title: New biosynthesis and biological actions of avian neurosteroids.
abstract: De novo neurosteroidogenesis from cholesterol occurs in the brain of various avian species. However, the biosynthetic pathways leading to the formation of neurosteroids are still not completely elucidated. We have recently found that the avian brain produces 7α-hydroxypregnenolone, a novel bioactive neurosteroid that stimulates locomotor activity. Until recently, it was believed that neurosteroids are produced in neurons and glial cells in the central and peripheral nervous systems. However, our recent studies on birds have demonstrated that the pineal gland, an endocrine organ located close to the brain, is an important site of production of neurosteroids de novo from cholesterol. 7α-Hydroxypregnenolone is a major pineal neurosteroid that stimulates locomotor activity of juvenile birds, connecting light-induced gene expression with locomotion. The other major pineal neurosteroid allopregnanolone is involved in Purkinje cell survival during development. This paper highlights new aspects of neurosteroid synthesis and actions in birds.
authors.affiliation: Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Tsutsui
authors.affiliation: Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Haraguchi
authors.affiliation: Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Miyabara
authors.affiliation: Laboratory of Integrative Brain Sciences, Department of Biology and Center for Medical Life Science, Waseda University, Tokyo, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ubuka
authors.affiliation: Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Hatori
authors.affiliation: Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Hirota
authors.affiliation: Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Fukada
keywords: 7α-hydroxypregnenolone; Purkinje cell; allopregnanolone; brain; locomotor activity; neuroprotection; neurosteroids; pineal gland