SSD114 is a novel GABAB receptor positive allosteric modulator.

In conditions containing 10 μM GABA, 25 μM SSD114 hydrochloride significantly increased the level of [35S]GTPγS activation induced by GABA alone to approximately 170% of basal levels.SSD114 hydrochloride (15 or 30 μM) caused a shift in the GABA concentration-response curve to the left and at the highest concentration slightly increased the maximal stimulatory effect of GABA. In the co-presence of 15 and 30 μM SSD114 hydrochloride, the EC50 of GABA was reduced by 2-fold and 2.5-fold, respectively, while the maximal stimulatory effect (Emax) was enhanced only at the 30 μM concentration to 161 ± 5.09% of the basal value [1].

SSD114 hydrochloride pretreatment significantly shortened the onset time of the loss-of-orientation reflex (LORR) [F(5,30)=4.55, P<0.005]. Follow-up analyses showed that the onset time of LORR was significantly shorter in the group of mice that received pretreatment at doses equal to or higher than 10 mg/kg SSD114 hydrochloride compared to the control group. In addition, SSD114 hydrochloride pretreatment prolonged the duration of LORR [F(5,30)=4.81, P<0.005]. Follow-up analysis indicated that the LORR duration was significantly prolonged in the group of mice receiving 10 and 100 mg/kg SSD114 hydrochloride pretreatment compared to the control group [1].