxybutyrate (GHB) is an approved therapeutic for the excessive sleepiness and sudden loss of muscle tone (cataplexy) characteristic of narcolepsy. The mechanism of action for these therapeutic effects is hypothesized to be GABAB receptor dependent. We evaluated the effects of chronic administration of GHB and the GABAB agonist R-baclofen (R-BAC) on arousal state and cataplexy in two models of narcolepsy: orexin/ataxin-3 (Atax) and orexin/tTA; TetO diphtheria toxin mice (DTA). Mice were implanted for EEG/EMG monitoring and dosed with GHB (150 mg/kg), R-BAC (2.8 mg/kg), or vehicle (VEH) bid for 15 d-a treatment paradigm designed to model the twice nightly GHB dosing regimen used by human narcoleptics. In both models, R-BAC increased NREM sleep time, intensity, and consolidation during the light period; wake bout duration increased and cataplexy decreased during the subsequent dark period. GHB did not increase NREM sleep consolidation or duration, although NREM delta power increased in the first hour after dosing. Cataplexy decreased from baseline in 57 and 86% of mice after GHB and R-BAC, respectively, whereas cataplexy increased in 79% of the mice after VEH. At the doses tested, R-BAC suppressed cataplexy to a greater extent than GHB. These results suggest utility of R-BAC-based therapeutics for narcolepsy. PMID:24806675

  13. GABAB Agonism Promotes Sleep and Reduces Cataplexy in Murine Narcolepsy

    PubMed Central

    Black, Sarah Wurts; Morairty, Stephen R.; Chen, Tsui-Ming; Leung, Andrew K.; Wisor, Jonathan P.

    2014-01-01

    γ-Hydroxybutyrate (GHB) is an approved therapeutic for the excessive sleepiness and sudden loss of muscle tone (cataplexy) characteristic of narcolepsy. The mechanism of action for these therapeutic effects is hypothesized to be GABAB receptor dependent. We evaluated the effects of chronic administration of GHB and the GABAB agonist R-baclofen (R-BAC) on arousal state and cataplexy in two models of narcolepsy: orexin/ataxin-3 (Atax) and orexin/tTA; TetO diphtheria toxin mice (DTA). Mice were implanted for EEG/EMG monitoring and dosed with GHB (150 mg/kg), R-BAC (2.8 mg/kg), or vehicle (VEH) bid for 15 d–a treatment paradigm designed to model the twice nightly GHB dosing regimen used by human narcoleptics. In both models, R-BAC increased NREM sleep time, intensity, and consolidation during the light period; wake bout duration increased and cataplexy decreased during the subsequent dark period. GHB did not increase NREM sleep consolidation or duration, although NREM delta power increased in the first hour after dosing. Cataplexy decreased from baseline in 57 and 86% of mice after GHB and R-BAC, respectively, whereas cataplexy increased in 79% of the mice after VEH. At the doses tested, R-BAC suppressed cataplexy to a greater extent than GHB. These results suggest utility of R-BAC-based therapeutics for narcolepsy. PMID:24806675

  14. Play

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    Designing a game with a serious purpose involves considering the worlds of Reality and Meaning yet it is undeniably impossible to create a game without a third world, one that is specifically concerned with what makes a game a game: the play elements. This third world, the world of people like designers and artists, and disciplines as computer science and game design, I call the world of Play and this level is devoted to it. The level starts off with some of the misperceptions people have of play. Unlike some may think, we play all the time, even when we grow old—this was also very noticeable in designing the game Levee Patroller as the team exhibited very playful behavior at many occasions. From there, I go into the aspects that characterize this world. The first concerns the goal of the game. This relates to the objectives people have to achieve within the game. This is constituted by the second aspect: the gameplay. Taking actions and facing challenges is subsequently constituted by a gameworld, which concerns the third aspect. And all of it is not possible without the fourth and final aspect, the type of technology that creates and facilitates the game. The four aspects together make up a “game concept” and from this world such a concept can be judged on the basis of three closely interrelated criteria: engagement, immersion, and fun.

  15. Antitussive effects of GABAB agonists in the cat and guinea-pig.

    PubMed Central

    Bolser, D. C.; Aziz, S. M.; DeGennaro, F. C.; Kreutner, W.; Egan, R. W.; Siegel, M. I.; Chapman, R. W.

    1993-01-01

    1. GABAB agonists inhibit neuronal processes which are important in the pathogenesis of airway disease, such as bronchospasm. Cough is a prominent symptom of pulmonary disease, but the effects of GABAB agonists on this airway reflex are unknown. Experiments were conducted to determine the antitussive effect of GABAB receptor agonists in comparison to the known antitussive agents, codeine and dextromethorphan. 2. Unanaesthetized guinea-pigs were exposed to aerosols of 0.3 mM capsaicin to elicit coughing, which was detected with a microphone and counted. Cough also was produced in anaesthetized cats by mechanical stimulation of the intrathoracic trachea and was recorded from electromyograms of respiratory muscle activity. 3. In guinea-pigs, the GABAB agonists baclofen and 3-aminopropyl-phosphinic acid (3-APPi) produced dose-dependent inhibition of capsaicin-induced cough when administered by subcutaneous or inhaled routes. The potencies of baclofen and 3-APPi compared favourably with codeine and dextromethorphan. 4. The GABAB antagonist, CGP 35348 (0.3- 30 mg kg-1, s.c.) inhibited the antitussive effect of baclofen (3.0 mg kg-1, s.c.). However, CGP 35348 (10 mg kg-1, s.c.) had no effect on the antitussive activity of codeine (30 mg kg-1, s.c.). The antitussive effect of baclofen was not influenced by the GABAA antagonist, bicuculline (3 mg kg-1, s.c.) or naloxone (0.3 mg kg-1, s.c.). 5. In the cat, baclofen (0.3-3.0 mg kg-1, i.v.) decreased mechanically-induced cough in a dose-dependent manner. In this model, baclofen (ED50 = 0.63 mg kg-1) was less potent than either codeine or dextromethorphan.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8220912

  16. Contribution of NMDA, GABAA and GABAB receptors and l-arginine-NO-cGMP, MEK1/2 and CaMK-II pathways in the antidepressant-like effect of 7-fluoro-1,3-diphenylisoquinoline-1-amine in mice.

    PubMed

    Pesarico, Ana Paula; Stangherlin, Eluza Curte; Rosa, Suzan Gonçalves; Mantovani, Anderson C; Zeni, Gilson; Nogueira, Cristina Wayne

    2016-07-01

    It has been reported that the antidepressant-like effect of 7-fluoro-1,3-diphenylisoquinoline-1-amine (FDPI) may result from the modulation of brain monoaminergic systems. However, the mechanisms of FDPI action are not fully understood. The aim of this study was to investigate the contribution of N-methyl-d-aspartate (NMDA) and gamma-aminobutyric acid (GABA) systems as well as l-arginine-nitric oxide-(NO)-cyclic guanosine monophosphate-(cGMP), mitogen-activated protein/extracellular signal-regulated kinase (MEK1/2) and Ca(2+)/calmodulin-dependent protein kinase II (CaMK-II) signaling pathways in the antidepressant-like effect of FDPI in the mouse forced swimming test (FST). The levels of NO and uptake of [(3)H]glutamate and [(3)H]GABA were determined in prefrontal cortices of Swiss mice. Pretreatments with NMDA (0.1 pmol/site, i.c.v., a NMDA receptor agonist), bicuculline (1mg/kg, i.p., a GABAA receptor antagonist), phaclofen (2mg/kg, i.p., a GABAB receptor antagonist) and l-arginine (750mg/kg, i.p., a NO precursor), KN-62 (1μg/site, a CaMK-II inhibitor), U0126 (5μg/site, a MEK1/2 inhibitor) and PD09058 (5μg/site, a MEK1/2 inhibitor) blocked the antidepressant-like effect of FDPI, at a dose of 1mg/kg, in the FST. ODQ (30 pmol/site, i.c.v., a soluble guanylate cyclase (sGC) inhibitor) in combination with a sub-effective dose of FDPI (0.1mg/kg, i.g.) reduced the immobility time in the FST. The administration of FDPI (50mg/kg) to mice increased the glutamate uptake and reduced NO levels in the prefrontal cortex of mice. The results suggest a contribution of NMDA, GABAA and GABAB receptors and l-arginine-NO-cGMP pathway in the antidepressant-like action of FDPI in mice, and this effect is related to CaMK-II and MEK 1/2 activation. PMID:27112660

  17. Rescue of GABAB and GIRK function in the lateral habenula by protein phosphatase 2A inhibition ameliorates depression-like phenotypes in mice.

    PubMed

    Lecca, Salvatore; Pelosi, Assunta; Tchenio, Anna; Moutkine, Imane; Lujan, Rafael; Hervé, Denis; Mameli, Manuel

    2016-03-01

    The lateral habenula (LHb) encodes aversive signals, and its aberrant activity contributes to depression-like symptoms. However, a limited understanding of the cellular mechanisms underlying LHb hyperactivity has precluded the development of pharmacological strategies to ameliorate depression-like phenotypes. Here we report that an aversive experience in mice, such as foot-shock exposure (FsE), induces LHb neuronal hyperactivity and depression-like symptoms. This occurs along with increased protein phosphatase 2A (PP2A) activity, a known regulator of GABAB receptor (GABABR) and G protein-gated inwardly rectifying potassium (GIRK) channel surface expression. Accordingly, FsE triggers GABAB1 and GIRK2 internalization, leading to rapid and persistent weakening of GABAB-activated GIRK-mediated (GABAB-GIRK) currents. Pharmacological inhibition of PP2A restores both GABAB-GIRK function and neuronal excitability. As a consequence, PP2A inhibition ameliorates depression-like symptoms after FsE and in a learned-helplessness model of depression. Thus, GABAB-GIRK plasticity in the LHb represents a cellular substrate for aversive experience. Furthermore, its reversal by PP2A inhibition may provide a novel therapeutic approach to alleviate symptoms of depression in disorders that are characterized by LHb hyperactivity. PMID:26808347

  18. Nerve Regenerative Effects of GABA-B Ligands in a Model of Neuropathic Pain

    PubMed Central

    Cavalli, Erica; Pajardi, Giorgio

    2014-01-01

    Neuropathic pain arises as a direct consequence of a lesion or disease affecting the peripheral somatosensory system. It may be associated with allodynia and increased pain sensitivity. Few studies correlated neuropathic pain with nerve morphology and myelin proteins expression. Our aim was to test if neuropathic pain is related to nerve degeneration, speculating whether the modulation of peripheral GABA-B receptors may promote nerve regeneration and decrease neuropathic pain. We used the partial sciatic ligation- (PSL-) induced neuropathic model. The biochemical, morphological, and behavioural outcomes of sciatic nerve were analysed following GABA-B ligands treatments. Simultaneous 7-days coadministration of baclofen (10 mg/kg) and CGP56433 (3 mg/kg) alters tactile hypersensitivity. Concomitantly, specific changes of peripheral nerve morphology, nerve structure, and myelin proteins (P0 and PMP22) expression were observed. Nerve macrophage recruitment decreased and step coordination was improved. The PSL-induced changes in nociception correlate with altered nerve morphology and myelin protein expression. Peripheral synergic effects, via GABA-B receptor activation, promote nerve regeneration and likely ameliorate neuropathic pain. PMID:25165701

  19. Acute kidney injury: what part do toll-like receptors play?

    PubMed Central

    Vallés, Patricia G; Lorenzo, Andrea Gil; Bocanegra, Victoria; Vallés, Roberto

    2014-01-01

    The innate immune system plays an important role as a first response to tissue injury. This first response is carried out via germline-encoded receptors. Toll-like receptors (TLRs) are the first identified and best studied family of pattern recognition receptors. TLRs are expressed on a variety of cell types, including epithelial cells, endothelia, dendritic cells, monocytes/macrophages, and B- and T-cells. TLRs initiate innate immune responses and concurrently shape the subsequent adaptive immune response. They are sensors of both pathogens, through the exogenous pathogen-associated molecular patterns (PAMPs), and tissue injury, through the endogenous danger-associated molecular patterns (DAMPs). TLR signaling is critical in defending against invading microorganisms; however, sustained receptor activation is also implicated in the pathogenesis of inflammatory diseases. Ischemic kidney injury involves early TLR-driven immunopathology, and the resolution of inflammation is needed for rapid regeneration of injured tubule cells. Notably, the activation of TLRs also has been implicated in epithelial repair. This review focuses on the role of TLRs and their endogenous ligands within the inflammatory response of acute kidney injury. PMID:24971030

  20. GABAA receptors in the dorsal raphé nucleus of mice: escalation of aggression after alcohol consumption

    PubMed Central

    Takahashi, Aki; Kwa, Carolyn; DeBold, Joseph F.

    2010-01-01

    Rationale The dorsal raphé nucleus (DRN), the origin for serotonin (5-HT) in forebrain areas, has been implicated in the neural control of escalated aggression. Gamma aminobutyric acid type-A (GABAA) and type-B (GABAB) receptors are expressed in the DRN and modulate 5-HT neuronal activity, and both play a role in the behavioral effect of alcohol. Objective The purpose of this study is to examine the interaction between drugs acting on GABA receptors in the DRN and alcohol in their effects on aggressive behaviors. Method Male CFW mice, housed with a female, were trained to self-administer ethanol (1.0 g/kg) or water via an operant conditioning panel in their home cage. Immediately after they drank either ethanol or water, the animals were microinfused with a GABAergic drug into the DRN, and their aggressive behaviors were assessed 10 min later. Muscimol (0.006 nmol), a GABAA receptor agonist, escalated alcohol-heightened aggression but had no effect in the absence of ethanol. This effect of muscimol was prominent in the animals that showed alcohol-heightened aggression, but not the animals that reduced or did not change aggressive behavior after ethanol infusion compared to water. On the other hand, the GABAB agonist baclofen (0.06 nmol) increased aggressive behavior similarly in both water and ethanol conditions. Antagonists of the GABAA and GABAB receptors, bicuculline (0.006 nmol) and phaclofen (0.3 nmol) respectively, did not suppress heightened-aggressive behavior induced by ethanol self-administration. Conclusion GABAA receptors in the DRN are one of the neurobiological targets of alcohol-heightened aggression. Activation of the GABAB receptors in the DRN also produced escalated aggression, but that is independent of the effect of alcohol. PMID:20589493

  1. Arabidopsis abscisic acid receptors play an important role in disease resistance.

    PubMed

    Lim, Chae Woo; Lee, Sung Chul

    2015-06-01

    Stomata are natural pores of plants and constitute the entry points for water during transpiration. However, they also facilitate the ingress of potentially harmful bacterial pathogens. The phytohormone abscisic acid (ABA) plays a pivotal role in protecting plants against biotic stress, by regulating stomatal closure. In the present study, we investigated the mechanism whereby ABA influences plant defense responses to Pseudomonas syringae pv. tomato (Pst) DC3000, which is a virulent bacterial pathogen of Arabidopsis, at the pre-invasive stage. We found that overexpression of two ABA receptors, namely, RCAR4/PYL10-OX and RCAR5/PYL11-OX (hereafter referred to as RCARs), resulted in ABA-hypersensitive phenotypes being exhibited during the seed germination and seedling growth stages. Sensitivity to ABA enhanced the resistance of RCAR4-OX and RCAR5-OX plants to Pst DC3000, through promoting stomatal closure leading to the development of resistance to this bacterial pathogen. Protein phosphatase HAB1 is an important component that is responsible for ABA signaling and which interacts with ABA receptors. We found that hab1 mutants exhibited enhanced resistance to Pst DC3000; moreover, similar to RCAR4-OX and RCAR5-OX plants, this enhanced resistance was correlated with stomatal closure. Taken together, our findings demonstrate that alteration of RCAR4- or RCAR5-HAB1 mediated ABA signaling influences resistance to bacterial pathogens via stomatal regulation. PMID:25969135

  2. Toll-like receptor 4 plays a central role in cardiac dysfunction during trauma hemorrhage shock

    PubMed Central

    Zhang, Xia; Lu, Chen; Gao, Ming; Cao, Xinyun; Ha, Tuanzhu; Kalbfleisch, John H.; Williams, David L.; Li, Chuanfu; Kao, Race L.

    2014-01-01

    Cardiac dysfunction is a major consequence that contributes to the high mortality of trauma-hemorrhage (TH) patients. Recent evidence suggests that innate immune and inflammatory responses mediated by Toll-like receptors (TLRs) play a critical role in the pathophysiologic mechanisms of acute organ dysfunction during TH. This study investigated the role of TLR4 in cardiac dysfunction following TH. TLR4 deficient (TLR4−/−, n=7/group) and age-matched wild type (WT, n=8/group) mice were subjected to TH that was induced by soft tissue injury and blood withdrawal from the jugular vein to a mean arterial pressure of 35 ± 5 mm Hg. Cardiac function and mean arterial pressure were measured with a Millar system before, during and after blood withdrawal. Sham surgical operated mice served as control (WT, n=9/group; TLR4−/−, n=10/group). Cardiac function in WT mice was significantly reduced following TH. However cardiac function was well preserved in TLR4−/− mice. Administration of a TLR4 antagonist (3mg/kg) to WT mice also significantly attenuated TH-induced cardiac dysfunction. Western blot showed that either TLR4−/− or TLR4 antagonist markedly attenuated TH-induced decreases in the levels of phosphorylated-Akt in myocardium. In addition, inhibition of TLR4 attenuated TH-induced myocardial NF-κB binding activity as well as lung MPO activity and TNFα production. The data indicate that TLR4 plays a central role in TH-induced cardiac dysfunction. TLR4 deficiency or TLR4 inhibition attenuated cardiac dysfunction following TH which may involve activation of the PI3K/Akt signaling and decrease of NF-κB binding activity. TLR4 antagonism may be a new and novel approach for the treatment and management of cardiac dysfunction in TH patients. PMID:24569510

  3. GPR55, a G-protein coupled receptor for lysophosphatidylinositol, plays a role in motor coordination.

    PubMed

    Wu, Chia-Shan; Chen, Hongmei; Sun, Hao; Zhu, Jie; Jew, Chris P; Wager-Miller, James; Straiker, Alex; Spencer, Corinne; Bradshaw, Heather; Mackie, Ken; Lu, Hui-Chen

    2013-01-01

    The G-protein coupled receptor 55 (GPR55) is activated by lysophosphatidylinositols and some cannabinoids. Recent studies found prominent roles for GPR55 in neuropathic/inflammatory pain, cancer and bone physiology. However, little is known about the role of GPR55 in CNS development and function. To address this question, we performed a detailed characterization of GPR55 knockout mice using molecular, anatomical, electrophysiological, and behavioral assays. Quantitative PCR studies found that GPR55 mRNA was expressed (in order of decreasing abundance) in the striatum, hippocampus, forebrain, cortex, and cerebellum. GPR55 deficiency did not affect the concentrations of endocannabinoids and related lipids or mRNA levels for several components of the endocannabinoid system in the hippocampus. Normal synaptic transmission and short-term as well as long-term synaptic plasticity were found in GPR55 knockout CA1 pyramidal neurons. Deleting GPR55 function did not affect behavioral assays assessing muscle strength, gross motor skills, sensory-motor integration, motor learning, anxiety or depressive behaviors. In addition, GPR55 null mutant mice exhibited normal contextual and auditory-cue conditioned fear learning and memory in a Pavlovian conditioned fear test. In contrast, when presented with tasks requiring more challenging motor responses, GPR55 knockout mice showed impaired movement coordination. Taken together, these results suggest that GPR55 plays a role in motor coordination, but does not strongly regulate CNS development, gross motor movement or several types of learned behavior. PMID:23565223

  4. Unbalanced upregulation of ryanodine receptor 2 plays a particular role in early development of daunorubicin cardiomyopathy

    PubMed Central

    Kucerova, Dana; Doka, Gabriel; Kruzliak, Peter; Turcekova, Katarina; Kmecova, Jana; Brnoliakova, Zuzana; Kyselovic, Jan; Kirchhefer, Uwe; Müller, Frank U; Krenek, Peter; Boknik, Peter; Klimas, Jan

    2015-01-01

    Calcium release channel on the sarcoplasmic reticulum of cardiomyocytes (ryanodine receptor type 2, RyR2) plays a critical role in the regulation of calcium and was identified as a crucial factor for development of chronic anthracycline cardiomyopathy. Its early stages are less well described although these determine the later development. Hence, we tested the effect of repeated, short-term anthracycline (daunorubicin) administration on cardiac performance, cardiomyocyte function and accompanied changes in calcium regulating proteins expression. Ten-twelve weeks old male Wistar rats were administered with 6 doses of daunorubicin (DAU, 3 mg/kg, i.p., every 48 h), controls (CON) received vehicle. Left ventricular function (left ventricular pressure, LVP; rate of pressure development, +dP/dt and decline, -dP/dt) was measured using left ventricular catheterization under tribromethanol anaesthesia (15 ml/kg b.w.). Cell shortening was measured in enzymatically isolated cardiomyocytes. The expressions of RyR2 and associated intracellular calcium regulating proteins, cytoskeletal proteins (alpha-actinin, alpha-tubul in) as well as oxidative stress regulating enzymes (gp91phox, MnSOD) were detected in ventricular tissue samples using immunoblotting. mRNA expressions of cardiac damage markers (Nppa and Nppb, atrial and brain natriuretic peptides; Myh6, Myh7 and Myh7b, myosin heavy chain alpha and beta) were detected using RT-PCR. Thiobarbituric acid reactive substances concentration was measured to estimate oxidative stress. DAU rats exhibited significantly depressed left ventricular features (LVP by 14%, +dP/dt by 36% and -dP/dt by 30%; for all P<0.05), in line with concomitant increase in Nppa and Nppb gene expressions (3.23- and 2.18-fold, for both P<0.05), and a 4.34-fold increase in Myh7 (P<0.05). Controversially, we observed increased cell shortening of isolated cardiac cells by 31% (p<0.05). DAU administration was associated with a twofold upregulation of RyR2 (P<0

  5. Importance of the gamma-aminobutyric acid(B) receptor C-termini for G-protein coupling.

    PubMed

    Grünewald, Sylvia; Schupp, Bettina J; Ikeda, Stephen R; Kuner, Rohini; Steigerwald, Frank; Kornau, Hans-Christian; Köhr, Georg

    2002-05-01

    Functional gamma-aminobutyric acid(B) (GABA(B)) receptors assemble from two subunits, GABA(B(1)) and GABA(B(2).) This heteromerization, which involves a C-terminal coiled-coil interaction, ensures efficient surface trafficking and agonist-dependent G-protein activation. In the present study, we took a closer look at the implications of the intracellular C termini of GABA(B(1)) and GABA(B(2)) for G-protein coupling. We generated a series of C-terminal mutants of GABA(B(1)) and GABA(B(2)) and tested them for physical interaction, surface trafficking, coupling to adenylyl cyclase, and G-protein-gated inwardly rectifying potassium channels in human embryonic kidney (HEK) 293 cells as well as on endogenous calcium channels in sympathetic neurons of the superior cervical ganglion (SCG). We found that the C-terminal interaction contributes only partly to the heterodimeric assembly of the subunits, indicating the presence of an additional interaction site. The described endoplasmic reticulum retention signal within the C terminus of GABA(B(1)) functioned only in the context of specific amino acids, which constitute part of the GABA(B(1)) coiled-coil sequence. This finding may provide a link between the retention signal and its shielding by the coiled coil of GABA(B(2).) In HEK293 cells, we observed that the two well-known GABA(B) receptor antagonists [S-(R*,R*)]-[3-[[1-(3,4-dichlorophenyl)ethyl]amino]-2-hydroxypropyl](cyclohexylmethyl) phosphinic acid (CGP54626) and (+)-(2S)-5,5-dimethyl-2-morpholineacetic acid (SCH50911) CGP54626 and SCH50911 function as inverse agonists. The C termini of GABA(B(1)) and GABA(B(2)) strongly influenced agonist-independent G-protein coupling, although they were not necessary for agonist-dependent G-protein coupling. The C-terminal GABA(B) receptor mutants described here demonstrate that the active receptor conformation is stabilized by the coiled-coil interaction. Thus, the C-terminal conformation of the GABA(B) receptor may determine its

  6. Sodium salicylate potentiates the GABAB-GIRK pathway to suppress rebound depolarization in neurons of the rat's medial geniculate body.

    PubMed

    Wang, Xin-Xing; Jin, Yan; Luo, Bin; Sun, Jing-Wu; Zhang, Jinsheng; Wang, Ming; Chen, Lin

    2016-02-01

    Rebound depolarization (RD) is a voltage response to the offset from pre-hyperpolarization of neuronal membrane potential, which manifests a particular form of the postsynaptic membrane potential response to inhibitory presynaptic inputs. We previously demonstrated that sodium salicylate (NaSal), a tinnitus inducer, can drastically suppress the RD in neurons of rat medial geniculate body (MGB) (Su et al, 2012; PLoS ONE 7, e46969). The purpose of the present study was to investigate the underlying cellular mechanism by using whole-cell patch-clamp recordings in rat MGB slices. NaSal (1.4 mM) had no effects on the current mediated by T-type Ca(2+) channels, indicating that it does not target these channels to suppress the RD. Instead, NaSal was shown to hyperpolarize the resting membrane potential to suppress the RD. NaSal had no effects on the current mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, indicating that it does not target these channels to hyperpolarize the resting membrane potential. NaSal induced an outward leak current that could be abolished by CGP55845, a GABAB receptor blocker, or respectively by Ba(2+) and Tertiapin-Q, blockers for G-protein-gated inwardly rectifying potassium (GIRK) channels, indicating that NaSal potentiates the GABAB-GIRK pathway to hyperpolarize the resting membrane potential. Our study demonstrates that NaSal targets GABAB receptors to alter functional behaviors of MGB neurons, which may be implicated in NaSal-induced tinnitus. PMID:26688177

  7. The amide linker in nonpeptide neurotensin receptor ligands plays a key role in calcium signaling at the neurotensin receptor type 2.

    PubMed

    Thomas, James B; Giddings, Angela M; Olepu, Srinivas; Wiethe, Robert W; Warner, Keith R; Sarret, Philippe; Longpre, Jean-Michel; Runyon, Scott P; Gilmour, Brian P

    2015-01-01

    Compounds acting via the GPCR neurotensin receptor type 2 (NTS2) display analgesia in relevant preclinical models. The amide bond in nonpeptide NTS1 antagonists plays a central role in receptor recognition and molecular conformation. Using NTS2 FLIPR and binding assays, we found that it is also a key molecular structure for binding and calcium mobilization at NTS2. We found that reversed amides display a shift from agonist to antagonist activity and provided examples of the first competitive nonpeptide antagonists observed in the NTS2 FLIPR assay. These compounds will be valuable tools for determining the role of calcium signaling in vitro to NTS2 mediated analgesia. PMID:25881832

  8. Integrin Receptors Play a Key Role in the Regulation of Hepatic CYP3A.

    PubMed

    Jonsson-Schmunk, Kristina; Wonganan, Piynauch; Choi, Jin Huk; Callahan, Shellie M; Croyle, Maria A

    2016-05-01

    Landmark studies describing the effect of microbial infection on the expression and activity of hepatic CYP3A used bacterial lipopolysaccharide as a model antigen. Our efforts to determine whether these findings were translatable to viral infections led us to observations suggesting that engagement of integrin receptors is key in the initiation of processes responsible for changes in hepatic CYP3A4 during infection and inflammation. Studies outlined in this article were designed to evaluate whether engagement of integrins, receptors commonly used by a variety of microbes to enter cellular targets, is vital in the regulation of CYP3A in the presence and absence of virus infection. Mice infected with a recombinant adenovirus (AdlacZ) experienced a 70% reduction in hepatic CYP3A catalytic activity. Infection with a mutant virus with integrin-binding arginine-glycine-aspartic acid (RGD) sequences deleted from the penton base protein of the virus capsid (AdΔRGD) did not alter CYP3A activity. CYP3A mRNA and protein levels in AdlacZ-treated animals were also suppressed, whereas those of mice given AdΔRGD were not significantly different from uninfected control mice. Silencing of the integrinβ-subunit reverted adenovirus-mediated CYP3A4 suppression in vitro. Silencing of theα-subunit did not. Suppression of integrin subunits had a profound effect on nuclear receptors pregnane X receptor and constitutive androstane receptor, whereas retinoid X receptorαwas largely unaffected. To our knowledge, this is the first time that extracellular receptors, like integrins, have been indicated in the regulation of CYP3A. This finding has several implications owing to the important role of integrins in normal physiologic process and in many disease states. PMID:26868618

  9. Chemokines and their receptors play important roles in the development of hepatocellular carcinoma

    PubMed Central

    Liang, Chun-Min; Chen, Long; Hu, Heng; Ma, Hui-Ying; Gao, Ling-Ling; Qin, Jie; Zhong, Cui-Ping

    2015-01-01

    The chemokine system consists of four different subclasses with over 50 chemokines and 19 receptors. Their functions in the immune system have been well elucidated and research during the last decades unveils their new roles in hepatocellular carcinoma (HCC). The chemokines and their receptors in the microenvironment influence the development of HCC by several aspects including: inflammation, effects on immune cells, angiogenesis, and direct effects on HCC cells. Regarding these aspects, pre-clinical research by targeting the chemokine system has yielded promising data, and these findings bring us new clues in the chemokine-based therapies for HCC. PMID:26052384

  10. Marlin-1, a novel RNA-binding protein associates with GABA receptors.

    PubMed

    Couve, Andrés; Restituito, Sophie; Brandon, Julia M; Charles, Kelly J; Bawagan, Hinayana; Freeman, Katie B; Pangalos, Menelas N; Calver, Andrew R; Moss, Stephen J

    2004-04-01

    GABA(B) receptors are heterodimeric G protein-coupled receptors that mediate slow synaptic inhibition in the central nervous system. Whereas heterodimerization between GABA(B) receptor GABA(B)R1 and GABA(B)R2 subunits is essential for functional expression, how neurons coordinate the assembly of these critical receptors remains to be established. Here we have identified Marlin-1, a novel GABA(B) receptor-binding protein that associates specifically with the GABA(B)R1 subunit in yeast, tissue culture cells, and neurons. Marlin-1 is expressed in the brain and exhibits a granular distribution in cultured hippocampal neurons. Marlin-1 binds different RNA species including the 3'-untranslated regions of both the GABA(B)R1 and GABA(B)R2 mRNAs in vitro and also associates with RNA in cultured neurons. Inhibition of Marlin-1 expression via small RNA interference technology results in enhanced intracellular levels of the GABA(B)R2 receptor subunit without affecting the level of GABA(B)R1. Together our results suggest that Marlin-1 functions to regulate the cellular levels of GABA(B) R2 subunits, which may have significant effects on the production of functional GABA(B) receptor heterodimers. Therefore, our observations provide an added level of regulation for the control of GABA(B) receptor expression and for the efficacy of inhibitory synaptic transmission. PMID:14718537

  11. Host kinin B1 receptor plays a protective role against melanoma progression

    PubMed Central

    Maria, Andrea G.; Dillenburg-Pilla, Patrícia; Reis, Rosana I.; Floriano, Elaine M.; Tefé-Silva, Cristiane; Ramos, Simone G.; Pesquero, João B.; Nahmias, Clara; Costa-Neto, Claudio M.

    2016-01-01

    Melanoma is a very aggressive tumor that arises from melanocytes. Late stage and widely spread diseases do not respond to standard therapeutic approaches. The kallikrein-kinin system (KKS) participates in biological processes such as vasodilatation, pain and inflammatory response. However, the role of KKS in tumor formation and progression is not completely understood. The role of the host kinin B1 receptor in melanoma development was evaluated using a syngeneic melanoma model. Primary tumors and metastasis were respectively induced by injecting B16F10 melanoma cells, which are derived from C57BL/6 mice, subcutaneously or in the tail vein in wild type C57BL/6 and B1 receptor knockout mice (B1−/−). Tumors developed in B1−/− mice presented unfavorable prognostic factors such as increased incidence of ulceration, higher levels of IL-10, higher activation of proliferative pathways such as ERK1/2 and Akt, and increased mitotic index. Furthermore, in the metastasis model, B1−/− mice developed larger metastatic colonies in the lung and lower CD8+immune effector cells when compared with WT animals. Altogether, our results provide evidences that B1−/− animals developed primary tumors with multiple features associated with poor prognosis and unfavorable metastatic onset, indicating that the B1 receptor may contribute to improve the host response against melanoma progression. PMID:26898917

  12. Two dopamine receptors play different roles in phase change of the migratory locust

    PubMed Central

    Guo, Xiaojiao; Ma, Zongyuan; Kang, Le

    2015-01-01

    The migratory locust, Locusta migratoria, shows remarkable phenotypic plasticity at behavioral, physiological, and morphological levels in response to fluctuation in population density. Our previous studies demonstrated that dopamine (DA) and the genes in the dopamine metabolic pathway mediate phase change in Locusta. However, the functions of different dopamine receptors in modulating locust phase change have not been fully explored. In the present study, DA concentration in the brain increased during crowding and decreased during isolation. The expression level of dopamine receptor 1 (Dop1) increased from 1 to 4 h of crowding, but remained unchanged during isolation. Injection of Dop1 agonist SKF38393 into the brains of solitary locusts promoted gregarization, induced conspecific attraction-response and increased locomotion. RNAi knockdown of Dop1 and injection of antagonist SCH23390 in gregarious locusts induced solitary behavior, promoted the shift to repulsion-response and reduced locomotion. By contrast, the expression level of dopamine receptor 2 (Dop2) gradually increased during isolation, but remained stable during crowding. During the isolation of gregarious locusts, injection of Dop2 antagonist S(–)-sulpiride or RNAi knockdown of Dop2 inhibited solitarization, maintained conspecific attraction-response and increased locomotion; by comparison, the isolated controls displayed conspecific repulsion-response and weaker motility. Activation of Dop2 in solitary locusts through injection of agonist, R(-)-TNPA, did not affect their behavioral state. Thus, DA-Dop1 signaling in the brain of Locusta induced the gregariousness, whereas DA-Dop2 signaling mediated the solitariness. Our study demonstrated that Dop1 and Dop2 modulated locust phase change in two different directions. Further investigation of Locusta Dop1 and Dop2 functions in modulating phase change will improve our understanding of the molecular mechanism underlying phenotypic plasticity in locusts

  13. Liver X Receptors (LXRs) Alpha and Beta Play Distinct Roles in the Mouse Epididymis.

    PubMed

    Whitfield, Marjorie; Ouvrier, Aurélia; Cadet, Rémi; Damon-Soubeyrand, Christelle; Guiton, Rachel; Janny, Laurent; Kocer, Ayhan; Marceau, Geoffroy; Pons-Rejraji, Hanae; Trousson, Amalia; Drevet, Joël R; Saez, Fabrice

    2016-03-01

    After its production in the testis, a spermatozoon has to undergo posttesticular maturation steps to become fully motile and fertile. The first step is epididymal maturation, during which immature spermatozoa are transformed into biochemically mature cells ready to proceed to the next step, capacitation, a physiological process occurring in the female genital tract. The biochemical transformations include modification of sperm lipid composition during epididymal transit, with significant changes in fatty acids, phospholipids, and sterols between the caput and the cauda epididymal spermatozoa. Although quantitative aspects of these changes are well documented for several mammalian species, molecular mechanisms governing these steps are poorly understood. Transgenic male mice invalidated for the two liver X receptors (LXRalpha and LXRbeta, nuclear oxysterol receptors regulating cholesterol and lipid metabolism) become sterile when aging, showing an epididymal phenotype. We used single-knockout-model mice to characterize the role of each LXR isoform during sperm maturation in the epididymis. We show here that although a certain redundancy exists in the functions of the two LXR isoforms, some physiological processes are more under the influence of only one of them. In both cases, aging males showed slight subfertility, associated with dyslipidemia, emphasizing the importance of lipid metabolism in relation with male fertility. PMID:26792941

  14. Endoperoxide 4 receptors play a role in evoking the exercise pressor reflex in rats with simulated peripheral artery disease.

    PubMed

    Yamauchi, Katsuya; Kim, Joyce S; Stone, Audrey J; Ruiz-Velasco, Victor; Kaufman, Marc P

    2013-06-01

    Ligating the femoral artery for 72 h in decerebrated rats exaggerates the exercise pressor reflex. The sensory arm of this reflex is comprised of group III and IV afferents, which can be either sensitized or stimulated by PGE2. In vitro studies showed that endoperoxide (EP) 3 and 4 receptors were responsible for the PGE2-induced sensitization of rat dorsal root ganglion cells. This in vitro finding prompted us to test the hypothesis that blockade of EP3 and/or EP4 receptors attenuated the exaggerated exercise pressor reflex in rats with ligated femoral arteries. We measured the cardiovascular responses to static hindlimb contraction or tendon stretch before and after femoral arterial injection of L798106 (an EP3 antagonist) or L161982 (an EP4 antagonist). The pressor and cardioaccelerator responses to either contraction or tendon stretch were not attenuated by L798106 in either the ligated or freely perfused rats. Likewise in five rats whose hindlimb muscles were freely perfused, the pressor and cardioaccelerator responses to either contraction or tendon stretch were not attenuated by L161982. In the six ligated rats, however, the pressor response to contraction was attenuated by L161982, averaging 37 ± 3 mmHg before, 18 ± 2 mmHg afterward (P < 0.05). Western blotting analysis revealed that ligation of the femoral artery for 72 h increased the EP4 receptor protein in the L4 and L5 dorsal root ganglia over their freely perfused counterparts by 24% (P < 0.05). We conclude that EP4 receptors, but not EP3 receptors, play an important role in the exaggerated exercise pressor reflex found in rats with ligated femoral arteries. PMID:23568893

  15. CHASE domain-containing receptors play an essential role in the cytokinin response of the moss Physcomitrella patens

    PubMed Central

    von Schwartzenberg, Klaus; Lindner, Ann-Cathrin; Gruhn, Njuscha; Šimura, Jan; Novák, Ondřej; Strnad, Miroslav; Gonneau, Martine; Nogué, Fabien; Heyl, Alexander

    2016-01-01

    While the molecular basis for cytokinin action is quite well understood in flowering plants, little is known about the cytokinin signal transduction in early diverging land plants. The genome of the bryophyte Physcomitrella patens (Hedw.) B.S. encodes three classical cytokinin receptors, the CHASE domain-containing histidine kinases, CHK1, CHK2, and CHK3. In a complementation assay with protoplasts of receptor-deficient Arabidopsis thaliana as well as in cytokinin binding assays, we found evidence that CHK1 and CHK2 receptors can function in cytokinin perception. Using gene targeting, we generated a collection of CHK knockout mutants comprising single (Δchk1, Δchk2, Δchk3), double (Δchk1,2, Δchk1,3, Δchk2,3), and triple (Δchk1,2,3) mutants. Mutants were characterized for their cytokinin response and differentiation capacities. While the wild type did not grow on high doses of cytokinin (1 µM benzyladenine), the Δchk1,2,3 mutant exhibited normal protonema growth. Bud induction assays showed that all three cytokinin receptors contribute to the triggering of budding, albeit to different extents. Furthermore, while the triple mutant showed no response in this bioassay, the remaining mutants displayed budding responses in a diverse manner to different types and concentrations of cytokinins. Determination of cytokinin levels in mutants showed no drastic changes for any of the cytokinins; thus, in contrast to Arabidopsis, revealing only small impacts of cytokinin signaling on homeostasis. In summary, our study provides a first insight into the molecular action of cytokinin in an early diverging land plant and demonstrates that CHK receptors play an essential role in bud induction and gametophore development. PMID:26596764

  16. GABAB-mediated modulation of ionic conductances in type I hair cells isolated from guinea-pig semicircular canals.

    PubMed

    Lapeyre, P N; Kolston, P J; Ashmore, J F

    1993-04-23

    Mammalian vestibular type I hair cells (VIHCs) are innervated by an afferent synaptic calyx which contains vesicles and is immunoreactive for GABA. We describe here the effects of GABA on electrophysiological properties and on cytosolic free-calcium levels ([Ca2+]i) of VIHCs isolated from guinea-pig ampullae. Whole-cell tight-seal macroscopic currents recorded from VIHCs showed that 100 microM GABA induced a decrease in the outward currents elicited by depolarizing membrane potentials. These are known to comprise potassium calcium-dependent currents. This effect was mimicked by baclofen, a GABAB agonist, and was not affected by picrotoxin, a GABAA antagonist. GABA also induced an increase in the inward current elicited at hyperpolarized membrane potentials in 50% of the tested cells. Single channel recording in cell-attached patches revealed that externally applied GABA produced a decrease and an increase in the open probability of 170 pS and 45 pS and of 15 pS channels, respectively. In imaging experiments using the dye Fura-2 to measure [Ca2+]i, the only reversible modulation of [Ca2+]i observed in response to GABA application was a decrease. These results demonstrate a modulation of calcium and potassium conductances by GABA, via GABAB receptors, in guinea-pig VIHCs. PMID:7685230

  17. Eukaryotic Initiation Factor 5A Plays an Essential Role in Luteinizing Hormone Receptor Regulation

    PubMed Central

    Menon, Bindu; Gulappa, Thippeswamy

    2014-01-01

    Down-regulation of LH receptor (LHR) in the ovary by its ligand is mediated by a specific RNA-binding protein, designated LH receptor mRNA–binding protein (LRBP), through translational suppression and mRNA degradation. Using yeast 2-hybrid screens, we previously identified eukaryotic initiation factor 5A (eIF5A) as one of the proteins that interacts with LRBP during LHR mRNA down-regulation. The present study examined the role of eIF5A and its hypusination in the context of LHR mRNA down-regulation. The association of eIF5A with LRBP or LHR mRNA was determined using immunoprecipitation and RNA immunoprecipitation assays. The results showed that the association of eIF5A with the LHR mRNA-LRBP complex increased significantly during down-regulation. Furthermore, gel fractionation and the hypusination activity assay both showed increased hypusination of eIF5A during LHR mRNA down-regulation. Abolishment of hypusination by pretreatment with the chemical inhibitor GC7 prevented the association of eIF5A with LHR mRNA and LRBP. Inhibition of hypusination also reduced the extent of ligand-induced down-regulation of LHR mRNA as well as the expression of functional LHRs assessed by real-time PCR and 125I-human chorionic gonadotropin (hCG) binding assays, respectively. The loss of human chorionic gonadotropin–mediated downstream signaling during LHR down-regulation was also restored by inhibition of hypusination of eIF5A. Thus, the present study, for the first time, reveals the crucial role of eIF5A and its hypusination in the regulation of LHR expression in the ovary. PMID:25216047

  18. Ischemia-like Oxygen and Glucose Deprivation Mediates Down-regulation of Cell Surface γ-Aminobutyric AcidB Receptors via the Endoplasmic Reticulum (ER) Stress-induced Transcription Factor CCAAT/Enhancer-binding Protein (C/EBP)-homologous Protein (CHOP)*

    PubMed Central

    Maier, Patrick J.; Zemoura, Khaled; Acuña, Mario A.; Yévenes, Gonzalo E.; Zeilhofer, Hanns Ulrich; Benke, Dietmar

    2014-01-01

    Cerebral ischemia frequently leads to long-term disability and death. Excitotoxicity is believed to be the main cause for ischemia-induced neuronal death. Although a role of glutamate receptors in this process has been firmly established, the contribution of metabotropic GABAB receptors, which control excitatory neurotransmission, is less clear. A prominent characteristic of ischemic insults is endoplasmic reticulum (ER) stress associated with the up-regulation of the transcription factor CCAAT/enhancer-binding protein-homologous protein (CHOP). After inducing ER stress in cultured cortical neurons by sustained Ca2+ release from intracellular stores or by a brief episode of oxygen and glucose deprivation (in vitro model of cerebral ischemia), we observed an increased expression of CHOP accompanied by a strong reduction of cell surface GABAB receptors. Our results indicate that down-regulation of cell surface GABAB receptors is caused by the interaction of the receptors with CHOP in the ER. Binding of CHOP prevented heterodimerization of the receptor subunits GABAB1 and GABAB2 and subsequent forward trafficking of the receptors to the cell surface. The reduced level of cell surface receptors diminished GABAB receptor signaling and, thus, neuronal inhibition. These findings indicate that ischemia-mediated up-regulation of CHOP down-regulates cell surface GABAB receptors by preventing their trafficking from the ER to the plasma membrane. This mechanism leads to diminished neuronal inhibition and may contribute to excitotoxicity in cerebral ischemia. PMID:24668805

  19. Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression.

    PubMed

    Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-Il; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y L; Choi, Hueng-Sik

    2015-09-01

    Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ-binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism. PMID:26348907

  20. Structural, signalling and regulatory properties of the group I metabotropic glutamate receptors: prototypic family C G-protein-coupled receptors.

    PubMed Central

    Hermans, E; Challiss, R A

    2001-01-01

    In 1991 a new type of G-protein-coupled receptor (GPCR) was cloned, the type 1a metabotropic glutamate (mGlu) receptor, which, despite possessing the defining seven-transmembrane topology of the GPCR superfamily, bore little resemblance to the growing number of other cloned GPCRs. Subsequent studies have shown that there are eight mammalian mGlu receptors that, together with the calcium-sensing receptor, the GABA(B) receptor (where GABA is gamma-aminobutyric acid) and a subset of pheromone, olfactory and taste receptors, make up GPCR family C. Currently available data suggest that family C GPCRs share a number of structural, biochemical and regulatory characteristics, which differ markedly from those of the other GPCR families, most notably the rhodopsin/family A GPCRs that have been most widely studied to date. This review will focus on the group I mGlu receptors (mGlu1 and mGlu5). This subgroup of receptors is widely and differentially expressed in neuronal and glial cells within the brain, and receptor activation has been implicated in the control of an array of key signalling events, including roles in the adaptative changes needed for long-term depression or potentiation of neuronal synaptic connectivity. In addition to playing critical physiological roles within the brain, the mGlu receptors are also currently the focus of considerable attention because of their potential as drug targets for the treatment of a variety of neurological and psychiatric disorders. PMID:11672421

  1. Adenosine A2A receptor plays an important role in radiation-induced dermal injury.

    PubMed

    Perez-Aso, Miguel; Mediero, Aránzazu; Low, Yee Cheng; Levine, Jamie; Cronstein, Bruce N

    2016-01-01

    Ionizing radiation is a common therapeutic modality and following irradiation dermal changes, including fibrosis and atrophy, may lead to permanent changes. We have previously demonstrated that occupancy of A2A receptor (A2AR) stimulates collagen production, so we determined whether blockade or deletion of A2AR could prevent radiation-induced fibrosis. After targeted irradiation (40 Gy) of the skin of wild-type (WT) or A2AR knockout (A2ARKO) mice, the A2AR antagonist ZM241385 was applied daily for 28 d. In irradiated WT mice treated with the A2AR antagonist, there was a marked reduction in collagen content and skin thickness, and ZM241385 treatment reduced the number of myofibroblasts and angiogenesis. After irradiation, there is an increase in loosely packed collagen fibrils, which is significantly diminished by ZM241385. Irradiation also induced an increase in epidermal thickness, prevented by ZM241385, by increasing the number of proliferating keratinocytes. Similarly, in A2ARKO mice, the changes in collagen alignment, skin thickness, myofibroblast content, angiogenesis, and epidermal hyperplasia were markedly reduced following irradiation. Radiation-induced changes in the dermis and epidermis were accompanied by an infiltrate of T cells, which was prevented in both ZM241385-treated and A2ARKO mice. Radiation therapy is administered to a significant number of patients with cancer, and radiation reactions may limit this therapeutic modality. Our findings suggest that topical application of an A2AR antagonist prevents radiation dermatitis and may be useful in the prevention or amelioration of radiation changes in the skin. PMID:26415936

  2. Role of post-translational modifications on structure, function and pharmacology of class C G protein-coupled receptors.

