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c‐fos gene expression is increased in the paraventricular hypothalamic nucleus of Sprague‐Dawley rats With visceral pain induced by acetic acid without detectable changes of corticotrophin‐releasing factor mRNA: A quantitative approach with an image analysis system
Author(s) -
Hwang Bang H.,
Chang HungMing,
Gu ZhuHua,
Suzuki Ryoji
Publication year - 2007
Publication title -
the anatomical record: advances in integrative anatomy and evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.678
H-Index - 62
eISSN - 1932-8494
pISSN - 1932-8486
DOI - 10.1002/ar.20495
Subject(s) - c fos , nucleus , in situ hybridization , messenger rna , immediate early gene , endocrinology , immunostaining , medicine , immunohistochemistry , hypothalamus , gene expression , central nucleus of the amygdala , chemistry , biology , microbiology and biotechnology , gene , neuroscience , biochemistry
Abstract This study is the first of its kind to demonstrate that c‐Fos immunoreactivity (ir) together with c‐fos mRNA in their immediately adjacent tissue sections of a discrete brain region can be reliably measured. The c‐fos gene expression in the paraventricular hypothalamic nucleus (PVN) of Sprague‐Dawley rats for an animal model for visceral or somatovisceral pain induced by 2% acetic acid (AA) was used in this study. Specifically, c‐fos mRNA signals were measured by quantitative autoradiography after in situ hybridization using c‐fos oligodeoxynucleotide probe, and c‐Fos‐ir signals were represented by c‐Fos immunostaining, as detected using c‐Fos antibody in a regular immunohistochemistry. Signals from both c‐Fos‐ir and c‐fos mRNA in the PVN were measured from their immediately adjacent cryostat sections. For the measurement of c‐Fos‐ir, it was carried out by reading 10 rectangles (1,000 μm 2 /rectangle) on each PVN section with c‐Fos immunostaining. Specific signals were obtained from subtracting the nonspecific background signal from the total signals using a computer‐assisted image analysis system. Results indicated that the AA treatment induced a significant increase of both c‐Fos‐ir and c‐fos mRNA in the PVN. Interestingly, there was no increase of corticotrophin‐releasing factor (CRF) mRNA expression in the PVN and central nucleus of the amygdala of Sprague‐Dawley rats subjected to the AA treatment. In summary, this study has demonstrated that c‐Fos‐ir in the PVN with an anatomical resolution can be semiquantitatively measured after immunohistochemistry using an image analysis system, and that increased c‐fos mRNA in the PVN 1 hr after the AA treatment is associated with no changes of the CRF mRNA expression. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.