[Effect of benzodiazepines on interneuronal transmission in afferent systems and their antagonism with Ro 15-1788].

: The tranquilizers diazepam and phenazepam inhibited the responses in ventrolateral columns and segmental polysynaptic potentials in the spinal cord evoked by electrical stimulation of somatic nerves. The drugs also inhibited the responses in somavisceral and associative areas of the brain cortex, in specific, associative and nonspecific nuclei of the thalamus and mesencephalic reticular formation evoked by stimulation of visceral and somatic nerves as well as by sound and photostimulation. Diazepam and phenazepam inhibited cortical responses to single and pair stimulation of the fibers of thalamocortical radiation. Ro 15-1788 which is a specific benzodiazepine antagonist promoted the recovery of bioelectrical responses decreased by diazepam and phenazepam. It is suggested that the inhibitory action of diazepam and phenazepam on interneuronal transmission in afferent systems is realized via the involvement of benzodiazepine receptors.