Changes in glutamate-evoked currents of frog motoneurones by extracellular Mg2+.
Responses of frog motoneurones to glutamate were studied using a single electrode voltage clamp method. At resting membrane potential glutamate evoked biphasic effects: firstly a transient outward current with reversal potential between -90 and -100 mV. Secondly an inward current with reversal potential near 0 mV and non-linearly related to the holding potential. Mg2+ (1 mM) had no effect on the outward current but reduced the inward current and its slope conductance at holding potentials more negative than -60 mV. These data indicate that the operation of the inward current activated by glutamate was partly but not solely controlled by extracellular Mg2+.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D005971:Glutamates / Q000494:pharmacology*; D018698:Glutamic Acid; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D011896:Rana temporaria; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*
D005971:Glutamates; D018698:Glutamic Acid; D008274:Magnesium