RT Journal Article
SR Electronic
T1 Effects of local anesthetic QX-314 on the membrane properties of hippocampal pyramidal neurons.
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 476
OP 481
VO 220
IS 3
A1 B W Connors
A1 D A Prince
YR 1982
UL http://jpet.aspetjournals.org/content/220/3/476.abstract
AB The quaternary lidocaine derivative QX-314 was applied internally to CA1 pyramidal neurons of the guinea-pig hippocampal slice preparation. This local anesthetic blocked both fast, Na+-dependent action potentials and the voltage-dependent, non-inactivating Na+ conductance. Partially blocked Na+ spikes exhibited pronounced frequency-dependent depression at rates as low as 0.2 Hz. Ca++-dependent electrogenesis, synaptic potentials and glutamate-induced depolarizations were apparently unaffected even after large doses of QX-314. The results indicate that the cellular mechanisms of local anesthetics on central neuronal membranes are similar to those described for peripheral axons. The frequency-dependence of spike blockade may account for some of the effects of local anesthetics on the central nervous system in vivo. Additionally, the localized intracellular application of QX-314 may prove useful as a specific pharmacological tool in studies of central neurons.