Meprobamate is administered orally. The smallest effective individual doses should be used to avoid oversedation. Typical dose is 1.2–1.6 g daily in 3 or 4 divided doses.

All electrophysiological recordings were conducted on the stage of a Nikon Diaphot inverted phase contrast microscope at room temperature (23–25°C). Currents were monitored with either an Axopatch 1B or 200A patch clamp amplifier. Voltages corresponding to the currents were acquired with a high-speed chart recorder, and digitized for off-line analysis with the Axotape software package. The holding potential for whole-cell recordings was −60 mV unless otherwise noted. Drugs were dissolved in buffer on the day of use and applied via a nine-barrel rapid perfusion system in which all barrels (320 μm outer diameter quartz tubes; J & W Scientific, Folsom, CA) emptied via a common tip positioned within 200 μm from the tip of the patch electrode in excised patch recordings and 400 μm from the cell under study in whole-cell recordings. Flow through each barrel was gravity fed and regulated by high-speed solenoid microvalves (The Lee Co., Westbrook, CT) operated by a programmable microprocessor-based controller. Switching between solutions occurred within <10 ms (seeDonevan et al., 1992). One barrel contained buffer and the others were filled with various drugs alone and in combination. Only one valve was open at a time, and the buffer solution was applied continuously between drug applications. In the single-channel recordings, drugs were applied for 15- to 60-s epochs, separated by 30- to 60-s wash periods. In whole-cell voltage-clamp recordings from cultured rat hippocampal neurons, meprobamate enhanced GABA-evoked responses in a concentration-dependent manner with EC50 of 1.2 mM.