    PubMed

    Nørskov-Lauritsen, Lenea; Bräuner-Osborne, Hans

    2015-09-15

    G protein-coupled receptors are divided into three classes (A, B and C) based on homology of their seven transmembrane domains. Class C is the smallest class with 22 human receptor subtypes including eight metabotropic glutamate (mGlu1-8) receptors, two GABAB receptors (GABAB1 and GABAB2), three taste receptors (T1R1-3), one calcium-sensing (CaS) receptor, one GPCR, class C, group 6, subtype A (GPRC6) receptor, and seven orphan receptors. G protein-coupled receptors undergo a number of post-translational modifications, which regulate their structure, function and/or pharmacology. Here, we review the existence of post-translational modifications in class C G protein-coupled receptors and their regulatory roles, with particular focus on glycosylation, phosphorylation, ubiquitination, SUMOylation, disulphide bonding and lipidation. PMID:25981296

  3. Calcium-Sensing Receptors of Human Neural Cells Play Crucial Roles in Alzheimer's Disease

    PubMed Central

    Chiarini, Anna; Armato, Ubaldo; Liu, Daisong; Dal Prà, Ilaria

    2016-01-01

    In aged subjects, late-onset Alzheimer's disease (LOAD) starts in the lateral entorhinal allocortex where a failure of clearance mechanisms triggers an accumulation of neurotoxic amyloid-β42 oligomers (Aβ42-os). In neurons and astrocytes, Aβ42-os enhance the transcription of Aβ precursor protein (APP) and β-secretase/BACE1 genes. Thus, by acting together with γ-secretase, the surpluses of APP and BACE1 amplify the endogenous production of Aβ42-os which pile up, damage mitochondria, and are oversecreted. At the plasmalemma, exogenous Aβ42-os bind neurons' and astrocytes' calcium-sensing receptors (CaSRs) activating a set of intracellular signaling pathways which upkeep Aβ42-os intracellular accumulation and oversecretion by hindering Aβ42-os proteolysis. In addition, Aβ42-os accumulating in the extracellular milieu spread and reach mounting numbers of adjacent and remoter teams of neurons and astrocytes which in turn are recruited, again via Aβ42-os•CaSR-governed mechanisms, to produce and release additional Aβ42-os amounts. This relentless self-sustaining mechanism drives AD progression toward upper cortical areas. Later on accumulating Aβ42-os elicit the advent of hyperphosphorylated (p)-Tau oligomers which acting together with Aβ42-os and other glial neurotoxins cooperatively destroy wider and wider cognition-related cortical areas. In parallel, Aβ42-os•CaSR signals also elicit an excess production and secretion of nitric oxide and vascular endothelial growth factor-A from astrocytes, of Aβ42-os and myelin basic protein from oligodendrocytes, and of proinflammatory cytokines, nitric oxide and (likely) Aβ42-os from microglia. Activated astrocytes and microglia survive the toxic onslaught, whereas neurons and oligodendrocytes increasingly die. However, we have shown that highly selective allosteric CaSR antagonists (calcilytics), like NPS 2143 and NPS 89626, efficiently suppress all the neurotoxic effects Aβ42-os•CaSR signaling drives in

  4. Yes and Lyn play a role in nuclear translocation of the epidermal growth factor receptor.

    PubMed

    Iida, M; Brand, T M; Campbell, D A; Li, C; Wheeler, D L

    2013-02-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR antibody that has been approved for use in oncology. Previously we investigated mechanisms of resistance to cetuximab using a model derived from the non-small cell lung cancer line NCI-H226. We demonstrated that cetuximab-resistant clones (Ctx(R)) had increased nuclear localization of the EGFR. This process was mediated by Src family kinases (SFKs), and nuclear EGFR had a role in resistance to cetuximab. To better understand SFK-mediated nuclear translocation of EGFR, we investigated which SFK member(s) controlled this process as well as the EGFR tyrosine residues that are involved. Analyses of mRNA and protein expression indicated upregulation of the SFK members Yes (v-Yes-1 yamaguchi sarcoma viral oncogene) and Lyn (v-yes-1 Yamaguchi sarcoma viral-related oncogene homolog) in all Ctx(R) clones. Further, immunoprecipitation analysis revealed that EGFR interacts with Yes and Lyn in Ctx(R) clones, but not in cetuximab-sensitive (Ctx(S)) parental cells. Using RNAi interference, we found that knockdown of either Yes or Lyn led to loss of EGFR translocation to the nucleus. Conversely, overexpression of Yes or Lyn in low nuclear EGFR-expressing Ctx(S) parental cells led to increased nuclear EGFR. Chromatin immunoprecipitation (ChIP) assays confirmed nuclear EGFR complexes associated with the promoter of the known EGFR target genes B-Myb and iNOS. Further, all Ctx(R) clones exhibited upregulation of B-Myb and iNOS at the mRNA and protein levels. siRNAs directed at Yes or Lyn led to decreased binding of EGFR complexes to the B-Myb and iNOS promoters based on ChIP analyses. SFKs have been shown to phosphorylate EGFR on tyrosines 845 and 1101 (Y845 and Y1101), and mutation of Y1101, but not Y845, impaired nuclear entry of the EGFR. Taken together, our findings demonstrate that Yes and Lyn phosphorylate EGFR at Y1101, which influences EGFR

  5. [GABA-Receptors in Modulation of Fear Memory Extinction].

    PubMed

    Dubrovina, N I

    2016-01-01

    GABA is the major inhibitory neurotransmitter in the central nervous system determining the efficacy of neuronal interaction. GABA-receptors play a key role in different aspects of fear memory--acquisition and consolidation, retention, reconsolidation and extinction. Extinction is an important behavioural phenomenon which allows organism to adapt its behavior to a changing environment. Extinction of fear memory is a form of new inhibitory learning which interferes with expression of the initial acquired fear conditioning. Resistance to extinction is symptom of depression and posttraumatic stress disorder. The aim of the present review was to summarize own and literary data about GABAergic modulation of fear extinction and pharmacological correction of extinction impairment at influences on GABA(A)- and GABA(B)- receptors. PMID:27538279

  6. Thyroid Hormone Receptor α Plays an Essential Role in Male Skeletal Muscle Myoblast Proliferation, Differentiation, and Response to Injury.

    PubMed

    Milanesi, Anna; Lee, Jang-Won; Kim, Nam-Ho; Liu, Yan-Yun; Yang, An; Sedrakyan, Sargis; Kahng, Andrew; Cervantes, Vanessa; Tripuraneni, Nikita; Cheng, Sheue-yann; Perin, Laura; Brent, Gregory A

    2016-01-01

    Thyroid hormone plays an essential role in myogenesis, the process required for skeletal muscle development and repair, although the mechanisms have not been established. Skeletal muscle develops from the fusion of precursor myoblasts into myofibers. We have used the C2C12 skeletal muscle myoblast cell line, primary myoblasts, and mouse models of resistance to thyroid hormone (RTH) α and β, to determine the role of thyroid hormone in the regulation of myoblast differentiation. T3, which activates thyroid hormone receptor (TR) α and β, increased myoblast differentiation whereas GC1, a selective TRβ agonist, was minimally effective. Genetic approaches confirmed that TRα plays an important role in normal myoblast proliferation and differentiation and acts through the Wnt/β-catenin signaling pathway. Myoblasts with TRα knockdown, or derived from RTH-TRα PV (a frame-shift mutation) mice, displayed reduced proliferation and myogenic differentiation. Moreover, skeletal muscle from the TRα1PV mutant mouse had impaired in vivo regeneration after injury. RTH-TRβ PV mutant mouse model skeletal muscle and derived primary myoblasts did not have altered proliferation, myogenic differentiation, or response to injury when compared with control. In conclusion, TRα plays an essential role in myoblast homeostasis and provides a potential therapeutic target to enhance skeletal muscle regeneration. PMID:26451739

  7. Integrin receptors play a role in the internalin B-dependent entry of Listeria monocytogenes into host cells.

    PubMed

    Auriemma, Clementina; Viscardi, Maurizio; Tafuri, Simona; Pavone, Luigi Michele; Capuano, Federico; Rinaldi, Laura; Della Morte, Rossella; Iovane, Giuseppe; Staiano, Norma

    2010-09-01

    Listeria monocytogenes enters non-phagocytic cells by binding its surface proteins inlA (internalin) and inlB to the host's E-cadherin and Met, respectively. The two internalins play either separate or cooperative roles in the colonization of infected tissues. Here, we studied bacterial uptake into HeLa cells using an L. monocytogenes mutant strain (DeltainlA) carrying a deletion in the gene coding for inlA. The DeltainlA mutant strain showed the capability to invade HeLa cells. The monoclonal anti-beta(3)- and anti-beta(1)-integrin subunit antibodies prevented bacterial uptake into the cells, while the anti-beta(2)- and anti-beta(4)-integrin subunit antibodies failed to affect L. monocytogenes entry into HeLa cells. Three structurally distinct disintegrins (kistrin, echistatin and flavoridin) also inhibited bacterial uptake, showing different potencies correlated to their selective affinity for the beta(3)- and beta(1)-integrin subunits. In addition to inducing Met phosphorylation, infection of cells by the L. monocytogenes DeltainlA mutant strain promoted the tyrosine phosphorylation of the focal adhesion-associated proteins FAK and paxillin. Our findings provide the first evidence that beta(3)- and beta(1)-integrin receptors play a role in the inlB-dependent internalization of L. monocytogenes into host cells. PMID:20526749

  8. Mitochondrial respiratory chain is involved in insulin-stimulated hydrogen peroxide production and plays an integral role in insulin receptor autophosphorylation in neurons

    PubMed Central

    Storozhevykh, Tatiana P; Senilova, Yana E; Persiyantseva, Nadezhda A; Pinelis, Vsevolod G; Pomytkin, Igor A

    2007-01-01

    Background Accumulated evidence suggests that hydrogen peroxide (H2O2) generated in cells during insulin stimulation plays an integral role in insulin receptor signal transduction. The role of insulin-induced H2O2 in neuronal insulin receptor activation and the origin of insulin-induced H2O2 in neurons remain unclear. The aim of the present study is to test the following hypotheses (1) whether insulin-induced H2O2 is required for insulin receptor autophosphorylation in neurons, and (2) whether mitochondrial respiratory chain is involved in insulin-stimulated H2O2 production, thus playing an integral role in insulin receptor autophosphorylation in neurons. Results Insulin stimulation elicited rapid insulin receptor autophosphorylation accompanied by an increase in H2O2 release from cultured cerebellar granule neurons (CGN). N-acetylcysteine (NAC), a H2O2 scavenger, inhibited both insulin-stimulated H2O2 release and insulin-stimulated autophosphorylation of insulin receptor. Inhibitors of respiratory chain-mediated H2O2 production, malonate and carbonyl cyanide-4-(trifluoromethoxy)-phenylhydrazone (FCCP), inhibited both insulin-stimulated H2O2 release from neurons and insulin-stimulated autophosphorylation of insulin receptor. Dicholine salt of succinic acid, a respiratory substrate, significantly enhanced the effect of suboptimal insulin concentration on the insulin receptor autophosphorylation in CGN. Conclusion Results of the present study suggest that insulin-induced H2O2 is required for the enhancement of insulin receptor autophosphorylation in neurons. The mitochondrial respiratory chain is involved in insulin-stimulated H2O2 production, thus playing an integral role in the insulin receptor autophosphorylation in neurons. PMID:17919343

  9. ZFAT plays critical roles in peripheral T cell homeostasis and its T cell receptor-mediated response

    SciTech Connect

    Doi, Keiko; Fujimoto, Takahiro; Okamura, Tadashi; Ogawa, Masahiro; Tanaka, Yoko; Mototani, Yasumasa; Goto, Motohito; Ota, Takeharu; Matsuzaki, Hiroshi; Kuroki, Masahide; Tsunoda, Toshiyuki; Sasazuki, Takehiko; Shirasawa, Senji

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer We generated Cd4-Cre-mediated T cell-specific Zfat-deficient mice. Black-Right-Pointing-Pointer Zfat-deficiency leads to reduction in the number of the peripheral T cells. Black-Right-Pointing-Pointer Impaired T cell receptor-mediated response in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Decreased expression of IL-7R{alpha}, IL-2R{alpha} and IL-2 in Zfat-deficient peripheral T cells. Black-Right-Pointing-Pointer Zfat plays critical roles in peripheral T cell homeostasis. -- Abstract: ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in apoptosis, development and primitive hematopoiesis. Zfat is highly expressed in T- and B-cells in the lymphoid tissues, however, its physiological function in the immune system remains totally unknown. Here, we generated the T cell-specific Zfat-deficient mice and demonstrated that Zfat-deficiency leads to a remarkable reduction in the number of the peripheral T cells. Intriguingly, a reduced expression of IL-7R{alpha} and the impaired responsiveness to IL-7 for the survival were observed in the Zfat-deficient T cells. Furthermore, a severe defect in proliferation and increased apoptosis in the Zfat-deficient T cells following T cell receptor (TCR) stimulation was observed with a reduced IL-2R{alpha} expression as well as a reduced IL-2 production. Thus, our findings reveal that Zfat is a critical regulator in peripheral T cell homeostasis and its TCR-mediated response.

  10. Epidermal growth factor receptor plays a role in the regulation of liver and plasma lipid levels in adult male mice

    PubMed Central

    Zhang, Xiuqi; Garcia, Oscar A.; Wang, Rebecca F.; Stevenson, Mary C.; Threadgill, David W.; Russell, William E.

    2014-01-01

    Dsk5 mice have a gain of function in the epidermal growth factor receptor (EGFR), caused by a point mutation in the kinase domain. We analyzed the effect of this mutation on liver size, histology, and composition. We found that the livers of 12-wk-old male Dsk5 heterozygotes (+/Dsk5) were 62% heavier compared with those of wild-type controls (+/+). The livers of the +/Dsk5 mice compared with +/+ mice had larger hepatocytes with prominent, polyploid nuclei and showed modestly increased cell proliferation indices in both hepatocytes and nonparenchymal cells. An analysis of total protein, DNA, and RNA (expressed relative to liver weight) revealed no differences between the mutant and wild-type mice. However, the livers of the +/Dsk5 mice had more cholesterol but less phospholipid and fatty acid. Circulating cholesterol levels were twice as high in adult male +/Dsk5 mice but not in postweaned young male or female mice. The elevated total plasma cholesterol resulted mainly from an increase in low-density lipoprotein (LDL). The +/Dsk5 adult mouse liver expressed markedly reduced protein levels of LDL receptor, no change in proprotein convertase subtilisin/kexin type 9, and a markedly increased fatty acid synthase and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Increased expression of transcription factors associated with enhanced cholesterol synthesis was also observed. Together, these findings suggest that the EGFR may play a regulatory role in hepatocyte proliferation and lipid metabolism in adult male mice, explaining why elevated levels of EGF or EGF-like peptides have been positively correlated to increased cholesterol levels in human studies. PMID:24407590

  11. Platelet-Activating Factor Receptor Plays a Role in Lung Injury and Death Caused by Influenza A in Mice

    PubMed Central

    Garcia, Cristiana C.; Russo, Remo C.; Guabiraba, Rodrigo; Fagundes, Caio T.; Polidoro, Rafael B.; Tavares, Luciana P.; Salgado, Ana Paula C.; Cassali, Geovanni D.; Sousa, Lirlândia P.; Machado, Alexandre V.; Teixeira, Mauro M.

    2010-01-01

    Influenza A virus causes annual epidemics which affect millions of people worldwide. A recent Influenza pandemic brought new awareness over the health impact of the disease. It is thought that a severe inflammatory response against the virus contributes to disease severity and death. Therefore, modulating the effects of inflammatory mediators may represent a new therapy against Influenza infection. Platelet activating factor (PAF) receptor (PAFR) deficient mice were used to evaluate the role of the gene in a model of experimental infection with Influenza A/WSN/33 H1N1 or a reassortant Influenza A H3N1 subtype. The following parameters were evaluated: lethality, cell recruitment to the airways, lung pathology, viral titers and cytokine levels in lungs. The PAFR antagonist PCA4248 was also used after the onset of flu symptoms. Absence or antagonism of PAFR caused significant protection against flu-associated lethality and lung injury. Protection was correlated with decreased neutrophil recruitment, lung edema, vascular permeability and injury. There was no increase of viral load and greater recruitment of NK1.1+ cells. Antibody responses were similar in WT and PAFR-deficient mice and animals were protected from re-infection. Influenza infection induces the enzyme that synthesizes PAF, lyso-PAF acetyltransferase, an effect linked to activation of TLR7/8. Therefore, it is suggested that PAFR is a disease-associated gene and plays an important role in driving neutrophil influx and lung damage after infection of mice with two subtypes of Influenza A. Further studies should investigate whether targeting PAFR may be useful to reduce lung pathology associated with Influenza A virus infection in humans. PMID:21079759

  12. Peroxisome proliferator-activated receptor alpha plays a crucial role in behavioral repetition and cognitive flexibility in mice

    PubMed Central

    D'Agostino, Giuseppe; Cristiano, Claudia; Lyons, David J.; Citraro, Rita; Russo, Emilio; Avagliano, Carmen; Russo, Roberto; Raso, Giuseppina Mattace; Meli, Rosaria; De Sarro, Giovambattista; Heisler, Lora K.; Calignano, Antonio

    2015-01-01

    Background/objectives Nuclear peroxisome proliferator activated receptor-α (PPAR-α) plays a fundamental role in the regulation of lipid homeostasis and is the target of medications used to treat dyslipidemia. However, little is known about the role of PPAR-α in mouse behavior. Methods To investigate the function of Ppar-α in cognitive functions, a behavioral phenotype analysis of mice with a targeted genetic disruption of Ppar-α was performed in combination with neuroanatomical, biochemical and pharmacological manipulations. The therapeutic exploitability of PPAR-α was probed in mice using a pharmacological model of psychosis and a genetic model (BTBR T + tf/J) exhibiting a high rate of repetitive behavior. Results An unexpected role for brain Ppar-α in the regulation of cognitive behavior in mice was revealed. Specifically, we observed that Ppar-α genetic perturbation promotes rewiring of cortical and hippocampal regions and a behavioral phenotype of cognitive inflexibility, perseveration and blunted responses to psychomimetic drugs. Furthermore, we demonstrate that the antipsychotic and autism spectrum disorder (ASD) medication risperidone ameliorates the behavioral profile of Ppar-α deficient mice. Importantly, we reveal that pharmacological PPAR-α agonist treatment in mice improves behavior in a pharmacological model of ketamine-induced behavioral dysinhibition and repetitive behavior in BTBR T + tf/J mice. Conclusion Our data indicate that Ppar-α is required for normal cognitive function and that pharmacological stimulation of PPAR-α improves cognitive function in pharmacological and genetic models of impaired cognitive function in mice. These results thereby reveal an unforeseen therapeutic application for a class of drugs currently in human use. PMID:26137440

  13. GABAB-mediated rescue of altered excitatory–inhibitory balance, gamma synchrony and behavioral deficits following constitutive NMDAR-hypofunction

    PubMed Central

    Gandal, M J; Sisti, J; Klook, K; Ortinski, P I; Leitman, V; Liang, Y; Thieu, T; Anderson, R; Pierce, R C; Jonak, G; Gur, R E; Carlson, G; Siegel, S J

    2012-01-01

    Reduced N-methyl-D-aspartate-receptor (NMDAR) signaling has been associated with schizophrenia, autism and intellectual disability. NMDAR-hypofunction is thought to contribute to social, cognitive and gamma (30–80 Hz) oscillatory abnormalities, phenotypes common to these disorders. However, circuit-level mechanisms underlying such deficits remain unclear. This study investigated the relationship between gamma synchrony, excitatory–inhibitory (E/I) signaling, and behavioral phenotypes in NMDA-NR1neo−/− mice, which have constitutively reduced expression of the obligate NR1 subunit to model disrupted developmental NMDAR function. Constitutive NMDAR-hypofunction caused a loss of E/I balance, with an increase in intrinsic pyramidal cell excitability and a selective disruption of parvalbumin-expressing interneurons. Disrupted E/I coupling was associated with deficits in auditory-evoked gamma signal-to-noise ratio (SNR). Gamma-band abnormalities predicted deficits in spatial working memory and social preference, linking cellular changes in E/I signaling to target behaviors. The GABAB-receptor agonist baclofen improved E/I balance, gamma-SNR and broadly reversed behavioral deficits. These data demonstrate a clinically relevant, highly translatable neural-activity-based biomarker for preclinical screening and therapeutic development across a broad range of disorders that share common endophenotypes and disrupted NMDA-receptor signaling. PMID:22806213

  14. Conserved Glycine Residues in the Cytoplasmic Domain of the Aspartate Receptor Play Essential Roles in Kinase Coupling and On–Off Switching†

    PubMed Central

    Coleman, Matthew D.; Bass, Randal B.; Mehan, Ryan S.; Falke, Joseph J.

    2010-01-01

    The aspartate receptor of the bacterial chemotaxis pathway serves as a scaffold for the formation of a multiprotein signaling complex containing the receptor and the cytoplasmic pathway components. Within this complex, the receptor regulates the autophosphorylation activity of histidine kinase CheA, thereby controlling the signals sent to the flagellar motor and the receptor adaptation system. The receptor cytoplasmic domain, which controls the on–off switching of CheA, possesses 14 glycine residues that are highly conserved in related receptors. In principle, these conserved glycines could be required for static turns, bends, or close packing in the cytoplasmic domain, or they could be required for conformational dynamics during receptor on–off switching. To determine which glycines are essential and to probe their functional roles, we have substituted each conserved glycine with both alanine and cysteine, and then measured the effects on receptor function in vivo and in vitro. The results reveal a subset of six glycines which are required for receptor function during cellular chemotaxis. Two of these essential glycines (G388 and G391) are located at a hairpin turn at the distal end of the folded cytoplasmic domain, where they are required for the tertiary fold of the signaling subdomain and for CheA kinase activation. Three other essential glycines (G338, G339, and G437) are located at the border between the adaptation and signaling subdomains, where they play key roles in CheA kinase activation and on–off switching. These three glycines form a ring around the four-helix bundle that comprises the receptor cytoplasmic domain, yielding a novel architectural feature termed a bundle hinge. The final essential glycine (G455) is located in the adaptation subdomain where it is required for on–off switching. Overall, the findings confirm that six of the 14 conserved cytoplasmic glycines are essential for receptor function because they enable helix turns and bends

  15. Repeated cocaine weakens GABAB-Girk signaling in Layer 5/6 pyramidal neurons in the prelimbic cortex

    PubMed Central

    Hearing, Matthew; Kotecki, Lydia; de Velasco, Ezequiel Marron Fernandez; Fajardo-Serrano, Ana; Luján, Rafael; Wickman, Kevin

    2013-01-01

    Summary Repeated cocaine exposure triggers adaptations in Layer 5/6 glutamatergic neurons in the medial prefrontal cortex (mPFC) that promote behavioral sensitization and drug-seeking behavior. While suppression of metabotropic inhibitory signaling has been implicated in these behaviors, underlying mechanisms are unknown. Here, we show that Girk/KIR3 channels mediate most of the GABAB receptor (GABABR)-dependent inhibition of Layer 5/6 pyramidal neurons in the mPFC and that repeated cocaine suppresses this pathway. This adaptation was selective for GABABR-dependent Girk signaling in Layer 5/6 pyramidal neurons of the prelimbic cortex (PrLC) and involved a D1/5 dopamine receptor- and phosphorylation-dependent internalization of GABABR and Girk channels. Persistent suppression of Girk signaling in Layer 5/6 of the dorsal mPFC enhanced cocaine-induced locomotor activity and occluded behavioral sensitization. Thus, the cocaine-induced suppression of GABABR-Girk signaling in Layer 5/6 pyramidal neurons of the prelimbic cortex appears to represent an early adaptation critical for promoting addiction-related behavior. PMID:24094109

  16. The Arabidopsis F-box E3 ligase RIFP1 plays a negative role in abscisic acid signalling by facilitating ABA receptor RCAR3 degradation.

    PubMed

    Li, Ying; Zhang, Liang; Li, Dekuan; Liu, Zhibin; Wang, Jianmei; Li, Xufeng; Yang, Yi

    2016-03-01

    The phytohormone abscisic acid (ABA) plays a vital role in plant growth and development. The function of ABA is mediated by a group of newly discovered ABA receptors, named PYRABACTIN RESISTANCE 1/PYR-LIKE/REGULATORY COMPONENTS OF ABA RECEPTORs (PYR1/PYLs/RCARs). Here, we report that an Arabidopsis thaliana F-box protein RCAR3 INTERACTING F-BOX PROTEIN 1 (RIFP1) interacts with ABA receptor (RCAR3) and SCF E3 ligase complex subunits Arabidopsis SKP1-LIKE PROTEINs (ASKs) in vitro and in vivo. The rifp1 mutant plants displayed increased ABA-mediated inhibition of seed germination and water loss of detached leaves, while the overexpression of RIFP1 in Arabidopsis led to plants being insensitive to ABA. Meanwhile, the rifp1 mutant plants showed greater tolerance to water deficit. In addition, the RCAR3 protein level was more stable in the rifp1 mutant plants than in the wild-type plants, indicating that RIFP1 facilitates the proteasome degradation of RCAR3. Accordingly, the loss of RIFP1 increased the transcript levels of several ABA-responsive genes. Taken together, these data indicate that RIFP1 plays a negative role in the RCAR3-mediated ABA signalling pathway and likely functions as an adaptor subunit of the SCF ubiquitin ligase complex to regulate ABA receptor RCAR3 stability. PMID:26386272

  17. A LysM Receptor-like Kinase Plays a Critical Role in Chitin Signaling and Fungal Resistance in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chitin, a polymer of N-acetyl-D-glucosamine, is found in fungal cell walls, but not in plants. Plant cells are capable of perceiving chitin fragments (chitooligosaccharides) to trigger plant defense. We identified a LysM receptor-like protein (AtLysM RLK1) that is required for the perception of chit...

  18. A LysM receptor-like kinase plays a critical role in chitin signaling and fungal resistance in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chitin, a polymer of N-acetyl-D-glucosamine, is found in fungal cell walls, but not in plants. Plant cells are capable of perceiving chitin fragments (chitooligosaccharides) to trigger plant defense. We identified a LysM receptor-like protein (AtLysM RLK1) that is required for the perception of chit...

  19. GENES, IN ADDITION TO TOLL-LIKE RECEPTOR 2, PLAY A ROLE IN ANTIBACTERIAL DEFENSE TO STREPTOCOCCAL PNEUMONIA

    EPA Science Inventory

    Streptococcus infection in human populations continues to be a major cause of morbidity and mortality. To evaluate the effect of genetic background and toll-like receptor 2 (TLR2) on antibacterial defense to streptococcal infection, eight genetically diverse strains of mic...

  20. Differential expression of metabotropic glutamate and GABA receptors at neocortical glutamatergic and GABAergic axon terminals

    PubMed Central

    Bragina, Luca; Bonifacino, Tiziana; Bassi, Silvia; Milanese, Marco; Bonanno, Giambattista; Conti, Fiorenzo

    2015-01-01

    Metabotropic glutamate (Glu) receptors (mGluRs) and GABAB receptors are highly expressed at presynaptic sites. To verify the possibility that the two classes of metabotropic receptors contribute to axon terminals heterogeneity, we studied the localization of mGluR1α, mGluR5, mGluR2/3, mGluR7, and GABAB1 in VGLUT1-, VGLUT2-, and VGAT- positive terminals in the cerebral cortex of adult rats. VGLUT1-positive puncta expressed mGluR1α (∼5%), mGluR5 (∼6%), mGluR2/3 (∼22%), mGluR7 (∼17%), and GABAB1 (∼40%); VGLUT2-positive terminals expressed mGluR1α (∼10%), mGluR5 (∼11%), mGluR2/3 (∼20%), mGluR7 (∼28%), and GABAB1 (∼25%); whereas VGAT-positive puncta expressed mGluR1α (∼27%), mGluR5 (∼24%), mGluR2/3 (∼38%), mGluR7 (∼31%), and GABAB1 (∼19%). Control experiments ruled out the possibility that postsynaptic mGluRs and GABAB1 might have significantly biased our results. We also performed functional assays in synaptosomal preparations, and showed that all agonists modify Glu and GABA levels, which return to baseline upon exposure to antagonists. Overall, these findings indicate that mGluR1α, mGluR5, mGluR2/3, mGluR7, and GABAB1 expression differ significantly between glutamatergic and GABAergic axon terminals, and that the robust expression of heteroreceptors may contribute to the homeostatic regulation of the balance between excitation and inhibition. PMID:26388733

  1. Association of adverse childhood experiences, age of menarche, and adult reproductive behavior: does the androgen receptor gene play a role?

    PubMed

    Jorm, Anthony F; Christensen, Helen; Rodgers, Bryan; Jacomb, Patricia A; Easteal, Simon

    2004-02-15

    Previous research has reported associations between adverse childhood experiences, early menarche, and early sexual activity. One hypothesis to account for these findings is that an X-linked androgen receptor GGC-repeat polymorphism predisposes fathers to behaviors which include family abandonment and their daughters to earlier menarche and sexual activity and less stable relationships. Retrospective data relevant to this theory were examined from a community survey involving 3,702 women in the age groups 20-24, 40-44, and 60-64 years, and another involving 908 women aged 18-79 years. Earlier age of menarche was found to be associated with adverse childhood experiences and earlier sexual activity. However, the androgen receptor gene polymorphism was unrelated to adverse fathering behavior or to marital breakdown. PMID:14755454

  2. Regional Fos-expression induced by γ-hydroxybutyrate (GHB): comparison with γ-butyrolactone (GBL) and effects of co-administration of the GABAB antagonist SCH 50911 and putative GHB antagonist NCS-382.

    PubMed

    van Nieuwenhuijzen, P S; McGregor, I S; Chebib, M; Hunt, G E

    2014-09-26

    γ-Hydroxybutyrate (GHB) has a complex array of neural actions that include effects on its own high-affinity GHB receptor, the release of neuroactive steroids, and agonist actions at GABAA and GABAB receptors. We previously reported partial overlap in the c-Fos expression patterns produced by GHB and the GABAB agonist, baclofen in rats. The present study extends these earlier findings by examining the extent to which GHB Fos expression and behavioral sedation are prevented by (2S)-(+)-5,5-dimethyl-2-morpholineacetic acid (SCH 50911), a GABAB antagonist, and NCS-382, a putative antagonist at the high-affinity GHB receptor. We also compare Fos expression caused by GHB and its precursor γ-butyrolactone (GBL), which is a pro-drug for GHB but lacks the high sodium content of the parent GHB molecule. Both GHB (1,000 mg/kg) and GBL (600 mg/kg) induced rapid sedation in rats that lasted over 90 min and caused similar Fos expression patterns, albeit with GBL causing greater activation of the nucleus accumbens (core and shell) and dentate gyrus (granular layer). Pretreatment with SCH 50911 (100mg/kg) partly reversed the sedative effects of GHB and significantly reduced GHB-induced Fos expression in only four regions: the tenia tecta, lateral habenula, dorsal raphe and laterodorsal tegmental nucleus. NCS-382 (50mg/kg) had no effect on GHB-induced sedation or Fos expression. When given alone, both NCS-382 and SCH 50911 increased Fos expression in the bed nucleus of the stria terminalis, central amygdala, parasubthalamic nucleus and nucleus of the solitary tract. SCH 50911 alone affected the Islands of Calleja and the medial, central and paraventricular thalamic nuclei. Overall, this study shows a surprising lack of reversal of GHB-induced Fos expression by two relevant antagonists, both of which have marked intrinsic actions. This may reflect the limited doses tested but also suggests that GHB Fos expression reflects mechanisms independent of GHB and GABAB receptors. PMID

  3. Tuning and playing a motor rhythm: how metabotropic glutamate receptors orchestrate generation of motor patterns in the mammalian central nervous system.

    PubMed

    Nistri, Andrea; Ostroumov, Konstantin; Sharifullina, Elina; Taccola, Giuliano

    2006-04-15

    Repeated motor activities like locomotion, mastication and respiration need rhythmic discharges of functionally connected neurons termed central pattern generators (CPGs) that cyclically activate motoneurons even in the absence of descending commands from higher centres. For motor pattern generation, CPGs require integration of multiple processes including activation of ion channels and transmitter receptors at strategic locations within motor networks. One emerging mechanism is activation of glutamate metabotropic receptors (mGluRs) belonging to group I, while group II and III mGluRs appear to play an inhibitory function on sensory inputs. Group I mGluRs generate neuronal membrane depolarization with input resistance increase and rapid fluctuations in intracellular Ca(2+), leading to enhanced excitability and rhythmicity. While synchronicity is probably due to modulation of inhibitory synaptic transmission, these oscillations occurring in coincidence with strong afferent stimuli or application of excitatory agents can trigger locomotor-like patterns. Hence, mGluR-sensitive spinal oscillators play a role in accessory networks for locomotor CPG activation. In brainstem networks supplying tongue muscle motoneurons, group I receptors facilitate excitatory synaptic inputs and evoke synchronous oscillations which stabilize motoneuron firing at regular, low frequency necessary for rhythmic tongue contractions. In this case, synchronicity depends on the strong electrical coupling amongst motoneurons rather than inhibitory transmission, while cyclic activation of K(ATP) conductances sets its periodicity. Activation of mGluRs is therefore a powerful strategy to trigger and recruit patterned discharges of motoneurons. PMID:16469790

  4. Insulin Receptor Signaling in the GnRH Neuron Plays a Role in the Abnormal GnRH Pulsatility of Obese Female Mice

    PubMed Central

    DiVall, Sara A.; Herrera, Danny; Sklar, Bonnie; Wu, Sheng; Wondisford, Fredric; Radovick, Sally; Wolfe, Andrew

    2015-01-01

    Infertility associated with obesity is characterized by abnormal hormone release from reproductive tissues in the hypothalamus, pituitary, and ovary. These tissues maintain insulin sensitivity upon peripheral insulin resistance. Insulin receptor signaling may play a role in the dysregulation of gonadotropin-releasing hormone (GnRH) secretion in obesity, but the interdependence of hormone secretion in the reproductive axis and the multi-hormone and tissue dysfunction in obesity hinders investigations of putative contributing factors to the disrupted GnRH secretion. To determine the role of GnRH insulin receptor signaling in the dysregulation of GnRH secretion in obesity, we created murine models of diet-induced obesity (DIO) with and without intact insulin signaling in the GnRH neuron. Obese control female mice were infertile with higher luteinizing hormone levels and higher GnRH pulse amplitude and total pulsatile secretion compared to lean control mice. In contrast, DIO mice with a GnRH specific knockout of insulin receptor had improved fertility, luteinizing hormone levels approaching lean mice, and GnRH pulse amplitude and total secretion similar to lean mice. Pituitary responsiveness was similar between genotypes. These results suggest that in the obese state, insulin receptor signaling in GnRH neurons increases GnRH pulsatile secretion and consequent LH secretion, contributing to reproductive dysfunction. PMID:25780937

  5. Human neutrophil Fcγ receptors initiate and play specialized nonredundant roles in antibody-mediated inflammatory diseases

    PubMed Central

    Tsuboi, Naotake; Asano, Kenichi; Lauterbach, Michael; Mayadas, Tanya N.

    2008-01-01

    Summary Antibody-antigen complex mediated inflammation is integral to the pathogenesis of many autoimmune diseases. Mice deficient in the γ-chain of Fc-receptors are protected in IgG-mediated glomerulonephritis and the Arthus reaction and FcR-bearing mast cells and macrophages have been assigned primary roles in these processes. Here we demonstrate that neutrophil selective transgenic expression of the two uniquely human activating FcγRs, FcγRIIA and FcγRIIIB was sufficient to restore susceptibility to progressive anti-glomerular basement membrane (GBM) nephritis and the cutaneous Reverse Passive Arthus (RPA) reaction in γ-chain deficient mice. Both FcγRIIA and FcγRIIIB mediated robust neutrophil accumulation in tissues suggesting direct roles for these human receptors in IC-induced neutrophil recruitment, while FcγRIIA alone mediated organ injury. In an acute model of anti-GBM nephritis, both FcγRIIIB and FcγRIIA promoted initial neutrophil recruitment to glomerular immune-complexes (ICs) accessible to circulating cells, while FcγRIIA further sustained accumulation. In a model of soluble ICs deposited strictly within the post-capillary venules of the cremaster muscle, FcγRIIIB was solely responsible for converting initial selectin-dependent tethers to slow rolling and adhesion. However, in the cremaster RPA reaction, dependent on vascular and tissue accumulation of soluble ICs, FcγRIIA predominated in neutrophil recruitment that was dependent on G-protein coupled receptor activation. Thus, human FcγRs on neutrophils serve as the primary molecular links between ICs and immunological disease with FcγRIIA promoting tissue injury, and FcγRIIIB and FcγRIIA displaying specialized context-dependent functions in IC-induced neutrophil recruitment. PMID:18538590

  6. The ABA receptor PYL9 together with PYL8 plays an important role in regulating lateral root growth.

    PubMed

    Xing, Lu; Zhao, Yang; Gao, Jinghui; Xiang, Chengbin; Zhu, Jian-Kang

    2016-01-01

    Abscisic acid is a phytohormone regulating plant growth, development and stress responses. PYR1/PYL/RCAR proteins are ABA receptors that function by inhibiting PP2Cs to activate SnRK2s, resulting in phosphorylation of ABFs and other effectors of ABA response pathways. Exogenous ABA induces growth quiescence of lateral roots, which is prolonged by knockout of the ABA receptor PYL8. Among the 14 members of PYR1/PYL/RCAR protein family, PYL9 is a close relative of PYL8. Here we show that knockout of both PYL9 and PYL8 resulted in a longer ABA-induced quiescence on lateral root growth and a reduced sensitivity to ABA on primary root growth and lateral root formation compared to knockout of PYL8 alone. Induced overexpression of PYL9 promoted the lateral root elongation in the presence of ABA. The prolonged quiescent phase of the pyl8-1pyl9 double mutant was reversed by exogenous IAA. PYL9 may regulate auxin-responsive genes in vivo through direct interaction with MYB77 and MYB44. Thus, PYL9 and PYL8 are both responsible for recovery of lateral root from ABA inhibition via MYB transcription factors. PMID:27256015

  7. The ABA receptor PYL9 together with PYL8 plays an important role in regulating lateral root growth

    PubMed Central

    Xing, Lu; Zhao, Yang; Gao, Jinghui; Xiang, Chengbin; Zhu, Jian-Kang

    2016-01-01

    Abscisic acid is a phytohormone regulating plant growth, development and stress responses. PYR1/PYL/RCAR proteins are ABA receptors that function by inhibiting PP2Cs to activate SnRK2s, resulting in phosphorylation of ABFs and other effectors of ABA response pathways. Exogenous ABA induces growth quiescence of lateral roots, which is prolonged by knockout of the ABA receptor PYL8. Among the 14 members of PYR1/PYL/RCAR protein family, PYL9 is a close relative of PYL8. Here we show that knockout of both PYL9 and PYL8 resulted in a longer ABA-induced quiescence on lateral root growth and a reduced sensitivity to ABA on primary root growth and lateral root formation compared to knockout of PYL8 alone. Induced overexpression of PYL9 promoted the lateral root elongation in the presence of ABA. The prolonged quiescent phase of the pyl8-1pyl9 double mutant was reversed by exogenous IAA. PYL9 may regulate auxin-responsive genes in vivo through direct interaction with MYB77 and MYB44. Thus, PYL9 and PYL8 are both responsible for recovery of lateral root from ABA inhibition via MYB transcription factors. PMID:27256015

  8. G Protein-Coupled Receptor Signaling and Sphingosine-1-Phosphate Play a Phylogenetically Conserved Role in Endocrine Pancreas Morphogenesis ▿

    PubMed Central

    Serafimidis, Ioannis; Heximer, Scott; Beis, Dimitris; Gavalas, Anthony

    2011-01-01

    During development pancreatic endocrine cells migrate in a coordinated fashion. This migration is necessary to form fully functional islets, but the mechanisms involved remain unknown. Therapeutic strategies to restore β-cell mass and islet functionality by reprogramming endogenous exocrine cells would be strengthened from simultaneous treatments that enhance endocrine cell clustering. We found that endocrine progenitors respond to and regulate G protein-coupled receptor (GPCR) signaling in order to cluster in islets. Rgs4, a dedicated regulator of GPCR signaling, was specifically expressed in early epithelial endocrine progenitors of both zebrafish and mouse, and its expression in the mouse endocrine progenitors was strictly dependent upon Ngn3, the key specification gene of the endocrine lineage. Rgs4 loss of function resulted in defects in islet cell aggregation. By genetically inactivating Gαi-mediated GPCR signaling in endocrine progenitors, we established its role in islet cell aggregation in both mouse and zebrafish. Finally, we identified sphingosine-1-phosphate (S1P) as a ligand mediating islet cell aggregation in both species acting through distinct but closely related receptors. PMID:21911471

  9. Toll-Like Receptor 3 (TLR3) Plays a Major Role in the Formation of Rabies Virus Negri Bodies

    PubMed Central

    Ménager, Pauline; Roux, Pascal; Mégret, Françoise; Bourgeois, Jean-Pierre; Le Sourd, Anne-Marie; Danckaert, Anne; Lafage, Mireille; Préhaud, Christophe; Lafon, Monique

    2009-01-01

    Human neurons express the innate immune response receptor, Toll-like receptor 3 (TLR3). TLR3 levels are increased in pathological conditions such as brain virus infection. Here, we further investigated the production, cellular localisation, and function of neuronal TLR3 during neuronotropic rabies virus (RABV) infection in human neuronal cells. Following RABV infection, TLR3 is not only present in endosomes, as observed in the absence of infection, but also in detergent-resistant perinuclear inclusion bodies. As well as TLR3, these inclusion bodies contain the viral genome and viral proteins (N and P, but not G). The size and composition of inclusion bodies and the absence of a surrounding membrane, as shown by electron microscopy, suggest they correspond to the previously described Negri Bodies (NBs). NBs are not formed in the absence of TLR3, and TLR3−/− mice—in which brain tissue was less severely infected—had a better survival rate than WT mice. These observations demonstrate that TLR3 is a major molecule involved in the spatial arrangement of RABV–induced NBs and viral replication. This study shows how viruses can exploit cellular proteins and compartmentalisation for their own benefit. PMID:19247444

  10. Molecular basis for amino acid sensing by family C G-protein-coupled receptors

    PubMed Central

    Wellendorph, P; Bräuner-Osborne, H

    2009-01-01

    Family C of human G-protein-coupled receptors (GPCRs) is constituted by eight metabotropic glutamate receptors, two γ-aminobutyric acid type B (GABAB1–2) subunits forming the heterodimeric GABAB receptor, the calcium-sensing receptor, three taste1 receptors (T1R1–3), a promiscuous L-α-amino acid receptor G-protein-coupled receptor family C, group 6, subtype A (GPRC6A) and seven orphan receptors. Aside from the orphan receptors, the family C GPCRs are dimeric receptors characterized by a large extracellular Venus flytrap domain which bind the endogenous agonists. Except from the GABAB1–2 and T1R2–3 receptor, all receptors are either activated or positively modulated by amino acids. In this review, we outline mutational, biophysical and structural studies which have elucidated the interaction of the amino acids with the Venus flytrap domains, molecular mechanisms of receptor selectivity and the initial steps in receptor activation. PMID:19298394

  11. Gender Effect in Experimental Models of Human Medulloblastoma: Does the Estrogen Receptor β Signaling Play a Role?

    PubMed Central

    Ciucci, Alessandra; Meco, Daniela; De Stefano, Ilaria; Travaglia, Daniele; Zannoni, Gian Franco; Scambia, Giovanni; Riccardi, Riccardo; Saran, Anna

    2014-01-01

    Background The male-to-female sex ratio for medulloblastoma (MB) is approximately 1.5∶1, female gender being also a favorable prognostic factor. This study aimed at evaluating the impact of gender on MB tumorigenesis. Methods In vitro activity of 17β-estradiol (E2), DPN [2,3-bis(4-hydroxyphenyl)-propionitrile, a selective estrogen receptor β (ERβ)-agonist], PPT [4,4′,4″-(4-Propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol, a selective ERα-agonist] or DHT (5 alpha-dihydrotestosterone) was evaluated in three human MB cell lines. D283 Med cells were transplanted into athymic mice. Results A significant expression of ERβ, with little or no ERα, and low AR (androgen receptor) was found in MB cell lines. The compounds tested did not affect cell proliferation. In vivo, we observed a significantly lower growth of D283 Med in nude female mice compared to males. At microscopic examination, tumors from females showed a shift towards differentiation, as evaluated by lower nestin, and higher NSE (neuron-specific enolase) and GFAP (glial fibrillary acidic protein) expression compared to males. Tumors from females also showed lower Ki67 and p53 expression. The wild-type ERβ protein (ERβ1) was lost in male tumors, while it was a permanent feature in females, and a strong negative correlation was found between Ki67 and ERβ1 expression. Conversely, tumor levels of ERβ2 and ERβ5 did not significantly differ between genders. Increased levels of cyclin-dependent kinase inhibitor p21 were observed in females, suggesting that estrogen may decrease tumor growth through blocking cell cycle progression. An inhibition of the insulin-like growth factor I (IGF-I) signaling was also evident in females. Conclusion We provides mechanistic evidence supporting the idea that ERβ1 signaling may have pro-differentiation and tumor suppressive function in medulloblastomas. PMID:25000562

  12. Sigma-2 Receptors Play a Role in Cellular Metabolism: Stimulation of Glycolytic Hallmarks by CM764 in Human SK-N-SH Neuroblastoma.

