Nerve cells in the intracranial part of the trigeminal nerve of man and dog
✓ Nerve cells histologically similar to the ganglionic cells of the trigeminal nerve were observed in the proximal part of the sensory root and in the motor root of the human trigeminal nerve. They were also seen in the sensory root of the trigeminal nerve of the dog. Counting of the nerve fibers showed doubling of the number of nerve fibers in the three divisions compared with the fibers in the sensory root adjacent to the trigeminal ganglion. There was also an increase in the number of fibers within the sensory root as it courses centrally, while a decrease was seen in the number of fibers in the proximal part of the motor root. Intermediate nerve bundles were seen leaving the motor root near the pons and joining the sensory root centrally. The fibers of the sensory root corresponding to each peripheral division maintained their specific location in the sensory root during the whole course centrally.