Abstract
We examined the effects of centrally administered orexin-A on corticotropin-releasing factor (CRF)-containing neurons in the hypothalamic paraventricular nucleus (PVN) and the central amygdaloid nucleus (CeA) of rats, using dual immunostaining for CRF and Fos. Ninety minutes after intracerebroventricular administration of orexin-A, approximately 96% and 45% of CRF-containing neurons expressed Fos-like immunoreactivity (LI) in the PVN and the CeA, respectively. We also examined the effects of immobilized stress and cold exposure on orexin-A-containing neurons in the rat hypothalamus using dual immunostaining for orexin-A and Fos. After immobilized stress for 20 min and cold exposure at 4 degrees C for 30 min, approximately 24% and 15% of orexin-A-containing neurons expressed Fos-LI, respectively. These results suggest that orexins in the central nervous system may be involved in the activation of central CRF neurons induced by stress.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amygdala / cytology
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Amygdala / drug effects
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Amygdala / metabolism*
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Animals
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Brain / drug effects
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Brain / metabolism
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Brain / surgery
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Catheterization
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Cell Count
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Central Nervous System / drug effects
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Central Nervous System / metabolism
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Cold Temperature
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Corticotropin-Releasing Hormone / analysis
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Corticotropin-Releasing Hormone / metabolism*
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Immunohistochemistry / methods
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Injections, Intraventricular
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Intracellular Signaling Peptides and Proteins / administration & dosage
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Intracellular Signaling Peptides and Proteins / pharmacology*
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Male
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Neurons / chemistry
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Neurons / drug effects
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Neurons / metabolism*
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Neuropeptides / administration & dosage
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Neuropeptides / pharmacology*
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Orexins
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Paraventricular Hypothalamic Nucleus / cytology
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Paraventricular Hypothalamic Nucleus / drug effects
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Paraventricular Hypothalamic Nucleus / metabolism*
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Proto-Oncogene Proteins c-fos / analysis
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Proto-Oncogene Proteins c-fos / metabolism*
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Rats
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Rats, Wistar
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Stress, Physiological / metabolism
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Stress, Physiological / physiopathology
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Temperature
Substances
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Intracellular Signaling Peptides and Proteins
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Neuropeptides
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Orexins
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Proto-Oncogene Proteins c-fos
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Corticotropin-Releasing Hormone