Noneffectiveness of midazolam on the thalamic-evoked responses in ventrobasal complex

The effect of midazolam on the rat thalamic-evoked responses in ventrobasal complex following strong electrical stimulation of the upper lip was investigated. The animals received i.p. doses of 5, 10, 20 mg/kg midazolam, or physiological saline. Relative amplitudes of the large negative potentials, which were considered to be an excitation of ventrobasal cells, were not suppressed after midazolam injection. No significant differences were found in latencies of the potentials before and after administration of the drug. It is suggested that the effective sites of midazolam may not be located at a diencephalon level.