Effect of naloxone-precipitated morphine withdrawal on c- fos expression in rat corticotropin-releasing hormone neurons in the paraventricular hypothalamus and extended amygdala
Morphine withdrawal is characterized by physical symptoms and a negative affective state. The 41 amino acid polypeptide corticotropin-releasing hormone (CRH) is hypothesized to mediate, in part, both the negative affective state and the physical withdrawal syndrome. Here, by means of dual-immunohist...
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Published in | Neuroscience letters Vol. 362; no. 1; pp. 39 - 43 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Shannon
Elsevier Ireland Ltd
13.05.2004
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Morphine withdrawal is characterized by physical symptoms and a negative affective state. The 41 amino acid polypeptide corticotropin-releasing hormone (CRH) is hypothesized to mediate, in part, both the negative affective state and the physical withdrawal syndrome. Here, by means of dual-immunohistochemical methodology, we examined the co-expression of the c-Fos protein and CRH following naloxone-precipitated morphine withdrawal. Rats were treated with slow-release morphine 50 mg/kg (subcutaneous, s.c.) or vehicle every 48 h for 5 days, then withdrawn with naloxone 5 mg/kg (s.c.) or saline 48 h after the final morphine injection. Two hours after withdrawal rats were perfused transcardially and their brains were removed and processed for immunohistochemistry. We found that naloxone-precipitated withdrawal of morphine-dependent rats increased c-Fos immunoreactivity (IR) in CRH positive neurons in the paraventricular hypothalamus. Withdrawal of morphine-dependent rats also increased c-Fos-IR in the central amygdala and bed nucleus of the stria terminalis, however these were in CRH negative neurons. |
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ISSN: | 0304-3940 1872-7972 |
DOI: | 10.1016/j.neulet.2004.02.033 |