Central projections of the lateral line nerves of Chelon labrosus (teleosts, order Perciformes).

The central projections of the anterior and posterior lateral line nerves were studied in the advanced teleost Chelon labrosus using silver staining techniques and anterograde axonal transport of horseradish peroxidase. The anterior lateral line nerve consists of two separated roots, dorsal and ventral. Both roots form descending and ascending tracts ending ipsilaterally in the octavolateral area and the granular eminence of the cerebellum. The posterior lateral line nerve enters the medulla oblongata in a single root originating ascending and descending tracts. Most of its fibres end in the octavolateral area whereas others reach the granular eminence dorsally to the anterior lateral line fibres. Contralateral projections of the lateral line nerves were not found. Lateral line fibres course below the cerebellar crest of the octavolateral area. They were never found ascending to the cerebellar crests as climbing-like fibres. The two neuron types found in the lateral are, Purkinje-like and oval shaped cells, have a different distribution pattern.