Morphology and Subtypes

Structurally, ependymoglial cells are characterized by different types of processes that are determined by contact with various microenvironmental compartments. The type I process is a feature of every ependymoglia cell. The endfoot comes into contact with a fluid or space into which extend many microvilli. The apical pole contains abundant mitochondria, which indicates a high level of metabolic activity. Another characteristic of apical processes in some but not all ependymoglia is the presence of kinocilia, a simple cilia consisting of a ring of nine pairs of tubules. Type 1 processes are interconnected by various types of apicolateral junctions. In regions where no endo-thelial blood-barrier exists, ependymoglia cells form a cerebrospinal fluid (CSF) barrier by the expression of tight junctions. Ependymoglial type 2 processes are characterized by basal mesenchymal contact and a cytoskeleton with abundant intermediate filaments. These filaments consist primarily of vimentin when the endfoot is in contact with CSF, but they consist primarily of GFAP when in contact with a blood vessel. The basal processes extend to the basal lamina of the mesenchymal layer underlying the nervous epithelium, forming processes of type IIa. Processes extending to the basal lamina of blood vessels are termed type IIb. Type III processes are defined by contact with neurons. These processes are characterized by the formation of flat or lamellar sheaths that enclose the neuronal somata (type Ilia), synapses (Illb), or axonal internodes (IIIc1) or by finger-like extensions that contact the nodal specializations of axons (IIIc2). These processes may act as stores of sodium or calcium ions and cannot be elaborated until neurons have completed their differentiation.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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