Sensitivity of transient outward rectification to ion channel blocking agents in guinea-pig substantia nigra pars compacta neurones in vitro.
The sensitivity of a transient outward rectifier in guinea-pig substantia nigra pars compacta (SNC) neurones in vitro was tested to a variety of ion channel blocking agents. This rectification was not blocked by TEA (10 mM), 4-aminopyridine (4-AP) (5 mM), apamin (0.2-1 microM) or Cd2+ ions (200 microM). Cs+ ions (5 mM) blocked the inward 'anomalous' rectifier but had no effect on the transient outward rectification. However, replacing Ca2+ ions in the bath perfusate by Ba2+ blocked the transient outward but not the inward rectifier. It is suggested that an atypical barium-sensitive conductance is responsible for the transient outward rectification of these neurones.
D000818:Animals; D001464:Barium / Q000494:pharmacology; D002478:Cells, Cultured; D004553:Electric Conductivity; D006168:Guinea Pigs; D007473:Ion Channels / Q000187:drug effects*; D009474:Neurons / Q000378:metabolism*; D013378:Substantia Nigra / Q000166:cytology / Q000378:metabolism*
D007473:Ion Channels; D001464:Barium