Cerebrospinal fluid total volume

After i.c.v. injection, the rate of elimination from the CNS compartment is dominated by cerebrospinal fluid dynamics. The CSF, which is secreted by the choroid plexus epithelium across the apical membrane, circulates along the surface and convexities of the brain in a rostral to caudal direction. It is reabsorbed by bulk flow into the peripheral bloodstream at the arachnoid vUh within both cranial and spinal arachnoid spaces [62]. Of note is that the turnover rate of total CSF volume is species dependent and varies between approximately... 

An assay should be validated using the same biological matrix as the study samples. If a matrix has limited availability, a suitable substitute may be used (e.g., plasma ultrafiltrate to substitute cerebrospinal fluid) for the preparation of standard (STD) calibrators. When spiking solution is needed to prepare STDs and Quality controls (QCs) in matrix, the spiking volume should be less than 5 % of the total volume of the matrix. 

The brain contains grey matter and white matter substances that are easily distinguished upon gross examination. Grey matter contains a densely packed network of neural cell bodies and associated glial cells, whereas white matter contains myelinated axonal tracts, relatively few neuronal cell bodies, and a supporting environment of glial cells. The entire brain is surrounded by cerebrospinal fluid contained within an extensive ventricular system that occupies approximately one-tenth of the total brain volume. The ventricular system supports the brain as well as the spinal cord, and provides nutrients to and removes waste products from the central nervous system. 

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