125I-lysergic acid diethylamide binds to a novel serotonergic site on rat choroid plexus epithelial cells
Journal of Neuroscience – December 01, 1985
Source: OpenAlex
Summary
A novel serotonergic binding site in the rat choroid plexus exhibits a remarkable density of 3,100 fmol/mg of protein, ten times higher than any other serotonergic site in brain tissues. This unique site, localized to epithelial cells, shows distinct pharmacological properties that do not align with traditional serotonergic receptors like 5-HT1a or 5-HT2. Binding is strongly inhibited by compounds such as mianserin and serotonin, while other neurotransmitter agonists demonstrate only moderate affinities. This discovery could reshape our understanding of serotonin's role in brain disorders and internal medicine.
Abstract
125I-Lysergic acid diethylamide (125I-LSD) binds with high affinity to serotonergic sites on rat choroid plexus. These sites were localized to choroid plexus epithelial cells by use of a novel high resolution stripping film technique for light microscopic autoradiography. In membrane preparations from rat choroid plexus, the serotonergic site density was 3100 fmol/mg of protein, which is 10-fold higher than the density of any other serotonergic site in brain homogenates. The choroid plexus site exhibits a novel pharmacology that does not match the properties of 5-hydroxytryptamine-1a (5-HT1a), 5-HT1b, or 5-HT2 serotonergic sites. 125I-LSD binding to the choroid plexus site is potently inhibited by mianserin, serotonin, and (+)-LSD. Other serotonergic, dopaminergic, and adrenergic agonists and antagonists exhibit moderate to weak affinities for this site. The rat choroid plexus 125I-LSD binding site appears to represent a new type of serotonergic site which is located on non-neuronal cells in this tissue.