ACETYLCHOLINE RECEPTORS IN THE CILIARY GANGLION AND IN THE IRIS MUSCLE OF THE CHICK: SPECIFIC BINDING AND EFFECT ON THE SYNAPTIC TRANSMISSION OF THE NEUROTOXIN FROM Naja naja siamensis

Open Access
Publisher Website
Google Scholar
Abstract
1 A specific binding of Naja naja siamensis neurotoxin was found both in the iris and in the ciliary ganglion of the chick. 2 Naja-toxin (125 nm) caused a complete block of the iris muscle contraction induced by carbamyl-choline. 3 Naja-toxin had a different effect on the two neuronal populations present in the ganglion: it blocked the synaptically evoked response of the ciliary cells, while the response of the choroid ones was only slightly reduced. The effects were the same in a wide range of concentrations (125 to 2500 nm). 4 The results obtained in the iris show the existence of an acetylcholine receptor population similar to the nicotinic receptor of the skeletal muscle. 5 In the ciliary ganglion the results confirm the existence of different acetylcholine receptors on the two cell types.