title: Serotonin receptor of type 6 (5-HT6) in human prefrontal cortex and hippocampus post-mortem: an immunohistochemical and immunofluorescence study.
abstract: Given the paucity of data on the distribution of serotonin (5-HT) receptors of type 6 (5-HT(6)) in the human brain, the aim of this study was to investigate their distribution in postmortem human prefrontal cortex, striatum and hippocampus by either immunohistochemical or immunofluorescence techniques. The brain samples were obtained from 6 subjects who had died for causes not involving primarily or secondarily the CNS. The 5-HT(6) receptor distribution was explored by the [(125)I]SB-258585 binding to brain membranes followed by immunohistochemical and immunofluorescence evaluations. A specific [(125)I]SB-258585 binding was detected in all the regions under investigation, whilst the content in the hippocampus and cortex being about 10-30 times lower than in the striatum. Immunohistochemistry and double-label immunofluorescence microscopy experiments, carried out in the prefrontal cortex and hippocampus only, since data in the striatum were already published, showed the presence of 5-HT(6) receptors in both pyramidal and glial cells of prefrontal cortex, while positive cells were mainly pyramidal neurons in the hippocampus. The heterogeneous distribution of 5-HT(6) receptors provides a preliminary explanation of how they might regulate different functions in different brain areas, such as, perhaps, brain trophism in the cortex and neuronal firing in the hippocampus. This study, taking into account all the limitations due to the postmortem model used, represents the starting point to explore the 5-HT(6) receptor functionality and its sub-cellular distribution.
authors.affiliation: Dipartimento di Psichiatria, Neurobiologia, Farmacologia e Biotecnologie, University of Pisa, Italy. dmarazzi@psico.med.unipi.it
authors.forename: Donatella
authors.initials: D
authors.lastname: Marazziti
authors.forename: Stefano
authors.initials: S
authors.lastname: Baroni
authors.forename: Andrea
authors.initials: A
authors.lastname: Pirone
authors.forename: Gino
authors.initials: G
authors.lastname: Giannaccini
authors.forename: Laura
authors.initials: L
authors.lastname: Betti
authors.forename: Giovanna
authors.initials: G
authors.lastname: Testa
authors.forename: Lara
authors.initials: L
authors.lastname: Schmid
authors.forename: Lionella
authors.initials: L
authors.lastname: Palego
authors.forename: Franco
authors.initials: F
authors.lastname: Borsini
authors.forename: Fabio
authors.initials: F
authors.lastname: Bordi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Piano
authors.forename: Claudia
authors.initials: C
authors.lastname: Gargini
authors.forename: Maura
authors.initials: M
authors.lastname: Castagna
authors.forename: Mario
authors.initials: M
authors.lastname: Catena-Dell'osso
authors.forename: Antonio
authors.initials: A
authors.lastname: Lucacchini
mesh_terms: D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007457:Iodine Radioisotopes; D010879:Piperazines / Q000378:metabolism; D011180:Postmortem Changes; D017397:Prefrontal Cortex / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000378:metabolism*; D013449:Sulfonamides / Q000378:metabolism
chemical_list: D007457:Iodine Radioisotopes; D010879:Piperazines; D011985:Receptors, Serotonin; C418570:SB 258585; D013449:Sulfonamides; C097216:serotonin 6 receptor