SSD114 is a novel GABAB receptor positive allosteric modulator.

在含有10μM GABA的条件下，25μM的SSD114 hydrochloride 显著增加GABA单独诱导的[35S]GTPγS激活水平，大约增至基础水平的170%。SSD114 hydrochloride （15或30μM）引起GABA浓度-反应曲线向左移动，并在最高浓度下轻微增加GABA的最大刺激效果。在15和30μM SSD114 hydrochloride 的共同存在下，GABA的EC50分别降低了2倍和2.5倍，而最大刺激效果（Emax）仅在30μM浓度下被增强，达到基础值的161±5.09%[1]。

SSD114 hydrochloride预处理显著缩短了失去翻正反射（LORR）的起始时间[F(5,30)=4.55, P<0.005]。后续分析表明，与对照组相比，接受等于或高于10 mg/kg SSD114 hydrochloride剂量预处理的小鼠组LORR起始时间显著缩短。此外，SSD114 hydrochloride预处理延长了LORR的持续时间[F(5,30)=4.81, P<0.005]。后续分析指出，与对照组相比，接受10和100 mg/kg SSD114 hydrochloride预处理的小鼠组LORR持续时间显著延长[1]。

Cells are transfected and seeded into 96-well microplates. 24 h after transfection, cells are washed twice with PBS and incubated in the presence or absence of SSD114 hydrochloride (different concentrations) for 15 min before substrate addition in a 96-well microplate. The Bioluminescence resonance energy transfer (BRET) ratio is calculated as the emission of YFP (530 to 570 nm) over the emission of RLuc (370 to 470 nm). The curves are fitted using Graph Pad Prism 5.0. The amplitude-weighted mean time constant is obtained by fitting the BRET recovery phase to a double exponential function [1].

Male Sprague-Dawley rats and DBA mice, weighing 200 to 250 and 20 to 25 g, respectively, are used. On the test day, mice are divided into six groups (n=6 each) matched by body weight. Mice are treated acutely and intraperitoneally with 0, 1, 3, 10, 30, and 100 mg/kg SSD114 hydrochloride and sedation/hypnosis are measured. Specifically, after baclofen injection, each mouse is placed on its back once every 60 s until it is unable to right itself within 60 s. The time between baclofen injection and the start of the 60-s interval during which the mouse is unable to right itself is measured at the onset of loss of righting reflex (LORR). Each mouse is then left undisturbed on its back until it spontaneously regained its righting reflex (determined as having at least three paws under its body). Complete recovery of the righting reflex is defined as the mouse being able to turn itself upright twice more within 60 s. If this criterion is not fulfilled, the mouse is left undisturbed until it spontaneously regained its righting reflex. The time between loss and recovery of the righting reflex is monitored in each mouse and defined as the duration of LORR. Observations are conducted by an operator unaware of the drug treatment [1].