A heart-like Na+ current in the medial entorhinal cortex.
Acutely dissociated neurons from the superficial layers of the medial entorhinal cortex of the rat were studied under voltage clamp using the whole-cell patch-clamp configuration. Neurons from the medial entorhinal cortex exhibit a tetrodotoxin (TTX)-resistant Na+ current (ITTX-R; IC50 approximately 146 nM), in addition to the normal TTX-sensitive Na+ current (ITTX-S; IC50 approximately 6 nM). ITTX-R was found in both putative stellate and putative pyramidal neurons from the medial entorhinal cortex. ITTX-R is kinetically indistinguishable from ITTX-S, but can be distinguished from ITTX-S based on its enhanced sensitivity to block by Cd2+, La3+, and Zn2+. ITTX-R is kinetically and pharmacologically similar to the TTX-resistant Na+ current found in cardiac muscle.
White
J A
JA
Department of Biological Sciences, University of Iowa, Iowa City 52242-1324.
Alonso
A
A
Kay
A R
AR
D000818:Animals; D002412:Cations / Q000494:pharmacology; D004594:Electrophysiology / Q000379:methods; D006321:Heart / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011712:Pyramidal Tracts / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D051381:Rats; D026941:Sodium Channel Blockers; D015222:Sodium Channels / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology
D002412:Cations; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D013779:Tetrodotoxin