Rouquier L

References (2)

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 : Muscarinic receptor-mediated increase in extracellular inositol 1,4,5-trisphosphate levels in the rat hippocampus: an in vivo microdialysis study - Minisclou_1994_J.Neurochem_62_557
Author(s) : Minisclou C , Rouquier L , Benavides J , Scatton B , Claustre Y
Ref : Journal of Neurochemistry , 62 :557 , 1994
Abstract : The extracellular concentration of inositol 1,4,5-trisphosphate (IP3) has been monitored in the ventral hippocampus of the anesthetized rat by using a microdialysis technique coupled to a radioreceptor assay. Three hours after the implantation of the cannula, basal extracellular concentration of IP3 (corrected for a 9% recovery) was 71 nM (0.39 pmol/60-microliters fraction) and remained stable for at least 5 h. Local infusion of carbachol for 60 min caused a significant concentration-related increase in extracellular IP3 levels (0, 24, and 57% at 1, 50, and 100 microM, respectively). Acetylcholine (100 microM) and muscarine (100 microM) increased IP3 outflow by 40 and 42%, respectively. The effect of carbachol was fully prevented by coinfusion of 10 microM pirenzepine and reduced by 1 microM tetrodotoxin indicating that the carbachol response is mediated by neuronal muscarinic receptors. These data demonstrate the feasibility of using microdialysis and a radioreceptor assay to measure IP3 in the extracellular space. This approach could prove useful for the study of the in vivo operation of muscarinic and, by extension, a number of receptors coupled to phosphoinositide turnover.
ESTHER : Minisclou_1994_J.Neurochem_62_557
PubMedSearch : Minisclou_1994_J.Neurochem_62_557
PubMedID: 8294918