COMPARATIVE HISTOMETRICAL STUDY OF THE CEREBELLUM AND THE DETERMINATION OF SOME AgNOR PARAMETERS IN DIFFERENT AVIAN SPECIES

The study was carried out to determine some characteristics of silver stained nucleolus organising regions (AgNOR parameters) of the Purkinje cells and structural differences of the cortex, if any, in the cerebellum of turkeys, ducks, pigeons, and starlings. The thickness of the molecular and granular layer at the summit of the folia was the highest in pigeons, whereas the highest value of the molecular and granular layer was determined at the deep of the folia in turkeys. The highest number of Purkinje cells per unit scale was observed in pigeons and starlings. The mean sizes of the Purkinje cells were greater in turkeys than in other species. The mean area of the Purkinje cell nucleus, AgNOR area and AgNOR counts were found to be higher in turkeys. However, there was no difference in the mean ratio of AgNOR area to Purkinje cell nucleous area among the species. In conclusion, it seems that the results obtained from this study could be of particular interest to comparative biologists and physiologists.