    PubMed

    Nicholson, Hilary; Mesangeau, Christophe; McCurdy, Christopher R; Bowen, Wayne D

    2016-02-01

    Sigma-2 receptors are attractive antineoplastic targets due to their ability to induce apoptosis and their upregulation in rapidly proliferating cancer cells compared with healthy tissue. However, this role is inconsistent with overexpression in cancer, which is typically associated with upregulation of prosurvival factors. Here, we report a novel metabolic regulatory function for sigma-2 receptors. CM764 [6-acetyl-3-(4-(4-(2-amino-4-fluorophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one] binds with Ki values of 86.6 ± 2.8 and 3.5 ± 0.9 nM at the sigma-1 and sigma-2 receptors, respectively. CM764 increased reduction of MTT [3-[4,5 dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide] in human SK-N-SH neuroblastoma compared with untreated cells, an effect not due to proliferation. This effect was attenuated by five different sigma antagonists, including CM572 [3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)-6-isothiocyanatobenzo[d]oxazol-2(3H)-one], which has no significant affinity for sigma-1 receptors. This effect was also observed in MG-63 osteosarcoma and HEK293T cells, indicating that this function is not exclusive to neuroblastoma or to cancer cells. CM764 produced an immediate, robust, and transient increase in cytosolic calcium, consistent with sigma-2 receptor activation. Additionally, we observed an increase in the total NAD(+)/NADH level and the ATP level in CM764-treated SK-N-SH cells compared with untreated cells. After only 4 hours of treatment, basal levels of reactive oxygen species were reduced by 90% in cells treated with CM764 over untreated cells, and HIF1α and VEGF levels were increased after 3-24 hours of treatment. These data indicate that sigma-2 receptors may play a role in induction of glycolysis, representing a possible prosurvival function for the sigma-2 receptor that is consistent with its upregulation in cancer cells compared with healthy tissue. PMID:26574517

  13. The Nuclear Orphan Receptor COUP-TFII Plays an Essential Role in Adipogenesis, Glucose Homeostasis, and Energy Metabolism

    PubMed Central

    Li, Luoping; Xie, Xin; Qin, Jun; Jeha, George S.; Saha, Pradip K.; Yan, Jun; Haueter, Claire Menoza; Chan, Lawrence; Tsai, Sophia Y.; Tsai, Ming-Jer.

    2009-01-01

    Summary Adipose tissue development and function play a central role in the pathogenesis and pathophysiology of metabolic syndromes. Here we show that Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP-TFII) plays a pivotal role in adipogenesis and energy homeostasis. COUP-TFII is expressed in the early stages of white adipocyte (WAT) development. COUP-TFII heterozygous mice (COUP-TFII+/-) have much less WAT than wild type mice (COUP-TFII+/+). COUP-TFII+/- mice display a decreased expression of key regulators for WAT development. Knock down COUP-TFII in 3T3-L1 cells resulted in an increased expression of Wnt10b, while chromatin immunoprecipitation analysis revealed that Wnt10b is a direct target of COUP-TFII. Moreover, COUP-TFII+/− mice have increased mitochondrial biogenesis in WAT, and COUP-TFII+/− mice have improved glucose homeostasis and increased energy expenditure. Thus, COUP-TFII regulates adipogenesis by regulating the key molecules in adipocyte development, and can serve as a new target for regulating energy metabolism. PMID:19117548

  14. Nod-Like Receptor Protein-3 Inflammasome Plays an Important Role during Early Stages of Wound Healing

    PubMed Central

    Weinheimer-Haus, Eileen M.; Mirza, Rita E.; Koh, Timothy J.

    2015-01-01

    The Nod-like receptor protein (NLRP)-3 inflammasome/IL-1β pathway is involved in the pathogenesis of various inflammatory skin diseases, but its biological role in wound healing remains to be elucidated. Since inflammation is typically thought to impede healing, we hypothesized that loss of NLRP-3 activity would result in a downregulated inflammatory response and accelerated wound healing. NLRP-3 null mice, caspase-1 null mice and C57Bl/6 wild type control mice (WT) received four 8 mm excisional cutaneous wounds; inflammation and healing were assessed during the early stage of wound healing. Consistent with our hypothesis, wounds from NLRP-3 null and caspase-1 null mice contained lower levels of the pro-inflammatory cytokines IL-1β and TNF-α compared to WT mice and had reduced neutrophil and macrophage accumulation. Contrary to our hypothesis, re-epithelialization, granulation tissue formation, and angiogenesis were delayed in NLRP-3 null mice and caspase-1 null mice compared to WT mice, indicating that NLRP-3 signaling is important for early events in wound healing. Topical treatment of excisional wounds with recombinant IL-1β partially restored granulation tissue formation in wounds of NLRP-3 null mice, confirming the importance of NLRP-3-dependent IL-1β production during early wound healing. Despite the improvement in healing, angiogenesis and levels of the pro-angiogenic growth factor VEGF were further reduced in IL-1β treated wounds, suggesting that IL-1β has a negative effect on angiogenesis and that NLRP-3 promotes angiogenesis in an IL-1β-independent manner. These findings indicate that the NLRP-3 inflammasome contributes to the early inflammatory phase following skin wounding and is important for efficient healing. PMID:25793779

  15. Toll-Like Receptor 6 Plays an Important Role in Host Innate Resistance to Brucella abortus Infection in Mice

    PubMed Central

    de Almeida, Leonardo A.; Macedo, Gilson C.; Marinho, Fábio A. V.; Gomes, Marco T. R.; Corsetti, Patrícia P.; Silva, Aristóbolo M.; Cassataro, Juliana; Giambartolomei, Guillermo H.

    2013-01-01

    Brucella abortus is recognized by several Toll-like receptor (TLR)-associated pathways triggering proinflammatory responses that affect both the nature and intensity of the immune response. Previously, we demonstrated that B. abortus-mediated dendritic cell (DC) maturation and control of infection are dependent on the adaptor molecule MyD88. However, the involvement of all TLRs in response to B. abortus infection is not completely understood. Therefore, we decided to evaluate the requirement for TLR6 in host resistance to B. abortus. Here, we demonstrated that TLR6 is an important component for triggering an innate immune response against B. abortus. An in vitro luciferase assay indicated that TLR6 cooperates with TLR2 to sense Brucella and further activates NF-κB signaling. However, in vivo analysis showed that TLR6, not TLR2, is required for the efficient control of B. abortus infection. Additionally, B. abortus-infected dendritic cells require TLR6 to induce tumor necrosis factor alpha (TNF-α) and interleukin-12 (IL-12). Furthermore, our findings demonstrated that the mitogen-activated protein kinase (MAPK) signaling pathway is impaired in TLR2, TLR6, and TLR2/6 knockout (KO) DCs when infected with B. abortus, which may account for the lower proinflammatory cytokine production observed in TLR6 KO mouse dendritic cells. In summary, the results presented here indicate that TLR6 is required to trigger innate immune responses against B. abortus in vivo and is required for the full activation of DCs to induce robust proinflammatory cytokine production. PMID:23460520

  16. Behavioral Analyses of GHB: Receptor Mechanisms

    PubMed Central

    Carter, Lawrence P.; Koek, Wouter; France, Charles P.

    2009-01-01

    GHB is used therapeutically and recreationally, although the precise mechanism of action responsible for its different behavioral effects is not entirely clear. The purpose of this review is to summarize how behavioral procedures, especially drug discrimination procedures, have been used to study the mechanism of action of GHB. More specifically, we will review several different drug discrimination procedures and discuss how they have been used to qualitatively and quantitatively study different components of the complex mechanism of action of GHB. A growing number of studies have provided evidence that the behavioral effects of GHB are mediated predominantly by GABAB receptors. However, there is also evidence that the mechanisms mediating the effects of GHB and the prototypical GABAB receptor agonist baclofen are not identical, and that other mechanisms such as GHB receptors and subtypes of GABAA and GABAB receptors might contribute to the effects of GHB. These findings are consistent with the different behavioral profile, abuse liability, and therapeutic indications of GHB and baclofen. A better understanding of the similarities and differences between GHB and baclofen, as well as the pharmacological mechanisms of action underlying the recreational and therapeutic effects of GHB, could lead to more effective medications with fewer adverse effects. PMID:19010351

  17. Do HLA genes play a prominent role in determining T cell receptor V{alpha} segment usage in humans?

    SciTech Connect

    Gulwani-Akolkar, B.; Shi, B.; Akolkar, P.N.

    1995-04-15

    Previous studies in humans have demonstrated that HLA genes can profoundly influence the TCR V{beta} repertoire. To similarly assess the influence of HLA genes on the TCR V{alpha} segment repertoire, the V{alpha} repertoires of 12 individuals from three unrelated families were determined by quantitative PCR. Each family contained at least one pair of HLA-identical and -nonidentical siblings. Repertoire analysis was performed on purified CD4{sup +} and CD8{sup +} cells by using V{alpha}-specific primers. We were unable to demonstrate more similar V{alpha} repertoires between HLA-identical siblings than between HLA-nonidentical siblings. In contrast, when a similar analysis was performed on the same individuals for the V{beta} repertoire, HLA-identical siblings were found to have significantly more similar repertoires than HLA-nonidentical siblings. Furthermore, both the V{alpha} and V{beta} repertoires of monozygotic twins showed striking similarity. Despite our inability to shown an influence of HLA genes on the V{alpha} repertoire, we did observe a very strong skewing in terms of preferential expression on CD4{sup +} or CD8{sup +} cells of several V{alpha} segments, notably TCRAV1, -2, -5, -6, -7, -11, -12, and -13. These studies suggest that HLA genes play less of a role in determining V{alpha} segment usage than V{beta}. Nevertheless, the pronounced skewing of V{alpha} segment expression in the CD4{sup +} or CD8{sup +} populations suggests some role for HLA genes in determining the V{alpha} TCR repertoire. Furthermore, the striking similarity of V{alpha} repertoires of identical twins suggests a major role for non-HLA genes in determining the V{alpha} repertoire. 35 refs., 8 figs., 3 tabs.

  18. Endocytic trafficking towards the vacuole plays a key role in the auxin receptor SCF(TIR)-independent mechanism of lateral root formation in A. thaliana.

    PubMed

    Pérez-Henríquez, Patricio; Raikhel, Natasha V; Norambuena, Lorena

    2012-11-01

    Plants' developmental plasticity plays a pivotal role in responding to environmental conditions. One of the most plastic plant organs is the root system. Different environmental stimuli such as nutrients and water deficiency may induce lateral root formation to compensate for a low level of water and/or nutrients. It has been shown that the hormone auxin tunes lateral root development and components for its signaling pathway have been identified. Using chemical biology, we discovered an Arabidopsis thaliana lateral root formation mechanism that is independent of the auxin receptor SCF(TIR). The bioactive compound Sortin2 increased lateral root occurrence by acting upstream from the morphological marker of lateral root primordium formation, the mitotic activity. The compound did not display auxin activity. At the cellular level, Sortin2 accelerated endosomal trafficking, resulting in increased trafficking of plasma membrane recycling proteins to the vacuole. Sortin2 affected Late endosome/PVC/MVB trafficking and morphology. Combining Sortin2 with well-known drugs showed that endocytic trafficking of Late E/PVC/MVB towards the vacuole is pivotal for Sortin2-induced SCF(TIR)-independent lateral root initiation. Our results revealed a distinctive role for endosomal trafficking in the promotion of lateral root formation via a process that does not rely on the auxin receptor complex SCF(TIR). PMID:22848095

  19. The Ron Receptor Tyrosine Kinase Regulates Macrophage Heterogeneity and Plays a Protective Role in Diet-Induced Obesity, Atherosclerosis, and Hepatosteatosis.

    PubMed

    Yu, Shan; Allen, Joselyn N; Dey, Adwitia; Zhang, Limin; Balandaram, Gayathri; Kennett, Mary J; Xia, Mingcan; Xiong, Na; Peters, Jeffrey M; Patterson, Andrew; Hankey-Giblin, Pamela A

    2016-07-01

    Obesity is a chronic inflammatory disease mediated in large part by the activation of inflammatory macrophages. This chronic inflammation underlies a whole host of diseases including atherosclerosis, hepatic steatosis, insulin resistance, type 2 diabetes, and cancer, among others. Macrophages are generally classified as either inflammatory or alternatively activated. Some tissue-resident macrophages are derived from yolk sac erythromyeloid progenitors and fetal liver progenitors that seed tissues during embryogenesis and have the ability to repopulate through local proliferation. These macrophages tend to be anti-inflammatory in nature and are generally involved in tissue remodeling, repair, and homeostasis. Alternatively, during chronic inflammation induced by obesity, bone marrow monocyte-derived macrophages are recruited to inflamed tissues, where they produce proinflammatory cytokines and exacerbate inflammation. The extent to which these two populations of macrophages are plastic in their phenotype remains controversial. We have demonstrated previously that the Ron receptor tyrosine kinase is expressed on tissue-resident macrophages, where it limits inflammatory macrophage activation and promotes a repair phenotype. In this study, we demonstrate that Ron is expressed in a subpopulation of macrophages during chronic inflammation induced by obesity that exhibit a repair phenotype as determined by the expression of arginase 1. In addition, we demonstrate that the Ron receptor plays a protective role in the progression of diet-induced obesity, hepatosteatosis, and atherosclerosis. These results suggest that altering macrophage heterogeneity in vivo could have the potential to alleviate obesity-associated diseases. PMID:27233965

  20. Outdoor Play and Play Equipment.

    ERIC Educational Resources Information Center

    Naylor, Heather

    1985-01-01

    Discusses aspects of the play environment and its effect on children's play behavior. Indoor and outdoor play spaces are considered along with factors affecting the use of outdoor environments for play. Children's preferences for different outdoor play environments and for various play structures are explored. Guides for choosing play equipment…

  1. Identification and characterization of GABA(A) receptor autoantibodies in autoimmune encephalitis.

    PubMed

    Ohkawa, Toshika; Satake, Shin'Ichiro; Yokoi, Norihiko; Miyazaki, Yu; Ohshita, Tomohiko; Sobue, Gen; Takashima, Hiroshi; Watanabe, Osamu; Fukata, Yuko; Fukata, Masaki

    2014-06-11

    Autoimmune forms of encephalitis have been associated with autoantibodies against synaptic cell surface antigens such as NMDA- and AMPA-type glutamate receptors, GABA(B) receptor, and LGI1. However, it remains unclear how many synaptic autoantigens are yet to be defined. Using immunoproteomics, we identified autoantibodies against the GABA(A) receptor in human sera from two patients diagnosed with encephalitis who presented with cognitive impairment and multifocal brain MRI abnormalities. Both patients had antibodies directed against the extracellular epitope of the β3 subunit of the GABA(A) receptor. The β3-subunit-containing GABA(A) receptor was a major target of the patients' serum antibodies in rat hippocampal neurons because the serum reactivity to the neuronal surface was greatly decreased by 80% when the β3 subunit was knocked down. Our developed multiplex ELISA testing showed that both patients had similar levels of GABA(A) receptor antibodies, one patient also had a low level of LGI1 antibodies, and the other also had CASPR2 antibodies. Application of the patients' serum at the time of symptom presentation of encephalitis to rat hippocampal neuron cultures specifically decreased both synaptic and surface GABA(A) receptors. Furthermore, treatment of neurons with the patients' serum selectively reduced miniature IPSC amplitude and frequency without affecting miniature EPSCs. These results strongly suggest that the patients' GABA(A) receptor antibodies play a central role in the patients' symptoms. Therefore, this study establishes anti-GABA(A) receptor encephalitis and expands the pathogenic roles of GABA(A) receptor autoantibodies. PMID:24920620

  2. Scavenger Receptor Class A Plays a Central Role in Mediating Mortality and the Development of the Pro-Inflammatory Phenotype in Polymicrobial Sepsis

    PubMed Central

    Ozment, Tammy R.; Ha, Tuanzhu; Breuel, Kevin F.; Ford, Tiffany R.; Ferguson, Donald A.; Kalbfleisch, John; Schweitzer, John B.; Kelley, Jim L.; Li, Chuanfu; Williams, David L.

    2012-01-01

    Sepsis is a frequent complication in critical illness. The mechanisms that are involved in initiation and propagation of the disease are not well understood. Scavenger receptor A (SRA) is a membrane receptor that binds multiple polyanions such as oxidized LDL and endotoxin. Recent studies suggest that SRA acts as a pattern recognition receptor in the innate immune response. The goal of the present study was to determine the role of SRA in polymicrobial sepsis. SRA deficient (SRA−/−) and C57BL/6JB/6J (WT) male mice were subjected to cecal ligation and puncture (CLP) to induce polymicrobial sepsis. NFκB activity, myeloperoxidase activity, and co-association of SRA with toll like receptor (TLR) 4 and TLR2 was analyzed in the lungs. Spleens were analyzed for apoptosis. Serum cytokines and chemokines were assayed. Blood and peritoneal fluid were cultured for aerobic and anaerobic bacterial burdens. Long term survival was significantly increased in SRA−/− septic mice (53.6% vs. 3.6%, p<0.05) when compared to WT mice. NFκB activity was 45.5% lower in the lungs of SRA−/− septic mice versus WT septic mice (p<0.05). Serum levels of interleukin (IL)-5, IL-6, IL-10 and monocyte chemoattractant protein −1 were significantly lower in septic SRA−/− mice when compared to septic WT mice (p<0.05). We found that SRA immuno-precipitated with TLR4, but not TLR2, in the lungs of WT septic mice. We also found that septic SRA−/− mice had lower bacterial burdens than WT septic mice. SRA deficiency had no effect on pulmonary neutrophil infiltration or splenocyte apoptosis during sepsis. We conclude that SRA plays a pivotal, and previously unknown, role in mediating the pathophysiology of sepsis/septic shock in a murine model of polymicrobial sepsis. Mechanistically, SRA interacts with TLR4 to enhance the development of the pro-inflammatory phenotype and mediate the morbidity and mortality of sepsis/septic shock. PMID:23071440

  3. Phosphorylation of Tyr-610 in the Receptor Kinase BAK1 Plays a Role in Brassinosteroid Signaling and Basal Defense Gene Expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BAK1 is a leucine-rich repeat receptor-like kinase (LRR-RLK) that functions as a co-receptor with the brassinosteroid (BR) receptor BRI1 and the flagellin receptor FLS2, and also functions as a negative regulator of programmed cell death. BAK1 has been shown to autophosphorylate on numerous serine/t...

  4. New Play.

    ERIC Educational Resources Information Center

    Lersten, Kenneth C.

    There have been many theories and hypotheses about play, one of which is the equation of play with "transcendence." Play may have the ingredients to allow us to transcend and, for a moment, remythologize life. There have been recent authors who have given play the status of theology, indicating that play contains elements also found in religion.…

  5. Playful Gaming.

    ERIC Educational Resources Information Center

    Makedon, Alexander

    A philosophical analysis of play and games is undertaken in this paper. Playful gaming, which is shown to be a synthesis of play and games, is utilized as a category for undertaking the examination of play and games. The significance of playful gaming to education is demonstrated through analyses of Plato's, Dewey's, Sartre's, and Marcuse's…

  6. Plectin regulates the signaling and trafficking of the HIV-1 co-receptor CXCR4 and plays a role in HIV-1 infection

    SciTech Connect

    Ding Yun; Zhang Li; Goodwin, J. Shawn; Wang Ziqing; Liu Bingdong; Zhang Jingwu; Fan Guohuang

    2008-02-01

    The CXC chemokine CXCL12 and its cognate receptor CXCR4 play an important role in inflammation, human immunodeficiency virus (HIV) infection and cancer metastasis. The signal transduction and intracellular trafficking of CXCR4 are involved in these functions, but the underlying mechanisms remain incompletely understood. In the present study, we demonstrated that the CXCR4 formed a complex with the cytolinker protein plectin in a ligand-dependent manner in HEK293 cells stably expressing CXCR4. The glutathione-S-transferase (GST)-CXCR4 C-terminal fusion proteins co-precipitated with the full-length and the N-terminal fragments of plectin isoform 1 but not with the N-terminal deletion mutants of plectin isoform 1, thereby suggesting an interaction between the N-terminus of plectin and the C-terminus of CXCR4. This interaction was confirmed by confocal microscopic reconstructions showing co-distribution of these two proteins in the internal vesicles after ligand-induced internalization of CXCR4 in HEK293 cells stably expressing CXCR4. Knockdown of plectin with RNA interference (RNAi) significantly inhibited ligand-dependent CXCR4 internalization and attenuated CXCR4-mediated intracellular calcium mobilization and activation of extracellular signal regulated kinase 1/2 (ERK1/2). CXCL12-induced chemotaxis of HEK293 cells stably expressing CXCR4 and of Jurkat T cells was inhibited by the plectin RNAi. Moreover, CXCR4 tropic HIV-1 infection in MAGI (HeLa-CD4-LTR-Gal) cells was inhibited by the RNAi of plectin. Thus, plectin appears to interact with CXCR4 and plays an important role in CXCR4 signaling and trafficking and HIV-1 infection.

  7. Diabetes-induced upregulation of urotensin II and its receptor plays an important role in TGF-beta1-mediated renal fibrosis and dysfunction.

    PubMed

    Tian, Lin; Li, Cai; Qi, Jiping; Fu, Peng; Yu, Xiaoyan; Li, Xiaokun; Cai, Lu

    2008-11-01

    Urotensin II (UII) was identified as the ligand for a novel G protein-coupled receptor, GPR14. UII was found not only to have a potent vasoconstrictive action but also to have profibrotic effects in the heart. The present study was to define whether UII and GPR14 also play important roles in diabetes-induced renal fibrosis and dysfunction. Diabetic rats were induced using streptozotocin, and the rat proximal tubular epithelial cells (NRK-52E) were used for the in vitro mechanism study. Results showed that expression of UII and GPR14 was significantly upregulated at both mRNA and protein levels in the diabetic kidneys compared with controls. The upregulated expressions of UII and GPR14 in the kidney were accompanied by significant increases in the renal profibrotic factor transforming growth factor (TGF)-beta1 expression, the renal extracellular matrix (fibronectin and collagen IV) accumulation, and the renal dysfunction (increases in urinal N-acetyl-beta-d-glucosaminidase content, 24-h urinary retinol-binding protein excretion rate, and decrease in creatinine clearance rate). Exposure of NRK-52E cells to 10(-8) mol/l UII for 48 h caused a significant increase of TGF-beta1, but not ANG II, production that was GPR14- and calcium-dependent, since GPR14 small-interfering RNA and calcium channel blocker nimodipine or calcium chelator EDTA all could abolish the induction of TGF- beta1 by UII. Furthermore, exposure of NRK-52E cells to TGF-beta1 or ANG II also increased UII and GPR14 mRNA expressions. These results suggested that diabetes-induced upregulation of UII and GPR14, most likely through autocrine and/or paracrine mechanisms, plays an important role in TGF-beta1-mediated renal fibrosis and dysfunction. PMID:18796544

  8. SARI, a novel target gene of glucocorticoid receptor, plays an important role in dexamethasone-mediated killing of B lymphoma cells.

    PubMed

    Huang, Yinghui; Zhou, Jie; Huang, Yan; He, Jintao; Wang, Yuting; Yang, Chaohui; Liu, Dongbo; Zhang, Li; He, Fengtian

    2016-04-01

    Dexamethasone (Dex) has been commonly used in lymphoma and leukemia treatment, but the detailed mechanisms are not fully understood. Suppressor of AP-1 regulated by interferon (SARI) has tumor-selective growth inhibitory effect. However, it's unclear whether SARI is involved in the Dex-mediated lymphoma growth suppression. In this study, we found that Dex-treated B lymphoma tissues had a higher level of SARI. Dex repressed the growth of B lymphoma cells and upregulated SARI expression by activating glucocorticoid receptor (GR) in vitro and in vivo. Silencing of SARI attenuated the Dex-mediated growth suppression of B lymphoma cells and inhibition of AP-1 activity. Reporter assays revealed that activation of GR enhanced the transcriptional activity of SARI promoter. EMSA and ChIP assays showed that GR directly bound to the ER9 element in SARI promoter region. These results for the first time demonstrated that SARI is a novel target gene of GR, and the upregulation of SARI plays an important role in Dex's killing effect on B lymphoma cells, suggesting that SARI may serve as a novel target and a potential indicator of Dex sensitivity in B lymphoma treatment. PMID:26808579

  9. Pseudo-piano playing motions and nocturnal hypoventilation in anti-NMDA receptor encephalitis: response to prompt tumor removal and immunotherapy.

    PubMed

    Uchino, Akiko; Iizuka, Takahiro; Urano, Yoshiaki; Arai, Masahide; Hara, Atsuko; Hamada, Junichi; Hirose, Ryuichi; Dalmau, Josep; Mochizuki, Hideki

    2011-01-01

    Tumor resection is recommended in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, however it is often difficult during an early stage of the disease. We report here the efficacy of early tumor removal in a patient with anti-NMDAR encephalitis. This 21-year-old woman was admitted to another hospital with rapidly progressive psychiatric symptoms, a decreased level of consciousness, and seizures. Abdominal CT showed a pelvic mass. On day 1 of admission to our center, she developed hypoventilation requiring mechanical support. She had orofacial dyskinesias with well-coordinated, pseudo-piano playing involuntary finger movements. Based on these clinical features, she was immediately scheduled for tumor resection on day 3. While awaiting surgery, she began to receive high-dose intravenous methylprednisolone. After tumor removal, she received plasma exchange, followed by intravenous immunoglobulin and additional high-dose methylprednisolone. Two weeks after tumor removal, she started following simple commands and progressive improvement, although she remained on mechanical ventilation for 10 weeks due to nocturnal central hypoventilation. Anti-NMDAR antibodies in serum/CSF were detected. Pathological examination showed immature teratoma with foci of infiltrates of B- and T-cells. Early tumor resection with immunotherapy facilitates recovery from this disease, but central hypoventilation may require long mechanical support. Non-jerky elaborate finger movements suggest antibody-mediated disinhibition of the cortico-striatal systems. PMID:21422691

  10. Pseudo-Piano Playing Motions and Nocturnal Hypoventilation in Anti-NMDA Receptor Encephalitis: Response to Prompt Tumor Removal and Immunotherapy

    PubMed Central

    Uchino, Akiko; Iizuka, Takahiro; Urano, Yoshiaki; Arai, Masahide; Hara, Atsuko; Hamada, Junichi; Hirose, Ryuichi; Dalmau, Josep; Mochizuki, Hideki

    2013-01-01

    Tumor resection is recommended in anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, however it is often difficult during an early stage of the disease. We report here the efficacy of early tumor removal in a patient with anti-NMDAR encephalitis. This 21-year-old woman was admitted to another hospital with rapidly progressive psychiatric symptoms, a decreased level of consciousness, and seizures. Abdominal CT showed a pelvic mass. On day 1 of admission to our center, she developed hypoventilation requiring mechanical support. She had orofacial dyskinesias with well-coordinated, pseudo-piano playing involuntary finger movements. Based on these clinical features, she was immediately scheduled for tumor resection on day 3. While awaiting surgery, she began to receive high-dose intravenous methylprednisolone. After tumor removal, she received plasma exchange, followed by intravenous immunoglobulin and additional high-dose methylprednisolone. Two weeks after tumor removal, she started following simple commands and progressive improvement, although she remained on mechanical ventilation for 10 weeks due to nocturnal central hypoventilation. Anti-NMDAR antibodies in serum/CSF were detected. Pathological examination showed immature teratoma with foci of infiltrates of B- and T-cells. Early tumor resection with immunotherapy facilitates recovery from this disease, but central hypoventilation may require long mechanical support. Non-jerky elaborate finger movements suggest antibody-mediated disinhibition of the cortico-striatal systems. PMID:21422691

  11. Stimulation of TM3 Leydig cell proliferation via GABAA receptors: A new role for testicular GABA

    PubMed Central

    Geigerseder, Christof; Doepner, Richard FG; Thalhammer, Andrea; Krieger, Annette; Mayerhofer, Artur

    2004-01-01

    The neurotransmitter gamma-aminobutyric acid (GABA) and subtypes of GABA receptors were recently identified in adult testes. Since adult Leydig cells possess both the GABA biosynthetic enzyme glutamate decarboxylase (GAD), as well as GABAA and GABAB receptors, it is possible that GABA may act as auto-/paracrine molecule to regulate Leydig cell function. The present study was aimed to examine effects of GABA, which may include trophic action. This assumption is based on reports pinpointing GABA as regulator of proliferation and differentiation of developing neurons via GABAA receptors. Assuming such a role for the developing testis, we studied whether GABA synthesis and GABA receptors are already present in the postnatal testis, where fetal Leydig cells and, to a much greater extend, cells of the adult Leydig cell lineage proliferate. Immunohistochemistry, RT-PCR, Western blotting and a radioactive enzymatic GAD assay evidenced that fetal Leydig cells of five-six days old rats possess active GAD protein, and that both fetal Leydig cells and cells of the adult Leydig cell lineage possess GABAA receptor subunits. TM3 cells, a proliferating mouse Leydig cell line, which we showed to possess GABAA receptor subunits by RT-PCR, served to study effects of GABA on proliferation. Using a colorimetric proliferation assay and Western Blotting for proliferating cell nuclear antigen (PCNA) we demonstrated that GABA or the GABAA agonist isoguvacine significantly increased TM3 cell number and PCNA content in TM3 cells. These effects were blocked by the GABAA antagonist bicuculline, implying a role for GABAA receptors. In conclusion, GABA increases proliferation of TM3 Leydig cells via GABAA receptor activation and proliferating Leydig cells in the postnatal rodent testis bear a GABAergic system. Thus testicular GABA may play an as yet unrecognized role in the development of Leydig cells during the differentiation of the testicular interstitial compartment. PMID:15040802

  12. Compartmental distribution of GABAB receptor-mediated currents along the somatodendritic axis of hippocampal principal cells

    PubMed Central

    Degro, Claudius E.; Kulik, Akos; Booker, Sam A.; Vida, Imre

    2015-01-01

    Activity of cortical principal cells is controlled by the GABAergic system providing inhibition in a compartmentalized manner along their somatodendritic axis. While GABAAR-mediated inhibitory synaptic transmission has been extensively characterized in hippocampal principal cells, little is known about the distribution of postsynaptic effects of GABABRs. In the present study, we have investigated the functional localization of GABABRs and their effector inwardly rectifying potassium (Kir3) channels by combining electrophysiological recordings in acute rat hippocampal slices, high-resolution immunoelectron microscopic analysis and single cell simulations. Pharmacologically isolated slow inhibitory postsynaptic currents were elicited in the three major hippocampal principal cell types by endogenous GABA released by electrical stimulation, photolysis of caged-GABA, as well as the canonical agonist baclofen, with the highest amplitudes observed in the CA3. Spatially restricted currents were assessed along the axis of principal cells by uncaging GABA in the different hippocampal layers. GABABR-mediated currents were present along the entire somatodendritic axis of principal cells, but non-uniformly distributed: largest currents and the highest conductance densities determined in the simulations were consistently found on the distal apical dendrites. Finally, immunocytochemical localization of GABABRs and Kir3 channels showed that distributions overlap but their densities diverge, particularly on the basal dendrites of pyramidal cells. GABABRs current amplitudes and the conductance densities correlated better with Kir3 density, suggesting a bottlenecking effect defined by the effector channel. These data demonstrate a compartmentalized distribution of the GABABR-Kir3 signaling cascade and suggest differential control of synaptic transmission, dendritic integration and synaptic plasticity at afferent pathways onto hippocampal principal cells. PMID:25852540

  13. Adult Play.

    ERIC Educational Resources Information Center

    Charles, John M.

    In its broadest context, play can be interpreted as any pleasurable use of discretionary time. Playfulness is an intrinsic feature of being human, and should be viewed in the light of a total lifestyle, not as an occurrence in an isolated time of life. Adult play appears to be an indefinable and controversial concept. A holistic approach should be…

  14. Wanna Play?

    ERIC Educational Resources Information Center

    Chenfeld, Mimi Brodsky

    2006-01-01

    In this article, the author talks about the importance of play in the lives of children and describes how games and imaginative play contribute to the development of children. From her decades-old collection of countless incidents demonstrating children's love for self-directed, informal, imaginative play, the author shares three incidents that…

  15. City Play.

    ERIC Educational Resources Information Center

    Dargan, Amanda; Zeitlin, Steve

    2000-01-01

    Today, fewer city blocks preserve the confidence of lifestyle and urban geography that sustain traditional games and outdoor play. Large groups of children choosing sides and organizing Red Rover games are no longer commonplace. Teachers must encourage free play; urban planners must build cities that are safe play havens. (MLH)

  16. Neonatal melanocortin receptor agonist treatment reduces play fighting and promotes adult attachment in prairie voles in a sex-dependent manner.

    PubMed

    Barrett, Catherine E; Modi, Meera E; Zhang, Billy C; Walum, Hasse; Inoue, Kiyoshi; Young, Larry J

    2014-10-01

    The melanocortin receptor (MCR) system has been studied extensively for its role in feeding and sexual behavior, but effects on social behavior have received little attention. α-MSH interacts with neural systems involved in sociality, including oxytocin, dopamine, and opioid systems. Acute melanotan-II (MTII), an MC3/4R agonist, potentiates brain oxytocin (OT) release and facilitates OT-dependent partner preference formation in socially monogamous prairie voles. Here we examined the long-term impact of early-life MCR stimulation on hypothalamic neuronal activity and social development in prairie voles. Male and female voles were given daily subcutaneous injections of 10 mg/kg MTII or saline between postnatal days (PND) 1-7. Neonatally-treated males displayed a reduction in initiated play fighting bouts as juveniles compared to control males. Neonatal exposure to MTII facilitated partner preference formation in adult females, but not males, after a brief cohabitation with an opposite-sex partner. Acute MTII injection elicited a significant burst of the immediate early gene EGR-1 immunoreactivity in hypothalamic OT, vasopressin, and corticotrophin releasing factor neurons, when tested in PND 6-7 animals. Daily neonatal treatment with 1 mg/kg of a more selective, brain penetrant MC4R agonist, PF44687, promoted adult partner preferences in both females and males compared with vehicle controls. Thus, developmental exposure to MCR agonists lead to a persistent change in social behavior, suggestive of structural or functional changes in the neural circuits involved in the formation of social relationships. PMID:24923239

  17. COUP-TFI and -TFII nuclear receptors are expressed in amacrine cells and play roles in regulating the differentiation of retinal progenitor cells.

    PubMed

    Inoue, Mariko; Iida, Atsumi; Satoh, Shinya; Kodama, Tatsuhiko; Watanabe, Sumiko

    2010-01-01

    Chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are members of the steroid/thyroid hormone receptor superfamily. We have shown that two homologous COUP-TF genes, COUP-TFI and COUP-TFII, are expressed in developing mouse retina with a unique gradient along the dorsal-ventral axis. In this work, we aimed to characterize the detailed expression patterns of COUP-TFs in mature retina. Their functions in retinal progenitor cell differentiation into subtypes of mature retinal cells were also examined. Immunostaining of frozen mouse retinal sections with antibodies against COUP-TFs and markers for retinal subtypes revealed that COUP-TFI and -TFII are expressed in amacrine cells, especially in a glycinergic subtype in mature mouse retina. Forced expression of COUP-TFI and -TFII in mouse retinal explant culture by retrovirus-mediated gene transfer promoted amacrine and cone photoreceptor cell differentiation, whereas that of rod photoreceptors decreased. Cell proliferation and apoptosis were not affected by the perturbation of COUP-TFI and -TFII expression levels. Using the Y79 retinoblastoma cell line, we observed that COUP-TFI and -TFII suppressed the transcriptional activation of the Nrl gene. We then analyzed one another member of COUP-TF transcription factors, COUP-TFgamma, whose structure is relatively distant from those of COUP-TFI and -TFII. It is expressed mainly in horizontal cells and has weak activity in inducing amacrine cells when COUP-TFgamma was ectopically expressed in retinal explants. In summary, we found that COUP-TFI and -TFII play roles in amacrine cell differentiation, and COUP-TFgamma has distinct expression pattern and roles during retinal development. PMID:19766631

  18. Toll-Like Receptor 9 Is Required for Full Host Resistance to Mycobacterium avium Infection but Plays No Role in Induction of Th1 Responses▿

    PubMed Central

    Carvalho, Natália B.; Oliveira, Fernanda S.; Durães, Fernanda V.; de Almeida, Leonardo A.; Flórido, Manuela; Prata, Luana O.; Caliari, Marcelo V.; Appelberg, Rui; Oliveira, Sérgio C.

    2011-01-01

    To investigate the role of Toll-like receptor 9 (TLR9) in innate immunity to Mycobacterium avium, TLR9, TLR2, and MyD88 knockout (KO) mice were infected with this bacterium. Bacterial burdens were higher in the spleens, livers, and lungs of infected TLR9 KO mice than in those of C57BL/6 mice, indicating that TLR9 is required for efficient control of M. avium infection. However, TLR9 KO or TLR2 KO spleen cells displayed normal M. avium-induced tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) responses. This finding was confirmed by determining the number of splenic CD4+ T cells producing IFN-γ by flow cytometry. Furthermore, TLR2 and MyD88, but not TLR9, played a major role in interleukin-12 and TNF-α production by M. avium-infected macrophages and dendritic cells (DCs). We also found that major histocompatibility complex class II molecule expression on DCs is regulated by TLR2 and MyD88 signaling but not by TLR9. Finally, lack of TLR9, TLR2, or MyD88 reduced the numbers of macrophages, epithelioid cells, and lymphocytes in M. avium-induced granulomas but only MyD88 deficiency affected the number of liver granulomas. In summary, our data demonstrated that the involvement of TLR9 in the control of M. avium infection is not related to the induction of Th1 responses. PMID:21300776

  19. Complement Factor B is the Downstream Effector of Toll-Like Receptors and Plays an Important Role in a Mouse Model of Severe Sepsis¶

    PubMed Central

    Zou, Lin; Feng, Yan; Li, Yan; Zhang, Ming; Chen, Chan; Cai, Jiayan; Gong, Yu; Wang, Larry; Thurman, Joshua M.; Wu, Xiaobo; Atkinson, John P.; Chao, Wei

    2013-01-01

    Severe sepsis involves massive activation of the innate immune system and leads to high mortality. Previous studies have demonstrated that various types of Toll-like receptors (TLRs) mediate a systemic inflammatory response and contribute to organ injury and mortality in animal models of severe sepsis. However, the downstream mechanisms responsible for TLR-mediated septic injury are poorly understood. Here, we show that activation of TLR2, TLR3 and TLR4 markedly enhanced complement factor B (cfB) synthesis and release by macrophages and cardiac cells. Polymicrobial sepsis, created by cecal ligation and puncture (CLP) in a mouse model, augmented cfB levels in the serum, peritoneal cavity and major organs including the kidney and heart. CLP also led to the alternative pathway (AP) activation, C3 fragment deposition in the kidney and heart, and cfB-dependent C3dg elevation. Bacteria isolated from septic mice activated the serum AP via a factor D-dependent manner. MyD88 deletion attenuated cfB/C3 up-regulation as well as cleavage induced by polymicrobial infection. Importantly, during sepsis, absence of cfB conferred a protective effect with improved survival and cardiac function, and markedly attenuated acute kidney injury. cfB deletion also led to increased neutrophil migratory function during the early phase of sepsis, decreased local and systemic bacterial load, attenuated cytokine production and reduced neutrophil reactive oxygen species production. Together, our data indicate that cfB acts as a downstream effector of TLR signaling and plays a critical role in the pathogenesis of severe bacterial sepsis. PMID:24154627

  20. GPR39, a receptor of the ghrelin receptor family, plays a role in the regulation of glucose homeostasis in a mouse model of early onset diet-induced obesity.

    PubMed

    Verhulst, P J; Lintermans, A; Janssen, S; Loeckx, D; Himmelreich, U; Buyse, J; Tack, J; Depoortere, I

    2011-06-01

    GPR39, which may function as a Zn(2+) sensor, is a member of the G protein-coupled receptor family that also includes the receptor for the hunger hormone ghrelin. The down-regulation of GPR39 mRNA in adipose tissue of obese type 2 diabetic patients suggests that GPR39 may contribute to the pathogenesis of the disease. The present study aimed to investigate the role of GPR39 in the regulation of energy balance and glucose homeostasis in wild-type (GPR39(+/+) ) and GPR39 knockout mice (GPR39(-/-) ) with obesity-related type 2 diabetes. GPR39 mRNA levels in adipose tissue of fasted GPR39(+/+) mice fed a high-fat diet (HFD) for 30 weeks were reduced and correlated positively with blood glucose levels. Body weight, fat percentage and energy intake were increased in the HFD group but did not differ between both genotypes. Within the HFD group, blood glucose levels were lower in GPR39(-/-) than in GPR39(+/+) mice, despite significant reductions in prandial plasma insulin levels. The latter may not be a result of changes in β-cell hyperplasia because immunohistochemical staining of pancreata of mice on a HFD showed no differences between genotypes. The lower blood glucose levels may involve alterations in insulin sensitivity as revealed by glucose tolerance tests and respiratory quotient measurements that showed a preference of obese GPR39(-/-) mice for the use of carbohydrates as metabolic fuel. The increase in plasma ghrelin levels in GPR39(-/-) mice fed a HFD may contribute to the alterations in glucose homeostasis, whereas changes in gastric emptying or intestinal Zn(2+) absorption are not involved. The results obtained in the present study suggest that GPR39 plays a role in the pathogenesis of obesity-related type 2 diabetes by affecting the regulation of glucose homeostasis. PMID:21470317

  1. GHB receptor targets in the CNS: focus on high-affinity binding sites.

    PubMed

    Bay, Tina; Eghorn, Laura F; Klein, Anders B; Wellendorph, Petrine

    2014-01-15

    γ-Hydroxybutyric acid (GHB) is an endogenous compound in the mammalian brain with both low- and high-affinity receptor targets. GHB is used clinically in the treatment of symptoms of narcolepsy and alcoholism, but also illicitly abused as the recreational drug Fantasy. Major pharmacological effects of exogenous GHB are mediated by GABA subtype B (GABAB) receptors that bind GHB with low affinity. The existence of GHB high-affinity binding sites has been known for more than three decades, but the uncovering of their molecular identity has only recently begun. This has been prompted by the generation of molecular tools to selectively study high-affinity sites. These include both genetically modified GABAB knock-out mice and engineered selective GHB ligands. Recently, certain GABA subtype A (GABAA) receptor subtypes emerged as high-affinity GHB binding sites and potential physiological mediators of GHB effects. In this research update, a description of the various reported receptors for GHB is provided, including GABAB receptors, certain GABAA receptor subtypes and other reported GHB receptors. The main focus will thus be on the high-affinity binding targets for GHB and their potential functional roles in the mammalian brain. PMID:24269284

  2. Pretend play.

    PubMed

    Weisberg, Deena Skolnick

    2015-01-01

    Pretend play is a form of playful behavior that involves nonliteral action. Although on the surface this activity appears to be merely for fun, recent research has discovered that children's pretend play has connections to important cognitive and social skills, such as symbolic thinking, theory of mind, and counterfactual reasoning. The current article first defines pretend play and then reviews the arguments and evidence for these three connections. Pretend play has a nonliteral correspondence to reality, hence pretending may provide children with practice with navigating symbolic relationships, which may strengthen their language skills. Pretend play and theory of mind reasoning share a focus on others' mental states in order to correctly interpret their behavior, hence pretending and theory of mind may be mutually supportive in development. Pretend play and counterfactual reasoning both involve representing nonreal states of affairs, hence pretending may facilitate children's counterfactual abilities. These connections make pretend play an important phenomenon in cognitive science: Studying children's pretend play can provide insight into these other abilities and their developmental trajectories, and thereby into human cognitive architecture and its development. PMID:26263228

  3. Shadow Play

    ERIC Educational Resources Information Center

    Trundle, Kathy Cabe; Hilson, Margilee P.

    2012-01-01

    A bunny rabbit playfully hops across the wall. Then hands realign and fingers shift to make a hawk soar toward the ceiling. Most children have enjoyed the delightful experience of playing with shadow puppets. The authors build on this natural curiosity to help students link shadows to complex astronomical concepts such as seasons. The…

  4. Heteromeric Canonical Transient Receptor Potential 1 and 4 Channels Play a Critical Role in Epileptiform Burst Firing and Seizure-Induced Neurodegeneration

    PubMed Central

    Phelan, Kevin D.; Mock, Matthew M.; Kretz, Oliver; Shwe, U. Thaung; Kozhemyakin, Maxim; Greenfield, L. John; Dietrich, Alexander; Birnbaumer, Lutz; Freichel, Marc; Flockerzi, Veit

    2012-01-01

    Canonical transient receptor potential channels (TRPCs) are receptor-operated cation channels that are activated in response to phospholipase C signaling. Although TRPC1 is ubiquitously expressed in the brain, TRPC4 expression is the most restrictive, with the highest expression level limited to the lateral septum. The subunit composition of neuronal TRPC channels remains uncertain because of conflicting data from recombinant expression systems. Here we report that the large depolarizing plateau potential that underlies the epileptiform burst firing induced by metabotropic glutamate receptor agonists in lateral septal neurons was completely abolished in TRPC1/4 double-knockout mice, and was abolished in 74% of lateral septal neurons in TRPC1 knockout mice. Furthermore, neuronal cell death in the lateral septum and the cornu ammonis 1 region of hippocampus after pilocarpine-induced severe seizures was significantly ameliorated in TRPC1/4 double-knockout mice. Our data suggest that both TRPC1 and TRPC4 are essential for an intrinsic membrane conductance mediating the plateau potential in lateral septal neurons, possibly as heteromeric channels. Moreover, excitotoxic neuronal cell death, an underlying process for many neurological diseases, is not mediated merely by ionotropic glutamate receptors but also by heteromeric TRPC channels activated by metabotropic glutamate receptors. TRPC channels could be an unsuspected but critical molecular target for clinical intervention for excitotoxicity. PMID:22144671

  5. Heteromeric canonical transient receptor potential 1 and 4 channels play a critical role in epileptiform burst firing and seizure-induced neurodegeneration.

