Ependymal tables designated for differentiation of the ependyma based on the adjacent periventricular structures

Abstract

AbstractThe ependyma, lining of the brain ventricular system, is a heterogeneous structure. The brain ventricles, including the lateral-, third-, fourth-, and mesencephalic ones and cerebral aqueduct, are covered by a single uninterrupted layer, composed of squamous to columnar ependymocytes, possessing cilia, microvilli or cytoplasmic protrusions. Small ependymal areas are considered to be functionally different and therefore, accurate and systematic classification of ependymal areas might be helpful to perform mutual comparisons of the same types of ependymal areas under different experimental conditions. Thus, the aim of the present study was to create an anatomical guide that will be able to offer an easy and repeatable technique for the selection of anatomically precisely identified small ependymal areas. For this purpose, the periventricular structures, as a stable part of brain, localized most closely to the brain ventricle walls, were chosen as reference points. Classification of the ependymal areas is presented in a form of tables, i.e. ependymal tables, which prevent of an interchange of different types of ependymal areas, avoiding of their misinterpretation. Each table brings all the information needed to localize the selected ependymal sector in 5 columns, indicating: (1) the number of the frontal sections; (2) the labelling of the ventricle walls; (3) Latin names of the periventricular structures; (4) abbreviations of the periventricular structures; and (5) the final designation of the selected ependymal areas. The final designation of a small ependymal area is composed of several letters (e.g., "LvE-ca", where Lv = lateral ventricle, E = ependyma, and ca = caudate nucleus). The proposed anatomical classification of the ependymal lining represents an original approach with more unambiguous classification of ependymal areas than is only a structural naming of ependyma. This anatomical guide will be helpful in performing of an accurate mutual comparison of the same types of ependymal areas under different experimental conditions as well as a possibility to compare mutually the data from different morphological/biochemical studies.