Distribution of binding sites for 125I-labeled alpha-bungarotoxin in normal and deafferented antennal lobes of Manduca sexta.

125I-Labeled alpha-bungarotoxin has been used to determine the distribution of putative acetylcholine receptors in normal and chronically deafferented antennal lobes in the brain of the moth Manduca sexta. Toxin-binding sites are confined to synaptic regions in deafferented lobes. These findings suggest that receptors can develop in the insect central nervous system independently of normal synaptic influences.