Developmental effects of barium in planaria

An investigation was carried out of the stage-specific effects of barium, a wide spectrum potassium channel blocker that depolarizes cells, on planaria embryologic development. Barium exposure triggered a variety of axes abnormalities in planaria, including dorsoventral malformations (formation of pigmented dorsal bulges, suggestive of BMP up-regulation), anteroposterior abnormalities (two-headed worms with two eyes or a single eye on each end, worms with an ectopic anterior partial body embedded diagonally within the main body of the planaria), and other congenital anomalies (baby worms with extremely short bodies, worms with multiple eyes or with a strange tubular structure emerging from the malformed eyes). The implications of these findings for current understanding of planaria development are discussed.