Jegham S

References (3)

Title : SSR180711, a novel selective alpha7 nicotinic receptor partial agonist: (1) binding and functional profile - Biton_2007_Neuropsychopharmacology_32_1
Author(s) : Biton B , Bergis OE , Galli F , Nedelec A , Lochead AW , Jegham S , Godet D , Lanneau C , Santamaria R , Chesney F , Leonardon J , Granger P , Debono MW , Bohme GA , Sgard F , Besnard F , Graham D , Coste A , Oblin A , Curet O , Vige X , Voltz C , Rouquier L , Souilhac J , Santucci V , Gueudet C , Francon D , Steinberg R , Griebel G , Oury-Donat F , George P , Avenet P , Scatton B
Ref : Neuropsychopharmacology , 32 :1 , 2007
Abstract : In this paper, we report on the pharmacological and functional profile of SSR180711 (1,4-Diazabicyclo[3.2.2]nonane-4-carboxylic acid, 4-bromophenyl ester), a new selective alpha7 acetylcholine nicotinic receptor (n-AChRs) partial agonist. SSR180711 displays high affinity for rat and human alpha7 n-AChRs (K(i) of 22+/-4 and 14+/-1 nM, respectively). Ex vivo (3)[H]alpha-bungarotoxin binding experiments demonstrate that SSR180711 rapidly penetrates into the brain (ID(50)=8 mg/kg p.o.). In functional studies performed with human alpha7 n-AChRs expressed in Xenopus oocytes or GH4C1 cells, the compound shows partial agonist effects (intrinsic activity=51 and 36%, EC(50)=4.4 and 0.9 microM, respectively). In rat cultured hippocampal neurons, SSR180711 induced large GABA-mediated inhibitory postsynaptic currents and small alpha-bungarotoxin sensitive currents through the activation of presynaptic and somato-dendritic alpha7 n-AChRs, respectively. In mouse hippocampal slices, the compound increased the amplitude of both glutamatergic (EPSCs) and GABAergic (IPSCs) postsynaptic currents evoked in CA1 pyramidal cells. In rat and mouse hippocampal slices, a concentration of 0.3 muM of SSR180711 increased long-term potentiation (LTP) in the CA1 field. Null mutation of the alpha7 n-AChR gene totally abolished SSR180711-induced modulation of EPSCs, IPSCs and LTP in mice. Intravenous administration of SSR180711 strongly increased the firing rate of single ventral pallidum neurons, extracellularly recorded in anesthetized rats. In microdialysis experiments, administration of the compound (3-10 mg/kg i.p.) dose-dependently increased extracellular acetylcholine (ACh) levels in the hippocampus and prefrontal cortex of freely moving rats. Together, these results demonstrate that SSR180711 is a selective and partial agonist at human, rat and mouse alpha7 n-AChRs, increasing glutamatergic neurotransmission, ACh release and LTP in the hippocampus.
ESTHER : Biton_2007_Neuropsychopharmacology_32_1
PubMedSearch : Biton_2007_Neuropsychopharmacology_32_1
PubMedID: 17019409

