title: Selective targeting of somatostatin receptor 3 to neuronal cilia.
abstract: Recently, five members of the somatostatin receptor family have been cloned. However, little is known about their cellular and subcellular localization in the central nervous system. Using specific anti-peptide antisera, we observed somatostatin receptor 3-like immunoreactivity in many brain regions, including the cerebral cortex, hippocampus, hypothalamus, amygdala and cerebellum. In all of these regions (except for the cerebellar cortex), somatostatin receptor 3-like immunoreactivity was selectively targeted to 4-8-microm-long rod-shaped profiles which did not co-localize with axonal or dendritic markers. One immunoreactive profile was always associated with one neuronal cell body. This staining pattern was resistant to colchicine treatment and showed a closely overlapping distribution with somatostatin receptor 3 messenger RNA, suggesting that the receptor protein is not transported over long distances. Electron microscopic analysis revealed that somatostatin receptor 3-like immunoreactivity is localized to the plasma membrane of neuronal cilia which extended into an intercellular pocket and showed a 9+0 filament pattern in their basal body and proximal segments. Thus, somatostatin receptor 3 demonstrates a unique example of a G-protein-coupled receptor not localized to "classical" pre- or postsynaptic sites, but selectively targeted to neuronal cilia. The presence of the somatostatin receptor 3 receptor on neuronal cilia suggests that these presumably non-motile cilia may not merely represent developmental remnants, but rather function as chemical sensors of the immediate milieu.
authors: Department of Pharmacology and Toxicology, Otto-von-Guericke University, Magdeburg, Germany.
authors: M
authors: M
authors: Händel
authors: S
authors: S
authors: Schulz
authors: A
authors: A
authors: Stanarius
authors: M
authors: M
authors: Schreff
authors: M
authors: M
authors: Erdtmann-Vourliotis
authors: H
authors: H
authors: Schmidt
authors: G
authors: G
authors: Wolf
authors: V
authors: V
authors: Höllt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001370:Axonal Transport / Q000187:drug effects; D002490:Central Nervous System / Q000166:cytology / Q000378:metabolism*; D002923:Cilia / Q000378:metabolism*; D003078:Colchicine / Q000494:pharmacology; D017403:In Situ Hybridization; D008297:Male; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D009928:Organ Specificity; D010446:Peptide Fragments / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D017481:Receptors, Somatostatin / Q000378:metabolism*
chemical_list: D010446:Peptide Fragments; D012333:RNA, Messenger; D017481:Receptors, Somatostatin; C103631:somatostatin receptor 3; D003078:Colchicine