Structural Determinants for the Mode of Action of the Imidazopyridine DS2 at d-containing g-Aminobutyric Acid Type A (GABAA) Receptors

A SAR study of the delta-selective positive modulators DS2 was performed to assist the quest for the binding site. The modulatory effect was measured using a fluorometric inaging plate reader (FLIPR) membrane potential (FMP) functional assay. Specific positions in the structural scaffold of DS2 was found to severly affect the pharmacological profile. Analogs superior to DS2 were identified displaying higher potency and selectivity for the alfa4beta1delta over alfa4beta1gamma.