THE CEREBRAL EXPRESSION OF PLASMA-PROTEIN GENES IN DIFFERENT SPECIES

The cerebrospinal fluid (CSF) contains the same proteins as blood plas ma, but with a different pattern of concentrations, Protein concentrat ions in CSF are much lower than those in blood, CSF proteins are deriv ed from blood or synthesized within the brain, The choroid plexus is a n important source of CSF proteins, Transthyretin is the protein most abundantly synthesized and secreted by choroid plexus, It determines t he distribution of thyroxine in the cerebral compartment, Synthesis of transthyretin first evolved in the brain, then later it became a plas ma protein synthesized in the liver, Other proteins secreted by choroi d plexus are serum retinol-binding protein, transferrin, caeruloplasmi m, insulin-like growth factors, insulin-like growth factor binding pro teins, cystatin C, alpha(1)-antichymotrypsin, alpha(2)-macroglobulin, prothrombin, beta(2)-microglobulin and prostaglandin D synthetase. Spe cies differences in expression of the genes for these proteins are out lined, and their developmental pattern, regulation and roles in the ce rebral extracellular compartment are discussed.