The neurotransmitter  - aminobutyric acid (GABA) occurs ubiquitously in our central nervous system (CNS) and binds, inter alia, to a class of ligand-gated ion channels called GABAA receptors. These pentameric receptors are targets of many clinically relevant drugs (e.g. benzodiazepines). The family contains many different subunits which are further classified into isoforms (e.g. 1-6, 1-3, 1-3, etc). Thus, there exists an enormous number of possible different subunit assemblies (receptor subtypes) which results in a very complex pharmacology of these receptors. Hence, the exploration of selective pharmacological tool compounds to study GABAA receptors is of great importance. This is exemplified within a case study in this presentation.