THE EFFECTS OF GINKGOLIDE-B (BN52021) ON GUINEA-PIG VESTIBULAR NUCLEUS NEURONS IN-VITRO - IMPORTANCE OF CONTROLLING FOR EFFECTS OF DIMETHYLSULFOXIDE (DMSO) VEHICLES

The present study investigated the effects of the platelet-activating factor (PAF) receptor antagonist, ginkgolide B, on guinea pig medial v estibular nucleus (MVN) neurons in vitro and addressed the potential p roblem of using dimethylsulphoxide (DMSO) as a solvent. Using DMSO as a solvent, 10(-10), 10(-8) and 10(-4) M ginkgolide B had no effect on extracellularly recorded MVN neurons in brainstem slices in vitro. Usi ng 10(-6) M ginkgolide B, 50% (5/10) of MVN neurons exhibited a decrea se in firing rate and 10% (1/10) of neurons responded with an increase in firing rate. While attempting to control for possible DMSO vehicle effects, 40% (4/10) of MVN neurons displayed a decrease in firing rat e when ginkgolide B (10(-6) M) was presented before the DMSO control s olution. When the DMSO vehicle was presented first, only 10% (1/10) re sponded similarly. In some cases the DMSO vehicle alone also produced a decrease in MVN neuron firing rate. These results emphasise the impo rtance of using adequate DMSO control conditions in ginkgolide researc h. Copyright (C) 1996 Elsevier Science Ireland Ltd