Neuronal Organization of the Telencephalon in the Chum Salmon Onchorhynchus keta

This paper presents original data on the neuronal composition of various regions of the pallium of the telencephalon in Oncorhynchus keta. This study was carried out using routine neurohistologic techniques. Four basic areas were distinguished within the pallium: medial, dorsal, central, and lateral. The central pallium exhibited the most complicated cytoarchitectonics. In the central and lateral areas, pyramidal-like neurons with a well-developed dendritic spine apparatus were found. These were allodendritic cells, which appeared to be comparable to the pyramidal neurons of higher vertebrates in a number of features. Horizontal neurons and isodendritic radial neurons were also encountered. These cell types occurred in the ventral part of the central area and in the lateral area.