    PubMed

    Phelan, Kevin D; Mock, Matthew M; Kretz, Oliver; Shwe, U Thaung; Kozhemyakin, Maxim; Greenfield, L John; Dietrich, Alexander; Birnbaumer, Lutz; Freichel, Marc; Flockerzi, Veit; Zheng, Fang

    2012-03-01

    Canonical transient receptor potential channels (TRPCs) are receptor-operated cation channels that are activated in response to phospholipase C signaling. Although TRPC1 is ubiquitously expressed in the brain, TRPC4 expression is the most restrictive, with the highest expression level limited to the lateral septum. The subunit composition of neuronal TRPC channels remains uncertain because of conflicting data from recombinant expression systems. Here we report that the large depolarizing plateau potential that underlies the epileptiform burst firing induced by metabotropic glutamate receptor agonists in lateral septal neurons was completely abolished in TRPC1/4 double-knockout mice, and was abolished in 74% of lateral septal neurons in TRPC1 knockout mice. Furthermore, neuronal cell death in the lateral septum and the cornu ammonis 1 region of hippocampus after pilocarpine-induced severe seizures was significantly ameliorated in TRPC1/4 double-knockout mice. Our data suggest that both TRPC1 and TRPC4 are essential for an intrinsic membrane conductance mediating the plateau potential in lateral septal neurons, possibly as heteromeric channels. Moreover, excitotoxic neuronal cell death, an underlying process for many neurological diseases, is not mediated merely by ionotropic glutamate receptors but also by heteromeric TRPC channels activated by metabotropic glutamate receptors. TRPC channels could be an unsuspected but critical molecular target for clinical intervention for excitotoxicity. PMID:22144671

  6. Clay Play

    ERIC Educational Resources Information Center

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  7. Playing Teacher.

    ERIC Educational Resources Information Center

    Gilbert, Juan E.

    The acceptance of animation technologies is increasing. Video games, such as Sony PlayStation (SONY, 2002), have become part of the culture for young people from kindergarten through undergraduate school. Animation technologies have been implemented into educational systems in the form of animated pedagogical agents (Johnson, 2000). The research…

  8. Game playing.

    PubMed

    Rosin, Christopher D

    2014-03-01

    Game playing has been a core domain of artificial intelligence research since the beginnings of the field. Game playing provides clearly defined arenas within which computational approaches can be readily compared to human expertise through head-to-head competition and other benchmarks. Game playing research has identified several simple core algorithms that provide successful foundations, with development focused on the challenges of defeating human experts in specific games. Key developments include minimax search in chess, machine learning from self-play in backgammon, and Monte Carlo tree search in Go. These approaches have generalized successfully to additional games. While computers have surpassed human expertise in a wide variety of games, open challenges remain and research focuses on identifying and developing new successful algorithmic foundations. WIREs Cogn Sci 2014, 5:193-205. doi: 10.1002/wcs.1278 CONFLICT OF INTEREST: The author has declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. PMID:26304308

  9. Sweet Play

    ERIC Educational Resources Information Center

    Leung, Shuk-kwan S.; Lo, Jane-Jane

    2010-01-01

    This article features Sweet play math, a "math by the month" activity that involves decorating and making sugar cubes. Teachers may want to substitute straws, paper squares, alphabet blocks, or such commercially made manipulatives as Unifix[R] cubes for the real sweets. Given no allergy concerns, teachers and students alike would enjoy some sweet…

  10. The Cannabinoid Receptor CB1 Interacts with the WAVE1 Complex and Plays a Role in Actin Dynamics and Structural Plasticity in Neurons

    PubMed Central

    Njoo, Christian; Agarwal, Nitin; Lutz, Beat; Kuner, Rohini

    2015-01-01

    The molecular composition of the cannabinoid type 1 (CB1) receptor complex beyond the classical G-protein signaling components is not known. Using proteomics on mouse cortex in vivo, we pulled down proteins interacting with CB1 in neurons and show that the CB1 receptor assembles with multiple members of the WAVE1 complex and the RhoGTPase Rac1 and modulates their activity. Activation levels of CB1 receptor directly impacted on actin polymerization and stability via WAVE1 in growth cones of developing neurons, leading to their collapse, as well as in synaptic spines of mature neurons, leading to their retraction. In adult mice, CB1 receptor agonists attenuated activity-dependent remodeling of dendritic spines in spinal cord neurons in vivo and suppressed inflammatory pain by regulating the WAVE1 complex. This study reports novel signaling mechanisms for cannabinoidergic modulation of the nervous system and demonstrates a previously unreported role for the WAVE1 complex in therapeutic applications of cannabinoids. PMID:26496209

  11. Central NPY-Y5 receptors activation plays a major role in fasting-induced pituitary-thyroid axis suppression in adult rat.

    PubMed

    Costa-e-Sousa, Ricardo Henrique; Souza, Luana Lopes; Calviño, Camila; Cabanelas, Adriana; Almeida, Norma Aparecida Santos; Oliveira, Karen Jesus; Pazos-Moura, Carmen Cabanelas

    2011-11-10

    Neuropeptide Y (NPY) inhibits TRH neurons in fed state, and hypothalamic NPY higher expression during fasting has been proposed to be involved in fasting-induced suppression of the hypothalamus-pituitary-thyroid (HPT) axis. We investigated the role of central Y5 receptors in the control of thyrotropin (TSH) and thyroid hormone (TH) secretion. Fed and fasting rats received twice daily central injections (3rd ventricle) of Y5 receptor antagonist (CGP71683; 15nmol/rat) for 72h. Fasted rats also received a single central injection of CGP71683 (15nmol/rat) at the end of 72h of fasting. In fed rats, Y5 receptor blockade reduced total food intake by 32% and body mass by almost 10% (p<0.01), corroborating the role of this receptor in food intake control. 72h-fasted rats exhibited a 4-fold increase in serum TSH (p<0.001), 1h after a single injection of Y5 antagonist. Also with multiple injections during 72h of fasting, Y5 blockade resulted in activation of thyroid axis, as demonstrated by a 3-times rise in serum T4 (p<0.001), accompanied by unchanged TSH and T3. In fed rats, the chronic central administration of CGP71683 resulted in reduced total serum T4 without changes in free T4 and TSH. Serum leptin and PYY were not altered by the NPY central blockade in both fed and fasted rats, suggesting no role of these hormones in the alterations observed. Therefore, the inhibition of central Y5 neurotransmission resulted in activation of thyroid axis during fasting suggesting that NPY-Y5 receptors contribute to fasting-induced TSH and TH suppression. PMID:21771616

  12. Age-related changes in tonic activation of presynaptic versus extrasynaptic γ-amniobutyric acid type B receptors in rat medial prefrontal cortex.

    PubMed

    Carpenter, Haley E; Kelly, Kyle B; Bizon, Jennifer L; Frazier, Charles J

    2016-09-01

    The present study examined the effect of age on both glutamatergic and γ-aminobutyric acid mediated (GABAergic) signaling in the rodent medial prefrontal cortex (mPFC), with an emphasis on revealing novel changes contributing to increased inhibition in age. Whole-cell patch clamp recordings were obtained from layer 2/3 mPFC pyramidal neurons in acute cortical slices prepared from either young (4 months) or aged (20-24 months) male F344 rats. Results indicated that GABAB receptors on GABAergic, but not on glutamatergic, inputs to layer 2/3 pyramidal cells are tonically activated by ambient GABA in young animals and further demonstrated that this form of tonic inhibition is significantly attenuated in aged mPFC. Moreover, concurrent with loss of tonic presynaptic GABAB autoreceptor activation, layer 2/3 pyramidal cells in aged mPFC are subjected to increased tonic activation of extrasynaptic GABAA and GABAB receptors. These data demonstrate a shift in the site of GABAB receptor-mediated inhibitory tone in the aged mPFC that clearly promotes increased inhibition of pyramidal cells in aged animals, and that may plausibly contribute to impaired executive function. PMID:27459929

  13. γ-Aminobutyric Acid Type A (GABAA) Receptor Subunits Play a Direct Structural Role in Synaptic Contact Formation via Their N-terminal Extracellular Domains.

    PubMed

    Brown, Laura E; Nicholson, Martin W; Arama, Jessica E; Mercer, Audrey; Thomson, Alex M; Jovanovic, Jasmina N

    2016-07-01

    The establishment of cell-cell contacts between presynaptic GABAergic neurons and their postsynaptic targets initiates the process of GABAergic synapse formation. GABAA receptors (GABAARs), the main postsynaptic receptors for GABA, have been recently demonstrated to act as synaptogenic proteins that can single-handedly induce the formation and functional maturation of inhibitory synapses. To establish how the subunit composition of GABAARs influences their ability to induce synaptogenesis, a co-culture model system incorporating GABAergic medium spiny neurons and the HEK293 cells, stably expressing different combinations of receptor subunits, was developed. Analyses of HEK293 cell innervation by medium spiny neuron axons using immunocytochemistry, activity-dependent labeling, and electrophysiology have indicated that the γ2 subunit is required for the formation of active synapses and that its effects are influenced by the type of α/β subunits incorporated into the functional receptor. To further characterize this process, the large N-terminal extracellular domains (ECDs) of α1, α2, β2, and γ2 subunits were purified using the baculovirus/Sf9 cell system. When these proteins were applied to the co-cultures of MSNs and α1/β2/γ2-expressing HEK293 cells, the α1, β2, or γ2 ECD each caused a significant reduction in contact formation, in contrast to the α2 ECD, which had no effect. Together, our experiments indicate that the structural role of GABAARs in synaptic contact formation is determined by their subunit composition, with the N-terminal ECDs of each of the subunits directly participating in interactions between the presynaptic and postsynaptic elements, suggesting the these interactions are multivalent and specific. PMID:27129275

  14. γ-Aminobutyric Acid Type A (GABAA) Receptor Subunits Play a Direct Structural Role in Synaptic Contact Formation via Their N-terminal Extracellular Domains*

    PubMed Central

    Brown, Laura E.; Nicholson, Martin W.; Arama, Jessica E.; Thomson, Alex M.

    2016-01-01

    The establishment of cell-cell contacts between presynaptic GABAergic neurons and their postsynaptic targets initiates the process of GABAergic synapse formation. GABAA receptors (GABAARs), the main postsynaptic receptors for GABA, have been recently demonstrated to act as synaptogenic proteins that can single-handedly induce the formation and functional maturation of inhibitory synapses. To establish how the subunit composition of GABAARs influences their ability to induce synaptogenesis, a co-culture model system incorporating GABAergic medium spiny neurons and the HEK293 cells, stably expressing different combinations of receptor subunits, was developed. Analyses of HEK293 cell innervation by medium spiny neuron axons using immunocytochemistry, activity-dependent labeling, and electrophysiology have indicated that the γ2 subunit is required for the formation of active synapses and that its effects are influenced by the type of α/β subunits incorporated into the functional receptor. To further characterize this process, the large N-terminal extracellular domains (ECDs) of α1, α2, β2, and γ2 subunits were purified using the baculovirus/Sf9 cell system. When these proteins were applied to the co-cultures of MSNs and α1/β2/γ2-expressing HEK293 cells, the α1, β2, or γ2 ECD each caused a significant reduction in contact formation, in contrast to the α2 ECD, which had no effect. Together, our experiments indicate that the structural role of GABAARs in synaptic contact formation is determined by their subunit composition, with the N-terminal ECDs of each of the subunits directly participating in interactions between the presynaptic and postsynaptic elements, suggesting the these interactions are multivalent and specific. PMID:27129275

  15. Torso, a Drosophila receptor tyrosine kinase, plays a novel role in the larval fat body in regulating insulin signaling and body growth.

    PubMed

    Jun, Jong Woo; Han, Gangsik; Yun, Hyun Myoung; Lee, Gang Jun; Hyun, Seogang

    2016-08-01

    Torso is a receptor tyrosine kinase whose localized activation at the termini of the Drosophila embryo is mediated by its ligand, Trunk. Recent studies have unveiled a second function of Torso in the larval prothoracic gland (PG) as the receptor for the prothoracicotropic hormone, which triggers pupariation. As such, inhibition of Torso in the PG prolongs the larval growth period, thereby increasing the final pupa size. Here, we report that Torso also acts in the larval fat body, regulating body size in a manner opposite from that of Torso in PG. We confirmed the expression of torso mRNA in the larval fat body and its reduction by RNA interference (RNAi). Fat body-specific knockdown of torso, by either of the two independent RNAi transgenes, significantly decreased the final pupal size. We found that torso knockdown suppresses insulin/target of rapamycin (TOR) signaling in the fat body, as confirmed by repression of Akt and S6K. Notably, the decrease in insulin/TOR signaling and decrease of pupal size induced by the knockdown of torso were rescued by the expression of a constitutively active form of the insulin receptor or by the knockdown of FOXO. Our study revealed a novel role for Torso in the fat body with respect to regulation of insulin/TOR signaling and body size. This finding exemplifies the contrasting effects of the same gene expressed in two different organs on organismal physiology. PMID:27126913

  16. Spatial profile and differential recruitment of GABAB modulate oscillatory activity in auditory cortex

    PubMed Central

    Oswald, Anne-Marie M.; Doiron, Brent; Rinzel, John; Reyes, Alex D.

    2009-01-01

    The interplay between inhibition and excitation is at the core of cortical network activity. In many cortices, including auditory cortex (ACx), interactions between excitatory and inhibitory neurons generate synchronous network gamma oscillations (30–70 Hz). Here, we show that differences in the connection patterns and synaptic properties of excitatory-inhibitory microcircuits permit the spatial extent of network inputs to modulate the magnitude of gamma oscillations. Simultaneous multiple whole-cell recordings from connected fast-spiking (FS) interneurons and pyramidal cells (PC) in L2/3 of mouse ACx slices revealed that for intersomatic distances <50 µm, most inhibitory connections occurred in reciprocally connected (RC) pairs; at greater distances, inhibitory connections were equally likely in RC and non-reciprocally connected (nRC) pairs. Furthermore, the GABAB mediated inhibition in RC pairs was weaker than in nRC pairs. Simulations with a network model that incorporated these features showed strong, gamma-band oscillations only when the network inputs were confined to a small area. These findings suggest a novel mechanism by which oscillatory activity can be modulated by adjusting the spatial distribution of afferent input. PMID:19692606

  17. Loss of striatal cannabinoid CB1 receptor function in attention-deficit / hyperactivity disorder mice with point-mutation of the dopamine transporter.

    PubMed

    Castelli, Maura; Federici, Mauro; Rossi, Silvia; De Chiara, Valentina; Napolitano, Francesco; Studer, Valeria; Motta, Caterina; Sacchetti, Lucia; Romano, Rosaria; Musella, Alessandra; Bernardi, Giorgio; Siracusano, Alberto; Gu, Howard H; Mercuri, Nicola B; Usiello, Alessandro; Centonze, Diego

    2011-11-01

    Abnormal dopamine (DA) transmission in the striatum plays a pivotal role in attention-deficit/hyperactivity disorder (ADHD). As striatal DA signalling modulates the endocannabinoid system (ECS), the present study was aimed at investigating cannabinoid CB1 receptor (CB1R) function in a model of ADHD obtained by triple point-mutation in the dopamine transporter (DAT) gene in mice, making them insensitive to cocaine [DAT cocaine-insensitive (DAT-CI) mice]. DAT-CI mice had a marked hyperactive phenotype, and neurophysiological recordings revealed that the sensitivity of CB1Rs controlling GABA-mediated synaptic currents [CB1Rs((GABA)) ] in the striatum was completely lost. In contrast, CB1Rs modulating glutamate transmission [CB1Rs((Glu)) ], and GABA(B) receptors were not affected in this model of ADHD. In DAT-CI mice, the blockade of CB1R((GABA)) function was complete even after cocaine or environmental manipulations activating the endogenous DA-dependent reward system, which are known to sensitize these receptors in control animals. Conversely, the hedonic property of sucrose was intact in DAT-CI mice, indicating normal sweet perception in these animals. Our results point to CB1Rs as novel molecular players in ADHD, and suggest that therapeutic strategies aimed at interfering with the ECS might prove effective in this disorder. PMID:22034972

  18. γ-Hydroxybutyric acid (GHB) is not an agonist of extrasynaptic GABAA receptors.

    PubMed

    Connelly, William M; Errington, Adam C; Crunelli, Vincenzo

    2013-01-01

    γ-Hydroxybutyric acid (GHB) is an endogenous compound and a drug used clinically to treat the symptoms of narcolepsy. GHB is known to be an agonist of GABAB receptors with millimolar affinity, but also binds with much higher affinity to another site, known as the GHB receptor. While a body of evidence has shown that GHB does not bind to GABAA receptors widely, recent evidence has suggested that the GHB receptor is in fact on extrasynaptic α4β1δ GABAA receptors, where GHB acts as an agonist with an EC50 of 140 nM. We investigated three neuronal cell types that express a tonic GABAA receptor current mediated by extrasynaptic receptors: ventrobasal (VB) thalamic neurons, dentate gyrus granule cells and striatal medium spiny neurons. Using whole-cell voltage clamp in brain slices, we found no evidence that GHB (10 µM) induced any GABAA receptor mediated current in these cell types, nor that it modulated inhibitory synaptic currents. Furthermore, a high concentration of GHB (3 mM) was able to produce a GABAB receptor mediated current, but did not induce any other currents. These results suggest either that GHB is not a high affinity agonist at native α4β1δ receptors, or that these receptors do not exist in classical areas associated with extrasynaptic currents. PMID:24244421

  19. γ-Hydroxybutyric Acid (GHB) Is Not an Agonist of Extrasynaptic GABAA Receptors

    PubMed Central

    Connelly, William M.; Errington, Adam C.; Crunelli, Vincenzo

    2013-01-01

    γ-Hydroxybutyric acid (GHB) is an endogenous compound and a drug used clinically to treat the symptoms of narcolepsy. GHB is known to be an agonist of GABAB receptors with millimolar affinity, but also binds with much higher affinity to another site, known as the GHB receptor. While a body of evidence has shown that GHB does not bind to GABAA receptors widely, recent evidence has suggested that the GHB receptor is in fact on extrasynaptic α4β1δ GABAA receptors, where GHB acts as an agonist with an EC50 of 140 nM. We investigated three neuronal cell types that express a tonic GABAA receptor current mediated by extrasynaptic receptors: ventrobasal (VB) thalamic neurons, dentate gyrus granule cells and striatal medium spiny neurons. Using whole-cell voltage clamp in brain slices, we found no evidence that GHB (10 µM) induced any GABAA receptor mediated current in these cell types, nor that it modulated inhibitory synaptic currents. Furthermore, a high concentration of GHB (3 mM) was able to produce a GABAB receptor mediated current, but did not induce any other currents. These results suggest either that GHB is not a high affinity agonist at native α4β1δ receptors, or that these receptors do not exist in classical areas associated with extrasynaptic currents. PMID:24244421

  20. The nuclear receptor gene nhr-25 plays multiple roles in the C. elegans heterochronic gene network to control the larva-to-adult transition

    PubMed Central

    Hada, Kazumasa; Asahina, Masako; Hasegawa, Hiroshi; Kanaho, Yasunori; Slack, Frank J.; Niwa, Ryusuke

    2010-01-01

    Developmental timing in the nematode Caenorhabditis elegans is controlled by heterochronic genes, mutations in which cause changes in the relative timing of developmental events. One of the heterochronic genes, let-7, encodes a microRNA that is highly evolutionarily conserved, suggesting that similar genetic pathways control developmental timing across phyla. Here we report that the nuclear receptor nhr-25, which belongs to the evolutionarily conserved fushi tarazu-factor 1/nuclear receptor NR5A subfamily, interacts with heterochronic genes that regulate the larva-to-adult transition in C. elegans. We identified nhr-25 as a regulator of apl-1, a homolog of the Alzheimer’s amyloid precursor protein-like gene that is downstream of let-7 family microRNAs. NHR-25 controls not only apl-1 expression but also regulates developmental progression in the larva-to-adult transition. NHR-25 negatively regulates the expression of the adult-specific collagen gene col-19 in lateral epidermal seam cells. In contrast, NHR-25 positively regulates the larva-to-adult transition for other timed events in seam cells, such as cell fusion, cell division and alae formation. The genetic relationships between nhr-25 and other heterochronic genes are strikingly varied among several adult developmental events. We propose that nhr-25 has multiple roles in both promoting and inhibiting the C. elegans heterochronic gene pathway controlling adult differentiation programs. PMID:20678979

  1. Orphan G protein-coupled receptor GPR56 plays a role in cell transformation and tumorigenesis involving the cell adhesion pathway.

    PubMed

    Ke, Ning; Sundaram, Roshni; Liu, Guohong; Chionis, John; Fan, Wufang; Rogers, Cheryl; Awad, Tarif; Grifman, Mirta; Yu, Dehua; Wong-Staal, Flossie; Li, Qi-Xiang

    2007-06-01

    GPR56 is an orphan G protein - coupled receptor, mutations of which have recently been associated with bilateral frontoparietal polymicrogyria, a rare neurologic disease that has implications in brain development. However, no phenotype beyond central nervous system has yet been described for the GPR56-null mutations despite abundant GPR56 expression in many non - central nervous system adult tissues. In the present study, we show that higher GPR56 expression is correlated with the cellular transformation phenotypes of several cancer tissues compared with their normal counterparts, implying a potential oncogenic function. RNA interference-mediated GPR56 silencing results in apoptosis induction and reduced anchorage-independent growth of cancer cells via increased anoikis, whereas cDNA overexpression resulted in increased foci formation in mouse fibroblast NIH3T3 cell line. When GPR56 silencing was induced in vivo in several xenograft tumor models, significant tumor responses (including regression) were observed, suggesting the potential of targeting GPR56 in the development of tumor therapies. The expression profiling of GPR56-silenced A2058 melanoma cell line revealed several genes whose expression was affected by GPR56 silencing, particularly those in the integrin-mediated signaling and cell adhesion pathways. The potential role of GPR56 in cancer cell adhesion was further confirmed by the observation that GPR56 silencing also reduced cell adhesion to the extracellular matrix, which is consistent with the observed increase in anoikis and reduction in anchorage-independent growth phenotypes. The oncogenic potential and apparent absence of physiologic defects in adult human tissues lacking GPR56, as well as the targetable nature of G protein - coupled receptor by small molecule or antibody, make GPR56 an attractive drug target for the development of cancer therapies. PMID:17575113

  2. Of the multiple mechanisms leading to type 1 diabetes, T cell receptor revision may play a prominent role (is type 1 diabetes more than a single disease?).

    PubMed

    Wagner, D H

    2016-09-01

    A single determinant factor for autoimmunity does not exist; disease development probably involves contributions from genetics, the environment and immune dysfunction. Type 1 diabetes is no exception. Genomewide-associated studies (GWAS) analysis in T1D has proved disappointing in revealing contributors to disease prediction; the only reliable marker has been human leucocyte antigen (HLA). Specific HLAs include DR3/DR4/DQ2/DQ8, for example. Because HLA molecules present antigen to T cells, it is reasonable that certain HLA molecules have a higher affinity to present self-antigen. Recent studies have shown that additional polymorphisms in HLA that are restricted to autoimmune conditions are further contributory. A caveat is that not all individuals with the appropriate 'pro-autoimmune' HLA develop an autoimmune disease. Another crucial component is autoaggressive T cells. Finding a biomarker to discriminate autoaggressive T cells has been elusive. However, a subset of CD4 helper cells that express the CD40 receptor have been described as becoming pathogenic. An interesting function of CD40 on T cells is to induce the recombination-activating gene (RAG)1/RAG2 T cell receptor recombination machinery. This observation is contrary to immunology paradigms that changes in TCR molecules cannot take place outside the thymic microenvironment. Alteration in TCR, called TCR revision, not only occurs, but may help to account for the development of autoaggressive T cells. Another interesting facet is that type 1 diabetes (T1D) may be more than a single disease; that is, multiple cellular components contribute uniquely, but result ultimately in the same clinical outcome, T1D. This review considers the process of T cell maturation and how that could favor auto-aggressive T cell development in T1D. The potential contribution of TCR revision to autoimmunity is also considered. PMID:27271348

  3. Activation of family C G-protein-coupled receptors by the tripeptide glutathione.

    PubMed

    Wang, Minghua; Yao, Yi; Kuang, Donghui; Hampson, David R

    2006-03-31

    The Family C G-protein-coupled receptors include the metabotropic glutamate receptors, the gamma-aminobutyric acid, type B (GABAB) receptor, the calcium-sensing receptor (CaSR), which participates in the regulation of calcium homeostasis in the body, and a diverse group of sensory receptors that encompass the amino acid-activated fish 5.24 chemosensory receptor, the mammalian T1R taste receptors, and the V2R pheromone receptors. A common feature of Family C receptors is the presence of an amino acid binding site. In this study, a preliminary in silico analysis of the size and shape of the amino acid binding pocket in selected Family C receptors suggested that some members of this family could accommodate larger ligands such as peptides. Subsequent screening and docking experiments identified GSH as a potential ligand or co-ligand at the fish 5.24 receptor and the rat CaSR. These in silico predictions were confirmed using an [3H]GSH radioligand binding assay and a fluorescence-based functional assay performed on wild-type and chimeric receptors. Glutathione was shown to act as an orthosteric agonist at the 5.24 receptor and as a potent enhancer of calcium-induced activation of the CaSR. Within the mammalian receptors, this effect was specific to the CaSR because GSH neither directly activated nor potentiated other Family C receptors including GPRC6A (the putative mammalian homolog of the fish 5.24 receptor), the metabotropic glutamate receptors, or the GABAB receptor. Our findings reveal a potential new role for GSH and suggest that this peptide may act as an endogenous modulator of the CaSR in the parathyroid gland where this receptor is known to control the release of parathyroid hormone, and in other tissues such as the brain and gastrointestinal tract where the role of the calcium receptor appears to subserve other, as yet unknown, physiological functions. PMID:16455645

  4. Pharmacokinetics of CGP 36,742, an orally active GABAB antagonist, in humans.

    PubMed

    Gleiter, C H; Farger, G; Möbius, H J

    1996-05-01

    A study was conducted to evaluate the pharmacokinetics of CGP 36 742 (3-aminopropyl-n-butyl-phosphinic acid), an orally active gamma-aminobutyric acid B (GABAB) antagonist, in humans. Pharmacokinetic results after a single oral (600 mg) dose included maximum observed concentration (Cmax), 27 mumol/L (95% CI 22.9, 30.8); time to Cmax (tmax), 3 hours (median); half-life (t1/2), 3.6 hours (95% CI 3.24, 3.9); renal clearance (ClR), 125 mL/min (95% CI 114, 136); and absolute bioavailability (Fabs), 0.44 (95% CI 0.33, 0.47). Administration with food decreased the oral systemic availability (Frel) by 30%. The volume of distribution (285 L/kg) was in the order of magnitude of extracellular body water. The absorbed fraction of the compound was excreted completely and unchanged via the kidney, thus renal function would be the limiting factor for excretion. The rate of absorption and amount absorbed did not differ significantly between elderly and young healthy male volunteers, both after single and multiple doses. There was no gender-related difference in pharmacokinetics in healthy elderly volunteers. CGP 36 742 showed an excellent safety profile: there were no clinically relevant changes in cardiovascular variables, body temperature, or blood chemistry. In the placebo-controlled trial, adverse experiences were rare and evenly distributed among participants receiving placebo and the study drug. In addition, a newly developed high-performance liquid chromatography (HPLC) method for measurement of CGP 36 742 concentrations in plasma and urine using fluorescence detection is described. PMID:8739022

  5. NTS adenosine A2a receptors inhibit the cardiopulmonary chemoreflex control of regional sympathetic outputs via a GABAergic mechanism.

    PubMed

    Minic, Zeljka; O'Leary, Donal S; Scislo, Tadeusz J

    2015-07-01

    Adenosine is a powerful central neuromodulator acting via opposing A1 (inhibitor) and A2a (activator) receptors. However, in the nucleus of the solitary tract (NTS), both adenosine receptor subtypes attenuate cardiopulmonary chemoreflex (CCR) sympathoinhibition of renal, adrenal, and lumbar sympathetic nerve activity and attenuate reflex decreases in arterial pressure and heart rate. Adenosine A1 receptors inhibit glutamatergic transmission in the CCR pathway, whereas adenosine A2a receptors most likely facilitate release of an unknown inhibitory neurotransmitter, which, in turn, inhibits the CCR. We hypothesized that adenosine A2a receptors inhibit the CCR via facilitation of GABA release in the NTS. In urethane-chloralose-anesthetized rats (n = 51), we compared regional sympathetic responses evoked by stimulation of the CCR with right atrial injections of the 5-HT3 receptor agonist phenylbiguanide (1-8 μg/kg) before and after selective stimulation of NTS adenosine A2a receptors [microinjections into the NTS of CGS-21680 (20 pmol/50 nl)] preceded by blockade of GABAA or GABAB receptors in the NTS [bicuculline (10 pmol/100 nl) or SCH-50911 (1 nmol/100 nl)]. Blockade of GABAA receptors virtually abolished adenosine A2a receptor-mediated inhibition of the CCR. GABAB receptors had much weaker but significant effects. These effects were similar for the different sympathetic outputs. We conclude that stimulation of NTS adenosine A2a receptors inhibits CCR-evoked hemodynamic and regional sympathetic reflex responses via a GABA-ergic mechanism. PMID:25910812

  6. M1 and M3 muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product.

    PubMed

    Garcia, Raphael Caio Tamborelli; Dati, Livia Mendonça Munhoz; Torres, Larissa Helena; da Silva, Mariana Aguilera Alencar; Udo, Mariana Sayuri Berto; Abdalla, Fernando Maurício Francis; da Costa, José Luiz; Gorjão, Renata; Afeche, Solange Castro; Yonamine, Mauricio; Niswender, Colleen M; Conn, P Jeffrey; Camarini, Rosana; Sandoval, Maria Regina Lopes; Marcourakis, Tania

    2015-01-01

    The smoke of crack cocaine contains cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). AEME possesses greater neurotoxic potential than cocaine and an additive effect when they are combined. Since atropine prevented AEME-induced neurotoxicity, it has been suggested that its toxic effects may involve the muscarinic cholinergic receptors (mAChRs). Our aim is to understand the interaction between AEME and mAChRs and how it can lead to neuronal death. Using a rat primary hippocampal cell culture, AEME was shown to cause a concentration-dependent increase on both total [(3)H]inositol phosphate and intracellular calcium, and to induce DNA fragmentation after 24 hours of exposure, in line with the activation of caspase-3 previously shown. Additionally, we assessed AEME activity at rat mAChR subtypes 1-5 heterologously expressed in Chinese Hamster Ovary cells. l-[N-methyl-(3)H]scopolamine competition binding showed a preference of AEME for the M2 subtype; calcium mobilization tests revealed partial agonist effects at M1 and M3 and antagonist activity at the remaining subtypes. The selective M1 and M3 antagonists and the phospholipase C inhibitor, were able to prevent AEME-induced neurotoxicity, suggesting that the toxicity is due to the partial agonist effect at M1 and M3 mAChRs, leading to DNA fragmentation and neuronal death by apoptosis. PMID:26626425

  7. M1 and M3 muscarinic receptors may play a role in the neurotoxicity of anhydroecgonine methyl ester, a cocaine pyrolysis product

    PubMed Central

    Garcia, Raphael Caio Tamborelli; Dati, Livia Mendonça Munhoz; Torres, Larissa Helena; da Silva, Mariana Aguilera Alencar; Udo, Mariana Sayuri Berto; Abdalla, Fernando Maurício Francis; da Costa, José Luiz; Gorjão, Renata; Afeche, Solange Castro; Yonamine, Mauricio; Niswender, Colleen M.; Conn, P. Jeffrey; Camarini, Rosana; Sandoval, Maria Regina Lopes; Marcourakis, Tania

    2015-01-01

    The smoke of crack cocaine contains cocaine and its pyrolysis product, anhydroecgonine methyl ester (AEME). AEME possesses greater neurotoxic potential than cocaine and an additive effect when they are combined. Since atropine prevented AEME-induced neurotoxicity, it has been suggested that its toxic effects may involve the muscarinic cholinergic receptors (mAChRs). Our aim is to understand the interaction between AEME and mAChRs and how it can lead to neuronal death. Using a rat primary hippocampal cell culture, AEME was shown to cause a concentration-dependent increase on both total [3H]inositol phosphate and intracellular calcium, and to induce DNA fragmentation after 24 hours of exposure, in line with the activation of caspase-3 previously shown. Additionally, we assessed AEME activity at rat mAChR subtypes 1–5 heterologously expressed in Chinese Hamster Ovary cells. l-[N-methyl-3H]scopolamine competition binding showed a preference of AEME for the M2 subtype; calcium mobilization tests revealed partial agonist effects at M1 and M3 and antagonist activity at the remaining subtypes. The selective M1 and M3 antagonists and the phospholipase C inhibitor, were able to prevent AEME-induced neurotoxicity, suggesting that the toxicity is due to the partial agonist effect at M1 and M3 mAChRs, leading to DNA fragmentation and neuronal death by apoptosis. PMID:26626425

  8. The reinforcing effects of ethanol within the nucleus accumbens shell involve activation of local GABA and serotonin receptors

    PubMed Central

    Ding, Zheng-Ming; Ingraham, Cynthia M.; Rodd, Zachary A.; McBride, William J.

    2015-01-01

    Ethanol is reinforcing within the nucleus accumbens shell (NACsh), but the underlying mechanisms remain unclear. Ethanol can potentiate the function of the GABAA, GABAB, and 5-HT3 receptors. Therefore, the current study tested the hypothesis that activation of these receptors would be involved in the reinforcing effects of ethanol in the NACsh. An intracranial self-administration (ICSA) procedure was used to assess the reinforcing effects of ethanol in the NACsh of alcohol preferring (P) rats. The ICSA consisted of 7 sessions: 4 sessions to establish 150 mg% ethanol self-infusion into the NACsh; sessions 5 and 6 with co-infusion of ethanol plus one concentration of the GABAA antagonist bicuculline (10 or 100 µM), the GABAB antagonist SCH 50911 (50, 75 or 100 µM), or the 5-HT3 receptor antagonist zacopride (10 or 100 µM); and session 7 with 150 mg% ethanol alone. All groups self-infused ethanol into the NACsh and readily discriminated the active from inactive lever during the acquisition sessions. Co-infusion of 100 µM, but not 10 µM, bicuculline or zacopride significantly decreased active responses during sessions 5 and 6. Co-infusion of 75 µM, but not 50 or 100 µM, SCH 50911 significantly attenuated responses for ethanol. Overall, the results suggest that the reinforcing effects of ethanol in the NACsh may be modulated by activation of local GABAA, GABAB and 5-HT3 receptors. PMID:25922425

  9. Activation of P2X7 Receptor by ATP Plays an Important Role in Regulating Inflammatory Responses during Acute Viral Infection

    PubMed Central

    Lee, Benjamin H.; Hwang, David M.; Palaniyar, Nades; Grinstein, Sergio; Philpott, Dana J.; Hu, Jim

    2012-01-01

    Acute viral infection causes damages to the host due to uncontrolled viral replication but even replication deficient viral vectors can induce systemic inflammatory responses. Indeed, overactive host innate immune responses to viral vectors have led to devastating consequences. Macrophages are important innate immune cells that recognize viruses and induce inflammatory responses at the early stage of infection. However, tissue resident macrophages are not easily activated by the mere presence of virus suggesting that their activation requires additional signals from other cells in the tissue in order to trigger inflammatory responses. Previously, we have shown that the cross-talk between epithelial cells and macrophages generates synergistic inflammatory responses during adenoviral vector infection. Here, we investigated whether ATP is involved in the activation of macrophages to induce inflammatory responses during an acute adenoviral infection. Using a macrophage-epithelial cell co-culture system we demonstrated that ATP signaling through P2X7 receptor (P2X7R) is required for induction of inflammatory mediators. We also showed that ATP-P2X7R signaling regulates inflammasome activation as inhibition or deficiency of P2X7R as well as caspase-1 significantly reduced IL-1β secretion. Furthermore, we found that intranasal administration of replication deficient adenoviral vectors in mice caused a high mortality in wild-type mice with symptoms of acute respiratory distress syndrome but the mice deficient in P2X7R or caspase-1 showed increased survival. In addition, wild-type mice treated with apyrase or inhibitors of P2X7R or caspase-1 showed higher rates of survival. The improved survival in the P2X7R deficient mice correlated with diminished levels of IL-1β and IL-6 and reduced neutrophil infiltration in the early phase of infection. These results indicate that ATP, released during viral infection, is an important inflammatory regulator that activates the

  10. Phenobarbital and propiconazole toxicogenomic profiles in mice show major similarities consistent with the key role that constitutive androstane receptor (CAR) activation plays in their mode of action.

    PubMed

    Currie, Richard A; Peffer, Richard C; Goetz, Amber K; Omiecinski, Curtis J; Goodman, Jay I

    2014-07-01

    Toxicogenomics (TGx) is employed frequently to investigate underlying molecular mechanisms of the compound of interest and, thus, has become an aid to mode of action determination. However, the results and interpretation of a TGx dataset are influenced by the experimental design and methods of analysis employed. This article describes an evaluation and reanalysis, by two independent laboratories, of previously published TGx mouse liver microarray data for a triazole fungicide, propiconazole (PPZ), and the anticonvulsant drug phenobarbital (PB). Propiconazole produced an increase incidence of liver tumors in male CD-1 mice only at a dose that exceeded the maximum tolerated dose (2500 ppm). Firstly, we illustrate how experimental design differences between two in vivo studies with PPZ and PB may impact the comparisons of TGx results. Secondly, we demonstrate that different researchers using different pathway analysis tools can come to different conclusions on specific mechanistic pathways, even when using the same datasets. Finally, despite these differences the results across three different analyses also show a striking degree of similarity observed for PPZ and PB treated livers when the expression data are viewed as major signaling pathways and cell processes affected. Additional studies described here show that the postulated key event of hepatocellular proliferation was observed in CD-1 mice for both PPZ and PB, and that PPZ is also a potent activator of the mouse CAR nuclear receptor. Thus, with regard to the events which are hallmarks of CAR-induced effects that are key events in the mode of action (MOA) of mouse liver carcinogenesis with PB, PPZ-induced tumors can be viewed as being promoted by a similar PB-like CAR-dependent MOA. PMID:24675475

  11. Phenobarbital and propiconazole toxicogenomic profiles in mice show major similarities consistent with the key role that constitutive androstane receptor (CAR) activation plays in their mode of action

    PubMed Central

    Currie, Richard A.; Peffer, Richard C.; Goetz, Amber K.; Omiecinski, Curtis J.; Goodman, Jay I.

    2014-01-01

    Toxicogenomics (TGx) is employed frequently to investigate underlying molecular mechanisms of the compound of interest and, thus, has become an aid to mode of action determination. However, the results and interpretation of a TGx dataset are influenced by the experimental design and methods of analysis employed. This article describes an evaluation and reanalysis, by two independent laboratories, of previously published TGx mouse liver microarray data for a triazole fungicide, propiconazole (PPZ), and the anticonvulsant drug phenobarbital (PB). Propiconazole produced an increase incidence of liver tumors in male CD-1 mice only at a dose that exceeded the maximum tolerated dose (2500 ppm). Firstly, we illustrate how experimental design differences between two in vivo studies with PPZ and PB may impact the comparisons of TGx results. Secondly, we demonstrate that different researchers using different pathway analysis tools can come to different conclusions on specific mechanistic pathways, even when using the same datasets. Finally, despite these differences the results across three different analyses also show a striking degree of similarity observed for PPZ and PB treated livers when the expression data are viewed as major signaling pathways and cell processes affected. Additional studies described here show that the postulated key event of hepatocellular proliferation was observed in CD-1 mice for both PPZ and PB, and that PPZ is also a potent activator of the mouse CAR nuclear receptor. Thus, with regard to the events which are hallmarks of CAR-induced effects that are key events in the mode of action (MOA) of mouse liver carcinogenesis with PB, PPZ-induced tumors can be viewed as being promoted by a similar PB-like CAR-dependent MOA. PMID:24675475

  12. Fibroblast Growth Factor Receptor 3 activation plays a causative role in urothelial cancer pathogenesis in cooperation with Pten loss in mice

    PubMed Central

    Foth, Mona; Ahmad, Imran; van Rhijn, Bas W. G.; van der Kwast, Theodorus; Bergman, Andre M.; King, Louise; Ridgway, Rachel; Leung, Hing Y.; Fraser, Sioban; Sansom, Owen J.; Iwata, Tomoko

    2015-01-01

    Although somatic mutations and overexpression of the tyrosine kinase Fibroblast Growth Factor Receptor 3 (FGFR3) are strongly associated with bladder cancer, evidence for their functional involvement in the pathogenesis remains elusive. Previously we showed that activation of Fgfr3 alone is not sufficient to initiate urothelial tumourigenesis in mice. Here we hypothesise that cooperating mutations are required for Fgfr3-dependent tumourigenesis in the urothelium and analyse a mouse model in which an inhibitor of Pi3k-Akt signalling, Pten, is deleted in concert with Fgfr3 activation (UroIICreFgfr3+/K644EPtenflox/flox). Two main phonotypical characteristics observed in the urothelium were increased urothelial thickness and abnormal cellular histopathology, including vacuolisation, condensed cellular appearance, enlargement of cells and nuclei, and loss of polarity. These changes were not observed when either mutation was present individually. Expression patterns of known urothelial proteins indicated the abnormal cellular differentiation. Furthermore, quantitative analysis showed that Fgfr3 and Pten mutations cooperatively caused cellular enlargement, while Pten contributed to an increased cell proliferation. Finally, FGFR3 overexpression was analysed along the level of phosphorylated mTOR in sixty-six T1 urothelial tumours in tissue microarray, which supported the occurrence of functional association of these two signalling pathways in urothelial pathogenesis. Taken together, this study provides evidence supporting a functional role of FGFR3 in the process of pathogenesis in urothelial neoplasm. Given the wide availability of inhibitors specific to FGF signalling pathways, our model may open the avenue for FGFR3-targeted translation in urothelial disease. PMID:24519156

  13. The ion channel transient receptor potential melastatin-2 does not play a role in inflammatory mouse models of chronic obstructive pulmonary diseases

    PubMed Central

    2012-01-01

    Background There is strong evidence that oxidative stress is associated with the pathogenesis of chronic obstructive pulmonary disease (COPD). The transient receptor potential melastatin-2 (TRPM2) is an oxidative stress sensing channel that is expressed in a number of inflammatory cells and therefore it has been suggested that inhibition of TRPM2 could lead to a beneficial effect in COPD patients. In this study, we have investigated the role of TRPM2 in a variety of mouse models of oxidative stress and COPD using TRPM2-deficent mice. Methods Mice were exposed to ozone (3 ppm for 4 h) or lipopolysaccharide (LPS, 0.3 mg/kg, intranasaly). In another model, mice were exposed to tobacco smoke (750 μg/l total wet particulate matter) for 30 min twice a day on three consecutive days. For the exacerbation model, the smoke exposure on the morning of day 3 animals was replaced with intranasal administration of LPS (0.3 mg/kg). Animals were killed 3 and 24 h after the challenge (ozone and LPS model) or 18 h after the last tobacco smoke exposure. In vitro neutrophil chemotaxis and monocyte activation were also studied using cells isolated from wild type and TRPM2-deficient animals. Statistical significance for the in vivo data (P < 0.05) was determined using analysis of variance with Kruskal-Wallis and Dunns multiple comparison test. Results In all models studied, no difference in the bronchoalveolar lavage inflammation could be evidenced when comparing wild type and TRPM2-deficient mice. In addition, no difference could be seen in the lung inflammation as assessed by the measurement of various cytokines/chemokines. Similarly in various in vitro cellular activation assays using isolated neutrophils and monocytes no significant differences could be observed when comparing wild type and TRPM2-deficient mice. Discussion We have shown, in all the models tested, no difference in the development of airway inflammation or cell activation between TRPM2-deficient mice and their wild

  14. Transient Receptor Potential (TRP) and Cch1-Yam8 Channels Play Key Roles in the Regulation of Cytoplasmic Ca2+ in Fission Yeast

    PubMed Central

    Ma, Yan; Sugiura, Reiko; Koike, Atsushi; Ebina, Hidemine; Sio, Susie O.; Kuno, Takayoshi

    2011-01-01

    The regulation of cytoplasmic Ca2+ is crucial for various cellular processes. Here, we examined the cytoplasmic Ca2+ levels in living fission yeast cells by a highly sensitive bioluminescence resonance energy transfer-based assay using GFP-aequorin fusion protein linked by 19 amino acid. We monitored the cytoplasmic Ca2+ level and its change caused by extracellular stimulants such as CaCl2 or NaCl plus FK506 (calcineurin inhibitor). We found that the extracellularly added Ca2+ caused a dose-dependent increase in the cytoplasmic Ca2+ level and resulted in a burst-like peak. The overexpression of two transient receptor potential (TRP) channel homologues, Trp1322 or Pkd2, markedly enhanced this response. Interestingly, the burst-like peak upon TRP overexpression was completely abolished by gene deletion of calcineurin and was dramatically decreased by gene deletion of Prz1, a downstream transcription factor activated by calcineurin. Furthermore, 1 hour treatment with FK506 failed to suppress the burst-like peak. These results suggest that the burst-like Ca2+ peak is dependent on the transcriptional activity of Prz1, but not on the direct TRP dephosphorylation. We also found that extracellularly added NaCl plus FK506 caused a synergistic cytosolic Ca2+ increase that is dependent on the inhibition of calcineurin activity, but not on the inhibition of Prz1. The synergistic Ca2+ increase is abolished by the addition of the Ca2+ chelator BAPTA into the media, and is also abolished by deletion of the gene encoding a subunit of the Cch1-Yam8 Ca2+ channel complex, indicating that the synergistic increase is caused by the Ca2+ influx from the extracellular medium via the Cch1-Yam8 complex. Furthermore, deletion of Pmk1 MAPK abolished the Ca2+ influx, and overexpression of the constitutively active Pek1 MAPKK enhanced the influx. These results suggest that Pmk1 MAPK and calcineurin positively and negatively regulate the Cch1-Yam8 complex, respectively, via modulating the

  15. 12-HETER1/GPR31, a high-affinity 12(S)-hydroxyeicosatetraenoic acid receptor, is significantly up-regulated in prostate cancer and plays a critical role in prostate cancer progression.

