ASCENDING PATHWAYS OF THE TRIGEMINAL NERVE IN CAT

Abstract

Exploration centrally with a unipolar electrode (15 - 50[mu]) while stimulating the infraorbital nerve with single shocks (0.14 msec.) was followed by locating and plotting the points of evoked activity. The ventral secondary tract followed the contralateral medial lemniscus while a dorsal pathway of rapidly conducted potentials was found bilaterally just lateral to the medial longitudinal fasciculus in the midbrain. These pathways were traced to the thalamus where nuclear areas and single units fired repetitively. Single unit potentials from a dorsolateral band in the mid-brain including the internal gray stratum of the superior colliculus were evoked by both ipsilateral and contralateral stimulation.