Expression of EGR-1 in a subset of olfactory bulb dopaminergic cells.
In the adrenal medulla, binding of the immediate early gene (IEG) proteins, EGR-1 (ZIF-268/KROX-24/NGFI-A) and AP-1, to the tyrosine hydroxylase (Th) proximal promoter mediate inducible Th expression. The current study investigated the potential role of EGR-1 in inducible Th expression in the olfactory bulb (OB) since IEGs bound to the AP-1 site in the Th proximal promoter are also necessary for activity-dependent OB TH expression. Immunohistochemical analysis of a naris-occluded mouse model of odor deprivation revealed weak EGR-1 expression levels in the OB glomerular layer that were activity-dependent. Immunofluorescence analysis indicated that a majority of glomerular cells expressing EGR-1 also co-expressed TH, but only small subset of TH-expressing cells contained EGR-1. By contrast, granule cells, which lack TH, exhibited EGR-1 expression levels that were unchanged by naris closure. Together, these finding suggest that EGR-1 mediates activity-dependent TH expression in a subset of OB dopaminergic neurons, and that there is differential regulation of EGR-1 in periglomerular and granule cells.
Akiba
Nami
N
Department of Neurology and Neuroscience, Burke Medical Research Institute, Weill Cornell Medical College, 785 Mamaroneck Ave., White Plains, NY 10605, USA.
Jo
Sunna
S
Akiba
Yosuke
Y
Baker
Harriet
H
Cave
John W
JW
D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D051766:Early Growth Response Protein 1 / Q000378:metabolism*; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism*; D009830:Olfactory Bulb / Q000378:metabolism*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine