Ketamine and phencyclidine cause a voltage-dependent block of responses to L-aspartic acid.
Excitatory amino acids depolarize central mammalian neurons by increasing membrane conductance. This increase in conductance can be voltage-dependent (i.e. N-methyl-D-aspartate or L-aspartic acid (L-ASP)) or voltage-independent (i.e. kainic acid (KA)) depending on whether or not the channel is blocked by Mg2+ [8,9]. Intracellular recordings were made from dissociated mouse spinal cord cells and conductance was calculated using constant current techniques. The dissociative anesthetics, ketamine and phencyclidine caused a selective depression in the change in conductance evoked by L-ASP but not that by KA. Under whole cell voltage-clamp (in the absence of extracellular Mg2+) this depression of responses to L-ASP was found to be highly voltage-dependent suggesting a blockade of the channel.
C R
CR
Honey
Z
Z
Miljkovic
J F
JF
MacDonald
D000818:Animals; D001224:Aspartic Acid / Q000037:antagonists & inhibitors*; D002462:Cell Membrane / Q000187:drug effects; D002478:Cells, Cultured; D004553:Electric Conductivity; D007473:Ion Channels / Q000187:drug effects; D007649:Ketamine / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D010622:Phencyclidine / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects*
D007473:Ion Channels; D001224:Aspartic Acid; D007649:Ketamine; D008274:Magnesium; D010622:Phencyclidine