and neuronal excitability
GABA (ɣ-aminobutyric acid) is the primary inhibitory neurotransmitter in the central nervous system. GABA receptors belong to a family of ligand gated ion channels mediating fast synaptic transmission. They are of major importance as pharmacological targets for anxiolytics (e.g. benzodiazepines), schizophrenia, and sleep aids. At least nineteen different individual GABA A receptor subunits assemble into pentameric structures in different combinations to form the native receptor ( α1-6, β1-3, ɣ1-3, δ, ρ1-3, plus minor subunits). When activated, these receptor/channels conduct a Cl- current that desensitizes at higher GABA concentrations, with a characteristic rate for different subunit combinations. Receptors containing α1-5 subunits, any β subunits, and the ɣ2 subunit are the most prevalent in the brain. These receptors are sensitive to benzodiazepine modulation. The search for subtype-selective drugs for GABA A channels has been hampered by the lack of suitable high throughput electrophysiology platforms with the ability to interrogate ligand gated channels.
IonFlux Mercury is the recognized gold standard for GABA A screening. Features include:
Continuous flow of solutions prolongs the length and stability of recordings
In-plate exchange of solution enables parallel and fast exchange of solutions
No dependence on intra-assay liquid handling; eliminates pipetting noise and enables solution exchange during recording
Inward Cl- current from one ensemble of cells exposed to GABA with increasing concentrations (1μM to 100μM)
Rapid change of solutions during GABA current activation sweeps.