Effects of Nicotinic Antagonists on the Development of the Chick Lumbar Sympathetic Ganglia, Ciliary Ganglion and Iris

Publisher Website
Google Scholar
Abstract
The effects of in ovo injections of nicotinic blockers on the development of two neuronal systems in the chick embryo have been examined. Chlorisondamine, a ganglionic blocking drug, caused a long-term hypotrophy in both the ciliary ganglion and the lumbar sympathetic ganglia. Choline acetyltransferase activity was reduced in both ganglia while cholinesterase activity was reduced in the ciliary ganglion. Development of the iris, the end organ of the ciliary ganglion, was not significantly altered by chlorisondamine. α-Bungarotoxin injections delayed development in the striated iris muscle, while having little effect on the ontogeny of the ciliary and sympathetic ganglia. While normal synaptic transmission does not appear to be essential for the survival of developing neurons, blocking postsynaptic receptors significantly altered the developmental course in the ganglia after ganglionic receptor blockade and in the iris after neuromuscular junction receptor blockade. Thus, synaptic transmission may play a regulatory role in the process of synaptogenesis.