Midazolam does not affect the field potentials in the caudal part of the spinal trigeminal nucleus.

The effect of midazolam on the field potentials (FPs) in the caudal part of the spinal trigeminal nucleus following strong electrical stimulation of the upper lip was investigated in Wistar albino rats. The rats received i.p. dosages of 5, 10, or 20 mg/kg midazolam, or physiological saline. Relative amplitudes of the negative deflection were not suppressed after midazolam injection. No significant differences were found in the latencies of the potentials before and after midazolam injection. It is suggested that the main action site of midazolam may be located at a higher level than the spinal trigeminal nucleus.