Phencyclidine at low concentrations selectively blocks the sustained but not the transient voltage-dependent potassium current in cultured hippocampal neurons.
We studied the effects of phencyclidine (PCP) on voltage-dependent K+ currents in cultured embryonic rat hippocampal neurons. Whole cell voltage-clamp recordings were made in the presence of tetrodotoxin to block Na+ current. Depolarizing voltage steps activated two outward current components: (i) a rapidly activating and inactivating ('transient') component, IA, and (ii) a slowly activating, minimally inactivating ('sustained'), component, IK. At low concentrations (less than 50-100 microM), PCP produced a selective, reversible blockade of IK with minimal effect on IA; however, at higher concentrations both currents were suppressed. The IC50's for blockade of IK and IA were 36 and 310 microM, respectively.
ffrench-Mullen
J M
JM
Laboratory of Neurophysiology, National Institute of Neurological and Communicative Disorders and Stroke, Bethesda, MD 20892.
Rogawski
M A
MA
Barker
J L
JL
D000818:Animals; D002478:Cells, Cultured; D004558:Electric Stimulation; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D010622:Phencyclidine / Q000494:pharmacology*; D011188:Potassium / Q000502:physiology*; D051381:Rats
D010622:Phencyclidine; D011188:Potassium