| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Lucifer Yellow CH (LY), a membrane-impermeant fluorescent dye, has been used in electrophysiological studies to visualize cell morphology, with little concern about its pharmacological effects. We investigated its effects on TTX-sensitive voltage-gated Na+ channels in mouse taste bud cells and hippocampal neurons under voltage-clamp conditions. LY applied inside cells irreversibly slowed the inactivation of Na+ currents upon exposure to light of usual intensities. The inactivation time constant of Na+ currents elicited by a depolarization to -15 mV was increased by fourfold after a 5 min exposure to halogen light of 3200 lx at source (3200 lx light), and sevenfold after a 1-min exposure to 12 000 lx light. A fraction of the Na+ current became non-inactivating following the exposure. The non-inactivating current was ~ 20 % of the peak total Na+ current after a 5 min exposure to 3200 lx light, and ~ 30 % after a 1 min exposure to 12 000 lx light. Light-exposed LY shifted slightly the current-voltage relationship of the peak Na+ current and of the steady-state inactivation curve, in the depolarizing direction. A similar light-dependent decrease in kinetics occurred in whole-cell Na+ currents of cultured mouse hippocampal neurones. Single-channel recordings showed that exposure to 6500 lx light for 3 min increased the mean open time of Na+ channels from 1.4 ms to 2.4 ms without changing the elementary conductance. The pre-incubation of taste bud cells with 1 mM dithiothreitol, a scavenger of radical species, blocked these LY effects. These results suggest that light-exposed LY yields radical species that modify Na+ channels.
This article has been cited by other articles:
|
|
 |
|
  K. Takeuchi and K. Yoshii Effect of Superoxide Derived from Lucifer Yellow CH on Voltage-Gated Currents of Mouse Taste Bud Cells Chem Senses, June 1, 2008; 33(5): 425 - 432. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Eguchi, Y. Ohtubo, and K. Yoshii Functional Expression of M3, a Muscarinic Acetylcholine Receptor Subtype, in Taste Bud Cells of Mouse Fungiform Papillae Chem Senses, January 1, 2008; 33(1): 47 - 55. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Hayato, Y. Ohtubo, and K. Yoshii Functional expression of ionotropic purinergic receptors on mouse taste bud cells J. Physiol., October 15, 2007; 584(2): 473 - 488. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. A. Prescott and Y. De Koninck Integration Time in a Subset of Spinal Lamina I Neurons Is Lengthened by Sodium and Calcium Currents Acting Synergistically to Prolong Subthreshold Depolarization J. Neurosci., May 11, 2005; 25(19): 4743 - 4754. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Heinke, R. Ruscheweyh, L. Forsthuber, G. Wunderbaldinger, and J. Sandkuhler Physiological, neurochemical and morphological properties of a subgroup of GABAergic spinal lamina II neurones identified by expression of green fluorescent protein in mice J. Physiol., October 1, 2004; 560(1): 249 - 266. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. Mycielska and M. B. A. Djamgoz Citrate transport in the human prostate epithelial PNT2-C2 cell line: electrophysiological analyses J. Physiol., September 15, 2004; 559(3): 821 - 833. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Ruscheweyh, H. Ikeda, B. Heinke, and J. Sandkuhler Distinctive membrane and discharge properties of rat spinal lamina I projection neurones in vitro J. Physiol., March 1, 2004; 555(2): 527 - 543. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
