Hyperpolarizing inward rectification in rat neocortical neurons located in the superficial layers.
Intracellular recordings were performed in neurons located in layers II/III of rat neocortical slices maintained in vitro. High intensity negative current pulses elicited hyperpolarizing responses that were characterized by a sag of membrane potential towards the resting level. Graphically, this inward rectification was reflected as a break in the slope of the I-V plot at membrane level of around -98 mV. The inward rectification was only partially reduced by the bath perfusion of Cs+ (3 mM). In contrast, it was abolished by the extracellular addition of Ba2+ (3 mM) or the intracellular injection of QX-314 (50 mM). Our findings indicate that Ba2+ and QX-314 are more effective than Cs+ in blocking the hyperpolarizing inward rectification generated by rat neocortical cells located in the superficial layers.
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Montreal Neurological Institute, McGill University, Qué, Canada.
Avoli
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D000818:Animals; D001464:Barium / Q000494:pharmacology; D002540:Cerebral Cortex / Q000166:cytology*; D002586:Cesium / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects; D008012:Lidocaine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D015221:Potassium Channels / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
D015221:Potassium Channels; D002586:Cesium; C012647:QX-314; D001464:Barium; D008012:Lidocaine