Single 5-HT3 receptor-gated ion channel events resolved in N1E-115 mouse neuroblastoma cells.
In order to resolve single channel events underlying the 5-HT3 receptor-gated ion current in N1E-115 neuroblastoma cells patch clamp experiments have been performed on excised outside-out membrane patches under optimized experimental conditions. When the driving force for Na+ through the 5-HT3 receptor-gated ion channel is enhanced by raising the external Na+ concentration to 180 mM and by substituting internal K+ with the relatively impermeable cation N-methyl-D-glucamine, a single conductance level is observed in the presence of 5-HT. Single channel activity is observed only in the presence of the agonist and is blocked by 50 nM of the selective 5-HT3 receptor antagonist MDL 72222 in a reversible manner. At membrane potentials more negative than -60 mV discrete single channel events can be resolved with a conductance of 5.6 +/- 1.2 pS.
van Hooft
J A
JA
Research Institute of Toxicology, Utrecht University, The Netherlands.
Kooyman
A R
AR
Verkerk
A
A
van Kleef
R G
RG
Vijverberg
H P
HP
D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D004553:Electric Conductivity; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D008564:Membrane Potentials; D051379:Mice; D009447:Neuroblastoma / Q000503:physiopathology*; D011985:Receptors, Serotonin / Q000502:physiology*; D012701:Serotonin / Q000502:physiology; D014326:Tropanes / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D011985:Receptors, Serotonin; D014326:Tropanes; D012701:Serotonin; C042253:bemesetron