    PubMed

    Honn, Kenneth V; Guo, Yande; Cai, Yinlong; Lee, Menq-Jer; Dyson, Gregory; Zhang, Wenliang; Tucker, Stephanie C

    2016-06-01

    Previously we identified and deorphaned G-protein-coupled receptor 31 (GPR31) as the high-affinity 12(S)-hydroxyeicosatetraenoic acid [12(S)-HETE] receptor (12-HETER1). Here we have determined its distribution in prostate cancer tissue and its role in prostate tumorigenesis using in vitro and in vivo assays. Data-mining studies strongly suggest that 12-HETER1 expression positively correlates with the aggressiveness and progression of prostate tumors. This was corroborated with real-time PCR analysis of human prostate tumor tissue arrays that revealed the expression of 12-HETER1 positively correlates with the clinical stages of prostate cancers and Gleason scores. Immunohistochemistry analysis also proved that the expression of 12-HETER1 is positively correlated with the grades of prostate cancer. Knockdown of 12-HETER1 in prostate cancer cells markedly reduced colony formation and inhibited tumor growth in animals. To discover the regulatory factors, 5 candidate 12-HETER1 promoter cis elements were assayed as luciferase reporter fusions in Chinese hamster ovary (CHO) cells, where the putative cis element required for gene regulation was mapped 2 kb upstream of the 12-HETER1 transcriptional start site. The data implicate 12-HETER1 in a critical new role in the regulation of prostate cancer progression and offer a novel alternative target for therapeutic intervention.-Honn, K. V., Guo, Y., Cai, Y., Lee, M.-J., Dyson, G., Zhang, W., Tucker, S. C. 12-HETER1/GPR31, a high-affinity 12(S)-hydroxyeicosatetraenoic acid receptor, is significantly up-regulated in prostate cancer and plays a critical role in prostate cancer progression. PMID:26965684

  16. NMDA and GABA receptors as potential targets in cough hypersensitivity syndrome.

    PubMed

    Chung, Kian Fan

    2015-06-01

    Chronic cough is a common symptom that can be difficult to treat. It is proposed to be part of a cough hypersensitivity syndrome characterised by troublesome coughing often triggered by low levels of thermal, mechanical or chemical exposure. Upper airway and laryngeal neural dysfunction may also be present. There is evidence that this hypersensitivity may be due to sensory nerve damage caused by inflammatory, infective and allergic factors. Antitussive therapies based on opioid medications are generally not efficacious. Antagonists of N-methyl-d-aspartate receptors in the brain stem and use of GABAB receptor agonists such as baclofen acting centrally and possibly peripherally may represent novel therapeutic approaches. PMID:25792008

  17. Striatal GABA receptor alterations in hypoxic neonatal rats: role of glucose, oxygen and epinephrine treatment.

    PubMed

    Anju, T R; Binoy, J; Anitha, M; Paulose, C S

    2012-03-01

    Hypoxia in neonates disrupts the oxygen flow to the brain, essentially starving the brain and preventing it from performing vital biochemical processes important for central nervous system development. Hypoxia results in a permanent brain damage by gene and receptor level alterations mediated through neurotransmitters. The present study evaluated GABA, GABAA, GABAB receptor functions and gene expression changes in glutamate decarboxylase in the corpus striatum of hypoxic neonatal rats and the treatment groups with glucose, oxygen and epinephrine. Since GABA is the principal neurotransmitter involved in hypoxic ventilatory decline, the alterations in its level under hypoxic stress points to an important aspect of respiratory control. Following hypoxic stress, a significant decrease in total GABA, GABAA and GABAB receptors function and GAD expression was observed in the striatum, which accounts for the ventilator decline. Hypoxic rats treated with glucose alone and with oxygen showed a reversal of the receptor alterations and changes in GAD to near control. Being a source of immediate energy, glucose can reduce the ATP-depletion-induced changes in GABA and oxygenation helps in overcoming reduction in oxygen supply. Treatment with oxygen alone and epinephrine was not effective in reversing the altered receptor functions. Thus, our study point to the functional role of GABA receptors in mediating ventilatory response to hypoxia and the neuroprotective role of glucose treatment. This has immense significance in the proper management of neonatal hypoxia for a better intellect in the later stages of life. PMID:22089934

  18. Identification of the transmitter and receptor mechanisms responsible for REM sleep paralysis.

    PubMed

    Brooks, Patricia L; Peever, John H

    2012-07-18

    During REM sleep the CNS is intensely active, but the skeletal motor system is paradoxically forced into a state of muscle paralysis. The mechanisms that trigger REM sleep paralysis are a matter of intense debate. Two competing theories argue that it is caused by either active inhibition or reduced excitation of somatic motoneuron activity. Here, we identify the transmitter and receptor mechanisms that function to silence skeletal muscles during REM sleep. We used behavioral, electrophysiological, receptor pharmacology and neuroanatomical approaches to determine how trigeminal motoneurons and masseter muscles are switched off during REM sleep in rats. We show that a powerful GABA and glycine drive triggers REM paralysis by switching off motoneuron activity. This drive inhibits motoneurons by targeting both metabotropic GABA(B) and ionotropic GABA(A)/glycine receptors. REM paralysis is only reversed when motoneurons are cut off from GABA(B), GABA(A) and glycine receptor-mediated inhibition. Neither metabotropic nor ionotropic receptor mechanisms alone are sufficient for generating REM paralysis. These results demonstrate that multiple receptor mechanisms trigger REM sleep paralysis. Breakdown in normal REM inhibition may underlie common sleep motor pathologies such as REM sleep behavior disorder. PMID:22815493

  19. GABA Receptors on Orexin and Melanin-Concentrating Hormone Neurons Are Differentially Homeostatically Regulated Following Sleep Deprivation123

    PubMed Central

    Toossi, Hanieh; del Cid-Pellitero, Esther

    2016-01-01

    Abstract Though overlapping in distribution through the hypothalamus, orexin (Orx) and melanin-concentrating hormone (MCH) neurons play opposite roles in the regulation of sleep–wake states. Orx neurons discharge during waking, whereas MCH neurons discharge during sleep. In the present study, we examined in mice whether GABAA and GABAB receptors (Rs) are present on Orx and MCH neurons and might undergo differential changes as a function of their different activities following sleep deprivation (SD) and sleep recovery (SR). Applying quantitative stereological image analysis to dual-immunofluorescent stained sections, we determined that the proportion of Orx neurons positively immunostained for GABAARs was significantly higher following SD (∼48%) compared with sleep control (SC; ∼24%) and SR (∼27%), and that the luminance of the GABAARs was significantly greater. In contrast, the average proportion of the MCH neurons immunostained for GABAARs was insignificantly lower following SD (∼43%) compared with SC (∼54%) and SR (56%), and the luminance of the GABAARs was significantly less. Although, GABABRs were observed in all Orx and MCH neurons (100%), the luminance of these receptors was differentially altered following SD. The intensity of GABABRs in the Orx neurons was significantly greater after SD than after SC and SR, whereas that in the MCH neurons was significantly less. The present results indicate that GABA receptors undergo dynamic and differential changes in the wake-active Orx neurons and the sleep-active MCH neurons as a function of and homeostatic adjustment to their preceding activity and sleep–wake state. PMID:27294196

  20. GABA Receptors on Orexin and Melanin-Concentrating Hormone Neurons Are Differentially Homeostatically Regulated Following Sleep Deprivation.

    PubMed

    Toossi, Hanieh; Del Cid-Pellitero, Esther; Jones, Barbara E

    2016-01-01

    Though overlapping in distribution through the hypothalamus, orexin (Orx) and melanin-concentrating hormone (MCH) neurons play opposite roles in the regulation of sleep-wake states. Orx neurons discharge during waking, whereas MCH neurons discharge during sleep. In the present study, we examined in mice whether GABAA and GABAB receptors (Rs) are present on Orx and MCH neurons and might undergo differential changes as a function of their different activities following sleep deprivation (SD) and sleep recovery (SR). Applying quantitative stereological image analysis to dual-immunofluorescent stained sections, we determined that the proportion of Orx neurons positively immunostained for GABAARs was significantly higher following SD (∼48%) compared with sleep control (SC; ∼24%) and SR (∼27%), and that the luminance of the GABAARs was significantly greater. In contrast, the average proportion of the MCH neurons immunostained for GABAARs was insignificantly lower following SD (∼43%) compared with SC (∼54%) and SR (56%), and the luminance of the GABAARs was significantly less. Although, GABABRs were observed in all Orx and MCH neurons (100%), the luminance of these receptors was differentially altered following SD. The intensity of GABABRs in the Orx neurons was significantly greater after SD than after SC and SR, whereas that in the MCH neurons was significantly less. The present results indicate that GABA receptors undergo dynamic and differential changes in the wake-active Orx neurons and the sleep-active MCH neurons as a function of and homeostatic adjustment to their preceding activity and sleep-wake state. PMID:27294196

  1. Inhibition of Olfactory Receptor Neuron Input to Olfactory Bulb Glomeruli Mediated by Suppression of Presynaptic Calcium Influx

    PubMed Central

    Wachowiak, Matt; McGann, John P.; Heyward, Philip M.; Shao, Zuoyi; Puche, Adam C.; Shipley, Michael T.

    2005-01-01

    We investigated the cellular mechanism underlying presynaptic regulation of olfactory receptor neuron (ORN) input to the mouse olfactory bulb using optical-imaging techniques that selectively report activity in the ORN pre-synaptic terminal. First, we loaded ORNs with calcium-sensitive dye and imaged stimulus-evoked calcium influx in a slice preparation. Single olfactory nerve shocks evoked rapid fluorescence increases that were largely blocked by the N-type calcium channel blocker ω-conotoxin GVIA. Paired shocks revealed a long-lasting suppression of calcium influx with ~40% suppression at 400-ms interstimulus intervals and a recovery time constant of ~450 ms. Blocking activation of postsynaptic olfactory bulb neurons with APV/CNQX reduced this suppression. The GABAB receptor agonist baclofen inhibited calcium influx, whereas GABAB antagonists reduced paired-pulse suppression without affecting the response to the conditioning pulse. We also imaged transmitter release directly using a mouse line that expresses synaptopHluorin selectively in ORNs. We found that the relationship between calcium influx and transmitter release was superlinear and that paired-pulse suppression of transmitter release was reduced, but not eliminated, by APV/CNQX and GABAB antagonists. These results demonstrate that primary olfactory input to the CNS can be presynaptically regulated by GABAergic interneurons and show that one major intracellular pathway for this regulation is via the suppression of calcium influx through N-type calcium channels in the pre-synaptic terminal. This mechanism is unique among primary sensory afferents. PMID:15917320

  2. MicroRNA-27b plays a role in pulmonary arterial hypertension by modulating peroxisome proliferator-activated receptor γ dependent Hsp90-eNOS signaling and nitric oxide production

    SciTech Connect

    Bi, Rui; Bao, Chunrong; Jiang, Lianyong; Liu, Hao; Yang, Yang; Mei, Ju; Ding, Fangbao

    2015-05-01

    Pulmonary artery endothelial dysfunction is associated with pulmonary arterial hypertension (PAH). Based on recent studies showing that microRNA (miR)-27b is aberrantly expressed in PAH, we hypothesized that miR-27b may contribute to pulmonary endothelial dysfunction and vascular remodeling in PAH. The effect of miR-27b on pulmonary endothelial dysfunction and the underlying mechanism were investigated in human pulmonary artery endothelial cells (HPAECs) in vitro and in a monocrotaline (MCT)-induced model of PAH in vivo. miR-27b expression was upregulated in MCT-induced PAH and inversely correlated with the levels of peroxisome proliferator-activated receptor (PPAR)-γ, and miR-27b inhibition attenuated MCT-induced endothelial dysfunction and remodeling and prevented PAH associated right ventricular hypertrophy and systolic pressure in rats. PPARγ was confirmed as a direct target of miR-27b in HPAECs and shown to mediate the effect of miR-27b on the disruption of endothelial nitric oxide synthase (eNOS) coupling to Hsp90 and the suppression of NO production associated with the PAH phenotype. We showed that miR-27b plays a role endothelial function and NO release and elucidated a potential mechanism by which miR-27b regulates Hsp90-eNOS and NO signaling by modulating PPARγ expression, providing potential therapeutic targets for the treatment of PAH. - Highlights: • miR-27b plays a role in endothelial function and NO release. • miR-27b inhibition ameliorates MCT-induced endothelial dysfunction and PAH. • miR-27b targets PPARγ in HPAECs. • miR-27b regulates PPARγ dependent Hsp90-eNOS and NO signaling.

  3. Glycogen Synthase Kinase-3β Plays a Pro-Apoptotic Role in β-Adrenergic Receptor-Stimulated Apoptosis in Adult Rat Ventricular Myocytes: Role of β1 Integrins

    PubMed Central

    Menon, Bindu; Johnson, Jennifer N.; Ross, Robert S.; Singh, Mahipal; Singh, Krishna

    2007-01-01

    β-adrenergic receptor (β-AR) stimulation induces apoptosis in adult rat ventricular myocytes (ARVM). β1 integrin signaling plays a protective role in β-AR-stimulated apoptosis. Glycogen synthase kinase-3β (GSK-3β), a multifunctional serine/threonine kinase, negatively regulates cardiac hypertrophy. Here we show that β-AR stimulation (isoproterenol; 15 min) increases tyr216 phosphorylation and GSK-3β activity. Inclusion of LiCl, inhibitor of GSK-3β, in the reaction mix or expression of catalytically inactive GSK-3β (KM-GSK) inhibited β-AR-stimulated GSK-3β activity. Inhibition of tyrosine kinase using genistein or chelation of intracellular Ca2+ using BAPTA-AM inhibited β-AR-stimulated increases in tyr216 phosphorylation and GSK-3β activity. Inhibition of GSK-3β using pharmacological inhibitors or infection with KM-GSK decreased β-AR-stimulated cytosolic cytochrome C release and apoptosis. Expression of β1 integrins increased ser9 phosphorylation and inhibited β-AR-stimulated increase in GSK-3β activity. Wortmannin, inhibitor of PI3-kinase, reversed the effects of β1 integrins on GSK-3β activity and apoptosis. Purified active matrix metalloproteinase-2 (MMP-2), shown to interfere with β1 integrin signaling, increased GSK-3β activity, while inhibition of MMP-2 inhibited β-AR-stimulated increases in GSK-3β activity. β-AR stimulation induced nuclear accumulation of GSK-3β. β-AR stimulation (3 h) increased the expression of transcription factor Gadd153 (growth arrest- and DNA damage-inducible gene 153). These data suggest that β-AR stimulation increases GSK-3β activity. Activation of GSK-3β plays a pro-apoptotic role in β-AR stimulated apoptosis via the involvement of mitochondrial death pathway. β1 integrins inactivate GSK-3β and play an anti-apoptotic role via the involvement of PI3-kinase pathway. The apoptotic effects of GSK-3β may be mediated, at least in part, via its nuclear localization and induction of pro-apoptotic genes

  4. Play Therapy: A Review

    ERIC Educational Resources Information Center

    Porter, Maggie L.; Hernandez-Reif, Maria; Jessee, Peggy

    2009-01-01

    This article discusses the current issues in play therapy and its implications for play therapists. A brief history of play therapy is provided along with the current play therapy approaches and techniques. This article also touches on current issues or problems that play therapists may face, such as interpreting children's play, implementing…

  5. Post-endocytotic Deubiquitination and Degradation of the Metabotropic γ-Aminobutyric Acid Receptor by the Ubiquitin-specific Protease 14.

    PubMed

    Lahaie, Nicolas; Kralikova, Michaela; Prézeau, Laurent; Blahos, Jaroslav; Bouvier, Michel

    2016-03-25

    Mechanisms controlling the metabotropic γ-aminobutyric acid receptor (GABAB) cell surface stability are still poorly understood. In contrast with many other G protein-coupled receptors (GPCR), it is not subject to agonist-promoted internalization, but is constitutively internalized and rapidly down-regulated. In search of novel interacting proteins regulating receptor fate, we report that the ubiquitin-specific protease 14 (USP14) interacts with the GABAB(1b)subunit's second intracellular loop. Probing the receptor for ubiquitination using bioluminescence resonance energy transfer (BRET), we detected a constitutive and phorbol 12-myristate 13-acetate (PMA)-induced ubiquitination of the receptor at the cell surface. PMA also increased internalization and accelerated receptor degradation. Overexpression of USP14 decreased ubiquitination while treatment with a small molecule inhibitor of the deubiquitinase (IU1) increased receptor ubiquitination. Treatment with the internalization inhibitor Dynasore blunted both USP14 and IU1 effects on the receptor ubiquitination state, suggesting a post-endocytic site of action. Overexpression of USP14 also led to an accelerated degradation of GABABin a catalytically independent fashion. We thus propose a model whereby cell surface ubiquitination precedes endocytosis, after which USP14 acts as an ubiquitin-binding protein that targets the ubiquitinated receptor to lysosomal degradation and promotes its deubiquitination. PMID:26817839

  6. Alpha9 nicotinic acetylcholine receptors and the treatment of pain.

    PubMed

    McIntosh, J Michael; Absalom, Nathan; Chebib, Mary; Elgoyhen, Ana Belén; Vincler, Michelle

    2009-10-01

    Chronic pain is a vexing worldwide problem that causes substantial disability and consumes significant medical resources. Although there are numerous analgesic medications, these work through a small set of molecular mechanisms. Even when these medications are used in combination, substantial amounts of pain often remain. It is therefore highly desirable to develop treatments that work through distinct mechanisms of action. While agonists of nicotinic acetylcholine receptors (nAChRs) have been intensively studied, new data suggest a role for selective antagonists of nAChRs. alpha-Conotoxins are small peptides used offensively by carnivorous marine snails known as Conus. A subset of these peptides known as alpha-conotoxins RgIA and Vc1.1 produces both acute and long lasting analgesia. In addition, these peptides appear to accelerate the recovery of function after nerve injury, possibly through immune mediated mechanisms. Pharmacological analysis indicates that RgIA and Vc1.1 are selective antagonists of alpha9alpha10 nAChRs. A recent study also reported that these alpha9alpha10 antagonists are also potent GABA-B agonists. In the current study, we were unable to detect RgIA or Vc1.1 binding to or action on cloned GABA-B receptors expressed in HEK cells or Xenopus oocytes. We review the background, findings and implications of use of compounds that act on alpha9* nAChRs.(1). PMID:19477168

  7. The Denial of Play.

    ERIC Educational Resources Information Center

    Sutton-Smith, Brian

    Well meaning parents and teachers often use children's play for the purposes of literacy and socialization. Yet, these attempts may deny play to children by subordinating play to some other concept. Evidence shows that even when parents play with their very young children they generally play games like shopping, cooking, and eating; whereas when…

  8. War, Conflict and Play. Debating Play

    ERIC Educational Resources Information Center

    Hyder, Tina

    2004-01-01

    Young refugees from many parts of the world are increasingly present in UK early years settings. This book explores the crucial importance of play for young refugee children's development. It considers the implications of war and conflict on young children and notes how opportunities for play are denied. It provides a framework for early years…

  9. Playing the Play: What the Children Want

    ERIC Educational Resources Information Center

    Kraus, Jo Anne

    2006-01-01

    Playing the Play describes the experiences of a storyteller and teacher of literature who created a literature-based literacy program at Concourse House, a homeless shelter in Bronx, New York, for women and their young children. This program is based on the belief that pleasure is the primary reason children want to learn to read, and that where…

  10. Bibliography on Play Therapy and Children's Play.

    ERIC Educational Resources Information Center

    Rogers, Mary Brown; L'Abate, Luciano

    The references listed are: (1) journals, (2) dissertation abstracts, (3) books, (4) reports, and (5) monographs. The main subjects covered are: (1) children's play, (2) psychotherapy with disturbed children through the medium of play therapy, and (3) various aspects of child development, both normal and abnormal. The materials listed date from…

  11. The Uses of Play

    ERIC Educational Resources Information Center

    Cabaniss, Thomas

    2005-01-01

    Teaching artists have techniques for keeping play alive and vital in their work. But how do they think of play as TAs? In this article, the author examines the role of play in the work and life of teaching artists.

  12. The level and distribution of the GABABR1 and GABABR2 receptor subunits in the rat's inferior colliculus

    PubMed Central

    Jamal, Lena; Khan, Aziz N.; Butt, Sehrish; Patel, Chirag R.; Zhang, Huiming

    2012-01-01

    The type B γ-aminobutyric acid receptor (GABAB receptor) is an important neurotransmitter receptor in the midbrain auditory structure, the inferior colliculus (IC). A functional GABAB receptor is a heterodimer consisting of two subunits, GABABR1 and GABABR2. Western blotting and immunohistochemical experiments were conducted to examine the expression of the two subunits over the IC including its central nucleus, dorsal cortex, and external cortex (ICc, ICd, and ICx). Results revealed that the two subunits existed in both cell bodies and the neuropil throughout the IC. The two subunits had similar regional distributions over the IC. The combined level of cell body and neuropil labeling was higher in the ICd than the other two subdivisions. Labeling in the ICc and ICx was stronger in the dorsal than the ventral regions. In spite of regional differences, no defined boundaries were formed between different areas. For both subunits, the regional distribution of immunoreactivity in the neuropil was parallel to that of combined immunoreactivity in the neuropil and cell bodies. The density of labeled cell bodies tended to be higher but sizes of cell bodies tended to be smaller in the ICd than in the other subdivisions. No systematic regional changes were found in the level of cell body immunoreactivity, except that GABABR2-immunoreactive cell bodies in the ICd had slightly higher optic density (OD) than in other regions. Elongated cell bodies existed throughout the IC. Many labeled cell bodies along the outline of the IC were oriented in parallel to the outline. No strong tendency of orientation was found in labeled cell bodies in ICc. Regional distributions of the subunits in ICc correlated well with inputs to this subdivision. Our finding regarding the contrast in the level of neuropil immunoreactivity among different subdivisions is consistent with the fact that the GABAB receptor has different pre- and postsynaptic functions in different IC regions. PMID:23189044

  13. γ-Hydroxybutyrate (GHB)-Induced Respiratory Depression: Combined Receptor-Transporter Inhibition Therapy for Treatment in GHB Overdose

    PubMed Central

    Morse, Bridget L.; Vijay, Nisha

    2012-01-01

    Overdose of γ-hydroxybutyrate (GHB) frequently causes respiratory depression, occasionally resulting in death; however, little is known about the dose-response relationship or effects of potential overdose treatment strategies on GHB-induced respiratory depression. In these studies, the parameters of respiratory rate, tidal volume, and minute volume were measured using whole-body plethysmography in rats administered GHB. Intravenous doses of 200, 600, and 1500 mg/kg were administered to assess the dose-dependent effects of GHB on respiration. To determine the receptors involved in GHB-induced respiratory depression, a specific GABAB receptor antagonist, (2S)-(+)-5,5-dimethyl-2-morpholineacetic acid (SCH50911), and a specific GABAA receptor antagonist, bicuculline, were administered before GHB. The potential therapeutic strategies of receptor inhibition and monocarboxylate transporter (MCT) inhibition were assessed by inhibitor administration 5 min after GHB. The primary effect of GHB on respiration was a dose-dependent decrease in respiratory rate, accompanied by an increase in tidal volume, resulting in little change in minute volume. Pretreatment with 150 mg/kg SCH50911 completely prevented the decrease in respiratory rate, indicating agonism at GABAB receptors to be primarily responsible for GHB-induced respiratory depression. Administration of 50 mg/kg SCH50911 after GHB completely reversed the decrease in respiratory rate; lower doses had partial effects. Administration of the MCT inhibitor l-lactate increased GHB renal and total clearance, also improving respiratory rate. Administration of 5 mg/kg SCH50911 plus l-lactate further improved respiratory rate compared with the same dose of either agent alone, indicating that GABAB and MCT inhibitors, alone and in combination, represent potential treatment options for GHB-induced respiratory depression. PMID:22561075

  14. γ-Hydroxybutyrate (GHB)-induced respiratory depression: combined receptor-transporter inhibition therapy for treatment in GHB overdose.

    PubMed

    Morse, Bridget L; Vijay, Nisha; Morris, Marilyn E

    2012-08-01

    Overdose of γ-hydroxybutyrate (GHB) frequently causes respiratory depression, occasionally resulting in death; however, little is known about the dose-response relationship or effects of potential overdose treatment strategies on GHB-induced respiratory depression. In these studies, the parameters of respiratory rate, tidal volume, and minute volume were measured using whole-body plethysmography in rats administered GHB. Intravenous doses of 200, 600, and 1500 mg/kg were administered to assess the dose-dependent effects of GHB on respiration. To determine the receptors involved in GHB-induced respiratory depression, a specific GABA(B) receptor antagonist, (2S)-(+)-5,5-dimethyl-2-morpholineacetic acid (SCH50911), and a specific GABA(A) receptor antagonist, bicuculline, were administered before GHB. The potential therapeutic strategies of receptor inhibition and monocarboxylate transporter (MCT) inhibition were assessed by inhibitor administration 5 min after GHB. The primary effect of GHB on respiration was a dose-dependent decrease in respiratory rate, accompanied by an increase in tidal volume, resulting in little change in minute volume. Pretreatment with 150 mg/kg SCH50911 completely prevented the decrease in respiratory rate, indicating agonism at GABA(B) receptors to be primarily responsible for GHB-induced respiratory depression. Administration of 50 mg/kg SCH50911 after GHB completely reversed the decrease in respiratory rate; lower doses had partial effects. Administration of the MCT inhibitor l-lactate increased GHB renal and total clearance, also improving respiratory rate. Administration of 5 mg/kg SCH50911 plus l-lactate further improved respiratory rate compared with the same dose of either agent alone, indicating that GABA(B) and MCT inhibitors, alone and in combination, represent potential treatment options for GHB-induced respiratory depression. PMID:22561075

  15. The Play of Psychotherapy

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2012-01-01

    The author reviews the role of play within psychotherapy. She does not discuss the formal play therapy especially popular for young children, nor play from the Jungian perspective that encourages the use of the sand tray with adults. Instead, she focuses on the informal use of play during psychotherapy as it is orchestrated intuitively. Because…

  16. Two people playing together: some thoughts on play, playing, and playfulness in psychoanalytic work.

    PubMed

    Vliegen, Nicole

    2009-01-01

    Children's play and the playfulness of adolescents and adults are important indicators of personal growth and development. When a child is not able to play, or an adolescent/adult is not able to be playful with thoughts and ideas, psychotherapy can help to find a more playful and creative stance. Elaborating Winnicott's (1968, p. 591) statement that "psychotherapy has to do with two people playing together," three perspectives on play in psychotherapy are discussed. In the first point of view, the child gets in touch with and can work through aspects of his or her inner world, while playing in the presence of the therapist. The power of play is then rooted in the playful communication with the self In a second perspective, in play the child is communicating aspects of his or her inner world to the therapist as a significant other. In a third view, in "playing together" child and therapist are coconstructing new meanings. These three perspectives on play are valid at different moments of a therapy process or for different children, depending on the complex vicissitudes of the child's constitution, life experiences, development, and psychic structure. Concerning these three perspectives, a parallel can be drawn between the therapist's attitude toward the child's play and the way the therapist responds to the verbal play of an adolescent or adult. We illustrate this with the case of Jacob, a late adolescent hardly able to play with ideas. PMID:20578437

  17. Child's Play: Therapist's Narrative

    PubMed Central

    Reddy, Rajakumari P.; Hirisave, Uma

    2014-01-01

    Play has been recognized as an essential component to children's healthy development. Schools of play therapy differ philosophically and technically, but they all embrace the therapeutic and developmental properties of play. This case report is an illustration of how a 6-year-old child with emotional disorder was facilitated to express concerns in child-centered play therapy. The paper discusses the therapist's narration of the child's play. PMID:24860228

  18. Play: early and eternal.

    PubMed Central

    Mears, C E; Harlow, H F

    1975-01-01

    A systematic 12-week investigation of development of play behavior was conducted with eight socially reared rhesus monkey infants. A new, basic and primary play form termed self-motion play or peragration was identified and examined. This behavior follows a human model which includes a wide range of pleasurable activities involving motion of the body through space, e.g., rocking, swinging, running, leaping, and water or snow skiing. It can be argued that self-motion play is the initial primate play form and because of its persistence constitutes a reinforcing agent for maintaining many complex patterns and even pastimes. Monkey self-motion play in the present study was divided into five separate patterns in order to compare the relative importance of social and individual peragration play, the role of apparatus and the overall developmental relationships between the different individual and social self-motion play patterns. The data showed that from 90 to 180 days of age self-motion play was independent of other forms of play, that individual self-motion play appeared earlier and with significantly greater increases in frequency than did social self-motion play, and that apparatus was a necessary component for significant increases in social self-motion play. Other findings were that self-motion play existed independent of locomotion and, though initiated by exploration, was separate from it. Therapeutic implications of self-motion play were discussed. Images PMID:1057178

  19. Calcium-stores mediate adaptation in axon terminals of Olfactory Receptor Neurons in Drosophila

    PubMed Central

    2011-01-01

    Background In vertebrates and invertebrates, sensory neurons adapt to variable ambient conditions, such as the duration or repetition of a stimulus, a physiological mechanism considered as a simple form of non-associative learning and neuronal plasticity. Although various signaling pathways, as cAMP, cGMP, and the inositol 1,4,5-triphosphate receptor (InsP3R) play a role in adaptation, their precise mechanisms of action at the cellular level remain incompletely understood. Recently, in Drosophila, we reported that odor-induced Ca2+-response in axon terminals of olfactory receptor neurons (ORNs) is related to odor duration. In particular, a relatively long odor stimulus (such as 5 s) triggers the induction of a second component involving intracellular Ca2+-stores. Results We used a recently developed in-vivo bioluminescence imaging approach to quantify the odor-induced Ca2+-activity in the axon terminals of ORNs. Using either a genetic approach to target specific RNAs, or a pharmacological approach, we show that the second component, relying on the intracellular Ca2+-stores, is responsible for the adaptation to repetitive stimuli. In the antennal lobes (a region analogous to the vertebrate olfactory bulb) ORNs make synaptic contacts with second-order neurons, the projection neurons (PNs). These synapses are modulated by GABA, through either GABAergic local interneurons (LNs) and/or some GABAergic PNs. Application of GABAergic receptor antagonists, both GABAA or GABAB, abolishes the adaptation, while RNAi targeting the GABABR (a metabotropic receptor) within the ORNs, blocks the Ca2+-store dependent component, and consequently disrupts the adaptation. These results indicate that GABA exerts a feedback control. Finally, at the behavioral level, using an olfactory test, genetically impairing the GABABR or its signaling pathway specifically in the ORNs disrupts olfactory adapted behavior. Conclusion Taken together, our results indicate that a relatively long lasting

  20. Learning through Role Play.

    ERIC Educational Resources Information Center

    Simmons, Sandra

    2001-01-01

    Explains how role playing can provide enriching experiences that develop children's literacy and numeracy skills. Lists key ingredients of good role playing and suggests ways to plan them and prepare space for them. (SK)

  1. Adlerian Play Therapy.

    ERIC Educational Resources Information Center

    Kottman, Terry; Warlick, Jayne

    1990-01-01

    Describes Adlerian method of play therapy. Claims Adlerian therapy represents an integration of the concepts and techniques of individual psychology into a method of using play to help troubled children. (Author/ABL)

  2. Role-Playing Mitosis.

    ERIC Educational Resources Information Center

    Wyn, Mark A.; Stegink, Steven J.

    2000-01-01

    Introduces a role playing activity that actively engages students in the learning process of mitosis. Students play either chromosomes carrying information, or cells in the cell membrane. (Contains 11 references.) (Author/YDS)

  3. The repertoire of olfactory C family G protein-coupled receptors in zebrafish: candidate chemosensory receptors for amino acids

    PubMed Central

    Alioto, Tyler S; Ngai, John

    2006-01-01

    Background Vertebrate odorant receptors comprise at least three types of G protein-coupled receptors (GPCRs): the OR, V1R, and V2R/V2R-like receptors, the latter group belonging to the C family of GPCRs. These receptor families are thought to receive chemosensory information from a wide spectrum of odorant and pheromonal cues that influence critical animal behaviors such as feeding, reproduction and other social interactions. Results Using genome database mining and other informatics approaches, we identified and characterized the repertoire of 54 intact "V2R-like" olfactory C family GPCRs in the zebrafish. Phylogenetic analysis – which also included a set of 34 C family GPCRs from fugu – places the fish olfactory receptors in three major groups, which are related to but clearly distinct from other C family GPCRs, including the calcium sensing receptor, metabotropic glutamate receptors, GABA-B receptor, T1R taste receptors, and the major group of V2R vomeronasal receptor families. Interestingly, an analysis of sequence conservation and selective pressure in the zebrafish receptors revealed the retention of a conserved sequence motif previously shown to be required for ligand binding in other amino acid receptors. Conclusion Based on our findings, we propose that the repertoire of zebrafish olfactory C family GPCRs has evolved to allow the detection and discrimination of a spectrum of amino acid and/or amino acid-based compounds, which are potent olfactory cues in fish. Furthermore, as the major groups of fish receptors and mammalian V2R receptors appear to have diverged significantly from a common ancestral gene(s), these receptors likely mediate chemosensation of different classes of chemical structures by their respective organisms. PMID:17156446

  4. Play, Policy & Practice.

    ERIC Educational Resources Information Center

    Klugman, Edgar, Ed.

    In 1992, the U.S.-Israel Binational Science Foundation (BSF), in conjunction with Wheelock College (Boston), sponsored its second workshop on children's play, entitled "Play and Cognitive Ability: The Cultural Context." This volume reflects the presentations and discussions held at the workshop, offering perspectives on children's play that, taken…

  5. The Pedagogy of Play

    ERIC Educational Resources Information Center

    Giesbrecht, Sheila

    2012-01-01

    Play is important. Environmental educators Sobel and Louv write about the relationship between children and outside play and suggest that early transcendental experiences within nature allow children to develop empathetic orientations towards the natural world. Children who play out-of-doors develop an appreciation for the environment and…

  6. Play Is the Way

    ERIC Educational Resources Information Center

    Gross, Steve; Sanderson, Rebecca Cornelli

    2012-01-01

    Historically, play has been viewed as a frivolous break from important endeavors like working and learning when, in fact, a child's ability to fully and freely engage in play is essential to their learning, productivity, and overall development. A natural drive to play is universal across all young mammals. Children from every society on earth…

  7. African oil plays

    SciTech Connect

    Clifford, A.J. )

    1989-09-01

    The vast continent of Africa hosts over eight sedimentary basins, covering approximately half its total area. Of these basins, only 82% have entered a mature exploration phase, 9% have had little or no exploration at all. Since oil was first discovered in Africa during the mid-1950s, old play concepts continue to bear fruit, for example in Egypt and Nigeria, while new play concepts promise to become more important, such as in Algeria, Angola, Chad, Egypt, Gabon, and Sudan. The most exciting developments of recent years in African oil exploration are: (1) the Gamba/Dentale play, onshore Gabon; (2) the Pinda play, offshore Angola; (3) the Lucula/Toca play, offshore Cabinda; (4) the Metlaoui play, offshore Libya/Tunisia; (5) the mid-Cretaceous sand play, Chad/Sudan; and (6) the TAG-I/F6 play, onshore Algeria. Examples of these plays are illustrated along with some of the more traditional oil plays. Where are the future oil plays likely to develop No doubt, the Saharan basins of Algeria and Libya will feature strongly, also the presalt of Equatorial West Africa, the Central African Rift System and, more speculatively, offshore Ethiopia and Namibia, and onshore Madagascar, Mozambique, and Tanzania.

  8. Cannabinoid Receptor 2 Participates in Amyloid-β Processing in a Mouse Model of Alzheimer's Disease but Plays a Minor Role in the Therapeutic Properties of a Cannabis-Based Medicine.

    PubMed

    Aso, Ester; Andrés-Benito, Pol; Carmona, Margarita; Maldonado, Rafael; Ferrer, Isidre

    2016-01-01

    The endogenous cannabinoid system represents a promising therapeutic target to modify neurodegenerative pathways linked to Alzheimer's disease (AD). The aim of the present study was to evaluate the specific contribution of CB2 receptor to the progression of AD-like pathology and its role in the positive effect of a cannabis-based medicine (1:1 combination of Δ9-tetrahidrocannabinol and cannabidiol) previously demonstrated to be beneficial in the AβPP/PS1 transgenic model of the disease. A new mouse strain was generated by crossing AβPP/PS1 transgenic mice with CB2 knockout mice. Results show that lack of CB2 exacerbates cortical Aβ deposition and increases the levels of soluble Aβ40. However, CB2 receptor deficiency does not affect the viability of AβPP/PS1 mice, does not accelerate their memory impairment, does not modify tau hyperphosphorylation in dystrophic neurites associated to Aβ plaques, and does not attenuate the positive cognitive effect induced by the cannabis-based medicine in these animals. These findings suggest a minor role for the CB2 receptor in the therapeutic effect of the cannabis-based medicine in AβPP/PS1 mice, but also constitute evidence of a link between CB2 receptor and Aβ processing. PMID:26890764

  9. Play and Digital Media

    ERIC Educational Resources Information Center

    Johnson, James E.; Christie, James F.

    2009-01-01

    This article examines how play is affected by computers and digital toys. Research indicates that when computer software targeted at children is problem-solving oriented and open-ended, children tend to engage in creative play and interact with peers in a positive manner. On the other hand, drill-and-practice programs can be quite boring and limit…

  10. Let's Just Play

    ERIC Educational Resources Information Center

    Schmidt, Janet

    2003-01-01

    Children have a right to play. The idea is so simple it seems self-evident. But a stroll through any toy superstore, or any half-hour of so-called "children's" programming on commercial TV, makes it clear that violence, not play, dominates what's being sold. In this article, the author discusses how teachers and parents share the responsibility in…

  11. Family Play Therapy.

    ERIC Educational Resources Information Center

    Ariel, Shlomo

    This paper examines a case study of family play therapy in Israel. The unique contributions of play therapy are evaluated including the therapy's accessibility to young children, its richness and flexibility, its exposure of covert patterns, its wealth of therapeutic means, and its therapeutic economy. The systematization of the therapy attempts…

  12. Clinical Intuition at Play

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2014-01-01

    A clinical psychologist and consulting psychotherapist discusses how elements of play, inherent in the intuition required in analysis, can provide a cornerstone for serious therapeutic work. She argues that many aspects of play--its key roles in human development, individual growth, and personal creativity, among others--can help therapists and…

  13. Intergenerational Learning through Play.

    ERIC Educational Resources Information Center

    Davis, Lindsay; Larkin, Elizabeth; Graves, Stephen B.

    2002-01-01

    Argues that shared play experiences are a good way to build mutually beneficial relationships among older and younger generations. Outlines why intergenerational play is important, focusing on its cognitive, social, physical, and emotional benefits for both older adults and young children. Describes toys, materials, and games conducive to positive…

  14. Poetry and Play.

    ERIC Educational Resources Information Center

    Law, Richard A.

    Philosophers and poets from classical times to the present have argued that playful and amiable discourse are conducive to teaching and learning. The play principle enhances reading and study and should be applied by teachers to benefit their students. Teachers should help their students see that it is fun to enliven the imagination with good…

  15. The Fear of Play

    ERIC Educational Resources Information Center

    Almon, Joan

    2009-01-01

    Real play--play that is initiated and directed by children and that bubbles up from within the child rather than being imposed by adults--has largely disappeared from the landscape of childhood in the United States. There are many reasons for this, such as the long hours spent in front of screens each day or in activities organized by adults. In…

  16. Return to Play

    ERIC Educational Resources Information Center

    Mangan, Marianne

    2013-01-01

    Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

  17. Role Playing and Skits

    ERIC Educational Resources Information Center

    Letwin, Robert, Ed.

    1975-01-01

    Explores non-scripted role playing, dialogue role playing, sociodrama, and skits as variations of simulation techniques. Provides step-by-step guidelines for conducting such sessions. Successful Meetings, Bill Communications, Inc., 1422 Chestnut Street, Philadelphia, Pa. 19102. Subscription Rates: yearly (US, Canada, Mexico) $14.00; elsewhere,…

  18. Play as Experience

    ERIC Educational Resources Information Center

    Henricks, Thomas S.

    2015-01-01

    The author investigates what he believes one of the more important aspects of play--the experience it generates in its participants. He considers the quality of this experience in relation to five ways of viewing play--as action, interaction, activity, disposition, and within a context. He treats broadly the different forms of affect, including…

  19. Playing with Autistic Children.

    ERIC Educational Resources Information Center

    Casner, Mary W.; Marks, Susan F.

    The paper looks at the development of a play group for autistic children with descriptions of the autistic population, the daily program, the program's philosophy, the play group model, and actual lessons. Children, who ranged in age from 5 to 9 years, often chose activities which were self-stimulating and/or repetitive. The daily program included…

  20. Television at Play.

    ERIC Educational Resources Information Center

    Reid, Leonard N.; Frazer, Charles F.

    1980-01-01

    Discusses children as television viewers capable of manipulating the co-viewing setting by interpreting, constructing, and carrying out planned lines of play in relation to television and its content. Examples illustrate program-oriented and free-form improvisational play situations. (JMF)

  1. Transient receptor potential-like channels mediate metabotropic glutamate receptor EPSCs in rat dopamine neurones.

    PubMed

    Bengtson, C Peter; Tozzi, Alessandro; Bernardi, Giorgio; Mercuri, Nicola B

    2004-03-01

    Transient receptor potential (TRP) channels form cationic channels activated by diverse factors including mechanical stimuli, changes in osmolarity, pH and temperature, as well as the exogenous irritant, capsaicin. Metabotropic glutamate receptors have also recently been linked to TRP channel activation in neurones of the substantia nigra, hippocampus and cerebellum, suggesting a novel role for such channels in synaptic communication via endogenous neurotransmitters. We tested this for dopamine neurones in rat brain slices by characterizing the current-voltage relationship and pharmacology of EPSCs mediated by group I metabotropic glutamate receptor subtype 1 (mGluR1). Slow inward currents (273 +/- 35 pA peak amplitude, 381 +/- 25 ms latency, holding potential (V(h)) =-73 mV) representing evoked mGluR1 EPSCs were isolated in the presence of antagonists of AMPA, NMDA, GABA(A), GABA(B), muscarinic and glycine receptors. CPCCOEt (100 microM), an mGluR1 antagonist, blocked the residual EPSC in all recordings. mGluR1-activated EPSCs reversed polarity near -10 mV, consistent with the involvement of a cationic channel. Extracellular application of the non-selective TRP channel blockers SKF 96365, flufenamic acid and ruthenium red caused reversible inhibition of mGluR1-activated EPSCs. These characteristics parallel those of mGluR1 activation with an agonist and indicate the involvement of a TRP-like channel in mGluR1-mediated EPSCs. PMID:14724196

  2. Gamma-hydroxybutyrate reduces mitogen-activated protein kinase phosphorylation via GABA B receptor activation in mouse frontal cortex and hippocampus.

    PubMed

    Ren, Xiuhai; Mody, Istvan

    2003-10-24

    gamma-Hydroxybutyrate (GHB) naturally occurs in the brain, but its exogenous administration induces profound effects on the central nervous system in animals and humans. The intracellular signaling mechanisms underlying its actions remain unclear. In the present study, the effects of GHB on the activation (phosphorylation) of mitogen-activated protein kinases (MAP kinases), extracellular signal-regulated kinase 1 and 2 (ERK1/2), were investigated. Acute administration of GHB (500 mg/kg, intraperitoneal) induced a fast and long lasting inhibition of MAP kinase phosphorylation in both frontal cortex and hippocampus. The reduced MAP kinase phosphorylation was observed in the CA1 and CA3 areas but not in the dentate gyrus. Pretreatment with the specific gamma-aminobutyric acid, type B (GABAB), receptor antagonist CGP56999A (20 mg/kg, intraperitoneal) prevented the action of GHB, and the effect of GHB was mimicked by baclofen, a selective GABAB receptor agonist, whereas the high affinity GHB receptor antagonist NCS-382 (200 mg/kg, intraperitoneal) had no effect on GHB-inhibited MAP kinase phosphorylation. Moreover, the GHB dehydrogenase inhibitor valproate (500 mg/kg, intraperitoneal), which inhibits the conversion of GHB into GABA, failed to block the effect of GHB on MAP kinase phosphorylation. Altogether, these data suggest that GHB, administered in vivo, reduces MAP kinase phosphorylation via a direct activation of GABAB receptors by GHB. In contrast, GHB (10 mm for 15 min) was found ineffective on MAP kinase phosphorylation in brain slices, indicating important differences in the conditions required for the second messenger activating action of GHB. PMID:12923192

  3. The Scottish Play.

    ERIC Educational Resources Information Center

    Wheat, Chris

    1999-01-01

    Recounts an episode when, as young schoolboys, Prince Charles and classmates presented "Macbeth" as an end-of-term-play. Traces the events at school that took on different meanings when viewed from maturity. (NH)

  4. The School Play

    ERIC Educational Resources Information Center

    Lathan, P. D.

    1977-01-01

    Offers a defense of the school play as a vastly underrated educational tool. Available from: Speech and Drama, Elizabeth Gradwell, Distribution Manager, The White Cottage, Allington, Chippenham, Wilts. (MH)

  5. Play Spaces in Denmark.

    ERIC Educational Resources Information Center

    Mitchell, Edna; Anderson, Robert T.

    1980-01-01

    Describes the variety of play spaces found in urban areas in Denmark: in banks, stores and individual businesses, neighborhood parks and small pocket playgrounds, specialized adventure and traffic playgrounds with supervised activities, and commercial amusement parks. (CM)

  6. Roles of forebrain GABA receptors in controlling vasopressin secretion and related phenomena under basal and hyperosmotic circumstances in conscious rats.

