Somatotopy of the lateral line projection in larval zebrafish

We examined the topography of the lateral line primary projection in zebraf ish larvae by double labeling. The projections of two identified neuromasts of the posterior lateral line are seen as two separate sets of fibers that show reproducible spatial relationships: the projection of the anterior ne uromast is always ventrolateral to that of a more posteriorly located neuro mast. The same rule applies to the projection of anterior lateral line neur omasts. The position of the neuromasts along the antero posterior axis of t he fish therefore is represented in the central projection of the sensory n eurons. This somatotopy is similar to, and may be at the origin of, the ton otopic projection of the cochlear hair cells in mammals.