title: Immunolocalization of muscarinic receptor subtypes in the reticular thalamic nucleus of rats.
abstract: In this study, to identify the precise localization of the muscarinic receptor subtypes m2, m3 and m4 in the rostral part of the rat reticular thalamic nucleus (rRt), namely, the limbic sector, we used receptor-subtype-specific antibodies and characterized the immunolabeled structures by light, confocal laser scanning, and electron microscopies. The m2-immunolabeling was preferentially distributed in the distal dendrite region where cholinergic afferent fibers tend to terminate and in the peripheral region of somata, whereas the m3-immunolabeling was more preferentially distributed in a large part of somata and in proximal dendrite shafts than in the distal dendrite region. Dual-immunofluorescence experiments demonstrated that majority of rRt neurons with parvalbumin immunoreactivity contain both m2 and m3. Neither m2 nor m3 was detected in presynaptic terminals or axonal elements. No m4-immunolabeling was detected in the rostral part of the thalamus including rRt. These results show the different distributions of m2 and m3 in rRt neurons, and strongly suggest that m2 is more closely associated with cholinergic afferents than m3.
authors.affiliation: Department of Anatomy, Toho University School of Medicine, Tokyo, Japan. odas@med.toho-u.ac.jp
authors.forename: Satoko
authors.initials: S
authors.lastname: Oda
authors.forename: Fumi
authors.initials: F
authors.lastname: Sato
authors.forename: Akiko
authors.initials: A
authors.lastname: Okada
authors.forename: Satomi
authors.initials: S
authors.lastname: Akahane
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Igarashi
authors.forename: Junko
authors.initials: J
authors.lastname: Yokofujita
authors.forename: Junli
authors.initials: J
authors.lastname: Yang
authors.forename: Masaru
authors.initials: M
authors.lastname: Kuroda
mesh_terms: D000818:Animals; D008297:Male; D016253:Microscopy, Immunoelectron / Q000379:methods; D008959:Models, Neurological; D010320:Parvalbumins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D043585:Receptor, Muscarinic M2 / Q000378:metabolism* / Q000648:ultrastructure; D043587:Receptor, Muscarinic M3 / Q000378:metabolism* / Q000648:ultrastructure; D043588:Receptor, Muscarinic M4 / Q000378:metabolism* / Q000648:ultrastructure; D013787:Thalamic Nuclei / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D010320:Parvalbumins; D043585:Receptor, Muscarinic M2; D043587:Receptor, Muscarinic M3; D043588:Receptor, Muscarinic M4