Voltage-clamp errors cause anomalous interaction between independent ion channels.
In voltage-clamp, uncompensated series resistance results in steady-state voltage errors that scale with the amplitude of the elicited current and are often correctable offline. However, while investigating mechanoelectric transduction currents at hair cells' resting potential, voltage-gated calcium channels and calcium-activated potassium channels (BK) were activated in voltage-clamp by displacing the sensory hair bundle. This resulted from steady-state voltage errors (<1.5 mV) induced by series resistance changing the holding potential. Thus, uncompensated series resistance, interacting with an elicited current, resulted in a voltage error that could induce the erroneous activation of other currents. This error is not correctable offline. Recognizing this type of error is critical when investigating multiple voltage-dependent conductances with steep voltage dependence.
Farris
Hamilton E
HE
Neuroscience Center and Kresge Hearing Labs, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA. hfarri@lsuhsc.edu
Ricci
Anthony J
AJ
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D015220:Calcium Channels / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D006198:Hair Cells, Auditory / Q000502:physiology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods*; D010812:Physical Stimulation / Q000379:methods; D024681:Potassium Channels, Calcium-Activated / Q000502:physiology*; D013997:Time Factors; D014426:Turtles
D015220:Calcium Channels; D024681:Potassium Channels, Calcium-Activated; D002118:Calcium