    PubMed

    Yamaguchi, Ken'ichi; Yamada, Takaho

    2008-09-01

    Although the anteroventral third ventricular region (AV3V), a forebrain area essential for homeostatic responses, includes receptors for gamma-aminobutyric acid (GABA), the roles of these receptors in controlling vasopressin (AVP) secretion and related phenomena have not been clarified as yet. This study aimed to pursue this problem in conscious rats implanted with indwelling catheters. Cerebral injection sites were determined histologically. Applications of bicuculline, a GABA(A) receptor antagonist, to the AV3V induced prompt and marked augmentations in plasma AVP, osmolality, glucose, arterial pressure and heart rate, without affecting plasma electrolytes. Such phenomena did not occur when phaclofen, a GABA(B) receptor antagonist, was applied to the AV3V. All of the effects of AV3V-administered bicuculline were abolished by preadministration of the GABA(A) receptor agonist muscimol. Preadministration of either MK-801 or NBQX, ionotropic glutamatergic receptor antagonists, was also potent to abolish the AVP response to AV3V bicuculline. When hypertonic saline was infused intravenously, plasma AVP increased progressively, in parallel with rises in plasma osmolality, sodium and arterial pressure. AV3V application of muscimol or baclofen, a GABA(B) receptor agonist, was found to abolish the response of plasma AVP, without inhibiting that of the osmolality or sodium. The response of arterial pressure was also blocked by muscimol treatment, but not by baclofen treatment. Based on these results, we concluded that, under basal conditions, GABA receptors in the AV3V or vicinity may tonically operate to attenuate AVP secretion and cardiovascular functions through mechanisms associated with glutamatergic activity, and that plasma hyperosmolality may cause facilitation of AVP release by decreasing forebrain GABAergic activity. PMID:18639747

  7. High-resolution Spatiotemporal Analysis of Receptor Dynamics by Single-molecule Fluorescence Microscopy

    PubMed Central

    Sungkaworn, Titiwat; Rieken, Finn; Lohse, Martin J.; Calebiro, Davide

    2014-01-01

    Single-molecule microscopy is emerging as a powerful approach to analyze the behavior of signaling molecules, in particular concerning those aspect (e.g., kinetics, coexistence of different states and populations, transient interactions), which are typically hidden in ensemble measurements, such as those obtained with standard biochemical or microscopy methods. Thus, dynamic events, such as receptor-receptor interactions, can be followed in real time in a living cell with high spatiotemporal resolution. This protocol describes a method based on labeling with small and bright organic fluorophores and total internal reflection fluorescence (TIRF) microscopy to directly visualize single receptors on the surface of living cells. This approach allows one to precisely localize receptors, measure the size of receptor complexes, and capture dynamic events such as transient receptor-receptor interactions. The protocol provides a detailed description of how to perform a single-molecule experiment, including sample preparation, image acquisition and image analysis. As an example, the application of this method to analyze two G-protein-coupled receptors, i.e., β2-adrenergic and γ-aminobutyric acid type B (GABAB) receptor, is reported. The protocol can be adapted to other membrane proteins and different cell models, transfection methods and labeling strategies. PMID:25145374

  8. Playing It Safe.

    ERIC Educational Resources Information Center

    O'Neill, Steve

    2000-01-01

    Provides tips on how to avoid accidents and injuries on school playgrounds. Tips include removing of old, dangerous equipment; relocating play areas to safer ground; choosing the right surface; factoring in long-term costs for replenishing and redistributing loose materials; and considering Americans with Disabilities Act issues. (GR)

  9. Predicting elections: child's play!

    PubMed

    Antonakis, John; Dalgas, Olaf

    2009-02-27

    In two experiments, children and adults rated pairs of faces from election races. Naïve adults judged a pair on competence; after playing a game, children chose who they would prefer to be captain of their boat. Children's (as well as adults') preferences accurately predicted actual election outcomes. PMID:19251621

  10. Want to Play Geometry?

    ERIC Educational Resources Information Center

    Kaufmann, Matthew L.; Bomer, Megan A.; Powell, Nancy Norem

    2009-01-01

    Students enter the geometry classroom with a strong concept of fairness and a sense of what it means to "play by the rules," yet many students have difficulty understanding the postulates, or rules, of geometry and their implications. Although they may never have articulated the properties of an axiomatic system, they have gained a practical…

  11. Statistics at Play

    ERIC Educational Resources Information Center

    English, Lyn D.

    2014-01-01

    An exciting event had occurred for the grade 3 classes at Woodlands State School. A new play space designated for the older grades had now been opened to the third graders. In sharing their excitement over this "real treat, real privilege," the teachers invited the children to find out more about playgrounds and, in particular, their new…

  12. "Playing" with Science

    ERIC Educational Resources Information Center

    Allen, Dave

    2012-01-01

    When faced with a multitude of tasks, any opportunity to "kill two birds with one stone" is welcome. Drama has always excited the author: as a child performing in plays, later as a student and now as a teacher directing performances and improvising within lessons. The author was lucky enough to have inspirational teachers during his primary and…

  13. Abstraction through Game Play

    ERIC Educational Resources Information Center

    Avraamidou, Antri; Monaghan, John; Walker, Aisha

    2012-01-01

    This paper examines the computer game play of an 11-year-old boy. In the course of building a virtual house he developed and used, without assistance, an artefact and an accompanying strategy to ensure that his house was symmetric. We argue that the creation and use of this artefact-strategy is a mathematical abstraction. The discussion…

  14. Who's Calling the Plays?

    ERIC Educational Resources Information Center

    Goldman, Jay P.

    1990-01-01

    Without an enforceable policy, school athletics programs are beset by politics, high finance, and public sentiment. The most nettlesome problems include loss of instructional time to sports and extracurricular activities; the appropriateness and effectiveness of no-pass/no-play rules; lack of sportsmanship; proliferation of interstate competition;…

  15. Playing with danger.

    PubMed

    Pearce, Lynne

    Young people who sit still for hours playing computer games can double their risk of potentially fatal blood clots. The charity Lifeblood is alerting nurses to 'e-thrombosis'. It is calling on them to ensure young people are aware of the risks of prolonged immobility and the need to take regular breaks from gaming or using a computer. PMID:23061127

  16. The Games Children Play

    ERIC Educational Resources Information Center

    Padak, Nancy; Rasinski, Timothy

    2008-01-01

    The games that children play are not just for fun-they often lead to important skill development. Likewise, word games are fun opportunities for parents and children to spend time together and for children to learn a lot about sounds and words. In this Family Involvement column, the authors describe 12 easy-to-implement word games that parents and…

  17. One Play a Day

    ERIC Educational Resources Information Center

    Blankenship, Mark

    2007-01-01

    Undergraduate theater students rarely get the chance to work on a major world premiere, but this year hundreds of them will. Currently, more than 70 colleges and universities are participating in "365 Days/365 Plays," an ambitious project from Pulitzer Prize-winning playwright Suzan-Lori Parks. Every week, as they mount their portion of this epic…

  18. Play's Importance in School

    ERIC Educational Resources Information Center

    Sandberg, Anette; Heden, Rebecca

    2011-01-01

    The purpose of this study is to contribute knowledge on and gain an understanding of elementary school teachers' perspectives on the function of play in children's learning processes. The study is qualitative with a hermeneutical approach and has George Herbert Mead as a theoretical frame of reference. Interviews have been carried out with seven…

  19. Playing It Safe.

    ERIC Educational Resources Information Center

    Jones, Rebecca

    1997-01-01

    Offers tips for avoiding sports-related injuries: (1) expect more of coaches; (2) develop an athletic-safety plan; (3) consider hiring an athletic trainer; (4) check facilities and equipment regularly; (5) recognize athletes' limitations; (6) take precautions beyond the playing field; and (7) check liability coverage and obtain informed consent.…

  20. Integrated Play Groups

    ERIC Educational Resources Information Center

    Glovak, Sandra

    2007-01-01

    As an occupational therapist running social play groups with sensory integration for children on the autism spectrum, the author frequently doubted the wisdom of combining several children on the spectrum into a group. In fact, as the owner of a clinic she said, "No more!" The groups seemed like a waste of parents' time and money, and she refused…

  1. Distribution of immunoreactive GABA and glutamate receptors in the gustatory portion of the nucleus of the solitary tract in rat.

    PubMed

    King, Michael S

    2003-05-15

    The distribution of glutamate (GLU) and gamma-aminobutyric acid (GABA) receptors within the gustatory portion of the rat nucleus of the solitary tract (gNST) was investigated using immunohistochemical, histological and neural tract tracing techniques. Numerous somata throughout the gNST were immunoreactive for alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and N-methyl-D-aspartate (NMDA) receptors, while few were labeled for kainate receptors. AMPA and NMDA receptors were particularly abundant in the rostral central (RC) subdivision of the gNST, which receives most of the primary afferent input from the oral cavity and contains most of the gNST neurons that project to the parabrachial nuclei (PBN). This finding supports electrophysiological evidence that AMPA and NMDA receptors are involved in responses to orosensory input and indicates that their action may influence ascending taste signals as well. Compared to the ionotropic GLU receptors, few cell bodies were immunoreactive for metabotropic GLU receptors. Somata immunoreactive for GABA(A) and GABA(B) receptors were located throughout the nucleus. The densest neuropil labeling was for GABA(A) receptors in the ventral (V) subnucleus, the gNST subdivision that sends output to brainstem oromotor centers. The distributions of immunolabeling for GLU and GABA receptors imply that different functional roles may exist for specific receptors within this nucleus. PMID:12754086

  2. AMPA Receptor–mTOR Activation is Required for the Antidepressant-Like Effects of Sarcosine during the Forced Swim Test in Rats: Insertion of AMPA Receptor may Play a Role

    PubMed Central

    Chen, Kuang-Ti; Tsai, Mang-Hung; Wu, Ching-Hsiang; Jou, Ming-Jia; Wei, I-Hua; Huang, Chih-Chia

    2015-01-01

    Sarcosine, an endogenous amino acid, is a competitive inhibitor of the type I glycine transporter and an N-methyl-d-aspartate receptor (NMDAR) coagonist. Recently, we found that sarcosine, an NMDAR enhancer, can improve depression-related behaviors in rodents and humans. This result differs from previous studies, which have reported antidepressant effects of NMDAR antagonists. The mechanisms underlying the therapeutic response of sarcosine remain unknown. This study examines the role of mammalian target of rapamycin (mTOR) signaling and α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor (AMPAR) activation, which are involved in the antidepressant-like effects of several glutamatergic system modulators. The effects of sarcosine in a forced swim test (FST) and the expression levels of phosphorylated mTOR signaling proteins were examined in the absence or presence of mTOR and AMPAR inhibitors. In addition, the influence of sarcosine on AMPAR trafficking was determined by analyzing the phosphorylation of AMPAR subunit GluR1 at the PKA site (often considered an indicator for GluR1 membrane insertion in neurons). A single injection of sarcosine exhibited antidepressant-like effects in rats in the FST and rapidly activated the mTOR signaling pathway, which were significantly blocked by mTOR inhibitor rapamycin or the AMPAR inhibitor 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX) pretreatment. Moreover, NBQX pretreatment eliminated the ability of sarcosine to stimulate the phosphorylated mTOR signaling proteins. Furthermore, GluR1 phosphorylation at its PKA site was significantly increased after an acute in vivo sarcosine treatment. The results demonstrated that sarcosine exerts antidepressant-like effects by enhancing AMPAR–mTOR signaling pathway activity and facilitating AMPAR membrane insertion. Highlights – A single injection of sarcosine rapidly exerted antidepressant-like effects with a concomitant increase in the activation of the mammalian

  3. Differential Expression of Brain Cannabinoid Receptors between Repeatedly Stressed Males and Females may Play a Role in Age and Gender-Related Difference in Traumatic Brain Injury: Implications from Animal Studies

    PubMed Central

    Xing, Guoqiang; Carlton, Janis; Jiang, Xiaolong; Wen, Jillian; Jia, Min; Li, He

    2014-01-01

    Inconsistent gender differences in the outcome of TBI have been reported. The mechanism is unknown. In a recent male animal study, repeated stress followed by TBI had synergistic effects on brain gene expression and caused greater behavioral deficits. Because females are more likely to develop anxiety after stress and because anxiety is mediated by cannabinoid receptors (CBRs) (CB1 and CB2), there is a need to compare CB1 and CB2 expression in stressed males and females. CB1 and CB2 mRNA expression was determined in the amygdala, hippocampus, prefrontal cortex (PFC), and hypothalamus of adolescent male and female rats after 3 days of repeated tail-shock stress using qPCR. PFC CB1 and CB2 protein levels were determined using Western blot techniques. Both gender and stress had significant effects on brain CB1 mRNA expression levels. Overall, females showed significantly higher CB1 and CB2 mRNA levels in all brain regions than males (p < 0.01). Repeated stress reduced CB1 mRNA levels in the amygdala, hippocampus, and PFC (p < 0.01, each). A gender × stress interaction was found in CB1 mRNA level in the hippocampus (p < 0.05), hypothalamus (p < 0.01), and PFC (p < 0.01). Within-sex one-way ANOVA analysis showed decreased CB1 mRNA in the hippocampus, hypothalamus, and PFC of stressed females (p < 0.01, each) but increased CB1 mRNA levels in the hypothalamus of stressed males (p < 01). There was a gender and stress interaction in prefrontal CB1 receptor protein levels (p < 0.05), which were decreased in stressed females only (p < 0.05). Prefrontal CB2 protein levels were decreased in both male and female animals after repeated stress (p < 0.05, each). High basal levels of CBR expression in young naïve females could protect against TBI damage whereas stress-induced CBR deficits could predict a poor outcome of TBI in repeatedly stressed females. Further animal studies could help evaluate this possibility. PMID:25221540

  4. Inhibition of estrogen receptor {beta}-mediated human telomerase reverse transcriptase gene transcription via the suppression of mitogen-activated protein kinase signaling plays an important role in 15-deoxy-{delta}{sup 12,14}-prostaglandin J{sub 2}-induced apoptosis in cancer cells

    SciTech Connect

    Kondoh, Kei; Tsuji, Naoki; Asanuma, Koichi; Kobayashi, Daisuke; Watanabe, Naoki

    2007-10-01

    The nuclear hormone receptor peroxisome proliferator-activated receptor (PPAR)-{gamma} plays a role in cancer development in addition to its role in glucose metabolism. The natural ligand of PPAR-{gamma}, namely, 15-deoxy-{delta}{sup 12,14}-prostaglandin J{sub 2} (15d-PGJ{sub 2}), has been shown to possess antineoplastic activity in cancer cells. However, the mechanism underlying its antineoplastic activity remains to be elucidated. Inhibition of the expression of human telomerase reverse transcriptase (hTERT), a major determinant of telomerase activity, reportedly induces rapid apoptosis in cancer cells. In this study, we investigated the effect of 15d-PGJ{sub 2} on hTERT expression. We found that 15d-PGJ{sub 2} induced apoptosis in the MIAPaCa-2 pancreatic cancer cells and dose-dependently decreased hTERT mRNA and protein expression. Down-regulation of hTERT expression by hTERT-specific small inhibitory RNA also induced apoptosis. Furthermore, 15d-PGJ{sub 2} attenuated the DNA binding of estrogen receptor (ER). MIAPaCa-2 expressed only ER{beta}, and although its expression did not decrease due to 15d-PGJ{sub 2}, its phosphorylation was suppressed. Additionally, a mitogen-activated protein kinase (MAPK) kinase inhibitor decreased ER{beta} phosphorylation, and 15d-PGJ{sub 2} attenuated MAPK activity. We conclude that hTERT down-regulation by 15d-PGJ{sub 2} plays an important role in the proapoptotic property of the latter. Furthermore, 15d-PGJ{sub 2} inhibits ER{beta}-mediated hTERT gene transcription by suppressing ER{beta} phosphorylation via the inhibition of MAP kinase signaling.

  5. Canada's east coast play

    SciTech Connect

    Doig, I.M.

    1984-02-01

    The intent of this paper is to give a basic overview presentation on Canada's east coast play - most likely the number one offshore play in the free world - and possibly the world. The play stretches 2,500 miles north and south, as it follows the Labrador Coast, past the Strait of Belle Isle and onto the Grand Banks of Newfoundland and as it makes a 90 degree turn, 1,000 miles east to west along the coast of Nova Scotia to the Georges Bank. 3,500 miles in all - which if placed in western Canada, would stretch from northern Alberta to southern Mexico. It's geologic potential is immense - 15-20 billion barrels of oil and 80-90 Tcf of natural gas. And so far only approximately 2 billion barrels of oil and 5 Tcf of natural gas have been found. There is more out there. And less than 200 wells have been drilled - still very virgin territory. Two world size discoveries have been made in the area. Hibernia, on the Grand Banks, is estimated to contain 1.8 billion barrels. Venture, on the Scotian Shelf, has a natural gas reserve of 2.5 Tcf - big by Canadian standards and significant in that Mobil Oil has also made some other interesting discoveries on the same Sable Island block which have not been delineated.

  6. The clathrin adaptor proteins ARH, Dab2, and numb play distinct roles in Niemann-Pick C1-Like 1 versus low density lipoprotein receptor-mediated cholesterol uptake.

    PubMed

    Wei, Jian; Fu, Zhen-Yan; Li, Pei-Shan; Miao, Hong-Hua; Li, Bo-Liang; Ma, Yi-Tong; Song, Bao-Liang

    2014-11-28

    The uptake of circulating low density lipoproteins (LDL) is mediated by LDL receptor (LDLR) through clathrin-dependent endocytosis. At the early stage of this process, adaptor proteins ARH and Dab2 specifically bind the endocytic signal motif in LDLR and recruit clathrin/AP2 to initiate internalization. On the other hand, intestinal cholesterol is absorbed by Niemann-Pick C1-Like 1 (NPC1L1) through clathrin-dependent endocytosis. Another adaptor protein, Numb recognizes the endocytic motif in NPC1L1 C terminus and couples NPC1L1 to endocytic machinery. The ARH, Dab2, and Numb proteins contain a homogeneous phosphotyrosine binding (PTB) domain that directly binds endocytic motifs. Because ARH, Dab2, and Numb are all PTB domain family members, the emerging mystery is whether these adaptors act complementally in LDLR and NPC1L1 endocytosis. Here, we found that ARH and Dab2 did not bind NPC1L1 and were not required for NPC1L1 internalization. Similarly, Numb lacked the ability to interact with the LDLR C terminus and was dispensable for LDL uptake. Only the Numb isoforms with shorter PTB domain could facilitate NPC1L1 endocytosis. Besides the reported function in intestinal cholesterol absorption, Numb also mediated cholesterol reabsorption from bile in liver. We further identified a Numb variant with G595D substitution in humans of low blood LDL-cholesterol. The G595D substitution impaired NPC1L1 internalization and cholesterol reabsorption, due to attenuating affinity of Numb to clathrin/AP2. These results demonstrate that Numb specifically regulates NPC1L1-mediated cholesterol absorption both in human intestine and liver, distinct from ARH and Dab2, which selectively participate in LDLR-mediated LDL uptake. PMID:25331956

  7. The region adjacent to the C-end of the inner gate in transient receptor potential melastatin 8 (TRPM8) channels plays a central role in allosteric channel activation.

    PubMed

    Taberner, Francisco José; López-Córdoba, Ainara; Fernández-Ballester, Gregorio; Korchev, Yuri; Ferrer-Montiel, Antonio

    2014-10-10

    The ability of transient receptor potential (TRP) channels to sense and respond to environmental and endogenous cues is crucial in animal sensory physiology. The molecular mechanism of channel gating is yet elusive. The TRP box, a conserved region in the N-end of the C terminus domain, has been signaled as pivotal for allosteric activation in TRP channels. Here, we have examined the role of the linker region between the TRPM8 inner gate and the TRP box (referred to as the S6-TRP box linker) to identify structural determinants of channel gating. Stepwise substitutions of segments in the S6-TRP box linker of TRPM8 channel with the cognate TRPV1 channel sequences produced functional chimeric channels, and identified Tyr(981) as a central molecular determinant of channel function. Additionally, mutations in the 986-990 region had a profound impact on channel gating by voltage and menthol, as evidenced by the modulation of the conductance-to-voltage (G-V) relationships. Simulation of G-V curves using an allosteric model for channel activation revealed that these mutations altered the allosteric constants that couple stimuli sensing to pore opening. A molecular model of TRPM8, based on the recently reported TRPV1 structural model, showed that Tyr(981) may lie in a hydrophobic pocket at the end of the S6 transmembrane segment and is involved in inter-subunit interactions with residues from neighbor subunits. The 986-990 region holds intrasubunit interactions between the TRP domain and the S4-S5 linker. These findings substantiate a gating mechanism whereby the TRP domain acts as a coupling domain for efficient channel opening. Furthermore, they imply that protein-protein interactions of the TRP domain may be targets for channel modulation and drug intervention. PMID:25157108

  8. Pathways to Play: Developing Play Skills in Young Children.

    ERIC Educational Resources Information Center

    Heidemann, Sandra; Hewitt, Deborah

    Play skills are vital to a child's overall healthy development. However, the training many caregivers receive may not include extensive information on play skills. This book presents a play checklist to help caregivers observe children's play skills, pinpoint play skills on which children need to work, and plan goals for improving those play…

  9. AT1 receptors as mechanosensors.

    PubMed

    Mederos y Schnitzler, Michael; Storch, Ursula; Gudermann, Thomas

    2011-04-01

    G-protein-coupled receptors are appreciated as central components of neurohormonal signaling. Recently, it turned out that they may also play a role in mechanotransduction. The angiotensin II AT(1) receptor was the first G-protein-coupled receptor claimed to be a mechanosensor. In the meantime, several other G(q/11)-coupled receptors were found to be sensitive to mechanical stimuli. Furthermore, there is first evidence to support the concept that G(i/o)-coupled receptors are susceptible to mechanical stimulation as well. Mechanical receptor activation appears to be agonist-independent and is initiated by a conformational change of the receptor protein discernible from agonist-bound conformations. Mechanically induced receptor activation plays a physiological role for myogenic vasoconstriction and is involved in the pathogenesis of cardiac hypertrophy. PMID:21147033

  10. Development through Work and Play.

    ERIC Educational Resources Information Center

    Hartung, Paul J.

    2002-01-01

    Five proposals are made for incorporating a work-play perspective in career development research: (1) fuse work and play conceptually over the life course; (2) imbue developmental career theory with a work-play fusion; (3) study work and play across the life span; (4) investigate work and play within the life space; and (5) consider a work-play…

  11. Play Theories: A Contemporary Review.

    ERIC Educational Resources Information Center

    Mellou, Eleni

    1994-01-01

    Reviews two sets of play theories, classical and modern, noting that the reason and purpose for play are explained by classical theories; the role of play in child development, determined by modern theories. States that process of play has dual functions of personal expression and social adaptation. Examines the relationship between play and…

  12. Play: Working Partner of Growth.

    ERIC Educational Resources Information Center

    McKee, Judy Spitler, Ed.

    This volume is a collection of nine papers focusing on different aspects of play. The first section, "Play, Growth, Development, and Learning," contains discussions dealing with make-believe play and learning; an all-in-fun approach to thinking, playing, and language learning for young children; and ways children learn through play. The second…

  13. Farm Hall: The Play

    NASA Astrophysics Data System (ADS)

    Cassidy, David C.

    2013-03-01

    It's July 1945. Germany is in defeat and the atomic bombs are on their way to Japan. Under the direction of Samuel Goudsmit, the Allies are holding some of the top German nuclear scientists-among them Heisenberg, Hahn, and Gerlach-captive in Farm Hall, an English country manor near Cambridge, England. As secret microphones record their conversations, the scientists are unaware of why they are being held or for how long. Thinking themselves far ahead of the Allies, how will they react to the news of the atomic bombs? How will these famous scientists explain to themselves and to the world their failure to achieve even a chain reaction? How will they come to terms with the horror of the Third Reich, their work for such a regime, and their behavior during that period? This one-act play is based upon the transcripts of their conversations as well as the author's historical work on the subject.

  14. Child's Play: Revisiting Play in Early Childhood Settings.

    ERIC Educational Resources Information Center

    Dau, Elizabeth, Ed.; Jones, Elizabeth, Ed.

    Noting that play is an essential aspect of learning for young children, this book presents a collection of articles on children's play in Australia. Part 1, "Play, Development, and Learning," contains the following chapters: (1) "The Role of Play in Development and Learning" (Ann Glover); (2) "Stop, Look, and Listen: Adopting an Investigative…

  15. Imagination, Playfulness, and Creativity in Children's Play with Different Toys

    ERIC Educational Resources Information Center

    Mo????ller, Signe?? Juhl?

    2015-01-01

    Based on a four-month experimental study of preschool children's play with creative-construction and social-fantasy toys, the author examines the in?uence of both types of toys on the play of preschool children. Her comparative analysis considers the impact of transformative play on the development of imagination during play activities and…

  16. Playing My Heart Out: Original Play as Adventure.

    ERIC Educational Resources Information Center

    Donaldson, O. Fred

    1999-01-01

    "Original" play denotes play that is pre-cultural--before conceptualizations and learned responses. Four anecdotes about play with an infant with Down's syndrome, a child with leukemia, a lioness, and a dying woman illustrate the connections between beings and between the ordinary and the sacred during trusting, fearless, playful encounters. (SV)

  17. Facilitation of Play Behavior from Associative to Cooperative Play Stages.

    ERIC Educational Resources Information Center

    Lounsbury, Karen Rasmussen; Bell, Corinne Reed

    An experimental investigation of the transition from associative play to cooperative play was conducted to determine if cooperative play in young children could be facilitated by (1) presenting a toy that required cooperative responses to make it operate, and (2) instructing the children in the use of the toy prior to having them play with it. A…

  18. Neuronal gamma-aminobutyric acid (GABA) type A receptors undergo cognate ligand chaperoning in the endoplasmic reticulum by endogenous GABA

    PubMed Central

    Wang, Ping; Eshaq, Randa S.; Meshul, Charles K.; Moore, Cynthia; Hood, Rebecca L.; Leidenheimer, Nancy J.

    2015-01-01

    GABAA receptors mediate fast inhibitory neurotransmission in the brain. Dysfunction of these receptors is associated with various psychiatric/neurological disorders and drugs targeting this receptor are widely used therapeutic agents. Both the efficacy and plasticity of GABAA receptor-mediated neurotransmission depends on the number of surface GABAA receptors. An understudied aspect of receptor cell surface expression is the post-translational regulation of receptor biogenesis within the endoplasmic reticulum (ER). We have previously shown that exogenous GABA can act as a ligand chaperone of recombinant GABAA receptors in the early secretory pathway leading us to now investigate whether endogenous GABA facilitates the biogenesis of GABAA receptors in primary cerebral cortical cultures. In immunofluorescence labeling experiments, we have determined that neurons expressing surface GABAA receptors contain both GABA and its degradative enzyme GABA transaminase (GABA-T). Treatment of neurons with GABA-T inhibitors, a treatment known to increase intracellular GABA levels, decreases the interaction of the receptor with the ER quality control protein calnexin, concomittantly increasing receptor forward-trafficking and plasma membrane insertion. The effect of GABA-T inhibition on the receptor/calnexin interaction is not due to the activation of surface GABAA or GABAB receptors. Consistent with our hypothesis that GABA acts as a cognate ligand chaperone in the ER, immunogold-labeling of rodent brain slices reveals the presence of GABA within the rough ER. The density of this labeling is similar to that present in mitochondria, the organelle in which GABA is degraded. Lastly, the effect of GABA-T inhibition on the receptor/calnexin interaction was prevented by pretreatment with a GABA transporter inhibitor. Together, these data indicate that endogenous GABA acts in the rough ER as a cognate ligand chaperone to facilitate the biogenesis of neuronal GABAA receptors. PMID

  19. Playful Learning and Montessori Education

    ERIC Educational Resources Information Center

    Lillard, Angeline S.

    2013-01-01

    Although Montessori education is often considered a form of playful learning, Maria Montessori herself spoke negatively about a major component of playful learning--pretend play, or fantasy--for young children. In this essay, the author discusses this apparent contradiction: how and why Montessori education includes elements of playful learning…

  20. The Child's Right To Play.

    ERIC Educational Resources Information Center

    Morris, Beverley

    This paper argues that play is an important and fundamental educational process and that the child's right to play should be respected. The paper also comments on the 1990 Tokyo International Conference on the Child's Right to Play. Several issues related to children's play, both in and out of school, are discussed. The focus is on the state of…

  1. Music Learning and Child's Play.

    ERIC Educational Resources Information Center

    Littleton, Danette

    1998-01-01

    Reviews various studies on childs play and its relation to young childrens development in music learning processes and explores the role that cognitive and social play categories have in studying childrens play with music. Provides strategies for initiating music-play opportunities in a preschool classroom. (CMK)

  2. Play and Positive Group Dynamics

    ERIC Educational Resources Information Center

    Thompson, Pam; White, Samantha

    2010-01-01

    Play is an important part of a child's life and essential to learning and development (Vygotsky, 1978). It is vital that students participate in play and that play be conducted in a restorative manner. Play allows a variety of group dynamics to emerge. Irvin Yalom (1995) identifies 11 curative factors of the group experience. These factors include…

  3. Toy Play, Play Tempo, and Reaction to Frustration in Infants.

    ERIC Educational Resources Information Center

    Longo, Josephine; And Others

    1982-01-01

    In two sessions, the duration and tempo of toy play of infants and reaction of frustration were measured. Correlations indicated a general relationship between response persistence during play and attempts to escape frustrating situations. (Author/CM)

  4. Playing with Switches, Birth through Two. Let's Play! Project.

    ERIC Educational Resources Information Center

    State Univ. of New York, Buffalo. Center for Assistive Technology.

    This guide to playing with switches for parents and early intervention personnel was developed by the "Let's Play! Project," a 3-year federally supported project that worked to promote play in infants and toddlers with disabilities through the use of assistive technology. Switches are used with electronic toys to help young children easily…

  5. Increasing Joint Attention, Play and Language through Peer Supported Play.

    ERIC Educational Resources Information Center

    Zercher, Craig; Hunt, Pam; Schuler, Adriana; Webster, Janice

    2001-01-01

    This study examined effects of participation in an integrated play group on the social skills of two 6-year-old twins with autism. Following intervention with adult coaching, typical peers implemented the play group techniques in weekly play group sessions. The autistic subjects showed dramatic increases in shared attention to objects, symbolic…

  6. Solar Power at Play

    NASA Astrophysics Data System (ADS)

    2007-03-01

    For the very first time, astronomers have witnessed the speeding up of an asteroid's rotation, and have shown that it is due to a theoretical effect predicted but never seen before. The international team of scientists used an armada of telescopes to discover that the asteroid's rotation period currently decreases by 1 millisecond every year, as a consequence of the heating of the asteroid's surface by the Sun. Eventually it may spin faster than any known asteroid in the solar system and even break apart. ESO PR Photo 11a/07 ESO PR Photo 11a/07 Asteroid 2000 PH5 "The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the way small bodies in the Solar System rotate," said Stephen Lowry (Queens University Belfast, UK), lead-author of one of the two companion papers in which this work is reported [1, 2]. "The warming caused by sunlight hitting the surfaces of asteroids and meteoroids leads to a gentle recoil effect as the heat is released," he added. "By analogy, if one were to shine light on a propeller over a long enough period, it would start spinning." Although this is an almost immeasurably weak force, its effect over millions of years is far from negligible. Astronomers believe the YORP effect may be responsible for spinning some asteroids up so fast that they break apart, perhaps leading to the formation of double asteroids. Others may be slowed down so that they take many days to complete a full turn. The YORP effect also plays an important role in changing the orbits of asteroids between Mars and Jupiter, including their delivery to planet-crossing orbits, such as those of near-Earth asteroids. Despite its importance, the effect has never been seen acting on a solar system body, until now. Using extensive optical and radar imaging from powerful Earth-based observatories, astronomers have directly observed the YORP effect in action on a small near-Earth asteroid, known as (54509) 2000 PH5. Shortly after its discovery in 2000, it was

  7. Vasopressin receptor antagonists.

    PubMed

    Palmer, Biff F

    2015-01-01

    Arginine vasopressin (AVP) is the principal hormone involved in regulating the tonicity of body fluids. Less appreciated is the role that AVP plays in a variety of other physiologic functions including glucose metabolism, cardiovascular homeostasis, bone metabolism, and cognitive behavior. AVP receptor antagonists are now available and currently approved to treat hyponatremia. There is a great deal of interest in exploring the potential benefits that these drugs may play in blocking AVP-mediated effects in other organ systems. The purpose of this report is to provide an update on the expanding role of AVP receptor antagonists and what disease states these drugs may eventually be used for. PMID:25604388

  8. Learning, Play, and Your Newborn

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Learning, Play, and Your Newborn KidsHealth > For Parents > Learning, ... juega su recién nacido What Is My Newborn Learning? Play is the chief way that infants learn ...

  9. Medical Play for Young Children.

    ERIC Educational Resources Information Center

    Jessee, Peggy O.; Wilson, Heidi; Morgan, Dee

    2000-01-01

    Discusses young children's emotional responses during medical examinations and procedures, developmental changes in how they conceptualize illness causation, and the role of play to reduce stress. Describes how teachers can best facilitate structured dramatic medical play therapeutically. (KB)

  10. Problematic game play: the diagnostic value of playing motives, passion, and playing time in men.

    PubMed

    Kneer, Julia; Rieger, Diana

    2015-01-01

    Internet gaming disorder is currently listed in the DSM-not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1) analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2) testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81) that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing. PMID:25942516

  11. Problematic Game Play: The Diagnostic Value of Playing Motives, Passion, and Playing Time in Men

    PubMed Central

    Kneer, Julia; Rieger, Diana

    2015-01-01

    Internet gaming disorder is currently listed in the DSM—not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1) analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2) testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81) that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing. PMID:25942516

  12. Play Memories and Place Identity.

    ERIC Educational Resources Information Center

    Sandberg, Anette

    2003-01-01

    This retrospective study examined play memories from childhood to adulthood of 478 university students between ages 20 and 62 as exhibited in drawings of play memories and questionnaire responses. The study focused on the role of the physical environment and place identity in play memories and individual identity development. Findings showed that…

  13. Meanings of Play among Children

    ERIC Educational Resources Information Center

    Glenn, Nicole M.; Knight, Camilla J.; Holt, Nicholas L.; Spence, John C.

    2013-01-01

    The purpose of this study was to examine meanings of play among children. Thirty-eight students aged 7-9 years from a suburban public school in Western Canada participated in focus groups. Data analysis revealed participants saw almost anything as an opportunity for play and would play almost anywhere with anyone. However, they perceived parents…

  14. Play Therapy in School Counseling

    ERIC Educational Resources Information Center

    Trice-Black, Shannon; Bailey, Carrie Lynn; Kiper Riechel, Morgan E.

    2013-01-01

    Play therapy is an empirically supported intervention used to address a number of developmental issues faced in childhood. Through the natural language of play, children and adolescents communicate feelings, thoughts, and experiences. Schools provide an ideal setting for play therapy in many ways; however, several challenges exist in implementing…

  15. Play in Evolution and Development

    ERIC Educational Resources Information Center

    Pellegrini, Anthony D.; Dupuis, Danielle; Smith, Peter K.

    2007-01-01

    In this paper we examine the role of play in human ontogeny and phylogeny, following Surplus Resource Theory. We consider how juveniles use play to sample their environment in order to develop adaptive behaviors. We speculate about how innovative behaviors developed in play in response to environmental novelty may influence subsequent evolutionary…

  16. Pretend Play and Creative Processes

    ERIC Educational Resources Information Center

    Russ, Sandra W.; Wallace, Claire E.

    2013-01-01

    The authors contend that many cognitive abilities and affective processes important in creativity also occur in pretend play and that pretend play in childhood affects the development of creativity in adulthood. They discuss a variety of theories and observations that attempt to explain the importance of pretend play to creativity. They argue that…

  17. Preschoolers' Thinking during Block Play

    ERIC Educational Resources Information Center

    Piccolo, Diana L.; Test, Joan

    2010-01-01

    Children build foundations for mathematical thinking in early play and exploration. During the preschool years, children enjoy exploring mathematical concepts--such as patterns, shape, spatial relationships, and measurement--leading them to spontaneously engage in mathematical thinking during play. Block play is one common example that engages…

  18. Why do adult dogs 'play'?

    PubMed

    Bradshaw, John W S; Pullen, Anne J; Rooney, Nicola J

    2015-01-01

    Among the Carnivora, play behaviour is usually made up of motor patterns characteristic of predatory, agonistic and courtship behaviour. Domestic dogs are unusual in that play is routinely performed by adults, both socially, with conspecifics and with humans, and also asocially, with objects. This enhanced playfulness is commonly thought to be a side effect of paedomorphosis, the perpetuation of juvenile traits into adulthood, but here we suggest that the functions of the different types of play are sufficiently distinct that they are unlikely to have arisen through a single evolutionary mechanism. Solitary play with objects appears to be derived from predatory behaviour: preferred toys are those that can be dismembered, and a complex habituation-like feedback system inhibits play with objects that are resistant to alteration. Intraspecific social play is structurally different from interspecific play and may therefore be motivationally distinct and serve different goals; for example, dogs often compete over objects when playing with other dogs, but are usually more cooperative when the play partner is human. The majority of dogs do not seem to regard competitive games played with a human partner as "dominance" contests: rather, winning possession of objects during games appears to be simply rewarding. Play may be an important factor in sociality, since dogs are capable of extracting social information not only from games in which they participate, but also from games that they observe between third parties. We suggest that the domestic dog's characteristic playfulness in social contexts is an adaptive trait, selected during domestication to facilitate both training for specific purposes, and the formation of emotionally-based bonds between dog and owner. Play frequency and form may therefore be an indicator of the quality of dog-owner relationships. PMID:25251020

  19. Thinking about Children's Play: Play Is Not Work, Nor Is Work Play.

    ERIC Educational Resources Information Center

    Elkind, David

    2001-01-01

    Addresses the concept of "play as a child's work," from the viewpoints of Montessori, Freud, and Piaget. Contends that children's play: (1) like adult play, may be individual or social; (2) has immediate value for the child as a way of expressing feelings; and (3) is a healthy counterpoise to work. (SD)

  20. Characterization of a metabotropic glutamate receptor in the honeybee (Apis mellifera): implications for memory formation.

    PubMed

    Kucharski, R; Mitri, C; Grau, Y; Maleszka, R

    2007-06-01

    G-protein-coupled metabotropic glutamate receptors (GPC mGluRs) are important constituents of glutamatergic synapses where they contribute to synaptic plasticity and development. Here we characterised a member of this family in the honeybee. We show that the honeybee genome encodes a genuine mGluR (AmGluRA) that is expressed at low to medium levels in both pupal and adult brains. Analysis of honeybee protein sequence places it within the type 3 GPCR family, which includes mGlu receptors, GABA-B receptors, calcium-sensing receptors, and pheromone receptors. Phylogenetic comparisons combined with pharmacological evaluation in HEK 293 cells transiently expressing AmGluRA show that the honeybee protein belongs to the group II mGluRs. With respect to learning and memory AmGluRA appears to be required for memory formation. Both agonists and antagonists selective against the group II mGluRs impair long-term (24 h) associative olfactory memory formation when applied 1 h before training, but have no effect when injected post-training or pre-testing. Our results strengthen the notion that glutamate is a key neurotransmitter in memory processes in the honeybee. PMID:17372777

  1. Playing with the Multiple Intelligences: How Play Helps Them Grow

    ERIC Educational Resources Information Center

    Eberle, Scott G.

    2011-01-01

    Howard Gardner first posited a list of "multiple intelligences" as a liberating alternative to the assumptions underlying traditional IQ testing in his widely read study "Frames of Mind" (1983). Play has appeared only in passing in Gardner's thinking about intelligence, however, even though play instructs and trains the verbal, interpersonal,…

  2. Understanding Young Children's Learning through Play: Building Playful Pedagogies

    ERIC Educational Resources Information Center

    Broadhead, Pat; Burt, Andy

    2011-01-01

    This timely and accessible text introduces, theorises and practically applies two important concepts which now underpin early years practice: those of "playful learning" and "playful pedagogies". Pat Broadhead and Andy Burt draw upon filmed material, conversations with children, reflection, observation, and parental and staff interviews, in their…

  3. Well Played: The Origins and Future of Playfulness

    ERIC Educational Resources Information Center

    Gordon, Gwen

    2014-01-01

    In this article, the author synthesizes research from several disciplines to shed light on play's central role in healthy development. Gordon builds on research in attachment theory that correlates secure attachment in infancy with adult well-being to demonstrate how playfulness might be a lifelong outcome of secure attachment and a primary…

  4. "Play for Real": Understanding Middle School Children's Dramatic Play.

    ERIC Educational Resources Information Center

    Sierra, Zayda

    2000-01-01

    Summarizes a dissertation that examines the theory and practice of dramatic play among middle school children. Finds that they are still adept and interested in dramatic play. Discusses four components describing the nature and product of the dramatic process (social interactions, metacognitive strategies, ideational processes, and content of…

  5. Playing To Get Smart. Viewpoint.

    ERIC Educational Resources Information Center

    Jones, Elizabeth

    2003-01-01

    Asserts that it is through play with materials and relationships, invention of classification systems, and solving problems in dialogue with others that young children develop the basic skills they will need to become effective contributors to the health of a changing world. Offers suggestions for teaching children play skills by providing…

  6. The Child's Right To Play.

    ERIC Educational Resources Information Center

    Guddemi, Marcy

    Several factors are eroding children's right to play. The first is continuing poverty throughout the world. This factor is evident in underdeveloped countries and the inner cities of industrialized countries. Changing cultural values are a second factor in developed societies where indifference toward the importance of play is prevalent. The many…

  7. Sand and Water Table Play

    ERIC Educational Resources Information Center

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  8. Young Children and War Play.

    ERIC Educational Resources Information Center

    Carlsson-Paige, Nancy; Levin, Diane E.

    1988-01-01

    In a recent survey of parents and early childhood professionals the prevalence of war play among children and an increase in the amount of violence in children's play was noted. Outlines how the deregulation of children's television during the Reagan administration has affected children's exposure to violence in children's television programming.…

  9. Invention at Play. Educators' Manual.

    ERIC Educational Resources Information Center

    Judd, Michael; Lacasse, Jane; Smith, Monica; Reilly, Katie

    A Smithsonian exhibition was developed that looked at invention in an innovative way. It aimed to encourage visitors to make connections between their own lives and abilities and those of inventors. The role of play in the invention process was examined. Play is a universal and familiar activity and can help people find the link between their own…

  10. The Play of Socratic Dialogue

    ERIC Educational Resources Information Center

    Smith, Richard

    2011-01-01

    Proponents of philosophy for children generally see themselves as heirs to the "Socratic" tradition. They often claim too that children's aptitude for play leads them naturally to play with abstract, philosophical ideas. However in Plato's dialogues we find in the mouth of "Socrates" many warnings against philosophising with the young. Those…

  11. Playground Play: Educational and Inclusive

    ERIC Educational Resources Information Center

    Moore, Lisa

    2011-01-01

    It is easy to understand that fun is one of the key ingredients to any playground activity. But what one may not realize is that play systems--including slides, tunnels, activity panels, and more--encourage a lot more than just fun: there is learning at work in playground play, as well as the opportunity to include children of all abilities in…

  12. Empowering Groups that Enable Play

    ERIC Educational Resources Information Center

    Wilson, David Sloan; Marshall, Danielle; Iserhott, Hindi

    2011-01-01

    Creating play environments for children usually requires groups of adults working together. An extensive scientific literature describes how groups function to achieve shared goals in general terms, and groups attempting to empower play may find this literature useful. Design principles for managing natural resources, identified by Elinor Ostrom…

  13. Let's Play Three on Three!

    ERIC Educational Resources Information Center

    Kern, Jack; Calleja, Paul

    2008-01-01

    Over the course of nine years as a supervisor of intern teachers, the first author collected observations of game play during lessons taught by intern teachers or their mentors. In general, the observations indicated that the majority of students got limited practice opportunities during game play. A close look at the data revealed an interesting…

  14. Outdoor Play: Combating Sedentary Lifestyles

    ERIC Educational Resources Information Center

    Thigpen, Betsy

    2007-01-01

    Increasingly sedentary lifestyles are contributing to overweight and other health concerns as children spend less and less time outside engaged in active play. Outdoor play provides important opportunities to explore the natural world, interact with peers, engage in vigorous physical activity, and learn about our environment. However, outdoor…

  15. The Fractal Self at Play

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2010-01-01

    In this article, the author draws on contemporary science to illuminate the relationship between early play experiences, processes of self-development, and the later emergence of the fractal self. She argues that orientation within social space is a primary function of early play and developmentally a two-step process. With other people and with…

  16. A Place for Block Play.

    ERIC Educational Resources Information Center

    Moore, Gary T.

    1997-01-01

    Discusses the importance of block play--including its contributions to perceptual, fine motor, and cognitive development--and components of a good preschool block play area. Recommends unit blocks complemented by stacking blocks, toys, beads, cubes, and Brio wooden toys. Makes recommendations for space, size, locations and connections to other…

  17. Niger Delta play types, Nigeria

    SciTech Connect

    Akinpelu, A.O.

    1995-08-01

    Exploration databases can be more valuable when sorted by play type. Play specific databases provide a system to organize E & P data used in evaluating the range of values of parameters for reserve estimation and risk assessment. It is important both in focusing the knowledge base and in orienting research effort. A play in this context is any unique combination of trap, reservoir and source properties with the right dynamics of migration and preservation that results in hydrocarbon accumulation. This definitions helps us to discriminate the subtle differences found with these accumulation settings. About 20 play types were identified around the Niger Delta oil province in Nigeria. These are grouped into three parts: (1) The proven plays-constituting the bulk of exploration prospects in Nigeria today. (2) The unproven or semi-proven plays usually with some successes recorded in a few tries but where knowledge is still inadequate. (3) The unproven or analogous play concept. These are untested but geologically sound ideas which may or may not have been tried elsewhere. With classification and sub grouping of these play types into specific databases, intrinsic attributes and uniqueness of each of them with respect to the four major risk elements and the eight parameters for reserve estimation can be better understood.

  18. Play Therapy with Special Populations.

    ERIC Educational Resources Information Center

    Carmichael, Karla D.

    This paper notes that therapists often feel unqualified to deal with special populations of children because of a lack of understanding of the universalness of play therapy. Suggestions are offered for beginning play therapists who may work with a number of special populations of children. It is recommended that the social learning approach to…

  19. Making Play Work for Education

    ERIC Educational Resources Information Center

    Weisberg, Deena Skolnick; Kittredge, Audrey K.; Hirsh-Pasek, Kathy; Golinkoff, Roberta Michnick; Klahr, David

    2015-01-01

    Children, especially in the preschool years, learn a tremendous amount through play. Research on guided play demonstrates how schools can couple a curriculum-centered preschool program with a developmentally appropriate pedagogical approach to classroom teaching. However, to fully test this claim, we need a clear definition of the term…

  20. Solitary Play: Some Functional Reconsiderations

    ERIC Educational Resources Information Center

    Moore, Nancy V.; And Others

    1974-01-01

    Solitary play in six kindergarten children was observed and coded for frequency and type in order to resolve iscrepancies in a Sex Birth Order interaction. Several facts concerning solitary play as indicative of independence and maturity are noted. (Author/ED)

  1. Engaging Families through Artful Play

    ERIC Educational Resources Information Center

    Brown, Robert

    2015-01-01

    This paper explores how aligned arts and play experiences can extend child and family engagement in a public outdoor space. The importance of outdoor play for children is strongly advocated and in response local governments provide playgrounds and recreational open spaces. To extend further the experiences afforded in such spaces some local…

  2. Three Plays from the Japanese.

    ERIC Educational Resources Information Center

    Mayfield, M. Kent

    This study is both an interpretation and a translation of three modern Japanese plays, providing an artistic perspective on the radical reordering of experience and thought with which modern man must grapple in cross-cultural encounters. An introductory essay prefaces each play, providing a historical, critical, or appreciative perspective from…

  3. Principles of Play for Soccer

    ERIC Educational Resources Information Center

    Ouellette, John

    2004-01-01

    Soccer coaches must understand the principles of play if they want to succeed. The principles of play are the rules of action that support the basic objectives of soccer and the foundation of a soccer coaching strategy. They serve as a set of permanent criteria that coaches can use to evaluate the efforts of their team. In this article, the author…

  4. Transmedia Play: Literacy across Media

    ERIC Educational Resources Information Center

    Alper, Meryl; Herr-Stephenson, Rebecca

    2013-01-01

    Transmedia play is a new way to understand how children develop critical media literacy and new media literacies through their interactions with contemporary media that links stories and structures across platforms. This essay highlights five characteristics of transmedia play that make it particularly useful for learning:…

  5. Neuroscience, Play, and Child Development.

    ERIC Educational Resources Information Center

    Frost, Joe L.

