GABAA receptors, the major inhibitory receptors in the brain, serve as targets of numerous classes of clinically important drugs. Benzodiazepines allosterically enhance the action of GABA at GABAA receptors through binding the high affinity benzodiazepine- binding site and thus, increase the channel opening frequency. Their five core properties, the anxiolytic, amnestic, muscle-relaxant, sedative-hypnotic and anticonvulsive effects, are mediated by the Diazepam-sensitive subtypes of GABAA receptors, but cannot be clearly separated by dosing. However, every subtype of the Diazepam-sensitive GABAA receptors is proposed to be responsible for mediating only one or two benzodiazepine properties. The sedative-hypnotic and the amnestic effect are both presumably mediated by the α1-containing subtype, and often arise as unwanted side effects. On the basis of experimentally investigated data (which relied on a so called “common binding mode”), our collaboration partner holds a patent based on the claim, that all benzodiazepine derivative holding an ethinyl as R8-residue should feature reduced affinity of the drugs to the α1-containing GABAA receptors. To test this hypothesis four systematically matched derivatives have been tested for their subtype selectivity on the Diazepam-sensitive GABAA-Rs (α1β3γ2, α2β3γ2, α3β3γ2 and α5β3γ2) using radio ligand binding assays to determine drug affinities. Data received from our experiments do not show a generally lower affinity for α1, but only for certain compounds.