title: Simultaneous optical recording in multiple cells by digital holographic microscopy of chloride current associated to activation of the ligand-gated chloride channel GABA(A) receptor.
abstract: Chloride channels represent a group of targets for major clinical indications. However, molecular screening for chloride channel modulators has proven to be difficult and time-consuming as approaches essentially rely on the use of fluorescent dyes or invasive patch-clamp techniques which do not lend themselves to the screening of large sets of compounds. To address this problem, we have developed a non-invasive optical method, based on digital holographic microcopy (DHM), allowing monitoring of ion channel activity without using any electrode or fluorescent dye. To illustrate this approach, GABA(A) mediated chloride currents have been monitored with DHM. Practically, we show that DHM can non-invasively provide the quantitative determination of transmembrane chloride fluxes mediated by the activation of chloride channels associated with GABA(A) receptors. Indeed through an original algorithm, chloride currents elicited by application of appropriate agonists of the GABA(A) receptor can be derived from the quantitative phase signal recorded with DHM. Finally, chloride currents can be determined and pharmacologically characterized non-invasively simultaneously on a large cellular sampling by DHM.
authors.affiliation: Brain and Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. pascal.jourdain@epfl.ch
authors.forename: Pascal
authors.initials: P
authors.lastname: Jourdain
authors.forename: Daniel
authors.initials: D
authors.lastname: Boss
authors.forename: Benjamin
authors.initials: B
authors.lastname: Rappaz
authors.forename: Corinne
authors.initials: C
authors.lastname: Moratal
authors.forename: Maria-Clemencia
authors.initials: MC
authors.lastname: Hernandez
authors.forename: Christian
authors.initials: C
authors.lastname: Depeursinge
authors.forename: Pierre Julius
authors.initials: PJ
authors.lastname: Magistretti
authors.forename: Pierre
authors.initials: P
authors.lastname: Marquet
mesh_terms: D018118:Chloride Channels / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism; D057809:HEK293 Cells; D006696:Holography / Q000379:methods; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D008853:Microscopy / Q000379:methods; D011963:Receptors, GABA-A / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism; D064506:Solute Carrier Family 12, Member 2; D027981:Symporters / Q000378:metabolism; D014162:Transfection; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology; D000096922:K Cl- Cotransporters
chemical_list: D018118:Chloride Channels; D002712:Chlorides; D011963:Receptors, GABA-A; D028021:Sodium-Potassium-Chloride Symporters; D064506:Solute Carrier Family 12, Member 2; D027981:Symporters; D005680:gamma-Aminobutyric Acid; D000096922:K Cl- Cotransporters; C578877:SLC12A2 protein, human