TY - JOUR 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 SP - 476 LP - 481 VL - 220 IS - 3 AU - B W Connors AU - D A Prince Y1 - 1982/03/01 UR - http://jpet.aspetjournals.org/content/220/3/476.abstract N2 - 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. ER -