Depolarizing actions of convulsant barbiturates on isolated rat dorsal root ganglion cells

The actions of convulsant barbiturates were studied on dorsal root ganglion (DRG) cells in vitro using intracellular recording techniques. Only the convulsant barbiturates (+)-DMBB and CHEB produced a concentration-dependent depression in the responses to gamma-aminobutyric acid (GABA). All convulsant barbiturates were found to produce a direct depolarization of the DRG cell membrane which was accompanied by a decrease in the input resistance of the cell and a reduction in the orthodromic action potential. A sub-population of DRG cells were found to be refractory to these actions but there was no relationship between the cell type (A beta, A delta and C) and ability to respond to the convulsant barbiturates.