What is a Tanycyte?
Tanycytes are nutrient-sensing cells that line the third ventricle within the hypothalamus. These data provide further evidence that tanycytes are an integral link between CSF nutrients and the hypothalamic neuronal networks that regulate appetite and energy balance.
Is glia a Tanycyte?
Tanycytes, glial-like cells that line the third ventricle, are emerging as components of the hypothalamic networks that control body weight and energy balance. They contact the cerebrospinal fluid (CSF) and send processes that come into close contact with neurons in the arcuate and ventromedial hypothalamic nuclei.
What are ependymal cells derived from?
Ependymal cells, similar to all other neuroglia, are derived from a layer of embryonic tissue known as neuroectoderm. Ependymal cells and their epithelial derivatives of the choroid plexus have several important functions.
Are tanycytes ependymal cells?
Tanycytes, highly specialized ependymal cells that have long cellular processes extending into parenchyma, have been described mainly in the ME/Arc of the hypothalamus14,38. Tanycytes are able to transport molecules between the blood and cerebrospinal fluid without the BBB leaky14.
What are protoplasmic astrocytes?
Protoplasmic astrocytes posses highly branched bushy processes and are widely distributed in the gray matter. They extend endfeet to blood vessels and enwrap them to form the glial limiting membrane, which is the outermost wall of the blood brain barrier (BBB).
What are microglia derived from?
The embryonic origin of microglia is distinct from other types of neuroglia. Whereas other neuroglia are derived from an embryonic layer of tissue known as neuroectoderm, which gives rise to nervous tissue, microglia are derived from embryonic mesoderm, which gives rise to cells of the blood and immune system.
What are astrocytes derived from?
Astrocytes are derived from heterogeneous populations of progenitor cells in the neuroepithelium of the developing central nervous system. There is remarkable similarity between the well known genetic mechanisms that specify the lineage of diverse neuron subtypes and that of macroglial cells.
What is subfornical organ?
The subfornical organ (SFO) is a circumventricular organ recognized for its ability to sense and integrate hydromineral and hormonal circulating fluid balance signals, information which is transmitted to central autonomic nuclei to which SFO neurons project.
Is the pineal gland a circumventricular organ?
The pineal gland, neurohypophysis and the median eminence lack the presence of neurons that are present in the rest of the circumventricular organs. Most of the circumventricular organs are lined by ependymal cells except the pineal and the neurohypophysis.
What is a tanycyte?
A variety of ependymal cell found principally in the walls of the third ventricle of the brain; the tanycytes may have branched or unbranched processes, some of which end on capillaries or neurons. Want to thank TFD for its existence? Tell a friend about us, add a link to this page, or visit the webmaster’s page for free fun content .
Where are tanycytes found in the brain?
Third ventricle wall in the brain of an immature rat. A tanycyte coexpressing CuZn SOD and GFAP is marked by the arrow. Tanycytes are special ependymal cells found in the third ventricle of the brain, and on the floor of the fourth ventricle and have processes extending deep into the hypothalamus.
Are tanycytes neural stem cells?
If tanycytes really are neural stem cells, they must be able to generate other cell types in the hypothalamus. In one of the first studies to address this problem, an adenoviral green fluorescent protein (GFP) construct was injected into the third ventricle to label tanycytes and ependymal cells [64].
Are tanycytes the descendants of radial glia cells?
Tanycytes also contain many proteins not found in radial glia cells. Thus, evidence now suggests that tanycytes are genealogical descendants of radial glia cells that do not develop into astrocytes, but rather into their own subpopulation. Tanycytes in adult mammals are found in the ventricular system and the circumventricular organs.