Choroid plexus receptors

The S-HTjc receptor has highest density in the choroid plexus on epithelial cells associated with production of cerebrospinal fluid (Razos and Palacios 1985]. 5-HT2C receptors are also found in the cingulate cortex, hippocam-... 

Mitsushima D, Hei DL, Terasawa E GABA is an inhibitory neurotransmitter restricting the release of luteinizing hormone-releasing hormone before the onset of puberty. Proc Natl Acad Sci USA 91 395-399, 1994 Miura N, Nakata N, Tanaka Y, et al Improving effects of FG-7080 a serotonin reuptake inhibitor on scopolamine-induced performance deficits of memory tasks in rats. Jpn J Pharmacol 62 203-206, 1993 Mizuta T, Segawa T Chronic effects of imipramine and lithium on 5-HT receptor subtypes in rat frontal cortex, hippocampus and choroid plexus quantitative receptor autoradiographic analysis. Jpn J Pharmacol 50 315-326, 1989... 

Nagata Y, Kusuhara H, Hirono S, et al. Carrier-mediated uptake of H2-receptor antagonists by the rat choroid plexus involvement of rat organic anion transporter 3. Drug Metab Dispos 2004 32 1040-1047. 

A landmark paper by Bums and colleagues (115) first described RNA editing events in rat brain. RNA editing involved an adenosine to inosine substitution, required the action of two separable double-stranded RNA (dsRNA) and adensosine deanimase(s) (ADARs), and occurred at four sites (A, B, C, and D) located within the second intracellular loop of the receptor. RNA editing in the r5-HT2C receptor resulted in seven major isoforms (VNV, VSV, VNI, VSI, INV, ISV, and INI) encoded by 11 RNA species (115). Also, patterns of RNA editing were tissue-specific the most common variants (VNV, VSV, VNI, and VSI) were expressed in the whole brain and hippocampus, whereas the least common variants (INV, ISV, and INI) were expressed in the choroid plexus. Functionally,... 

Identification of the 5-HT2C receptor as a 60-kDa N-glycosylated protein in the choroid plexus and hippocampus has also been carried out in another study (145). When rat choroid plexus and hippocampal membrane lysates were treated with PNGase F, 5-HT2C receptor polypeptides from both tissues were converted to a sharp 38-kDa band. In a time-course experiment performed in the choroid plexus,... 

Abramowski D, Staufenbiel M. Identification of the 5-hydroxytryptamine2C receptor as a 60-kDa N-glycosylated protein in choroid plexus and hippocampus. J Neurochem 1995 65(2) 782-790. 

The 5-HT2C receptor was originally termed the 5-HTlc receptor and was identified as a high-affinity 3H-5-HT binding site in the choroid plexus (186). The cloning of the receptor from several species (185,261-263) led to the... 

The 5-HT2C receptor can modulate a variety of secondary signals. The 5-HT2C receptor inhibits K+ channels in the choroid plexus (280) and when expressed in cell lines (281,282). The 5-HT2C receptor stimulates an apical Cl conductance in mouse choroid plexus (280). It can modulate the production of NO, although the... 

Sanders-Bush E, Breeding M. Putative selective 5-HT-2 antagonists block serotonin 5-HT-lc receptors in the choroid plexus. J Pharmacol Exp Ther 1988 247 169-173. 

Kaufman MJ, Hartig PR, Hoffman BJ. Serotonin 5-HT2C receptor stimulates cyclic GMP formation in choroid plexus. J Neurochem 1995 64 199-205. 

Conn PJ, Sanders-Bush E, Hoffman BJ, Hartig PR. A unique serotonin receptor in choroid plexus is linked to phosphatidylinositol turnover. Proc Natl Acad Sci USA 1986 83 4086-4088. 

A subset of FRAPs and 5-HT receptors share ultrastructural similarities, suggesting their close proximities in specialized subcellular regions. Confocal and electron microscopy demonstrated a concentration of 5-HT2C receptors in the microvilli bordering the apical surface of the epithelial cells in the choroids plexus where they colocalize with Veli-3 and MUPP1, both of which have been... 

One of the differential characteristics of the distribution of 5-HT2C receptors is the low density of binding sites in the gray matter of the brain as compared to the choroid plexus and with the abundance of mRNA coding for this receptor in different regions of the mammalian brain, as we will see below. 

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