Following the finding that cereal deafferentation of developing giant interneurons in the terminal abdominal ganglion (TG) of the cricket Ache& dome&us reduces TG protein metabolism within target interneuron dendrites and somata (Meyer and Edwards, 1982), it is now shown that deafferentation alters the turnover of three macromolecules associated with cholinergic transmission in the cereal sensory-giant interneuron pathway.The labeled specific ligands 3H-quinuclidinyl benzilate and 1251-cY-bungarotoxin were used to assay populations of putative TG muscarinic and nicotinic cholinergic receptors, respectively, in control and deafferented groups of ganglia. The AChE activity of TG was also determined by assay and histochemical methods.Long-term deafferentation sustained throughout postembryonic development markedly reduces the densities of both muscarinic and nicotinic binding sites in the TG, short-term deafferentation of adult TG also leads to characteristic alterations in the properties of all three choline@ markers within several days. Rapid changes seen in adults thus correlate with ultrastructural data demonstrating loss of afferent terminals within hours of sensory appendage removal.We propose that peripheral innervation-dependent regulatory mechanisms operate in both the developing and adult insect nervous system. Such mechanisms may influence transsynaptitally the synthesis and turnover of specilic macromolecules, some of which may reside on the cell surface of insect central neurons that are part of the cereal sensory-giant intemeuron system.