    This paper presents a brief overview of the array of neuroscience research as it applies to play and child development. The paper discusses research showing the importance of play for brain growth and child development, and recommends that families, schools and other social and corporate institutions rearrange their attitudes and priorities about…

  6. Laryngeal pressure receptors.

    PubMed

    Mathew, O P; Sant'Ambrogio, G; Fisher, J T; Sant'Ambrogio, F B

    1984-07-01

    We studied the response characteristics of laryngeal pressure receptors in anesthetized dogs, breathing through a tracheal cannula, by recording single unit action potentials from the peripheral cut end of the internal branch of the superior laryngeal nerve. The larynx, with the rest of the upper airway, was isolated and cannulated separately for the application of distending and collapsing pressures. We identified receptors responding to either negative or positive pressure and a few responding to both. All these receptors showed a marked dynamic sensitivity and had the characteristics of slowly adapting mechanoreceptors. The majority of pressure receptors were active at zero transmural pressure and the gain of their response to pressure was higher at lower values, suggesting a role for these receptors in eupnea. Reflex alterations in breathing pattern and upper airway muscle activity during upper airway pressure changes, previously reported, are presumably mediated by the receptors described here. Moreover, these receptors may play a role in certain pathological states, such as obstructive sleep apnea, in which the upper airway is transiently subjected to large collapsing pressure. PMID:6484319

  7. Depression of the vestibulospinal reflex adaptation by intravermal microinjection of GABA-A and GABA-B agonists in the cat.

    PubMed

    Manzoni, D; Andre, P; d'Ascanio, P; Pompeiano, O

    1994-10-01

    In decerebrate cats the gain of the vestibulospinal reflex (VSR), elicited by sinusoidal roll tilt of the animal at 0.15 Hz, +/- 10 degrees, was tested every 10-15 min during and after a sustained (3 h) period of roll tilt of the head at the parameters indicated above, associated with synchronous roll tilt of the body at 0.15 Hz, +/- 12.5 degrees; this stimulus led to 2.5 degrees of neck rotation, which was thus out of phase with respect to head rotation. In this condition the gain of the VSR progressively increased during the first h of neck-vestibular stimulation, to reach a plateau level at the end of the third h of stimulation. This adaptive process was followed for at least 1 h after stimulation. Microinjection into the zone B of the cerebellar anterior vermis of the GABA-A agonist muscimol (0.25 microliter at 8 micrograms/microliter saline) producing only a slight or negligible depression of the VSR gain in non-adaptive conditions, prevented the occurrence of the adapted increase in gain of the VSR following a 3-h period of sustained head and neck rotation. In addition, intravermal injection of the GABA-A or the GABA-B agonist muscimol or baclofen, respectively, at the same dose indicated above supressed the adapted increase in gain occurring after a 3-h period of continuous neck-vestibular stimulation. The effective sites were located into the zone B of the cerebellar anterior vermis, from which the direct corticocerebellar projection to the lateral vestibular nucleus originates. In conclusion, the results seem to indicate that the adaptive increase in gain of the VSR which occurs in decerebrate cats depend upon plastic changes which affect the Purkinje cells of the cerebellar anterior vermis. These changes were in fact suppressed by GABAergic inhibition of these neurons. The demonstration that the effects of the GABA agonists occurred suddenly makes unlikely the hypothesis that the cerebellar anterior vermis represents either a relay for adaptive changes

  8. Playful biometrics: controversial technology through the lens of play.

    PubMed

    Ellerbrok, Ariane

    2011-01-01

    This article considers the role of play in the context of technological emergence and expansion, particularly as it relates to recently emerging surveillance technologies. As a case study, I consider the trajectory of automated face recognition—a biometric technology of numerous applications, from its more controversial manifestations under the rubric of national security to a clearly emerging orientation toward play. This shift toward “playful” biometrics—or from a technology traditionally coded as “hard” to one now increasingly coded as “soft”—is critical insofar as it renders problematic the traditional modes of critique that have, up until this point, challenged the expansion of biometric systems into increasingly ubiquitous realms of everyday life. In response to this dynamic, I propose theorizing the expansion of face recognition specifically in relation to “play,” a step that allows us to broaden the critical space around newly emerging playful biometrics, as well as playful surveillance more generally. In addition, play may also have relevance for theorizing other forms of controversial technology, particularly given its potential role in processes of obfuscation, normalization, and marginalization. PMID:22175066

  9. Seizures induced by playing music.

    PubMed

    Sutherling, W W; Hershman, L M; Miller, J Q; Lee, S I

    1980-09-01

    A 67-year-old organist and minister with diabetes mellitus had stereotyped focal seizures of the left lower face, jaw, and neck. Attacks occurred spontaneously or were induced when he played a specific hymn on the organ. The seizures were not induced by reading, singing, hearing, or playing the hymn silently. The patient had interictal weakness of the left lower face and left side of the tongue. Focal seizures were recorded on an electroencephalogram (EEG) at the right temporofrontal area. This patient illustrates partial seizures induced by playing music. PMID:6775246

  10. Metabolomic Approaches to Defining the Role(s) of GABAρ Receptors in the Brain.

    PubMed

    Rae, Caroline; Nasrallah, Fatima A; Balcar, Vladimir J; Rowlands, Benjamin D; Johnston, Graham A R; Hanrahan, Jane R

    2015-09-01

    The inhibitory neurotransmitter γ-aminobutyric acid (GABA) acts through various types of receptors in the central nervous system. GABAρ receptors, defined by their characteristic pharmacology and presence of ρ subunits in the channel structure, are poorly understood and their role in the cortex is ill-defined. Here, we used a targeted pharmacological, NMR-based functional metabolomic approach in Guinea pig brain cortical tissue slices to identify a distinct role for these receptors. We compared metabolic fingerprints generated by a range of ligands active at GABAρ and included these in a principal components analysis with a library of other metabolic fingerprints obtained using ligands active at GABAA and GABAB, with inhibitors of GABA uptake and with compounds acting to inhibit enzymes active in the GABAergic system. This enabled us to generate a metabolic "footprint" of the GABAergic system which revealed classes of metabolic activity associated with GABAρ which are distinct from other GABA receptors. Antagonised GABAρ produce large metabolic effects at extrasynaptic sites suggesting they may be involved in tonic inhibition. PMID:25577264

  11. Changes in the expression of neurotransmitter receptors in Parkin and DJ-1 knockout mice--A quantitative multireceptor study.

    PubMed

    Cremer, J N; Amunts, K; Schleicher, A; Palomero-Gallagher, N; Piel, M; Rösch, F; Zilles, K

    2015-12-17

    Parkinson's disease (PD) is a well-characterized neurological disorder with regard to its neuropathological and symptomatic appearance. At the genetic level, mutations of particular genes, e.g. Parkin and DJ-1, were found in human hereditary PD with early onset. Neurotransmitter receptors constitute decisive elements in neural signal transduction. Furthermore, since they are often altered in neurological and psychiatric diseases, receptors have been successful targets for pharmacological agents. However, the consequences of PD-associated gene mutations on the expression of transmitter receptors are largely unknown. Therefore, we studied the expression of 16 different receptor binding sites of the neurotransmitters glutamate, GABA, acetylcholine, adrenaline, serotonin, dopamine and adenosine by means of quantitative receptor autoradiography in Parkin and DJ-1 knockout mice. These knockout mice exhibit electrophysiological and behavioral deficits, but do not show the typical dopaminergic cell loss. We demonstrated differential changes of binding site densities in eleven brain regions. Most prominently, we found an up-regulation of GABA(B) and kainate receptor densities in numerous cortical areas of Parkin and DJ-1 knockout mice, as well as increased NMDA but decreased AMPA receptor densities in different brain regions of the Parkin knockout mice. The alterations of three different glutamate receptor types may indicate the potential relevance of the glutamatergic system in the pathogenesis of PD. Furthermore, the cholinergic M1, M2 and nicotinic receptors as well as the adrenergic α2 and the adenosine A(2A) receptors showed differentially increased densities in Parkin and DJ-1 knockout mice. Taken together, knockout of the PD-associated genes Parkin or DJ-1 results in differential changes of neurotransmitter receptor densities, highlighting a possible role of altered non-dopaminergic, and in particular of glutamatergic neurotransmission in PD pathogenesis. PMID

  12. Self-playing musical instrument

    NASA Astrophysics Data System (ADS)

    Bouffard, Karen

    2001-05-01

    This do-ahead Physics Olympics competition is a musical challenge based on one designed by Dan Calder for a past New Hampshire Physics Olympics. The objective is to build a musical instrument that is self-playing.

  13. The Many Faces of Play.

    ERIC Educational Resources Information Center

    Werth, Louise H.

    1984-01-01

    Presents descriptions of play reflecting recent theories, including the psychoanalytic works of Freud, Erikson, and Peller; Piaget's developmental theory (with discussion of Sutton-Smith); and the views of Smilansky and Parten. (AS)

  14. A multiverse play divides opinion

    NASA Astrophysics Data System (ADS)

    Crease, Robert P.

    2015-03-01

    The stage lights rise. A man and woman meet in a cute way - "Do you know why it's impossible to lick the tips of your elbows?" she asks - they chat momentarily, and separate. The play is Constellations by Nick Payne.

  15. A New Family of Receptor Tyrosine Kinases with a Venus Flytrap Binding Domain in Insects and Other Invertebrates Activated by Aminoacids

    PubMed Central

    Ahier, Arnaud; Rondard, Philippe; Gouignard, Nadège; Khayath, Naji; Huang, Siluo; Trolet, Jacques; Donoghue, Daniel J.; Gauthier, Monique; Pin, Jean-Philippe; Dissous, Colette

    2009-01-01

    Background Tyrosine kinase receptors (RTKs) comprise a large family of membrane receptors that regulate various cellular processes in cell biology of diverse organisms. We previously described an atypical RTK in the platyhelminth parasite Schistosoma mansoni, composed of an extracellular Venus flytrap module (VFT) linked through a single transmembrane domain to an intracellular tyrosine kinase domain similar to that of the insulin receptor. Methods and Findings Here we show that this receptor is a member of a new family of RTKs found in invertebrates, and particularly in insects. Sixteen new members of this family, named Venus Kinase Receptor (VKR), were identified in many insects. Structural and phylogenetic studies performed on VFT and TK domains showed that VKR sequences formed monophyletic groups, the VFT group being close to that of GABAB receptors and the TK one being close to that of insulin receptors. We show that a recombinant VKR is able to autophosphorylate on tyrosine residues, and report that it can be activated by L-arginine. This is in agreement with the high degree of conservation of the alpha amino acid binding residues found in many amino acid binding VFTs. The presence of high levels of vkr transcripts in larval forms and in female gonads indicates a putative function of VKR in reproduction and/or development. Conclusion The identification of RTKs specific for parasites and insect vectors raises new perspectives for the control of human parasitic and infectious diseases. PMID:19461966

  16. Guided Play: Where Curricular Goals Meet a Playful Pedagogy

    ERIC Educational Resources Information Center

    Weisberg, Deena Skolnick; Hirsh-Pasek, Kathy; Golinkoff, Roberta Michnick

    2013-01-01

    Decades of research demonstrate that a strong curricular approach to preschool education is important for later developmental outcomes. Although these findings have often been used to support the implementation of educational programs based on direct instruction, we argue that "guided play" approaches can be equally effective at delivering content…

  17. Parent-Child Play across Cultures: Advancing Play Research

    ERIC Educational Resources Information Center

    Roopnarine, Jaipaul L.; Davidson, Kimberly L.

    2015-01-01

    In this article, the authors argue for a greater understanding of children's play across cultures through better integration of scientific thinking about the developed and developing societies, through consideration of socialization beliefs and goals, and, finally, through the use of more complex models in research investigations. They draw on…

  18. Dopamine Receptors and Neurodegeneration

    PubMed Central

    Rangel-Barajas, Claudia; Coronel, Israel; Florán, Benjamín

    2015-01-01

    Dopamine (DA) is one of the major neurotransmitters and participates in a number of functions such as motor coordination, emotions, memory, reward mechanism, neuroendocrine regulation etc. DA exerts its effects through five DA receptors that are subdivided in 2 families: D1-like DA receptors (D1 and D5) and the D2-like (D2, D3 and D4). All DA receptors are widely expressed in the central nervous system (CNS) and play an important role in not only in physiological conditions but also pathological scenarios. Abnormalities in the DAergic system and its receptors in the basal ganglia structures are the basis Parkinson’s disease (PD), however DA also participates in other neurodegenerative disorders such as Huntington disease (HD) and multiple sclerosis (MS). Under pathological conditions reorganization of DAergic system has been observed and most of the times, those changes occur as a mechanism of compensation, but in some cases contributes to worsening the alterations. Here we review the changes that occur on DA transmission and DA receptors (DARs) at both levels expression and signals transduction pathways as a result of neurotoxicity, inflammation and in neurodegenerative processes. The better understanding of the role of DA receptors in neuropathological conditions is crucial for development of novel therapeutic approaches to treat alterations related to neurodegenerative diseases. PMID:26425390

  19. An arylaminopyridazine derivative of gamma-aminobutyric acid (GABA) is a selective and competitive antagonist at the GABAA receptor site.

    PubMed Central

    Chambon, J P; Feltz, P; Heaulme, M; Restle, S; Schlichter, R; Biziere, K; Wermuth, C G

    1985-01-01

    In view of finding a new gamma-aminobutyric acid (GABA) receptor ligand we synthesized an arylaminopyridazine derivative of GABA, SR 95103 [2-(carboxy-3'-propyl)-3-amino-4-methyl-6-phenylpyridazinium chloride]. SR 95103 displaced [3H]GABA from rat brain membranes with an apparent Ki of 2.2 microM and a Hill number near 1.0. SR 95103 (1-100 microM) antagonized the GABA-mediated enhancement of [3H]diazepam binding in a concentration-dependent manner without affecting [3H]diazepam binding per se. SR 95103 competitively antagonized GABA-induced membrane depolarization in rat spinal ganglia. In all these experiments, the potency of SR 95103 was close to that of bicuculline. SR 95103 (100 microM) did not interact with a variety of central receptors--in particular the GABAB, the strychnine, and the glutamate receptors--did not inhibit Na+-dependent synaptosomal GABA uptake, and did not affect GABA-transaminase and glutamic acid decarboxylase activities. Intraperitoneally administered SR 95103 elicited clonicotonic seizures in mice (ED50 = 180 mg/kg). On the basis of these results it is postulated that St 95103 is a competitive antagonist of GABA at the GABAA receptor site. In addition to being an interesting lead structure for the search of GABA ligands, SR 95103 could also be a useful tool to investigate GABA receptor subtypes because it is freely soluble in water and chemically stable. Images PMID:2984669

  20. TAM receptor deficiency affects adult hippocampal neurogenesis

    PubMed Central

    Ji, Rui; Meng, Lingbin; Li, Qiutang; Lu, Qingxian

    2014-01-01

    The Tyro3, Axl and Mertk (TAM) subfamily of receptor protein tyrosine kinases functions in cell growth, differentiation, survival, and most recently found, in the regulation of immune responses and phagocytosis. All three receptors and their ligands, Gas6 (growth arrest-specific gene 6) and protein S, are expressed in the central nervous system (CNS). TAM receptors play pivotal roles in adult hippocampal neurogenesis. Loss of these receptors causes a comprised neurogenesis in the dentate gyrus of adult hippocampus. TAM receptors have a negative regulatory effect on microglia and peripheral antigen-presenting cells, and play a critical role in preventing overproduction of pro-inflammatory cytokines detrimental to the proliferation, differentiation, and survival of adult neuronal stem cells (NSCs). Besides, these receptors also play an intrinsic trophic function in supporting NSC survival, proliferation, and differentiation into immature neurons. All these events collectively ensure a sustained neurogenesis in adult hippocampus. PMID:25487541

  1. TAM receptor deficiency affects adult hippocampal neurogenesis.

    PubMed

    Ji, Rui; Meng, Lingbin; Li, Qiutang; Lu, Qingxian

    2015-06-01

    The Tyro3, Axl and Mertk (TAM) subfamily of receptor protein tyrosine kinases functions in cell growth, differentiation, survival, and most recently found, in the regulation of immune responses and phagocytosis. All three receptors and their ligands, Gas6 (growth arrest-specific gene 6) and protein S, are expressed in the central nervous system (CNS). TAM receptors play pivotal roles in adult hippocampal neurogenesis. Loss of these receptors causes a comprised neurogenesis in the dentate gyrus of adult hippocampus. TAM receptors have a negative regulatory effect on microglia and peripheral antigen-presenting cells, and play a critical role in preventing overproduction of pro-inflammatory cytokines detrimental to the proliferation, differentiation, and survival of adult neuronal stem cells (NSCs). Besides, these receptors also play an intrinsic trophic function in supporting NSC survival, proliferation, and differentiation into immature neurons. All these events collectively ensure a sustained neurogenesis in adult hippocampus. PMID:25487541

  2. Group II and III metabotropic glutamate receptors contribute to different aspects of visual response processing in the rat superior colliculus

    PubMed Central

    Cirone, Jennifer; Salt, Thomas E

    2001-01-01

    Neurones in the superior colliculus (SC) respond to novel sensory stimuli and response habituation is a key feature of this. It is known that both ionotropic and metabotropic glutamate (mGlu) receptors participate in visual responses of superficial SC neurones. A feature of Group II and Group III mGlu receptors is that they may modulate specific neural pathways, possibly via presynaptic mechanisms. However, less is known about how this may relate to functions of systems in whole animals. We have therefore investigated whether these receptors affect specific attributes of visual responses in the superficial SC. Recordings were made from visually responsive neurones in anaesthetised rats, and agonists and antagonists of Group II and III mGlu receptors were applied iontophoretically at the recording site. We found that application of the Group III metabotropic glutamate receptor agonist l-2-amino-4-phosphonobutyric acid (l-AP4) produced an increase in visual response habituation, whilst Group III antagonists decreased habituation. These effects were independent of the response habituation mediated via GABAB receptors. In contrast, modulation of Group II mGlu receptors with the specific agonist LY354740 or the antagonist LY341495 did not affect response habituation, although these compounds did modulate visual responses. This suggests a specific role for Group III mGlu receptors in visual response habituation. The magnitude of Group II effects was smaller during presentation of low contrast stimuli compared with high contrast stimuli. This suggests that activation of Group II receptors may be activity dependent and that these receptors can translate this into a functional effect in adapting to high contrast stimuli. PMID:11433000

  3. Play Chinese Games. 1987, Revised.

    ERIC Educational Resources Information Center

    White, Caryn

    This document, designed to introduce all ages to a selection of popular Chinese games, describes these games and provides instructions and materials for making the items needed to play most of them. Section 1 suggests class activities that can be related to some of the games. Section 2 presents instructions for the physical or outdoor games of:…

  4. Moral Education through Play Therapy

    ERIC Educational Resources Information Center

    Mahalle, Salwa; Zakaria, Gamal Abdul Nasir; Nawi, Aliff

    2014-01-01

    This paper will discuss on how sand therapy (as one type of play therapies) can be applied as an additional technique or approach in counseling. The research questions for this study are to see what are the development, challenges faced by the therapist during the sessions given and how sand therapy can aid to the progress of the client. It is a…

  5. In Search of Serious Play

    ERIC Educational Resources Information Center

    Wallace, David

    2005-01-01

    All teaching artists have taken unexpected detours that lead to miracles. They have all created magical experiences in which people are too engaged to notice the incredible amount they are learning. As a TA, one searches for "serious play"--purposeful fun that stimulates exhilarating work and genuine learning. But how does it happen? How do TAs…

  6. Sculpting Cells with Play Doh.

    ERIC Educational Resources Information Center

    Way, Virginia A.

    1982-01-01

    Suggests using Play Doh to mold models of the nucleus, mitochondria, and inner cellular structures. Students can conceptualize the cell's structures as three-dimensional even though they appear two-dimensional under a microscope. Includes instructions for preparing homemade dough. (Author/JN)

  7. Children's Voices through Dramatic Play.

    ERIC Educational Resources Information Center

    Sierra, Zayda

    Dramatic play provides children an excellent way to express their feelings and perceptions of the world that surrounds them. It is also an alternative way for researchers and teachers to capture, understand, and interpret children's voices because of the difficulties that children have in expressing ideas through oral and written language. While…

  8. Building Curriculum during Block Play

    ERIC Educational Resources Information Center

    Andrews, Nicole

    2015-01-01

    Blocks are not just for play! In this article, Nicole Andrews describes observing the interactions of three young boys enthusiastically engaged in the kindergarten block center of their classroom, using blocks in a building project that displayed their ability to use critical thinking skills, physics exploration, and the development of language…

  9. Interpretive Reproduction in Children's Play

    ERIC Educational Resources Information Center

    Corsaro, William A.

    2012-01-01

    The author looks at children's play from the perspective of interpretive reproduction, emphasizing the way children create their own unique peer cultures, which he defines as a set of routines, artifacts, values, and concerns that children engage in with their playmates. The article focuses on two types of routines in the peer culture of preschool…

  10. Fort Play Children Recreate Recess

    ERIC Educational Resources Information Center

    Powell, Mark

    2007-01-01

    Recess beckons well before it actually arrives. Its allure can be heard in children's lunchtime conversations as they discuss imaginary roles, plans, alliances and teams, with an obvious appetite for play and its unbounded possibility. For some children, recess provides the most important reasons to come to school. In team sports, games of chase…

  11. Obama Plays Cheerleader for STEM

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2010-01-01

    Amid a struggling economy, a raft of foreign-policy headaches, and the tail end of a heated campaign season, President Barack Obama carved out time in his schedule last month to watch students in the State Dining Room demonstrate a solar-powered model car, a water-purification system, and a soccer-playing robot. The science fair was the fifth…

  12. Science Adventures in Children's Play.

    ERIC Educational Resources Information Center

    Rieger, Edythe

    The stated purpose of this pamphlet is to suggest simple, natural, interesting experiences in children's play that have science implications. It tells how the teacher may capitalize on the innate curiosity of children by incorporating science discovery in daily classroom experiences. This how-to-do-it manual directs map-making and activities for…

  13. Play Therapy with the Nonverbal.

    ERIC Educational Resources Information Center

    Leland, Henry

    Four developmental outcomes of children's play were identified as acquaintance with the environment and the development of cognitive activity, verification of incidental learning, the development through sensory and motoric activities of relationships with objects and persons, and experience with roles and rules. A child developing atypically may…

  14. Building Math through Play Everyday

    ERIC Educational Resources Information Center

    Clements, Douglas H.; Sarama, Julie

    2005-01-01

    This article focuses on how young children build math skills in everyday play and activities. Children focus on six categories of mathematical content including classifying, exploring magnitude, enumerating, investigating dynamics, studying patterns, and exploring spatial relations. The article gives advice to both teachers and parents on how they…

  15. Creating Outdoor Play & Learning Environments.

    ERIC Educational Resources Information Center

    White, Randy; Stoecklin, Vicki L.

    Why typical playgrounds are designed the way they are by adults is discussed, including what the ideal outdoor play/learning environment for children is and how the outdoor space should be considered as an extension of the classroom. The paper emphasizes the importance of nature to children, discusses the criteria playground designers should…

  16. Playing It Safe: Part II.

    ERIC Educational Resources Information Center

    Penman, Kenneth A.; Niccolai, Frances R.

    1985-01-01

    Explains how to prevent outdoor sports injuries; discusses related litigation and specific cases involving playing field turf, tennis, skiing, and pools; and sets out facility design and maintenance considerations and recommendations. A sidebar provides information about injury insurance available to NCAA schools. Part I of this article appeared…

  17. Child-Centered Play Therapy

    ERIC Educational Resources Information Center

    VanFleet, Rise; Sywulak, Andrea E.; Sniscak, Cynthia Caparosa

    2010-01-01

    Highly practical, instructive, and authoritative, this book vividly describes how to conduct child-centered play therapy. The authors are master clinicians who explain core therapeutic principles and techniques, using rich case material to illustrate treatment of a wide range of difficulties. The focus is on nondirective interventions that allow…

  18. Playing Piano across the Curriculum.

    ERIC Educational Resources Information Center

    Hamel, Barbara L.

    2000-01-01

    Contends that the amount of piano study required of music education majors to pass the piano proficiency examination is insufficient. States that keyboarding across the curriculum will enable music education majors to become proficient in playing the piano. Offers suggestions for including the keyboard within other courses. (CMK)

  19. Caloric Cost of Playing Golf

    ERIC Educational Resources Information Center

    Lampley, James H.; And Others

    1977-01-01

    Women who play golf at the same rate of speed as men will use energy at a higher rate, but the rapidity with which the course is completed, which is dependent on the number of members of the golfing party, is a factor in the caloric expenditure of both sexes. (JD)

  20. Integrating Time, Place, and Play

    ERIC Educational Resources Information Center

    Gallavan, Nancy P.

    2004-01-01

    "Time, Place, and Play," is a short phrase, but is summarizes three very big concepts--history, geography, and culture--that are part of the elementary social studies curriculum. This article relates the story of how twenty-five elementary and middle school teachers, meeting over several weeks in a university class, designed a unit of study on the…

  1. Trafficking of Kainate Receptors

    PubMed Central

    Pahl, Steffen; Tapken, Daniel; Haering, Simon C.; Hollmann, Michael

    2014-01-01

    Ionotropic glutamate receptors (iGluRs) mediate the vast majority of excitatory neurotransmission in the central nervous system of vertebrates. In the protein family of iGluRs, kainate receptors (KARs) comprise the probably least well understood receptor class. Although KARs act as key players in the regulation of synaptic network activity, many properties and functions of these proteins remain elusive until now. Especially the precise pre-, extra-, and postsynaptic localization of KARs plays a critical role for neuronal function, as an unbalanced localization of KARs would ultimately lead to dysregulated neuronal excitability. Recently, important advances in the understanding of the regulation of surface expression, function, and agonist-dependent endocytosis of KARs have been achieved. Post-translational modifications like PKC-mediated phosphorylation and SUMOylation have been reported to critically influence surface expression and endocytosis, while newly discovered auxiliary proteins were shown to shape the functional properties of KARs. PMID:25141211

  2. Selective orexin receptor antagonists.

    PubMed

    Lebold, Terry P; Bonaventure, Pascal; Shireman, Brock T

    2013-09-01

    The orexin, or hypocretin, neuropeptides (orexin-A and orexin-B) are produced on neurons in the hypothalamus which project to key areas of the brain that control sleep-wake states, modulation of food intake, panic, anxiety, emotion, reward and addictive behaviors. These neuropeptides exert their effects on a pair of G-protein coupled receptors termed the orexin-1 (OX1) and orexin-2 (OX2) receptors. Emerging biology suggests the involvement of these receptors in psychiatric disorders as they are thought to play a key role in the regulation of multiple systems. This review is intended to highlight key selective OX1 or OX2 small-molecule antagonists. PMID:23891187

  3. Expression of GABA receptor subunits in the hippocampus and thalamus after experimental traumatic brain injury

    PubMed Central

    Drexel, Meinrad; Puhakka, Noora; Kirchmair, Elke; Hörtnagl, Heide; Pitkänen, Asla; Sperk, Günther

    2015-01-01

    Traumatic brain injury is a major cause of death and disability worldwide and often associated with post-traumatic epilepsy. We recently demonstrated that TBI induces acquired GABAA receptors channelopathy that associates with hyperexcitability in granule cell layer (GCL). We now assessed the expression of GABAA and GABAB receptor subunit mRNAs between 6 h and 6 months post-TBI in the hippocampus and thalamus. The expression of major GABAA receptor subunit mRNAs (α1, α2, α5, β2, β3, γ2 and δ) was, often bilaterally, down-regulated in the GCL and in the CA3 pyramidal cells. Instead, expression of α4 (GCL, CA3, CA1), α5 (CA1) and γ2 (GCL, CA3, CA1) mRNA was up-regulated after 10 d and/or 4 months. Many of these changes were reversible. In the thalamus, we found decreases in α1, α4, β2, γ2 and δ mRNAs in the laterodorsal thalamus and in the area combining the posterior thalamic nuclear group, ventroposterolateral and ventroposteromedial complex at 6 h to 4 months post-TBI. Unlike in the hippocampus, thalamic subunit down-regulations were irreversible and limited to the ipsilateral side. However, contralaterally there was up-regulation of the subunits δ and α4 6 h and 4 months after TBI, respectively. PCR array analysis suggested a mild long-lasting GABAA receptor channelopathy in the GCL and thalamus after TBI. Whereas TBI induces transient changes in the expression of GABAA receptor subunits in the hippocampus (presumably representing compensatory mechanisms), alterations of GABAA receptor subunit mRNAs in the thalamus are long-lasting and related to degeneration of receptor-containing neurons in thalamo-cortical relay nuclei. This article is part of the Special Issue entitled ‘GABAergic Signaling in Health and Disease’. PMID:25229716

  4. Involvement of GABA(A) receptors in myoclonus.

    PubMed

    Matsumoto, R R; Truong, D D; Nguyen, K D; Dang, A T; Hoang, T T; Vo, P Q; Sandroni, P

    2000-01-01

    Alterations in multiple neurochemical systems have been reported in animal and human studies of posthypoxic myoclonus. It is impossible, however, to establish causative relationships between the observed changes and the myoclonic movements from these studies. Therefore, to establish causative links between neurochemical changes and myoclonus, ligands that target neurotransmitter systems that are altered in posthypoxic myoclonus were microinjected into the lateral ventricles of normal rats to identify the changes that can produce myoclonus. Of the ligands that were tested, only the GABA(A) antagonists produced myoclonus after intracerebroventricular administration, suggesting the importance of disinhibition of GABAergic systems in myoclonus. To further examine the role of GABA in myoclonus, GABAergic antagonists were microinjected into the nucleus reticularis of the thalamus (NRT), an area of the brain in which extensive pathologic changes are seen in posthypoxic animals. GABA(A), but not GABA(B), antagonists produced myoclonus after microinjection into the NRT. Earlier investigators have further reported the ability of GABA(A) antagonists to produce myoclonus after microinjection into the caudate. The data therefore suggest that disruption of activity at GABA(A) receptors at any one of a number of levels in the neural axis can produce myoclonus. PMID:10755272

  5. Structure, Dynamics, and Allosteric Potential of Ionotropic Glutamate Receptor N-Terminal Domains

    PubMed Central

    Krieger, James; Bahar, Ivet; Greger, Ingo H.

    2015-01-01

    Ionotropic glutamate receptors (iGluRs) are tetrameric cation channels that mediate synaptic transmission and plasticity. They have a unique modular architecture with four domains: the intracellular C-terminal domain (CTD) that is involved in synaptic targeting, the transmembrane domain (TMD) that forms the ion channel, the membrane-proximal ligand-binding domain (LBD) that binds agonists such as L-glutamate, and the distal N-terminal domain (NTD), whose function is the least clear. The extracellular portion, comprised of the LBD and NTD, is loosely arranged, mediating complex allosteric regulation and providing a rich target for drug development. Here, we briefly review recent work on iGluR NTD structure and dynamics, and further explore the allosteric potential for the NTD in AMPA-type iGluRs using coarse-grained simulations. We also investigate mechanisms underlying the established NTD allostery in NMDA-type iGluRs, as well as the fold-related metabotropic glutamate and GABAB receptors. We show that the clamshell motions intrinsically favored by the NTD bilobate fold are coupled to dimeric and higher-order rearrangements that impact the iGluR LBD and ultimately the TMD. Finally, we explore the dynamics of intact iGluRs and describe how it might affect receptor operation in a synaptic environment. PMID:26255587

  6. Proteinase-activated receptors (PARs) – focus on receptor-receptor-interactions and their physiological and pathophysiological impact

    PubMed Central

    2013-01-01

    Proteinase-activated receptors (PARs) are a subfamily of G protein-coupled receptors (GPCRs) with four members, PAR1, PAR2, PAR3 and PAR4, playing critical functions in hemostasis, thrombosis, embryonic development, wound healing, inflammation and cancer progression. PARs are characterized by a unique activation mechanism involving receptor cleavage by different proteinases at specific sites within the extracellular amino-terminus and the exposure of amino-terminal “tethered ligand“ domains that bind to and activate the cleaved receptors. After activation, the PAR family members are able to stimulate complex intracellular signalling networks via classical G protein-mediated pathways and beta-arrestin signalling. In addition, different receptor crosstalk mechanisms critically contribute to a high diversity of PAR signal transduction and receptor-trafficking processes that result in multiple physiological effects. In this review, we summarize current information about PAR-initiated physical and functional receptor interactions and their physiological and pathological roles. We focus especially on PAR homo- and heterodimerization, transactivation of receptor tyrosine kinases (RTKs) and receptor serine/threonine kinases (RSTKs), communication with other GPCRs, toll-like receptors and NOD-like receptors, ion channel receptors, and on PAR association with cargo receptors. In addition, we discuss the suitability of these receptor interaction mechanisms as targets for modulating PAR signalling in disease. PMID:24215724

  7. Symbolic Play in Preschool and Primary Settings.

    ERIC Educational Resources Information Center

    Nourot, Patricia Moninghan; Van Hoorn, Judith L.

    1991-01-01

    A review of research on children's symbolic play discusses ways for teachers to (1) defend the inclusion of play in the curriculum; (2) understand and respect differences in the ways children play; and (3) facilitate play in the classroom. Discusses the complexity of play and the controversy about play as part of the curriculum. (GLR)

  8. Can Eph receptors stimulate the mind?

    PubMed

    Murai, Keith K; Pasquale, Elena B

    2002-01-17

    The Eph receptors are multitalented tyrosine kinases capable of performing many tasks. The receptors together with their ligands--the ephrins--are well known to play a critical role in the initial assembly of neuronal circuits in the embryo. However, the recently discovered function of these receptors in the adult brain is now receiving significant acclaim. Three new articles show that the Eph receptors continue to be important in modifying the strength of existing neuronal connections (synapses). They do so in close association with at least one family of ion channels, the NMDA receptors. PMID:11804564

  9. Dopamine receptors - IUPHAR Review 13.

    PubMed

    Beaulieu, Jean-Martin; Espinoza, Stefano; Gainetdinov, Raul R

    2015-01-01

    The variety of physiological functions controlled by dopamine in the brain and periphery is mediated by the D1, D2, D3, D4 and D5 dopamine GPCRs. Drugs acting on dopamine receptors are significant tools for the management of several neuropsychiatric disorders including schizophrenia, bipolar disorder, depression and Parkinson's disease. Recent investigations of dopamine receptor signalling have shown that dopamine receptors, apart from their canonical action on cAMP-mediated signalling, can regulate a myriad of cellular responses to fine-tune the expression of dopamine-associated behaviours and functions. Such signalling mechanisms may involve alternate G protein coupling or non-G protein mechanisms involving ion channels, receptor tyrosine kinases or proteins such as β-arrestins that are classically involved in GPCR desensitization. Another level of complexity is the growing appreciation of the physiological roles played by dopamine receptor heteromers. Applications of new in vivo techniques have significantly furthered the understanding of the physiological functions played by dopamine receptors. Here we provide an update of the current knowledge regarding the complex biology, signalling, physiology and pharmacology of dopamine receptors. PMID:25671228

  10. Cardiopulmonary changes during clarinet playing.

    PubMed

    Hahnengress, Maria L; Böning, Dieter

    2010-12-01

    Since playing wind instrument impedes normal respiratory functions, its effect on expiratory and blood gases as well as on cardiac function was investigated. In 15 skilled clarinettists expiratory PO(2) and PCO(2) were measured in gas drawn from a modified clarinet barrel when playing a composition (Robert Schumann's "Phantasiestücke" Op. 73 for clarinet and piano) with increasing difficulty from movement 1 to movement 3. Blood gases were measured in arterialized ear lobe blood at the end of each movement and the electrocardiogram was recorded continuously. From the expiratory gas pressures one may conclude that the most advanced players adapt their ventilation to the requirements of the composition and sustain expiration during difficult parts of the composition until hypoxic alveolar PO(2) values are reached (minimum 77 mmHg). Less trained clarinettists tend to hyperventilation or shallow breathing. Oxygen saturation in arterialized blood showed a slight step-wise decrease from movement to movement [control 96.6 ± 0.5 (SD)%, end of concert 95.6 ± 1.0%]. SO(2) was significantly higher because of possibly more effective ventilation in instrumentalists with practise time exceeding 2 h daily. Mean heart rate increased to values like during moderate to heavy physical exercise depending on artistic fitness and the difficulty of the movement (maximal individual value 173 beats/min). Additionally, a large variation might be caused through intrathoracic pressure changes, changing exertion, respiratory influences and emotion. The electrocardiogram showed no pathological events. In general, clarinet playing at a professional level imposes strain on ventilation and circulation but usually not on a pathophysiological level. PMID:20734060

  11. Oedipus: history, legends, plays, complexes.

    PubMed

    Kanzer, M

    A discussion of "Oedipus Was Not the Son of Laius and Jocasta" by Angel Garma, M.D. The thesis that Oedipus was not the son of the Theban royal pair but his Corinthian "foster parents" raises questions as to which Oedipus is under discussion--one of several different "historical" and legendary accounts, the hero of the plays of Sophocles, or the synthesized "Oedipuses" of millions of individual and ethnic fantasies. Oedipuses, in whom the particular variant described by Dr. Garma can be discerned, certainly abound and should be included among the many possibilities to be considered. PMID:738818

  12. Identification and Characterization of Novel Renal Sensory Receptors

    PubMed Central

    Rajkumar, Premraj; Aisenberg, William H.; Acres, Omar W.; Protzko, Ryan J.; Pluznick, Jennifer L.

    2014-01-01

    Recent studies have highlighted the important roles that “sensory” receptors (olfactory receptors, taste receptors, and orphan “GPR” receptors) play in a variety of tissues, including the kidney. Although several studies have identified important roles that individual sensory receptors play in the kidney, there has not been a systematic analysis of the renal repertoire of sensory receptors. In this study, we identify novel renal sensory receptors belonging to the GPR (n = 76), olfactory receptor (n = 6), and taste receptor (n = 11) gene families. A variety of reverse transcriptase (RT)- PCR screening strategies were used to identify novel renal sensory receptors, which were subsequently confirmed using gene-specific primers. The tissue-specific distribution of these receptors was determined, and the novel renal ORs were cloned from whole mouse kidney. Renal ORs that trafficked properly in vitro were screened for potential ligands using a dual-luciferase ligand screen, and novel ligands were identified for Olfr691. These studies demonstrate that multiple sensory receptors are expressed in the kidney beyond those previously identified. These results greatly expand the known repertoire of renal sensory receptors. Importantly, the mRNA of many of the receptors identified in this study are expressed highly in the kidney (comparable to well-known and extensively studied renal GPCRs), and in future studies it will be important to elucidate the roles that these novel renal receptors play in renal physiology. PMID:25340336

  13. Supervising the uncanny: the play within the play.

    PubMed

    Leader, Carol

    2015-11-01

    The writer offers a combined experience in analysis and the performing arts to explore uncanny aspects of the unconscious subtext of the patient's inner drama; subtext which can remain hidden from view in supervision. Freud and Jung's understanding of uncanny experience is considered together with a painting from medieval alchemy and Matte Blanco's conceptions concerning the symmetrical nature of unconscious process. Theatre and the work of the theatre director and actor in approaching the multidimensional aspects of a play are then introduced. Finally clinical case material from group supervision demonstrates how the 'theatre of therapy' and the work of the supervisory couple and group promote the emergence of a more authentic conscious asymmetrical response to the patient's 'script' that can break the 'spell' of the transference/countertransference relationship. This in turn brings meaning to the underlying and implicit 'stage directions' that the patient has been unconsciously communicating. PMID:26499298

  14. Dopaminergic Neurotransmission in the Nucleus Accumbens Modulates Social Play Behavior in Rats.

    PubMed

    Manduca, Antonia; Servadio, Michela; Damsteegt, Ruth; Campolongo, Patrizia; Vanderschuren, Louk Jmj; Trezza, Viviana

    2016-08-01

    Social play behavior is a highly rewarding form of social interaction displayed by young mammals. Social play is important for neurobehavioral development and it has been found to be impaired in several developmental psychiatric disorders. In line with the rewarding properties of social play, we have previously identified the nucleus accumbens (NAc) as an important site of action for endocannabinoid and opioid modulation of this behavior. NAc dopamine has a well-known role in certain components of reward processes, such as incentive motivation. However, its contribution to the positive emotional aspects of social interactions is less clear. Therefore, we investigated the role of dopaminergic neurotransmission in the NAc in social play behavior in rats. We found that intra-NAc infusion of the dopamine releaser/reuptake inhibitor amphetamine increased social play behavior that was dependent on activation of both D1 and D2 dopamine receptors. This increase in social play behavior was mimicked by intra-NAc infusion of the dopamine receptor agonist apomorphine, but not of the dopamine reuptake inhibitor GBR-12909. Blockade of either D1 or D2 NAc dopamine receptors reduced social play in animals highly motivated to play as a result of longer social isolation before testing. Last, blockade of NAc dopamine receptors prevented the play-enhancing effects of endocannabinoid and opioid receptor stimulation. These findings demonstrate an important modulatory role of NAc dopaminergic neurotransmission in social play. Thus, functional activity in the mesolimbic dopamine pathway plays an important role in adaptive social development, whereas abnormal NAc dopamine function may underlie the social impairments observed in developmental psychiatric disorders such as autism, attention deficit hyperactivity disorder or early-onset schizophrenia. PMID:26860202

  15. Mechanism of the cardiovascular effects of the GABAA receptors of the ventral tegmental area of the rat brain.

    PubMed

    Yeganeh, Fahimeh; Ranjbar, Afsaneh; Hatam, Masoumeh; Nasimi, Ali

    2015-07-23

    The ventral tegmental area (VTA) contains GABA terminals involved in the regulation of the cardiovascular system. Previously, we demonstrated that blocking GABAA but not GABAB receptors produced a pressor response accompanied by marked bradycardia. This study was performed to find the possible mechanisms involved in these responses by blocking ganglionic nicotinic receptors, peripheral muscarinic receptors or peripheral V1 vasopressin receptors. Experiments were performed on urethane anesthetized male Wistar rats. Drugs were microinjected unilaterally into the VTA (100 nl). The average changes in mean arterial pressure (MAP) and heart rate (HR) were compared between pre- and post-treatment using paired t-test. Injection of bicuculline methiodide (BMI), a GABAA antagonist, into the VTA caused a significant increase in MAP and a decrease in HR. Administration (i.v.) of the nicotinic receptor blocker, hexamethonium, enhanced the pressor response but abolished the bradycardic response to BMI, which ruled out involvement of the sympathetic nervous system. Blockade of the peripheral muscarinic receptors by homatropine (i.v.) abolished the bradycardic effect of BMI, but had no effect on the pressor response, indicating that bradycardia was produced by the parasympathetic outflow to the heart. Both the pressor and bradycardic responses to BMI were blocked by V1 receptor antagonist (i.v.), indicating that administration of BMI in the VTA disinhibited the release of vasopressin into the circulation. In conclusion, we demonstrated that GABAergic mechanism of the VTA exerts a tonic inhibition on vasopressin release through activation of GABAA receptors. The sympathetic system is not involved in the decrease of blood pressure by GABA of the VTA. PMID:26079327

  16. Play for All. [CD-ROM].

    ERIC Educational Resources Information Center

    Moore, Robin C.; Goltsman, Susan M.

    A CD-ROM provides a tour of some of the world's greatest play environments, presenting 94 photographic images that illustrate the key concepts and recommendations from Play For All guidelines. It is organized into 10 categories covering a range of play area settings, including play equipment, sand settings, water settings, play props, and animal…

  17. Caring About Kids: The Importance of Play.

    ERIC Educational Resources Information Center

    National Inst. of Mental Health (DHHS), Rockville, MD. Div. of Scientific and Public Information.

    In several brief sections, this pamphlet defines play, discusses how play helps a child develop, and how play changes as a child grows older, indicates the role of toys and certain play activities in promoting sex stereotypes, and identifies the role of fantasy and imagination in children's play. A discussion of the role of parents in fostering…

  18. Play Therapy: Voice of a Silent Scream

    ERIC Educational Resources Information Center

    Rakesh, Annuradha; H, Uma; Srinath, Shoba

    2010-01-01

    Play Therapy is based upon the fact that play is the child's natural medium of self-expression. It is an opportunity that is given to the child to "play out" his/her feelings and problems just as, in certain types of adult therapy, an individual "talks out" his difficulties. Children use play to express feelings and thoughts. Play emerges from the…

  19. Tetrahydroquinoline derivatives as opioid receptor antagonists.

    PubMed

    Zhang, Cunyu; Westaway, Susan M; Speake, Jason D; Bishop, Michael J; Goetz, Aaron S; Carballo, Luz Helena; Hu, Mike; Epperly, Andrea H

    2011-01-15

    Opioid receptors play an important role in both behavioral and homeostatic functions. We herein report tetrahydroquinoline derivatives as opioid receptor antagonists. SAR studies led to the identification of the potent antagonist 2v, endowed with 1.58nM (K(i)) functional activity against the μ opioid receptor. DMPK data suggest that novel tetrahydroquinoline analogs may be advantageous in peripheral applications. PMID:21193310

  20. Why do phage play dice?

    PubMed

    Avlund, Mikkel; Dodd, Ian B; Semsey, Szabolcs; Sneppen, Kim; Krishna, Sandeep

    2009-11-01

    Phage lambda is among the simplest organisms that make a developmental decision. An infected bacterium goes either into the lytic state, where the phage particles rapidly replicate and eventually lyse the cell, or into a lysogenic state, where the phage goes dormant and replicates along with the cell. Experimental observations by P. Kourilsky are consistent with a single phage infection deterministically choosing lysis and double infection resulting in a stochastic choice. We argue that the phage are playing a "game" of minimizing the chance of extinction and that the shift from determinism to stochasticity is due to a shift from a single-player to a multiplayer game. Crucial to the argument is the clonal identity of the phage. PMID:19740995

  1. Thermogenic characterization of ghrelin receptor null mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ghrelin is the only known circulating orexigenic hormone that increases food intake and promotes adiposity, and these physiological functions of ghrelin are mediated through its receptor growth hormone secretagogue receptor (GHS-R). Ghrelin/GHS-R signaling plays a crucial role in energy homeostasis....

