Consecutive demonstration of nerves containing catecholamine and acetylcholinesterase in the rat cornea

The innervation of the cornea of newborn (two day old) and adult rats was investigated using glyoxylic-acid-induced fluorescence (GIF) for catacholamines and subsequent acetylcholinesterase reaction. Fluorescent nerve were observed around the limbal vessels and in the pericorneal nerve plexus, from which they branched towards the central parts of the cornea. The fluorescent corneal nerves were either nonvaricose or had varicosities at intervals of 10 micra. When the animals had been pretreated with nialamide, noradrenaline and propranolol, some fluorescent branching nerve terminals with numerous varicosities also appeared. All fluorescent nerves disappeared two days after ipsilateral superior cervical sympathectomy. When the acetylcholinesterase (AChE) reaction was performed subsequently to the GIF reaction the following nerve types could be identified: 1. nerves containing both catecholamine (CA) fluorescence and AChE, 2. Nerves containing only AChE.