tokens: The analogs tested were : 11 - ketopregnenolone sulphate ( an agent that is inactive at GABA ( A ) Rs and NMDARs ) , epipregnanolone ( [ 3beta - hydroxy - 5beta - pregnan - 20 - one ] sulphate , an inhibitor of both GABA ( A ) Rs and NMDARs ) , and a newly synthesized ( - ) PREGS enantiomer ( which is identical to PREGS in effects on GABA ( A ) Rs and NMDARs ) .