Compounds > 6-cyano-7-nitroquinoxaline-2-3-dione

6-cyano-7-nitroquinoxaline-2-3-dione and phenyl-biguanide

6-cyano-7-nitroquinoxaline-2-3-dione has been researched along with phenyl-biguanide* in 1 studies

Other Studies

1 other study(ies) available for 6-cyano-7-nitroquinoxaline-2-3-dione and phenyl-biguanide

Article	Year
Activation of presynaptic 5-HT3 receptors facilitates glutamatergic synaptic inputs to area postrema neurons in rat brain slices. Methods and findings in experimental and clinical pharmacology, 2004, Volume: 26, Issue:8 Whole-cell voltage-clamp recordings were performed to investigate the serotonergic modulation of neurotransmitter release onto rat area postrema neurons in vitro. The bath application of serotonin (5-HT; 50 microM) or phenylbiguanide (PBA; 50 microM), a potent 5-HT3 receptor agonist, increased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) or miniature EPSCs (mEPSCs) in 35 of 83 neurons (42%). These increases occurred in all electrophysiological cell classes. No cells exhibited a decrease in EPSC frequency. The majority of responding cells showed no inward currents during the application of serotonergic agonists (n = 34/35). However, the amplitude of mEPSCs was increased in 11/11 cells with 5-HT or 3/11 cells with PBA. ICS-205,930, a potent 5-HT3 receptor antagonist, markedly suppressed the 5-HT-induced facilitation of sEPSCs (n = 5) or mEPSCs (n = 5). An increase in the frequency of mEPSCs after PBA exposure was found, even with media containing Cd2+ (50 microM) or zero Ca2+. mEPSCs and evoked EPSCs were completely blocked in media containing the non-NMDA ionotropic receptor antagonist, CNQX (10 microM), indicating that EPSCs were glutamate events. These results suggest that glutamate release is increased in the area postrema by presynaptic 5-HT3 receptor activation. Furthermore, we present evidence that 5-HT3 receptor activation may be able to directly release glutamate from terminals, bypassing a requirement for voltage-dependent calcium entry into terminals. Such a mechanism may contribute to the chemosensitive function of area postrema neurons. Topics: 6-Cyano-7-nitroquinoxaline-2,3-dione; Animals; Antiemetics; Area Postrema; Biguanides; Excitatory Amino Acid Agonists; Excitatory Postsynaptic Potentials; Glutamic Acid; In Vitro Techniques; Indoles; Neurons; Patch-Clamp Techniques; Rats; Rats, Sprague-Dawley; Receptors, Presynaptic; Serotonin; Serotonin 5-HT3 Receptor Agonists; Serotonin 5-HT3 Receptor Antagonists; Serotonin Receptor Agonists; Synaptic Transmission; Tropisetron	2004

Article

Year

Activation of presynaptic 5-HT3 receptors facilitates glutamatergic synaptic inputs to area postrema neurons in rat brain slices.

Methods and findings in experimental and clinical pharmacology, 2004, Volume: 26, Issue:8

Whole-cell voltage-clamp recordings were performed to investigate the serotonergic modulation of neurotransmitter release onto rat area postrema neurons in vitro. The bath application of serotonin (5-HT; 50 microM) or phenylbiguanide (PBA; 50 microM), a potent 5-HT3 receptor agonist, increased the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) or miniature EPSCs (mEPSCs) in 35 of 83 neurons (42%). These increases occurred in all electrophysiological cell classes. No cells exhibited a decrease in EPSC frequency. The majority of responding cells showed no inward currents during the application of serotonergic agonists (n = 34/35). However, the amplitude of mEPSCs was increased in 11/11 cells with 5-HT or 3/11 cells with PBA. ICS-205,930, a potent 5-HT3 receptor antagonist, markedly suppressed the 5-HT-induced facilitation of sEPSCs (n = 5) or mEPSCs (n = 5). An increase in the frequency of mEPSCs after PBA exposure was found, even with media containing Cd2+ (50 microM) or zero Ca2+. mEPSCs and evoked EPSCs were completely blocked in media containing the non-NMDA ionotropic receptor antagonist, CNQX (10 microM), indicating that EPSCs were glutamate events. These results suggest that glutamate release is increased in the area postrema by presynaptic 5-HT3 receptor activation. Furthermore, we present evidence that 5-HT3 receptor activation may be able to directly release glutamate from terminals, bypassing a requirement for voltage-dependent calcium entry into terminals. Such a mechanism may contribute to the chemosensitive function of area postrema neurons.

Topics: 6-Cyano-7-nitroquinoxaline-2,3-dione; Animals; Antiemetics; Area Postrema; Biguanides; Excitatory Amino Acid Agonists; Excitatory Postsynaptic Potentials; Glutamic Acid; In Vitro Techniques; Indoles; Neurons; Patch-Clamp Techniques; Rats; Rats, Sprague-Dawley; Receptors, Presynaptic; Serotonin; Serotonin 5-HT3 Receptor Agonists; Serotonin 5-HT3 Receptor Antagonists; Serotonin Receptor Agonists; Synaptic Transmission; Tropisetron

2004