RS-Zopiclone: Oral, 5 mg to 7.5 mg at bedtime.

To study the effects of Zopiclone , GABA currents were repeatedly elicited by puffer application of 3 mkM GABA every 12 s, and test substances were applied by bath perfusion. A pressurized (10 p.s.i.) puffer pipette (~2 mkm tip diameter) was positioned near the recorded cell, and GABA (3 mkM) was applied by opening a computer-controlled solenoid valve (50–100 ms). This activated a peak inward current (200–2000 pA) that rapidly decayed. Because the small volume of GABA released from the puffer pipette was rapidly diluted in the external bath, the neurons were exposed to a maximum concentration of <3 mkM GABA. This is less than the EC50 of GABA for native and cloned GABAA receptors and provided a reliable starting point to measure potentiation of the current by positive allosteric modulators. Drugs were applied for 3 min (15 evoked GABA currents), which was sufficient for an equilibrium response to be established. Drugs were washed out for at least 3 min. If the GABA current recovered to predrug control amplitude, a higher concentration of drug was applied