Organization of corneal afferent axons in the trigeminal nerve root entry zone in the cat

Experiments were carried out in cats to learn the location of sensory axons from the cornea in the trigeminal nerve root just prior to its entry into the brainstem. HRP injected into the cornea labelled these axons and indicated they were not restricted to the ophthalmic division of the nerve root as had been indicated from previous studies. These findings, if representative of other branches of this nerve, offer a partial explanation for the variable preservation of function following transection of an entire division of the trigeminal nerve root in cases of trigeminal neuralgia.