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

¹²⁵I-Labeled α-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 the neuropil of normal lobes and to rudiments of these regions in deafferented lobes. These findings suggest that receptors can develop in the insect central nervous system independently of normal synaptic influences.