Faster voltage-dependent activation of Na+ channels in growth cones versus somata of neuroblastoma N1E-115 cells.
Kinetics of voltage-gated ionic channels fundamentally reflect the response of the channels to local electric fields. In this report cell-attached patch-clamp studies reveal that the voltage-dependent activation rate of sodium channels residing in the growth cone membrane differs from that of soma sodium channels in differentiating N1E-115 neuroblastoma cells. Because other electrophysiological properties of these channels do not differ, this finding may be a reflection of the difference in intramembrane electric field in these two regions of the cell. This represents a new mechanism for channels to attain a range of activities both within and between cells.
Neuroscience Program, University of Connecticut Health Center, Farmington 06030, USA.
J
J
Zhang
L M
LM
Loew
R M
RM
Davidson
D000818:Animals; D002451:Cell Compartmentation; D002454:Cell Differentiation; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D008564:Membrane Potentials; D009447:Neuroblastoma / Q000473:pathology; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D015222:Sodium Channels / Q000502:physiology*
D015222:Sodium Channels