Effect of tetrodotoxin and potassium infusion on microdialysis extraction fraction and extracellular dopamine in the nucleus accumbens.
The effects of tetrodotoxin (TTX) and K+ perfusion on extracellular DA concentration (DAext) and extraction fraction (also known as relative recovery or Ed) were studied using a method for quantitative microdialysis under transient conditions. TTX administered through the microdialysis probe decreased DAext with no effect on Ed. Perfusion with high K+ increased DAext, with no initial effect on Ed. However, a decrease in Ed was observed under prolonged depolarization. These data provide further evidence that Ed may change over the course of drug administration. This method of quantitative microdialysis is a reliable means for measuring changes in DAext independently of possible changes in microdialysis probe efficiency.
Cosford
R J
RJ
Department of Chemistry, Emory University, Atlanta, GA 30322.
Parsons
L H
LH
Justice
J B
JB
D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D004594:Electrophysiology; D005110:Extracellular Space / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009994:Osmolar Concentration; D011188:Potassium / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013779:Tetrodotoxin / Q000494:pharmacology*
D013779:Tetrodotoxin; D011188:Potassium; D004298:Dopamine