Adrenergic nerves to the eye and to related structures in man and in the cynomolgus monkey (Macaca irus)

The number of adrenergic nerves in the •primate eye (Homo and cynomolgus monkey) is generally less than that seen in many lower mammals, as revealed by the fluorescence technique of Falck and Hillarp. Adrenergic nerves were found, in various numbers, to reach the limbus corneae, scleral aqueous drainage channels, dilator pupillae, sphincter pupillae, ciliary muscle, ciliary part of the nveal meshwork of the chamber angle, chorioid, lacrimal gland, tarsal muscle, and smooth muscles of the gland of Meibom. In the ciliary ganglion, monoaminecontaining neurons can be found under certain conditions. The perivascular sheath of adrenergic nerves has a peculiar spacious arrangement in the iris, similar to that found in the iris of other mammals. In some of the iridic vessels, adrenergic fibers are found throughout the smooth musculature. Varicose adrenergic nerves can be found to a considerable extent in nerve trunks as they approach their target organs. The retina contains a layer of adrenergic fibers between the inner nuclear and plexiform layers. Adrenergic cell bodies are found in the inner nuclear layer and, to a lesser extent, in the ganglion cell layer. No adrenergic fibers or cells were identified in the scleral trabeculae, at the canal of Schlemm, in the sclera proper, or in the optic nerve.