Ultrastructure of lateral line organs in aneurogenic amphibian larvae (Ambystoma).

An ultrastructural study was performed to determine the ability of presumptive lateral line tissue in A. maculatum embryos to migrate and differentiate in the absence of all sensory innervation. In experimental animals, all presumptive neural tissue was surgically removed at Harrison's stage 24, leaving only the posterior portion of the post-auditory placode. At later stages, completely differentiated aneural lateral line organs were found in the midbody region of the larvae. These were morphologically similar to those of control larvae. No signs of atrophy or degeneration of the neuromasts were seen even after several weeks of nerve-free conditions.