title: Visualization of corticotropin-releasing factor neurons by fluorescent proteins in the mouse brain and characterization of labeled neurons in the paraventricular nucleus of the hypothalamus.
abstract: Corticotropin-releasing factor (CRF) is the key regulator of the hypothalamic-pituitary-adrenal axis. CRF neurons cannot be distinguished morphologically from other neuroendocrine neurons in the paraventricular nucleus of the hypothalamus (PVH) without immunostaining. Thus, we generated a knock-in mouse that expresses modified yellow fluorescent protein (Venus) in CRF neurons (CRF-Venus), and yet its expression is driven by the CRF promoter and responds to changes in the interior milieu. In CRF-Venus, Venus-expressing neurons were distributed in brain regions harboring CRF neurons, including the PVH. The majority of Venus-expressing neurons overlapped with CRF-expressing neurons in the PVH, but many neurons expressed only Venus or CRF in a physiological glucocorticoid condition. After glucocorticoid deprivation, however, Venus expression intensified, and most Venus neurons coexpressed CRF. Conversely, Venus expression was suppressed by excess glucocorticoids. Expression of copeptin, a peptide encoded within the vasopressin gene, was induced in PVH-Venus neurons by glucocorticoid deprivation and suppressed by glucocorticoid administration. Thus, Venus neurons recapitulated glucocorticoid-dependent vasopressin expression in PVH-CRF neurons. Noradrenaline increased the frequency of glutamate-dependent excitatory postsynaptic currents recorded from Venus-expressing neurons in the voltage clamp mode. In addition, the CRF-iCre knock-in mouse was crossed with a CAG-CAT-EGFP reporter mouse to yield the Tg(CAG-CAT-EGFP/wt);CRF(iCre/wt) (EGFP/CRF-iCre) mouse, in which enhanced green fluorescent protein (EGFP) is driven by the CAG promoter. EGFP was expressed more constitutively in the PVH of EGFP/CRF-iCre mice. Thus, CRF-Venus may have an advantage for monitoring dynamic changes in CRF neurons and CRF networks in different glucocorticoid states.
authors: Laboratory of Information Biology (K.I., A.H.T., T.F., T.K., R.O., T.Sa., T.Su., K.U.), Graduate School of Information Sciences, Tohoku University, Sendai 980-8579, Japan; Department of Neuroendocrinology (K.I.), Graduate School of Medicine, Tohoku University, Sendai 980-8579, Japan; and Department of Cellular Neurobiology (M.Y., M.A., R.N., K.S.), Brain Research Institute, Niigata University, Niigata 951-8585, Japan.
authors: Keiichi
authors: K
authors: Itoi
authors: Ashraf Hossain
authors: AH
authors: Talukder
authors: Toshimitsu
authors: T
authors: Fuse
authors: Takuji
authors: T
authors: Kaneko
authors: Ryo
authors: R
authors: Ozawa
authors: Takayuki
authors: T
authors: Sato
authors: Takuma
authors: T
authors: Sugaya
authors: Katsuya
authors: K
authors: Uchida
authors: Maya
authors: M
authors: Yamazaki
authors: Manabu
authors: M
authors: Abe
authors: Rie
authors: R
authors: Natsume
authors: Kenji
authors: K
authors: Sakimura
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D058948:Cell Tracking / Q000379:methods; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D008164:Luminescent Proteins / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism*; D013194:Staining and Labeling / Q000379:methods; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C485184:enhanced green fluorescent protein; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; D003346:Corticotropin-Releasing Hormone; D001616:beta-Galactosidase