Innervation of the palpebral conjunctiva and the superior tarsal muscle in the cynomolgous monkey: a retrograde fluorescent tracing study.

Retrograde fluorescent transport of Fast Blue (FB) and Diamidino Yellow (DY) was used to study the localisation of neurons that innervate the palpebral conjunctiva and the superior tarsal muscle in the cynomolgous monkey. Labelled cell bodies of sensory neurons including a few double labelled cell bodies were found in the ophthalmic part of the ipsilateral trigeminal ganglion. Labelled cell bodies of the sympathetic neurons including a few double labelled cell bodies were located in the middle and cranial part of the ipsilateral superior cervical ganglion, with a few in the contralateral ganglion. Labelled cell bodies of the parasympathetic neurons were all found in the ipsilateral pterygopalatine ganglion and randomly distributed. Neurons were disposed in the opthalmic part of the trigeminal and superior cervical ganglia, whereas parasympathetic neurons were distributed randomly. Cells of the nodose, ciliary, geniculate, otic and first 3 spinal ganglia were unlabelled. Tracing FB and DY from the palpebral conjunctiva and superior tarsal muscle respectively, revealed double labelled neurons in the trigeminal and superior cervical ganglia, probably indicating the presence of collaterals of axons serving both the palpebral conjunctiva and the superior tarsal muscle.