Immunohistochemical demonstration of L-serine distribution in the rat brain

L-Serine has been suggested by in vitro studies to be an important neurotro phic factor which supports survival and neurite outgrowth of neurons. It is also a precursor of D-serine, a putative neurotransmitter. In the present study, we raised antibodies against L-serine in a rabbit and examined immun ohistochemical distribution of the amino acid in the rat brain. In the hipp ocampus and the cerebellar cortex, where neurotrophic effects of L-serine h ave been indicated, L-serine immunoreactivity was found primarily in astroc ytes. In the brain stem, where neuronal distribution of D-serine was report ed, positive staining for L-serine wag located primarily in neurons. Region al differences of cellular distribution of L-serine were indicated. NeuroRe port 12:1027-1030 (C) 2001 Lippincott Williams & Wilkins.