Abstract
Using the whole-cell configuration of the patch-clamp technique, outward K+ currents were recorded from acutely isolated stellate cells from superficial layers, and pyramidal cells from deep layers, of the entorhinal cortex of juvenile rats. In both cell types a fast transient and a slowly inactivating outward K+ current were obtained. Whereas the fast transient current (I A) activated at potentials beyond −50 mV, the activation threshold of the slowly inactivating current (I K) was measured at −40 mV in stellate and pyramidal cells. In stellate cells a half-maximal inactivation was estimated for I A at −80.4 mV and for I K at −74.6 mV, and in pyramidal cells at −81.1 mV and −71.8 mV, respectively. I K of both cell types were reduced by tetraethylammonium (TEA) in a concentration-dependent manner. IC50 values were 0.8 mM TEA for stellate cells and 1.1 mM TEA for pyramidal cells. Superfusion of 4-aminopyridine resulted in a reduction of the amplitudes of I A and I K as well as in an acceleration of the inactivation time constants of I A. Extracellularly applied dendrotoxin did not have any effect on entorhinal cortex K+ currents. In summary, kinetic and pharmacological properties of I A as well as of I K are rather similar in superficial-layer stellate and deep-layer pyramidal cells acutely isolated from the entorhinal cortex of juvenile rats.
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Eder, C., Heinemann, U. Potassium currents in acutely isolated neurons from superficial and deep layers of the juvenile rat entorhinal cortex. Pflügers Arch. 432, 637–643 (1996). https://doi.org/10.1007/s004240050180
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DOI: https://doi.org/10.1007/s004240050180