Title : SSR591813, a novel selective and partial alpha4beta2 nicotinic receptor agonist with potential as an aid to smoking cessation - Cohen_2003_J.Pharmacol.Exp.Ther_306_407
Author(s) : Cohen C , Bergis OE , Galli F , Lochead AW , Jegham S , Biton B , Leonardon J , Avenet P , Sgard F , Besnard F , Graham D , Coste A , Oblin A , Curet O , Voltz C , Gardes A , Caille D , Perrault G , George P , Soubrie P , Scatton B
Ref : Journal of Pharmacology & Experimental Therapeutics , 306 :407 , 2003
Abstract : (5aS,8S,10aR)-5a,6,9,10-Tetrahydro,7H,11H-8,10a-methanopyrido[2',3':5,6]pyrano[2, 3-d]azepine (SSR591813) is a novel compound that binds with high affinity to the rat and human alpha4beta2 nicotinic acetylcholine receptor (nAChR) subtypes (Ki = 107 and 36 nM, respectively) and displays selectivity for the alpha4beta2 nAChR (Ki, human alpha3beta4 > 1000, alpha3beta2 = 116; alpha1beta1deltagamma > 6000 nM and rat alpha7 > 6000 nM). Electrophysiological experiments indicate that SSR591813 is a partial agonist at the human alpha4beta2 nAChR subtype (EC50 = 1.3 micro M, IA =19% compared with the full agonist 1,1-dimethyl-4-phenyl-piperazinium). In vivo findings from microdialysis and drug discrimination studies confirm the partial intrinsic activity of SSR591813. The drug increases dopamine release in the nucleus accumbens shell (30 mg/kg i.p.) and generalizes to nicotine or amphetamine (10-20 mg/kg i.p.) in rats, with an efficacy approximately 2-fold lower than that of nicotine. Pretreatment with SSR591813 (10 mg/kg i.p.) reduces the dopamine-releasing and discriminative effects of nicotine. SSR591813 shows activity in animal models of nicotine dependence at doses devoid of unwanted side effects typically observed with nicotine (hypothermia and cardiovascular effects). The compound (10 mg/kg i.p.) also prevents withdrawal signs precipitated by mecamylamine in nicotine-dependent rats and partially blocks the discriminative cue of an acute precipitated withdrawal. SSR591813 (20 mg/kg i.p.) reduces i.v. nicotine self-administration and antagonizes nicotine-induced behavioral sensitization in rats. The present results confirm important role for alpha4beta2 nAChRs in mediating nicotine dependence and suggest that SSR591813, a partial agonist at this particular nAChR subtype, may have therapeutic potential in the clinical management of smoking cessation.
ESTHER : Cohen_2003_J.Pharmacol.Exp.Ther_306_407
PubMedSearch : Cohen_2003_J.Pharmacol.Exp.Ther_306_407
PubMedID: 12682217

Title : SL65.0155, A Novel 5-Hydroxytryptamine(4) Receptor Partial Agonist with Potent Cognition-Enhancing Properties - Moser_2002_J.Pharmacol.Exp.Ther_302_731
Author(s) : Moser PC , Bergis OE , Jegham S , Lochead A , Duconseille E , Terranova JP , Caille D , Berque-Bestel I , Lezoualc'h F , Fischmeister R , Dumuis A , Bockaert J , George P , Soubrie P , Scatton B
Ref : Journal of Pharmacology & Experimental Therapeutics , 302 :731 , 2002
Abstract : SL65.0155 [5-(8-amino-7-chloro-2,3-dihydro-1,4-benzodioxin-5-yl)-3-[1-(2-phenyl ethyl)-4-piperidinyl]-1,3,4-oxadiazol-2(3H)-one monohydrochloride] is a novel benzodioxanoxadiazolone compound with high affinity for human 5-hydroxytryptamine (5-HT)(4) receptors (K(i) of 0.6 nM) and good selectivity (greater than 100-fold for all other receptors tested). In cells expressing the 5-HT(4(b)) and 5-HT(4(e)) splice variants, SL65.0155 acted as a partial agonist, stimulating cAMP production with a maximal effect of 40 to 50% of serotonin. However, in the rat esophagus preparation, SL65.0155 acted as a 5-HT(4) antagonist with a pK(b) of 8.81. In addition, SL65.0155 potently improved performance in several tests of learning and memory. In the object recognition task, it improved retention at 24 h when administered i.p. or p.o. (0.001-0.1 mg/kg). This effect was antagonized by the 5-HT(4) antagonist SDZ 205,557, itself without effect, demonstrating that the promnesic effects of SL65.0155 are mediated by 5-HT(4) agonism. SL65.0155 also reversed the cognitive deficits of aged rats in the linear maze task and the scopolamine-induced deficit of mice in the water maze task. Furthermore, the combined administration of an inactive dose of SL65.0155 with the cholinesterase inhibitor rivastigmine resulted in a significant promnesic effect, suggesting a synergistic interaction. SL65.0155 was devoid of unwanted cardiovascular, gastrointestinal, or central nervous system effects with doses up to more than 100-fold higher than those active in the cognitive tests. These results characterize SL65.0155 as a novel promnesic agent acting via 5-HT(4) receptors, with an excellent preclinical profile. Its broad range of activity in cognitive tests and synergism with cholinesterase inhibitors suggest that SL65.0155 represents a promising new agent for the treatment of dementia.
ESTHER : Moser_2002_J.Pharmacol.Exp.Ther_302_731
PubMedSearch : Moser_2002_J.Pharmacol.Exp.Ther_302_731
PubMedID: 12130738