Regeneration in the central nervous system of a pulmonate mollusc, Melampus

The left cerebral ganglion was ablated from 72 anesthetized, adult Melampus bidentatus (Mollusca: Pulmonata). Skin incisions were well healed and normal feeding and locomotion observed four days after surgery. Dissections of animals sacrificed weekly showed that most nerves and connectives regrew within 30 days, attaching to the swollen end of the major labial nerve. The enlarged end of this nerve later developed into a distinctive bud; some of these buds contained cell bodies as soon as 42 days after surgery. As the first known report of central nervous tissue regeneration in molluscs, this study points to the need for controls in experiments involving section or ablation of nervous tissue in molluscs.