title: Errors in the measurement of voltage-activated ion channels in cell-attached patch-clamp recordings.
abstract: Patch-clamp recording techniques have revolutionized understanding of the function and sub-cellular location of ion channels in excitable cells. The cell-attached patch-clamp configuration represents the method of choice to describe the endogenous properties of voltage-activated ion channels in the axonal, somatic and dendritic membrane of neurons, without disturbance of the intracellular milieu. Here, we directly examine the errors associated with cell-attached patch-clamp measurement of ensemble ion channel activity. We find for a number of classes of voltage-activated channels, recorded from the soma and dendrites of neurons in acute brain-slices and isolated cells, that the amplitude and kinetics of ensemble ion channel activity recorded in cell-attached patches is significantly distorted by transmembrane voltage changes generated by the flow of current through the activated ion channels. We outline simple error-correction procedures that allow a more accurate description of the density and properties of voltage-activated channels to be incorporated into computational models of neurons.
authors.affiliation: Queensland Brain Institute, The University of Queensland, St Lucia, Queensland, Australia. srw@uq.edu.au
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Williams
authors.forename: Christian
authors.initials: C
authors.lastname: Wozny
mesh_terms: D000818:Animals; D016477:Artifacts; D001921:Brain / Q000502:physiology; D002462:Cell Membrane / Q000502:physiology; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000235:genetics / Q000378:metabolism*; D003712:Dendrites / Q000502:physiology; D004553:Electric Conductivity; D004560:Electricity; D015870:Gene Expression; D057809:HEK293 Cells; D006801:Humans; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D015640:Ion Channel Gating / Q000502:physiology*; D007477:Ions / Q000378:metabolism; D008564:Membrane Potentials / Q000502:physiology; D051379:Mice; D008954:Models, Biological; D009474:Neurons / Q000502:physiology; D018408:Patch-Clamp Techniques / Q000592:standards*; D010957:Plasmids; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection
chemical_list: D054815:Cyclic Nucleotide-Gated Cation Channels; D064428:Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; D007477:Ions; D015221:Potassium Channels