[Responses of premotor neurons for the trigeminal motor nucleus to stimulation of the cortical masticatory area and natural stimulation of the oral-facial area].

The premotor neurons for the trigeminal motor nucleus were recorded in the supratrigeminal region and parvocellular reticular formation. The responsiveness of these neurons were tested to electrical stimulation of the cortical masticatory area and to natural stimulation applied to the oral-facial area. Fourteen neurons were recorded in the supratrigeminal region and 16 neurons in the reticular formation. A greater number of neurons activated by stimulation of the cortical masticatory area was found in the reticular formation than in the supratrigeminal region. The latency of cortically induced responses of supratrigeminal neurons was longer than that of the neurons of reticular formation. Tactile stimulation of oral-facial area activated 14% of 14 supratrigeminal neurons, which would be including inhibitory relay neurons for the masticatory motoneurons. This result indicate that the many neurons with other functions would be existed in the supratrigeminal region.