Some connections of the area octavolateralis of Pleurodeles waltlii. A study with horseradish peroxidase under in vitro conditions.

Horseradish peroxidase application in exsanguinated, pre-perfused newts, Pleurodeles waltlii, appeared to be very useful to study the connections of the area octavolateralis. Efferents from the octavolateral area course via bilateral lemnisci to the tectum and a presumptive torus semicircularis in the midbrain. Additional projections to the oculomotor nuclei, cerebellum, reticular formation, contralateral octavolateral area, and spinal cord were observed. The area octavolateralis receives inputs from the cerebellum and the contralateral octavolateral area. It is concluded that the octavolateral second order projections in Pleurodeles waltlii resemble in many respects those reported for other vertebrates that possess a complete octavolateralis system.