Dual Cytology, Cellular Death and Their Significance in the Proximal Ganglionic Complex: An Investigation Through the Ontogeny of the Chick Gallus Gallus Domesticus

摘要

Chick embryos at different stages of development till hatching, as well as the adult tissues were fixed in formol-saline. Serial sections of 8-10 microns thickness were stained by cresyl fast violet to analyse the results in the proximal ganglionic complex of the cranial nerves IX and X. The dark cells are considered as active and the light cells are considered as inactive, resting, dying or degenerating ones. Cell death is most prominent and common among the small and medium sized ones; possibly it is during these stages of cellular growth, peripheral and central processes (of axons) begin to grow from the cell body and get established in their projection fields. The tiny cells are always dark; the very-small cells are also usually dark during the embryonic development till E18. The light cells have appeared among this group of cells just on the day of hatching. When cells fail to establish functional connections and are no more needed, they tend to become inactive, begin to die and disappear from the ganglion. It is assumed that the time of appearance of the light cells might be related to the onset of establishment of functional connections of neurons and to the functional importance of the organs that it supplies