[Principles of the structural organization of the cetacean neocortex].

The investigations performed demonstrate that morphologically cetacean neocortex is organized on the same principles as that of other mammals, as it has six layer structure, layer IV including. The results of investigations done for many years gave the possibility to establish quantitative characteristics of neocortex in different zoological cetacean genera, such as volume of neocortex, total number of its nervous cells (for dolphin the data were obtained for the first time), and clarify the problem fully enough. It became clear that morphologically dolphins belong to different genera. Three quantitative gradations of morphological enrichment of the dolphin neocortex are demonstrated. The only genus of Tursiops (bottle-nosed) can be compared with man, as to on what neuromorphological criteria it is behind, equal and surpasses the man. Representatives of the two other genera investigated, according to all neuromorphological indices studied, are far behind the man.