Microscopic focus on ependymal cells of the spinal cord of the one-humped camel (Camelus dromedarius): Histological, immunohistochemical, and transmission microscopic study

The current study was designed to give a complete microscopic description of the ependymal cells of the one-humped camel (Camelus dromedarius) using histological, immunohistochemical, and transmission microscopic descriptions of the ependymal cells of the fresh 35 spinal cord samples immediately after their slaughtering. In our findings, the central canal of the spinal cord was lined by multilayered stratified cuboidal or columnar ependymal cells. The ependymal cells had an irregular striated border at their free surface. The ependymal cells do not exhibit a basement membrane. The simple oval nucleus was occupied a large part of the cell with spherical mitochondria. The apical surface of the ependymal cells possesses long cilia; each cilium was bounded by an evagination of the luminal plasma membrane. Some ependymal cells had minute finger-like projections on their luminal plasma membrane. In the perinuclear zone of ependymal cells, many cristiform mitochondria, free ribosomes, and Golgi complexes usually occur. Vacuoles with homogenous and clear fluid were observed. The lateral surface of the adjacent ependymal cells exhibits several tight junctions represented by zonulae occludens and adherens. There were many desmosomes between the neighboring ependymal cells. A perinuclear whorl of filaments fills the lateral part of these ependymal cells. The ependymal cells revealed a clear immunohistochemical reaction with proliferating cell nuclear antigen and nestin stain. There were no obvious differences between the different segments of the spinal cord. Our data concluded that the ependymal cells display clear differences in anatomy as well as ultrastructure that may reflect their distinct functional activity.