title: Distribution of histaminergic neuronal cluster in the rat and mouse hypothalamus.
abstract: Histidine decarboxylase (HDC) catalyzes the biosynthesis of histamine from L-histidine and is expressed throughout the mammalian nervous system by histaminergic neurons. Histaminergic neurons arise in the posterior mesencephalon during the early embryonic period and gradually develop into two histaminergic substreams around the lateral area of the posterior hypothalamus and the more anterior peri-cerebral aqueduct area before finally forming an adult-like pattern comprising five neuronal clusters, E1, E2, E3, E4, and E5, at the postnatal stage. This distribution of histaminergic neuronal clusters in the rat hypothalamus appears to be a consequence of neuronal development and reflects the functional differentiation within each neuronal cluster. However, the close linkage between the locations of histaminergic neuronal clusters and their physiological functions has yet to be fully elucidated because of the sparse information regarding the location and orientation of each histaminergic neuronal clusters in the hypothalamus of rats and mice. To clarify the distribution of the five-histaminergic neuronal clusters more clearly, we performed an immunohistochemical study using the anti-HDC antibody on serial sections of the rat hypothalamus according to the brain maps of rat and mouse. Our results confirmed that the HDC-immunoreactive (HDCi) neuronal clusters in the hypothalamus of rats and mice are observed in the ventrolateral part of the most posterior hypothalamus (E1), ventrolateral part of the posterior hypothalamus (E2), ventromedial part from the medial to the posterior hypothalamus (E3), periventricular part from the anterior to the medial hypothalamus (E4), and diffusely extended part of the more dorsal and almost entire hypothalamus (E5). The stereological estimation of the total number of HDCi neurons of each clusters revealed the larger amount of the rat than the mouse. The characterization of histaminergic neuronal clusters in the hypothalamus of rats and mice may provide useful information for further investigations.
authors.affiliation: Department of Molecular Anatomy, Faculty of Medicine, Oita University, Japan.
authors.forename: Chinatsu
authors.initials: C
authors.lastname: Moriwaki
authors.affiliation: Department of Molecular Anatomy, Faculty of Medicine, Oita University, Japan. Electronic address: schiba@oita-u.ac.jp.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Chiba
authors.affiliation: Department of Molecular Anatomy, Faculty of Medicine, Oita University, Japan; Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Japan.
authors.forename: Huixing
authors.initials: H
authors.lastname: Wei
authors.affiliation: Department of Molecular Anatomy, Faculty of Medicine, Oita University, Japan; Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Japan.
authors.forename: Taishi
authors.initials: T
authors.lastname: Aosa
authors.affiliation: Department of Molecular Anatomy, Faculty of Medicine, Oita University, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kitamura
authors.affiliation: Department of Molecular Anatomy, Faculty of Medicine, Oita University, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ina
authors.affiliation: Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Shibata
authors.affiliation: Department of Molecular Anatomy, Faculty of Medicine, Oita University, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Fujikura
mesh_terms: D000465:Algorithms; D000818:Animals; D001931:Brain Mapping; D002535:Cerebral Aqueduct / Q000378:metabolism; D006632:Histamine / Q000378:metabolism*; D006640:Histidine Decarboxylase / Q000378:metabolism; D007031:Hypothalamus / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000145:classification / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D009626:Terminology as Topic
chemical_list: D006632:Histamine; D006640:Histidine Decarboxylase
keywords: Histamine; Histidine decarboxylase; Hypothalamus; Mouse; Neuron; Rat