DS-1 is a drug from the imidazopyridine family, which is the first drug developed that acts as a GABA<sub>A</sub> receptor positive allosteric modulator (PAM) selective for the ñ4ò3ô subtype, which is not targeted by other GABA<sub>A</sub> receptor PAMs such as the benzodiazepines or other nonbenzodiazepine drugs. Novel selective drugs such as DS-1 are useful in the study of this receptor subtype.