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Spatiotemporal profiles of arginine vasopressin transcription in cultured suprachiasmatic nucleus
Author(s) -
Yoshikawa Tomoko,
Nakajima Yoshihiro,
Yamada Yoshiko,
Enoki Ryosuke,
Watanabe Kazuto,
Yamazaki Maya,
Sakimura Kenji,
Honma Sato,
Honma Kenichi
Publication year - 2015
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.13061
Subject(s) - suprachiasmatic nucleus , circadian rhythm , vasopressin , supraoptic nucleus , endocrinology , biology , medicine , hypothalamus , neuropeptide , light effects on circadian rhythm , period (music) , microbiology and biotechnology , receptor , physics , acoustics
Arginine vasopressin ( AVP ), a major neuropeptide in the suprachiasmatic nucleus ( SCN ), is postulated to mediate the output of the circadian oscillation. Mice carrying a reporter gene of AVP transcription ( AVP EL uc ) were produced by knocking‐in a cDNA of Emerald‐luciferase ( EL uc) in the translational initiation site. Homozygous mice did not survive beyond postnatal day 7. Using the heterozygous ( AVP EL uc/+ ) mice, a bioluminescence reporter system was developed that enabled to monitor AVP transcription through AVP ‐ EL uc measurement in real time for more than 10 cycles in the cultured brain slice. AVP EL uc/+ mice showed circadian behaviour rhythms and light responsiveness indistinguishable from those of the wild‐type. Robust circadian rhythms in AVP ‐ EL uc were detected in the cultured SCN slice at a single cell as well as tissue levels. The circadian rhythm of the whole SCN slice was stable, with the peak at the mid‐light phase of a light–dark cycle, while that of a single cell was more variable. By comparison, rhythmicity in the paraventricular nucleus and supraoptic nucleus in the hypothalamus was unstable and damped rapidly. Spatiotemporal profiles of AVP expression at the pixel level revealed significant circadian rhythms in the entire area of AVP ‐positive cells in the SCN , and at least two clusters that showed different circadian oscillations. Contour analysis of bioluminescence intensity in a cell‐like region demonstrated the radiation area was almost identical to the cell size. This newly developed reporter system for AVP gene expression is a useful tool for the study of circadian rhythms.