VISUAL-EVOKED POTENTIALS AND NITROUS OXIDE-INDUCED NEURONAL DEPRESSION - ROLE FOR BENZODIAZEPINE RECEPTORS

We have examined the role of benzodiazepine receptors In nitrous oxide -induced neuronal depression in rats. The changes in neuronal excitabi lity induced by nitrous oxide and the benzodiazepine inverse agonist, Ro15-4513, were monitored by measurement of visual evoked potentials ( VEP). Administration of Ro15-4513 10 mg kg(-1) i.p., in rats breathing air, did not affect the amplitude or latency of VEP. However, the sam e concentrations of Ro15-4513 antagonized nitrous oxide-induced depres sion of VEP amplitudes. We conclude that antagonism of nitrous oxide-i nduced depression by Ro15-4513 indicates that at least part of the dec reased neuronal excitability caused by nitrous oxide could be ascribed to interactions with the GABA(A) receptor complex.