  2. Hand kinematics of piano playing

    PubMed Central

    Flanders, Martha; Soechting, John F.

    2011-01-01

    Dexterous use of the hand represents a sophisticated sensorimotor function. In behaviors such as playing the piano, it can involve strong temporal and spatial constraints. The purpose of this study was to determine fundamental patterns of covariation of motion across joints and digits of the human hand. Joint motion was recorded while 5 expert pianists played 30 excerpts from musical pieces, which featured ∼50 different tone sequences and fingering. Principal component analysis and cluster analysis using an expectation-maximization algorithm revealed that joint velocities could be categorized into several patterns, which help to simplify the description of the movements of the multiple degrees of freedom of the hand. For the thumb keystroke, two distinct patterns of joint movement covariation emerged and they depended on the spatiotemporal patterns of the task. For example, the thumb-under maneuver was clearly separated into two clusters based on the direction of hand translation along the keyboard. While the pattern of the thumb joint velocities differed between these clusters, the motions at the metacarpo-phalangeal and proximal-phalangeal joints of the four fingers were more consistent. For a keystroke executed with one of the fingers, there were three distinct patterns of joint rotations, across which motion at the striking finger was fairly consistent, but motion of the other fingers was more variable. Furthermore, the amount of movement spillover of the striking finger to the adjacent fingers was small irrespective of the finger used for the keystroke. These findings describe an unparalleled amount of independent motion of the fingers. PMID:21880938

  3. Hand kinematics of piano playing.

    PubMed

    Furuya, Shinichi; Flanders, Martha; Soechting, John F

    2011-12-01

    Dexterous use of the hand represents a sophisticated sensorimotor function. In behaviors such as playing the piano, it can involve strong temporal and spatial constraints. The purpose of this study was to determine fundamental patterns of covariation of motion across joints and digits of the human hand. Joint motion was recorded while 5 expert pianists played 30 excerpts from musical pieces, which featured ∼50 different tone sequences and fingering. Principal component analysis and cluster analysis using an expectation-maximization algorithm revealed that joint velocities could be categorized into several patterns, which help to simplify the description of the movements of the multiple degrees of freedom of the hand. For the thumb keystroke, two distinct patterns of joint movement covariation emerged and they depended on the spatiotemporal patterns of the task. For example, the thumb-under maneuver was clearly separated into two clusters based on the direction of hand translation along the keyboard. While the pattern of the thumb joint velocities differed between these clusters, the motions at the metacarpo-phalangeal and proximal-phalangeal joints of the four fingers were more consistent. For a keystroke executed with one of the fingers, there were three distinct patterns of joint rotations, across which motion at the striking finger was fairly consistent, but motion of the other fingers was more variable. Furthermore, the amount of movement spillover of the striking finger to the adjacent fingers was small irrespective of the finger used for the keystroke. These findings describe an unparalleled amount of independent motion of the fingers. PMID:21880938

  4. Chin force in violin playing.

    PubMed

    Obata, Satoshi; Kinoshita, Hiroshi

    2012-06-01

    Force generated between the left mandible of violinists and the chinrest of the violin was examined using a force-sensing chinrest developed in this study. A strain-gauge force sensor was built, and it was fixed between the violin's top plate and a chin cup. Fifteen professional/amateur violinists held the violin statically, played musical scales with different sound properties and sounding techniques, as well as an excerpt from a Max Bruch concerto. Peak and mean forces were evaluated for each task. In a separate experiment, lateral movement of the lower teeth due to different levels of voluntary chin force exertion was measured. Static holding forces observed were 15 and 22 N with and without the help of the left hand, respectively. Peak force increased from 16 N at soft dynamics to 20 N at strong dynamics during scales. The force further increased to 29 N with the use of vibrato technique and 35 N during shifts. Tempo and hand position did not affect the force. Playing a Bruch concerto induced a mean peak force of 52 N, ranging from 31 to 82 N among the violinists. The developed force-sensing chinrest could accurately record the generated chin force. Typical chin force to stabilize the violin during ordinary musical performance was less than 30 N, but it could momentarily exceed 50 N when technically demanding musical pieces were performed. The lateral shift of the mandible was fairly small (<0.4 mm) even with high chin-force exertion, possibly due to clenching of the molars. PMID:21952980

  5. Regulation of plasminogen receptors.

    PubMed

    Herren, Thomas; Swaisgood, Carmen; Plow, Edward F

    2003-01-01

    Many eukaryotic and prokaryotic cells bind plasminogen in a specific and saturable manner. When plasminogen is bound to cell-surface proteins with C-terminal lysines via its lysine binding sites, its activation to plasmin is accelerated, and cell-bound plasmin is protected from inactivation by natural inhibitors. Plasmin mediates direct or indirect degradation of the extracellular matrix, and bound plasmin is used by cells to facilitate migration through extracellular matrices. Since cell migration and tissue remodelling are the underpinnings of many physiological and pathological responses, the modulation of plasminogen receptors may serve as a primary regulatory mechanism for control of many cellular responses. Specific examples of cell types on which plasminogen receptors undergo modulation include: fibroblasts, where modulation may contribute to cartilage and bone destruction in rheumatoid arthritis; leukemic cells, where enhanced plasminogen binding may contribute to the heightened fibrinolytic state in the patients; other tumor cells, where up-regulation may support invasion and metastasis; bacteria, where enhanced plasminogen binding may facilitate tissue destruction and invasion; platelets, where up-regulation of plasminogen binding may play a role in regulating clot lysis; and adipocytes, where the modulation of plasminogen receptor expression may regulate cell differentiation and fat accumulation. Two pathways for modulation of plasminogen receptors have been characterized: A protease-dependent pathway can either up-regulate or down-regulate plasminogen binding to cells by changing the availability of plasminogen-binding proteins with C-terminal lysines. New receptors may be generated by trypsin-like proteases, including plasmin, which create new C-terminal lysines; other enzymes may expose existing membrane proteins by altering the cell surface; or receptor function may be lost by removal of C-terminal lysines. The basic carboxypeptidases of blood

  6. Superhero Play: What's a Teacher to Do?

    ERIC Educational Resources Information Center

    Bauer, Karen L.; Dettore, Ernest

    1997-01-01

    Examines the appeal of superheroes to children and adults' beliefs about superhero play, and suggests some potential benefits of such play. Offers examples of ways to successfully incorporate superhero play into an early childhood classroom. (Author/KB)

  7. Nicotinic Receptors in Neurodegeneration

    PubMed Central

    Posadas, Inmaculada; López-Hernández, Beatriz; Ceña, Valentín

    2013-01-01

    Many studies have focused on expanding our knowledge of the structure and diversity of peripheral and central nicotinic receptors. Nicotinic acetylcholine receptors (nAChRs) are members of the Cys-loop superfamily of pentameric ligand-gated ion channels, which include GABA (A and C), serotonin, and glycine receptors. Currently, 9 alpha (α2-α10) and 3 beta (β2-β4) subunits have been identified in the central nervous system (CNS), and these subunits assemble to form a variety of functional nAChRs. The pentameric combination of several alpha and beta subunits leads to a great number of nicotinic receptors that vary in their properties, including their sensitivity to nicotine, permeability to calcium and propensity to desensitize. In the CNS, nAChRs play crucial roles in modulating presynaptic, postsynaptic, and extrasynaptic signaling, and have been found to be involved in a complex range of CNS disorders including Alzheimer’s disease (AD), Parkinson’s disease (PD), schizophrenia, Tourette´s syndrome, anxiety, depression and epilepsy. Therefore, there is growing interest in the development of drugs that modulate nAChR functions with optimal benefits and minimal adverse effects. The present review describes the main characteristics of nAChRs in the CNS and focuses on the various compounds that have been tested and are currently in phase I and phase II trials for the treatment of neurodegenerative diseases including PD, AD and age-associated memory and mild cognitive impairment. PMID:24179465

  8. Nuclear receptors in bile acid metabolism

    PubMed Central

    Li, Tiangang; Chiang, John Y. L.

    2013-01-01

    Bile acids are signaling molecules that activate nuclear receptors, such as farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, and vitamin D receptor, and play a critical role in the regulation of lipid, glucose, energy, and drug metabolism. These xenobiotic/endobiotic-sensing nuclear receptors regulate phase I oxidation, phase II conjugation, and phase III transport in bile acid and drug metabolism in the digestive system. Integration of bile acid metabolism with drug metabolism controls absorption, transport, and metabolism of nutrients and drugs to maintain metabolic homeostasis and also protects against liver injury, inflammation, and related metabolic diseases, such as nonalcoholic fatty liver disease, diabetes, and obesity. Bile-acid–based drugs targeting nuclear receptors are in clinical trials for treating cholestatic liver diseases and fatty liver disease. PMID:23330546

  9. Targeting Nuclear Receptors with Marine Natural Products

    PubMed Central

    Yang, Chunyan; Li, Qianrong; Li, Yong

    2014-01-01

    Nuclear receptors (NRs) are important pharmaceutical targets because they are key regulators of many metabolic and inflammatory diseases, including diabetes, dyslipidemia, cirrhosis, and fibrosis. As ligands play a pivotal role in modulating nuclear receptor activity, the discovery of novel ligands for nuclear receptors represents an interesting and promising therapeutic approach. The search for novel NR agonists and antagonists with enhanced selectivities prompted the exploration of the extraordinary chemical diversity associated with natural products. Recent studies involving nuclear receptors have disclosed a number of natural products as nuclear receptor ligands, serving to re-emphasize the translational possibilities of natural products in drug discovery. In this review, the natural ligands of nuclear receptors will be described with an emphasis on their mechanisms of action and their therapeutic potentials, as well as on strategies to determine potential marine natural products as nuclear receptor modulators. PMID:24473166

  10. Opioid Receptor-Dependent Sex Differences in Synaptic Plasticity in the Hippocampal Mossy Fiber Pathway of the Adult Rat

    PubMed Central

    Harte-Hargrove, Lauren C.; Varga-Wesson, Ada; Duffy, Aine M.; Milner, Teresa A.

    2015-01-01

    The mossy fiber (MF) pathway is critical to hippocampal function and influenced by gonadal hormones. Physiological data are limited, so we asked whether basal transmission and long-term potentiation (LTP) differed in slices of adult male and female rats. The results showed small sex differences in basal transmission but striking sex differences in opioid receptor sensitivity and LTP. When slices were made from females on proestrous morning, when serum levels of 17β-estradiol peak, the nonspecific opioid receptor antagonist naloxone (1 μm) enhanced MF transmission but there was no effect in males, suggesting preferential opioid receptor-dependent inhibition in females when 17β-estradiol levels are elevated. The μ-opioid receptor (MOR) antagonist Cys2,Tyr3,Orn5,Pen7-amide (CTOP; 300 nm) had a similar effect but the δ-opioid receptor (DOR) antagonist naltrindole (NTI; 1 μm) did not, implicating MORs in female MF transmission. The GABAB receptor antagonist saclofen (200 μm) occluded effects of CTOP but the GABAA receptor antagonist bicuculline (10 μm) did not. For LTP, a low-frequency (LF) protocol was used because higher frequencies elicited hyperexcitability in females. Proestrous females exhibited LF-LTP but males did not, suggesting a lower threshold for synaptic plasticity when 17β-estradiol is elevated. NTI blocked LF-LTP in proestrous females, but CTOP did not. Electron microscopy revealed more DOR-labeled spines of pyramidal cells in proestrous females than males. Therefore, we suggest that increased postsynaptic DORs mediate LF-LTP in proestrous females. The results show strong MOR regulation of MF transmission only in females and identify a novel DOR-dependent form of MF LTP specific to proestrus. PMID:25632146

  11. Receptor architecture of visual areas in the face and word-form recognition region of the posterior fusiform gyrus.

    PubMed

    Caspers, Julian; Palomero-Gallagher, Nicola; Caspers, Svenja; Schleicher, Axel; Amunts, Katrin; Zilles, Karl

    2015-01-01

    Recently, two extrastriate visual areas on the posterior fusiform gyrus, areas FG1 and FG2, were identified based on cytoarchitectonical criteria (Caspers et al. in Brain Struct Funct 218:511-526, 2013a). They are located within the object-related ventral visual stream at the transition between early and higher-order (category-specific) visual areas. FG2 has a topographical position which is best comparable to the face or visual word-form recognition area. However, the precise function of FG2 is presently unknown. Since transmitter receptors are key molecules of neurotransmission, we analysed the regional and laminar distribution of 15 different receptor binding sites by means of quantitative in vitro receptor autoradiography. Significant differences between receptor densities of both areas were found for NMDA, GABAB, M3, nicotinic α4/β2 and 5-HT1A receptors as well as for GABAA associated benzodiazepine binding sites. These results support the cytoarchitectonic segregation of FG1 and FG2 into two distinct cortical areas. In addition, principal component and hierarchical cluster analyses of the multireceptor data of both fusiform areas and 24 visual, auditory, somatosensory and multimodal association areas not only revealed the typical receptor architectonic characteristics of visual areas for FG1 and FG2, but also suggest their putative function as object recognition regions due to the similarity of their receptor fingerprints with those of areas of the ventral visual stream. Furthermore, FG1 and FG2 build a cluster with the multimodal association areas of the inferior parietal lobule. This underlines their hierarchically high position in the visual system of the human cerebral cortex. PMID:24126835

  12. Lipoxin receptors.

    PubMed

    Romano, Mario; Recchia, Irene; Recchiuti, Antonio

    2007-01-01

    Lipoxins (LXs) represent a class of arachidonic acid (AA) metabolites that carry potent immunoregulatory and anti-inflammatory properties, LXA4 and LXB4 being the main components of this series. LXs are generated by cooperation between 5-lipoxygenase (LO) and 12- or 15-LO during cell-cell interactions or by single cell types. LX epimers at carbon 15, the 15-epi-LXs, are formed by aspirin-acetylated cyclooxygenase-2 (COX-2) in cooperation with 5-LO. 15-epi-LXA4 is also termed aspirin-triggered LX (ATL). In vivo studies with stable LX and ATL analogs have established that these eicosanoids possess potent anti-inflammatory activities. A LXA4 receptor has been cloned. It belongs to the family of chemotactic receptors and clusters with formyl peptide receptors on chromosome 19. Therefore, it was initially denominated formyl peptide receptor like 1 (FPRL1). This receptor binds with high affinity and stereoselectivity LXA4 and ATL. It also recognizes a variety of peptides, synthetic, endogenously generated, or disease associated, but with lower affinity compared to LXA4. For this reason, this receptor has been renamed ALX. This review summarizes the current knowledge on ALX expression, signaling, and potential pathophysiological role. The involvement of additional recognition sites in LX bioactions is also discussed. PMID:17767357

  13. Regulation of breast cancer metastasis by atypical chemokine receptors.

    PubMed

    Cheng, Xiaoyun; Hung, Mien-Chie

    2009-05-01

    The interaction between chemokines and their G-protein-coupled receptors plays an important role in promoting metastasis of different kinds of human cancers. However, the expression of an atypical chemokine receptor, CCX-CKR, which serves as a decoy receptor to attract chemokines, inhibits the growth and metastasis of breast cancer by sequestration of chemokines. PMID:19383808

  14. Cell surface receptors for CCN proteins.

    PubMed

    Lau, Lester F

    2016-06-01

    The CCN family (CYR61; CTGF; NOV; CCN1-6; WISP1-3) of matricellular proteins in mammals is comprised of six homologous members that play important roles in development, inflammation, tissue repair, and a broad range of pathological processes including fibrosis and cancer. Despite considerable effort to search for a high affinity CCN-specific receptor akin to growth factor receptors, no such receptor has been found. Rather, CCNs bind several groups of multi-ligand receptors as characteristic of other matricellular proteins. The most extensively documented among CCN-binding receptors are integrins, including αvβ3, αvβ5, α5β1, α6β1, αIIbβ3, αMβ2, and αDβ2, which mediate diverse CCN functions in various cell types. CCNs also bind cell surface heparan sulfate proteoglycans (HSPGs), low density liproprotein receptor-related proteins (LRPs), and the cation-independent mannose-6-phosphate (M6P) receptor, which are endocytic receptors that may also serve as co-receptors in cooperation with other cell surface receptors. CCNs have also been reported to bind FGFR-2, Notch, RANK, and TrkA, potentially altering the affinities of these receptors for their ligands. The ability of CCNs to bind a multitude of receptors in various cell types may account for the remarkable versatility of their functions, and underscore the diverse signaling pathways that mediate their activities. PMID:27098435

  15. CD109 Plays a Role in Osteoclastogenesis

    PubMed Central

    Jiang, Hongwei; Tenenbaum, Howard; Glogauer, Michael

    2013-01-01

    Osteoclasts are large multinucleated cells that arise from the fusion of cells from the monocyte/macrophage lineage. Osteoclastogenesis is mediated by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-kB ligand (RANKL) and involves a complex multistep process that requires numerous other elements, many of which remain undefined. The primary aim of this project was to identify novel factors which regulate osteoclastogenesis. To carry out this investigation, microarray analysis was performed comparing two pre-osteoclast cell lines generated from RAW264.7 macrophages: one that has the capacity to fuse forming large multinucleated cells and one that does not fuse. It was found that CD109 was up-regulated by>17-fold in the osteoclast forming cell line when compared to the cell line that does not fuse, at day 2 of the differentiation process. Results obtained with microarray were confirmed by RT-qPCR and Western blot analyses in the two cell lines, in the parental RAW264.7 cell line, as well as primary murine monocytes from bone marrow. A significant increase of CD109 mRNA and protein expression during osteoclastogenesis occurred in all tested cell types. In order to characterize the role of CD109 in osteoclastogenesis, CD109 stable knockdown cell lines were established and fusion of osteoclast precursors into osteoclasts was assessed. It was found that CD109 knockdown cell lines were less capable of forming large multinucleated osteoclasts. It has been shown here that CD109 is expressed in monocytes undergoing RANKL-induced osteoclastogenesis. Moreover, when CD109 expression is suppressed in vitro, osteoclast formation decreases. This suggests that CD109 might be an important regulator of osteoclastogenesis. Further research is needed in order to characterize the role played by CD109 in regulation of osteoclast differentiation. PMID:23593435

  16. Finger Forces in Clarinet Playing

    PubMed Central

    Hofmann, Alex; Goebl, Werner

    2016-01-01

    Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17) and professional clarinettists (N = 6) were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 × 2 × 2 design (register: low–high; tempo: slow–fast, dynamics: soft–loud). There was an additional condition controlled by the experimenter, which determined the expression levels (low–high) of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions). The melody was performed in three tempo conditions (slow, medium, fast) in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (Fmean) and peak force (Fmax) were calculated. The overall finger forces were low (Fmean = 1.17 N, Fmax = 3.05 N) compared to those on other musical instruments (e.g., guitar). Participants applied the largest finger forces during the high expression level performance conditions (Fmean = 1.21 N). For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (Fmean = 0.54 N). Such sensor instruments provide useful insights into player

  17. Biphasic GABA-A receptor-mediated effect on the spontaneous activity of the circular layer in cat terminal ileum.

    PubMed

    Pencheva, N; Radomirov, R

    1993-07-01

    1. The GABA and GABA-A receptor agonist muscimol changed the spontaneous mechanical activity of a circular layer isolated from cat terminal ileum, while the selective GABA-B receptor agonist (+/-)baclofen had no effect. 2. GABA at doses ranging from 1 microM to 2 mM elicited concentration-dependent biphasic responses which consisted of a relaxation followed by contraction, with a tonic and a phasic component. The EC50 values, calculated at 95% confidence limits (CL), were 94.9 microM (83.5-109.8 microM) and 66.0 microM (51.2-75.5 microM) for the relaxation and contractile phases, respectively. 3. The GABA-induced biphasic responses were sensitive to bicuculline and picrotoxinin and were entirely mimicked by muscimol. Bicuculline competitively antagonized the effects of GABA and gave closely similar pA2 values for both phases of these responses--inhibitory and stimulatory. Cross-desensitization occurred only between GABA and muscimol and not between (+/-)baclofen and GABA, or (+/-)baclofen and muscimol. 4. Both bicuculline-sensitive phases evoked by GABA and muscimol were abolished by tetrodotoxin or atropine, but were unaffected by guanethidine or naloxone. 5. The present results suggested that the biphasic GABA effect on the mechanical activity of the circular layer in cat terminal ileum was mediated by prejunctional GABA-A receptors, most probably through an action on the cholinergic pathway. PMID:8224749

  18. Strategies for Family Facilitation of Play Dates

    ERIC Educational Resources Information Center

    Chambers, Cynthia R.; Horn, Eva M.

    2010-01-01

    Play dates can serve several functions for young children, including children with social difficulties, such as developmental delays, behavioral disorders, autism spectrum disorders, and shyness. Play dates provide children with additional opportunities to be around peers and to practice skills associated with peer play interactions. Play dates…

  19. Children, Play, and Development. Fourth Edition

    ERIC Educational Resources Information Center

    Hughes, Fergus P.

    2010-01-01

    Children, Play, and Development, Fourth Edition, discusses the relationship of play to the physical, social, intellectual, and emotional growth of the child. Author Fergus P. Hughes focuses on the historical, sociocultural, and ethological context of play; the role of development in play; and the wide range of theories that provide a framework for…

  20. Play and the Young Child: Musical Implications.

    ERIC Educational Resources Information Center

    Brophy, Tim

    After noting the near-universal presence of rhythmic response in play in all cultures, this paper looks first at the historical development of theories of play, and then examines current theories of play and their implications in the teaching of music to young children. The first section reviews 19th and early 20th century theories of play,…

  1. How the Brain Makes Play Fun

    ERIC Educational Resources Information Center

    Vanderschuren, Louk J. M. J.

    2010-01-01

    In this article, the author describes the empirical studies that have investigated whether play (mostly social play) is rewarding. He then discusses the brain circuits and neurotransmitters that underlie the pleasurable aspects of play. He concludes that the pleasure of play has the ability to reinforce learning activities and that the brain's…

  2. Conceptualizing the Play Policies in Preschool Curriculums

    ERIC Educational Resources Information Center

    Sener, Tulin

    2013-01-01

    This research attempted to describe the play policies in preschool institutions in Ankara, Turkey. The aim of this study is to determine the approaches of the preschools to the children's play. "Play Policy Questionnaire" administered to all directors and teachers of 20 public preschools and 20 private preschools. Play policy of…

  3. Introduction to Plays, English: 5112.44.

    ERIC Educational Resources Information Center

    Ozan, Ruth S.

    Several plays are studied to introduce students to theatrical terms and to the elements of a play in this quinmester course for Dade County High Schools. Several approaches to the study of the play are suggested such as individual and a large group production of a play, the use of a unified theme such as Youth vs. Tradition, or the line of…

  4. Parent-Child Play: Descriptions and Implications.

    ERIC Educational Resources Information Center

    MacDonald, Kevin, Ed.

    This volume provides the latest research and theory in the area of children's play with their parents. It includes discussions of the basic processes involved in parent-child play, parent-child play in atypical populations of children, and parent-child play from a cross-cultural perspective. Fifteen chapters follow the introduction, "Parents and…

  5. Play in Cultural Contexts = Mang Kultuurikontekstis.

    ERIC Educational Resources Information Center

    Saar, Aino, Ed.; Hakkarainen, Pentti, Ed.

    1998-01-01

    This volume compiles articles based on the presentations delivered at two conferences. The conferences presented a multidisciplinary overview of research on children's play in different cultural contexts. The articles are grouped under six subheadings: play in the family context, play in the zone of proximal development, play in the kindergarten,…

  6. Play and Social Interaction in Middle Childhood

    ERIC Educational Resources Information Center

    Bergen, Doris; Fromberg, Doris Pronin

    2009-01-01

    This article discusses traditional and contemporary definitions of middle childhood play, the value of such play for children's development and learning, the implications of home, school, and societal practices that have resulted in changing the play scenario of middle childhood, and suggestions for assuring that play's value will be maintained…

  7. Monitored Play Therapy: Conceptual and Methodological Issues.

    ERIC Educational Resources Information Center

    Golden, Bobbie

    There are many unanswered questions about play therapy. Monitored play therapy is an attempt to discover answers to these questions. The main emphasis is on quantitative recording and analysis of the process and outcome of play therapy. However, because of its newness, monitored play therapy also has some weaknesses. The main strong point is the…

  8. Active Gaming: The Future of Play?

    ERIC Educational Resources Information Center

    Witherspoon, Lisa; Manning, John P.

    2012-01-01

    The authors examine technology-driven games--especially active gaming--as an evolving form of children's play. They offer an overview of play and its developmental benefits, describe the literature on the emergence of technology-driven play, and reflect on the diminishment of physical play in contemporary culture. They suggest that active gaming,…

  9. Reconceptualizing Play: Aesthetic Self-Definitions

    ERIC Educational Resources Information Center

    Guss, Faith

    2005-01-01

    This article aims to trouble the identity of children's dramatic play(ing). It contains two interweaving threads of discourse. In one thread lies a discussion of how children can trouble and extend their own identities through the aesthetic form-languages and conventions they employ and deploy in their dramatic playing/pretend playing.…

  10. Endocannabinoids in amygdala and nucleus accumbens mediate social play reward in adolescent rats

    PubMed Central

    Trezza, Viviana; Damsteegt, Ruth; Manduca, Antonia; Petrosino, Stefania; Van Kerkhof, Linda W.M.; Pasterkamp, R. Jeroen; Zhou, Yeping; Campolongo, Patrizia; Cuomo, Vincenzo; Di Marzo, Vincenzo; Vanderschuren, Louk J.M.J.

    2012-01-01

    The brain endocannabinoid system plays a crucial role in emotional processes. We have previously identified an important role for endocannabinoids in social play behavior, a highly rewarding form of social interaction in adolescent rats. Here, we tested the hypothesis that endocannabinoid modulation of social play behavior occurs in brain regions implicated in emotion and motivation. Social play increased levels of the endocannabinoid anandamide in the amygdala and nucleus accumbens (NAc), but not in prefrontal cortex or hippocampus of 4–5 week old male Wistar rats. Furthermore, social play increased phosphorylation of CB1 cannabinoid receptors in the amygdala. Systemic administration of the anandamide hydrolysis inhibitor URB597 increased social play behavior, and augmented the associated elevation in anandamide levels in the amygdala, but not the NAc. Infusion of URB597 into the basolateral amygdala (BLA) increased social play behavior, and blockade of BLA CB1 cannabinoid receptors with the antagonist/inverse agonist SR141716A prevented the play-enhancing effects of systemic administration of URB597. Infusion of URB597 into the NAc also increased social play, but blockade of NAc CB1 cannabinoid receptors did not antagonize the play-enhancing effects of systemic URB597 treatment. Last, SR141716A did not affect social play after infusion into the core and shell subregions of the NAc, while it reduced social play when infused into the BLA. These data show that increased anandamide signalling in the amygdala and NAc augments social play, and identify the BLA as a prominent site of action for endocannabinoids to modulate the rewarding properties of social interactions in adolescent rats. PMID:23100412

  11. Psychiatrists' Perceptions of Role-Playing Games.

    PubMed

    Lis, Eric; Chiniara, Carl; Biskin, Robert; Montoro, Richard

    2015-09-01

    The literature has seen a surge in research on the mental health impacts of technologies such as Facebook, video games, and massively-multiplayer online role-playing games such as World of Warcraft, but little is known regarding the mental health impact of non-video role-playing games, such as Dungeons & Dragons. The present study examines how psychiatrists' perceive role-playing games and whether they play them. Psychiatrists at a tertiary care centre in Canada completed a questionnaire assessing history of playing role-playing games and whether they associate them with psychopathology. Forty-eight psychiatrists responded. Twenty-three percent have played a role-playing game over their lifetimes. Twenty-two percent believed there was an association between psychopathology and role-playing games. A majority of psychiatrists who responded do not associate role-playing games with psychopathology. Implications for clinical practice and future research are discussed. PMID:25589035

  12. In vivo electroretinographic studies of the role of GABAC receptors in retinal signal processing.

    PubMed

    Wang, Jing; Mojumder, Deb Kumar; Yan, Jun; Xie, An; Standaert, Robert F; Qian, Haohua; Pepperberg, David R; Frishman, Laura J

    2015-10-01

    All three classes of receptors for the inhibitory neurotransmitter GABA (GABAR) are expressed in the retina. This study investigated roles of GABAR, especially GABACR (GABA(A)-ρ), in retinal signaling in vivo by studying effects on the mouse electroretinogram (ERG) of genetic deletion of GABACR versus pharmacological blockade using receptor antagonists. Brief full-field flash ERGs were recorded from anesthetized GABACR(-/-) mice, and WT C57BL/6 (B6) mice, before and after intravitreal injection of GABACR antagonists, TPMPA, 3-APMPA, or the more recently developed 2-AEMP; GABAAR antagonist, SR95531; GABABR antagonist, CGP, and agonist, baclofen. Intravitreal injections of TPMPA and SR95531 were also made in Brown Norway rats. The effect of 2-AEMP on GABA-induced current was tested directly in isolated rat rod bipolar cells, and 2-AEMP was found to preferentially block GABACR in those cells. Maximum amplitudes of dark (DA) and light-adapted (LA) ERG b-waves were reduced in GABACR(-/-) mice, compared to B6 mice, by 30-60%; a-waves were unaltered and oscillatory potential amplitudes were increased. In B6 mice, after injection of TPMPA (also in rats), 3-APMPA or 2-AEMP, ERGs became similar to ERGs of GABACR(-/-) mice. Blockade of GABAARs and GABABRs, or agonism of GABABRs did not alter B6 DA b-wave amplitude. The negative scotopic threshold response (nSTR) was slightly less sensitive in GABACR(-/-) than in B6 mice, and unaltered by 2-AEMP. However, amplitudes of nSTR and photopic negative response (PhNR), both of which originate from inner retina, were enhanced by TPMPA and 3-APMPA, each of which has GABAB agonist properties, and further increased by baclofen. The finding that genetic deletion of GABACR, the GABACR antagonist 2-AEMP, and other antagonists all reduced ERG b-wave amplitude, supports a role for GABACR in determining the maximum response amplitude of bipolar cells contributing to the b-wave. GABACR antagonists differed in their effects on nSTR and Ph

  13. Finger Forces in Clarinet Playing.

    PubMed

    Hofmann, Alex; Goebl, Werner

    2016-01-01

    Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17) and professional clarinettists (N = 6) were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 × 2 × 2 design (register: low-high; tempo: slow-fast, dynamics: soft-loud). There was an additional condition controlled by the experimenter, which determined the expression levels (low-high) of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions). The melody was performed in three tempo conditions (slow, medium, fast) in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (F mean ) and peak force (F max ) were calculated. The overall finger forces were low (F mean = 1.17 N, F max = 3.05 N) compared to those on other musical instruments (e.g., guitar). Participants applied the largest finger forces during the high expression level performance conditions (F mean = 1.21 N). For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (F mean = 0.54 N). Such sensor instruments provide useful insights into player

  14. Discoidin domain receptors in disease.

    PubMed

    Borza, Corina M; Pozzi, Ambra

    2014-02-01

    Discoidin domain receptors, DDR1 and DDR2, lie at the intersection of two large receptor families, namely the extracellular matrix and tyrosine kinase receptors. As such, DDRs are uniquely positioned to function as sensors for extracellular matrix and to regulate a wide range of cell functions from migration and proliferation to cytokine secretion and extracellular matrix homeostasis/remodeling. While activation of DDRs by extracellular matrix collagens is required for normal development and tissue homeostasis, aberrant activation of these receptors following injury or in disease is detrimental. The availability of mice lacking DDRs has enabled us to identify key roles played by these receptors in disease initiation and progression. DDR1 promotes inflammation in atherosclerosis, lung fibrosis and kidney injury, while DDR2 contributes to osteoarthritis. Furthermore, both DDRs have been implicated in cancer progression. Yet the mechanisms whereby DDRs contribute to disease progression are poorly understood. In this review we highlight the mechanisms whereby DDRs regulate two important processes, namely inflammation and tissue fibrosis. In addition, we discuss the challenges of targeting DDRs in disease. Selective targeting of these receptors requires understanding of how they interact with and are activated by extracellular matrix, and whether their cellular function is dependent on or independent of receptor kinase activity. PMID:24361528

  15. Discoidin Domain Receptors in Disease

    PubMed Central

    Borza, Corina M; Pozzi, Ambra

    2014-01-01

    Discoidin domain receptors, DDR1 and DDR2, lie at the intersection of two large receptor families, namely the extracellular matrix and tyrosine kinase receptors. As such, DDRs are uniquely positioned to function as sensors for extracellular matrix and to regulate a wide range of cell functions from migration and proliferation to cytokine secretion and extracellular matrix homeostasis/remodeling. While activation of DDRs by extracellular matrix collagens is required for normal development and tissue homeostasis, aberrant activation of these receptors following injury or in disease is detrimental. The availability of mice lacking DDRs has enabled us to identify key roles played by these receptors in disease initiation and progression. DDR1 promotes inflammation in atherosclerosis, lung fibrosis and kidney injury, while DDR2 contributes to osteoarthritis. Furthermore, both DDRs have been implicated in cancer progression. Yet the mechanisms whereby DDRs contribute to diseases progression are poorly understood. In this review we highlight the mechanisms whereby DDRs regulate two important processes, namely inflammation and tissue fibrosis. In addition, we discuss the challenges of targeting DDRs in disease. Selective targeting of these receptors requires understanding of how they interact with and are activated by extracellular matrix, and whether their cellular function is dependent on or independent of receptor kinase activity. PMID:24361528

  16. Exploring Play/Playfulness and Learning in the Adult and Higher Education Classroom

    ERIC Educational Resources Information Center

    Tanis, David J.

    2012-01-01

    Play and playfulness and their role in learning are researched extensively in early childhood education. However, as the child matures into an adult, play and playfulness are given less attention in the teaching and learning process. In adult education, there is very little research about play/playfulness and its significance for learning. Despite…

  17. Transforming Play: An Analysis of First-, Third-, and Fifth-Graders' Play.

    ERIC Educational Resources Information Center

    Bagley, Donna M.; Chaille, Christine

    1996-01-01

    Compared children's play with transformational objects (vehicles that change to robots) to play with representational objects (cars and figures). Found that those playing with transformers engaged in more parallel play and manipulative activity, while those with representational objects displayed more social play and more symbolic play. Found no…

  18. Forms of vitality play in infancy.

    PubMed

    Español, Silvia; Martínez, Mauricio; Bordoni, Mariana; Camarasa, Rosario; Carretero, Soledad

    2014-12-01

    In this paper we report a qualitative study based on the constant comparative method to initiate the systematic study of forms of vitality play. This is an unnoticed non-figurative play frame linked to early social play and temporal arts in which child and adult elaborate the dynamics of their own movements and sounds in a repetition-variation form. In the introduction we present the theoretical underpinnings and the sporadic observations we have done in previous studies. Then, by the iterative observations of the recorded material of a longitudinal case study on play during the third year of life, we generated the general category of forms of vitality play and four subcategories of display modes of forms of vitality play (improvised forms of vitality play, ritualized forms of vitality play, forms of vitality play combined with pretend play, and forms of vitality play combined with role playing) which are illustrated with descriptive narratives. We discuss the properties of the developed categories, the limits of the present study, and the need to continue systematizing the research on this playful activity. PMID:24909632

  19. Receptor Tyrosine Kinases in Drosophila Development

    PubMed Central

    Sopko, Richelle; Perrimon, Norbert

    2013-01-01

    Tyrosine phosphorylation plays a significant role in a wide range of cellular processes. The Drosophila genome encodes more than 20 receptor tyrosine kinases and extensive studies in the past 20 years have illustrated their diverse roles and complex signaling mechanisms. Although some receptor tyrosine kinases have highly specific functions, others strikingly are used in rather ubiquitous manners. Receptor tyrosine kinases regulate a broad expanse of processes, ranging from cell survival and proliferation to differentiation and patterning. Remarkably, different receptor tyrosine kinases share many of the same effectors and their hierarchical organization is retained in disparate biological contexts. In this comprehensive review, we summarize what is known regarding each receptor tyrosine kinase during Drosophila development. Astonishingly, very little is known for approximately half of all Drosophila receptor tyrosine kinases. PMID:23732470

  20. [Opioid receptors and their selective ligands].

    PubMed

    Piestrzeniewicz, Mariola Katarzyna; Fichna, Jakub; Michna, Jakub; Janecka, Anna

    2006-01-01

    Opioid receptors (micro, delta, and kappa) belong to a large family of G protein-coupled receptors and play an important physiological role. Stimulation of these receptors triggers analgesic effects and affects the function of gastrointestinal tract. The discovery of opioid peptides, which are endogenous ligands of opioid receptors, including delta-selective enkephalins, kappa-selective dynorphins, and micro-selective endomorphins, initiated their structure-activity relationship studies. For the last 30 years, hundreds of analogs of opioid peptides have been synthesized in an effort to obtain the compounds more active, selective, and resistant to biodegradation than the endogenous ligands. Different unnatural amino acids, as well as cyclisation procedures, leading to conformationaly restricted analogs, were employed. All these modifications resulted in obtaining very selective agonists and antagonists with high affinity at micro-, dlta-, and kappa-opioid receptors, which are extremely useful tools in further studies on the pharmacology of opioid receptors in a mammalian organism. PMID:17201067

  1. Eph Receptors and Ephrins: Therapeutic Opportunities

    PubMed Central

    Barquilla, Antonio; Pasquale, Elena B.

    2015-01-01

    The Eph receptor tyrosine kinase family plays important roles in developmental processes, adult tissue homeostasis and various diseases. Interaction with ephrin ligands on the surface of neighboring cells triggers Eph receptor kinase-dependent signaling. The ephrins can also transmit signals, leading to bidirectional cell contact-dependent communication. Moreover, Eph receptors and ephrins can function independently of each other, through interplay with other signaling systems. Given their involvement in many pathological conditions ranging from neurological disorders to cancer and viral infections, Eph receptors and ephrins are increasingly recognized as attractive therapeutic targets and a variety of strategies are being explored to modulate their expression and function. Eph receptor/ephrin upregulation in cancer cells, the angiogenic vasculature, and injured or diseased tissues also offers opportunities for Eph/ephrin-based targeted drug delivery and imaging. Thus, despite the challenges presented by the complex biology of the Eph receptor/ephrin system, exciting possibilities exist for therapies exploiting these molecules. PMID:25292427

  2. Play and Development From an Ethological Perspective

    ERIC Educational Resources Information Center

    Vandenberg, Brian

    1978-01-01

    A review of play in nonhuman animals indicates that play increases with phylogenetic status, is important for mature social development in more advanced species, reflects intentional activity, and is essential for the development of tool-using strategies. (Author)

  3. Teaching Strategies: Integrating Play into the Curriculum.

    ERIC Educational Resources Information Center

    Stone, Sandra J.

    1996-01-01

    Promotes the concept of serious play and discusses its role in learning, from early grades to graduate level. Provides guidelines for integrating serious play across the curriculum and includes sample primary and intermediate grade curriculum charts. (ET)

  4. Imaginary Play Companions: Characteristics and Functions.

    ERIC Educational Resources Information Center

    Kalyan-Masih, V.

    1986-01-01

    Investigates some of the following characteristics associated with young children playing with imaginary play companions (IPCs): intelligence, parental and socioeconomic and educational background, family size, and birth order. Compares these children to those without IPCs. (HOD)

  5. Growing as One Plays with a Balloon

    ERIC Educational Resources Information Center

    Torbert, Marianne

    2006-01-01

    In this article, the author recounts her experience with Tracy, who was playing with a balloon outside her office when she was five years old, and gives an up-to-date story of Tracy since 1985, 1990, and 2006. In reflecting on Tracy's play, the author realizes that Tracy is helping her see clearly what play is really all about, that in playing to…

  6. Children in Play, Story, and School.

    ERIC Educational Resources Information Center

    Goncu, Artin, Ed.; Klein, Elisa L.

    In honor of the contributions of Greta G. Fein to the fields of developmental psychology and early childhood education, a community of scholars prepared this volume to explore how social play arises, social play's developmental and educational significance, and the ways in which social play can be promoted in early childhood settings. In addition,…

  7. Superheroes: An Opportunity for Prosocial Play

    ERIC Educational Resources Information Center

    De-Souza, Desalyn; Radell, Jacqueline

    2011-01-01

    Superhero play has long been thought of as violent, aggressive, and disruptive. Some argue that aggressive play should not be allowed because it exposes children to inappropriate concepts and attitudes and sends the message that the use of aggression can achieve a desired goal. However, educators know that pretend play is an avenue for healthy…

  8. Turkish Adaptation of Test of Pretended Play

    ERIC Educational Resources Information Center

    Aydin, Aydan

    2012-01-01

    The objective of present research is to conduct validity and reliability analysis of the verbal section of Test of Pretended Play that will measure pretended play behaviors of pre-school age children (3-6 years of age). Test of Pretended Play was first developed by Vicky Lewis and Jill Boucher in 1997. This test aimed to measure pretended play…

  9. Young Children's Playfully Complex Communication: Distributed Imagination

    ERIC Educational Resources Information Center

    Alcock, Sophie

    2010-01-01

    This paper draws on research exploring young children's playful and humorous communication. It explores how playful activity mediates and connects children in complex activity systems where imagination, cognition, and consciousness become distributed across individuals. Children's playfulness is mediated and distributed via artefacts (tools, signs…

  10. Parental Distancing Strategies and Children's Fantasy Play.

    ERIC Educational Resources Information Center

    Perlmutter, Jane C.; Pellegrini, Anthony D.

    Effects of age and gender of preschool children and sex of parent on parental teaching strategies in a fantasy play situation were examined. Relations of parental strategies to children's fantasy play were assessed. Play sessions were held in a small playroom equipped with materials which facilitated dramatic production. The linguistic strategies…

  11. Empirically Based Play Interventions for Children

    ERIC Educational Resources Information Center

    Reddy, Linda A., Ed.; Files-Hall, Tara M., Ed.; Schaefer, Charles E., Ed.

    2005-01-01

    "Empirically Based Play Interventions for Children" is a compilation of innovative, well-designed play interventions, presented for the first time in one text. Play therapy is the oldest and most popular form of child therapy in clinical practice and is widely considered by practitioners to be uniquely responsive to children's developmental needs.…

  12. Dimensions of Play: Reflections and Directions.

    ERIC Educational Resources Information Center

    Jambor, Tom

    For many children, societal changes have restricted the opportunities for and the right to play. Adults deal with these violations of children's right to play by trying to correct problems, preventing future problems, or by denying that problems can or could exist. In order to meet the challenge of preserving children's play rights, we need to be…

  13. Playing Fields and Hard Surface Areas.

    ERIC Educational Resources Information Center

    Department of Education and Science, London (England).

    Guidelines are presented regarding the planning, layout, construction, and maintenance of outdoor playing fields for physical education. Consideration is given to the dual use of playing fields by the school and the community, the planning of hard surface playing areas, and specifications and bills of quantities. Maintenance costs of grass playing…

  14. Exploring Young Children's Literacy Development through Play.

    ERIC Educational Resources Information Center

    Saracho, Olivia N.

    2001-01-01

    This exploratory study examined effects of literacy- enriched play centers and the emergent literacy of 5-year-old kindergartners. Qualitative analysis indicated that a language or literacy component can be integrated into kindergartners' play activities. Play activities promoted the invented symbols and messages in children's writing. Teachers…

  15. Playing Fair: An Essential Element in Contracting

    ERIC Educational Resources Information Center

    Peeler, Tom

    2012-01-01

    Playing fair has a value with which people are all familiar. From the sandboxes of childhood and the competitive sports of youth to the business transactions of adulthood, people have been told how important it is to play fair. Playing fair in contracting is not only essential, it's the legal and ethical thing to do. In this article, the author…

  16. Pretend Play of Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Pfeifer, Luzia Iara; Pacciulio, Amanda Mota; dos Santos, Camila Abrao; dos Santos, Jair Licio; Stagnitti, Karen Ellen

    2011-01-01

    Background and Purpose: Evaluate self-initiated pretend play of children with cerebral palsy. Method: Twenty preschool children participated in the study. Pretend play ability was measured by using the child-initiated pretend play assessment culturally adapted to Brazil. Results: There were significant negative correlations between the children's…

  17. Play Therapy for Severe Psychological Trauma. [Videotape

    ERIC Educational Resources Information Center

    Gil, Eliana

    In this 36-minute educational video, a play and family therapist elucidates the nature of trauma, how to recognize it clinically, and how to manage its powerful effects upon children's development with the use of specific play materials and techniques. With a reenacted clinical interview, footage from an actual play therapy session, and a detailed…

  18. Play Culture in a Changing World

    ERIC Educational Resources Information Center

    Kalliala, Marjatta

    2005-01-01

    The cultural context in which children grow up has a powerful influence on the way they play. At a time of rapid change in post-industrial societies, childhood play is changing to reflect children's experiences. Adults need to understand that children have their own play culture, which might be different from that of the adults' own childhoods.…

  19. The Play Professional in the United Kingdom

    ERIC Educational Resources Information Center

    Millbank, Anna-Marie

    2005-01-01

    Playwork is a respected field of study composed of experts who have studied the theories and practices of play for the purposes of training other individuals in best practices to better facilitate children's play. The profession is founded on the belief that play is an essential childhood element and the right of every child. In this article, the…

  20. Game Playing: Negotiating Rules and Identities

    ERIC Educational Resources Information Center

    Winther-Lindqvist, Ditte

    2009-01-01

    Beginning with Lev Vygotsky's long-established assertion that the play of children always involves both imaginary play and rules of behavior, this article argues for a theoretical framework that connects such play with the construction of social identities in kindergarten peer groups. It begins with a discussion of Ivy Schousboe's model of the…