• 1
    Using a combination of patch-clamp, in situ hybridization and computer simulation techniques, we have analysed the contribution of potassium channels to the ability of a subset of mouse auditory neurones to fire at high frequencies.
  • 2
    Voltage-clamp recordings from the principal neurones of the medial nucleus of the trapezoid body (MNTB) revealed a low-threshold dendrotoxin (DTX)-sensitive current (ILT) and a high-threshold DTX-insensitive current (IHT).
  • 3
    IHT displayed rapid activation and deactivation kinetics, and was selectively blocked by a low concentration of tetraethylammonium (TEA; 1 mm).
  • 4
    The physiological and pharmacological properties of IHT very closely matched those of the Shaw family potassium channel Kv3.1 stably expressed in a CHO cell line.
  • 5
    An mRNA probe corresponding to the C-terminus of the Kv3.1 channel strongly labelled MNTB neurones, suggesting that this channel is expressed in these neurones.
  • 6
    TEA did not alter the ability of MNTB neurones to follow stimulation up to 200 Hz, but specifically reduced their ability to follow higher frequency impulses.
  • 7
    A computer simulation, using a model cell in which an outward current with the kinetics and voltage dependence of the Kv3.1 channel was incorporated, also confirmed that the Kv3.1- like current is essential for cells to respond to a sustained train of high-frequency stimuli.
  • 8
    We conclude that in mouse MNTB neurones the Kv3.1 channel contributes to the ability of these cells to lock their firing to high-frequency inputs.