This study was conducted on 16 adult specimens of molly fish (Poecilia sphenops) to investigate
ependymal cells (ECs) and their role in neurogenesis using ultrastructural examination and
immunohistochemistry. The ECs lined the ventral and lateral surfaces of the optic ventricle and their
processes extended through the tectal laminae and ended at the surface of the tectum as a subpial
end-foot. Two cell types of ECs were identified: cuboidal non-ciliated (5.68 0.84/100 m2) and
columnar ciliated (EC3.22 0.71/100 m2). Immunohistochemical analysis revealed two types of
GFAP immunoreactive cells: ECs and astrocytes. The ECs showed the expression of IL-1, APG5,
and Nfr2. Moreover, ECs showed immunostaining for myostatin, S100, and SOX9 in their cytoplasmic
processes. The proliferative activity of the neighboring stem cells was also distinct. The most
interesting finding in this study was the glia–neuron interaction, where the processes of ECs met the
progenitor neuronal cells in the ependymal area of the ventricular wall. These cells showed bundles
of intermediate filaments in their processes and basal poles and were connected by desmosomes,
followed by gap junctions. Many membrane-bounded vesicles could be demonstrated on the surface
of the ciliated ECs that contained neurosecretion. The abluminal and lateral cell surfaces of ECs
showed pinocytotic activities with many coated vesicles, while their apical cytoplasm contained
centrioles. The occurrence of stem cells in close position to the ECs, and the presence of bundles of
generating axons in direct contact with these stem cells indicate the role of ECs in neurogenesis. The
TEM results revealed the presence of neural stem cells in a close position to the ECs, in addition to
the presence of bundles of generating axons in direct contact with these stem cells. The present study
indicates the role of ECs in neurogenesis.