Pentobarbital promotes bursts of gamma-aminobutyric acid-activated single channel currents in cultured mouse central neurons.

The extracellular patch clamp method was used to study the influence of pentobarbital (PB) on membrane channels induced by gamma-aminobutyric acid (GABA) in cultured mouse spinal neurons. PB (200 microM) increased the probability of finding GABA-sensitive channels in the open state; it also increased the average frequency at which GABA-induced single channel currents occur, without decreasing the number of data sweeps which showed no single channel activity. These results indicate that PB potentiates GABA responses by promoting burst-like openings of the GABA-sensitive channel.