INNERVATION OF THE SUPERIOR TARSAL (MULLER) MUSCLE IN THE CYNOMOLGUS MONKEY - A RETROGRADE TRACING STUDY

Purpose. The retrograde transport of wheat germ agglutinin-horseradish peroxidase (WGA/HRP) was used to study the localization of the neuron s that innervate the superior tarsal muscle in the cynomolgous monkey. Methods. A 5-10% WGA-HRP solution was applied to the medial part of t he superior tarsal muscle. Seventy-two hours later, the animals were k illed and perfused with fixative. Results. The WGA-HRP-labeled neurons were localized in the ipsilateral trigeminal ganglion, the ipsilatera l pterygopalatine ganglion, and the ipsilateral superior cervical gang lion. The labeled somata of the sensory neurons were all found in the ophthalmic ganglionic part and the ophthalmic nerve part of the ipsila teral trigeminal ganglion. Most of the labeled somata were distributed somatotopically in the dorsal region of the ophthalmic part of the ga nglion. The labeled somata of the sympathetic neurons were all located in the ipsilateral superior cervical ganglion. Most of these labeled somata, which were distributed somatotopically, were found in the cran ial part of the ganglion. The labeled somata of the parasympathetic ne urons were all located in the ipsilateral pterygopalatine ganglion, pa rticularly in the central ovoid part of the ganglion. No labeled neuro ns were detected in the ipsilateral parasympathetic ciliary ganglion, the ipsilateral nodose ganglion, or the first three ipsilateral sensor y spinal ganglia; labeled somata could not be detected in any of the c ontralateral ganglia examined. Conclusions. A complete documentation o f all projections of the superior tarsal muscle in the monkey has been presented, and convincing data has been given about the parasympathet ic innervation of Muller's muscle.