A visual thalamo-telencephalic pathway in a teleost fish (Holocentrus rufus)

Injections of large doses of horseradish peroxidase (HRP) into the telencephalon of the squirrel fish (Holocentrus rufus) revealed the first anatomical evidence for a visual thalamo-telencephalic projection in a teleost. The central optic nucleus of the thalamus appears to be the only visual thalamic nucleus projecting to the telencephalon in this species. Since the central optic nucleus has a large tectal input but not a direct one from the retina, it is suggested that a retino-geniculo-telencephalic pathway does not exist in this species.