Title
Inescapable shock-induced potentiation of morphine analgesia in rats: Sites of action
Abbreviated Journal Title
Behav. Neurosci.
Keywords
NUCLEUS RAPHE MAGNUS; FREELY MOVING CATS; SEROTONIN-CONTAINING NEURONS; DORSAL RAPHE; PERIAQUEDUCTAL GRAY; BRAIN-STEM; INDUCED ANTINOCICEPTION; PAIN MODULATION; 5-HT METABOLISM; INTERFERENCE; Behavioral Sciences; Neurosciences
Abstract
Inescapable shock (IS) enhances analgesia to systemic morphine (MOR) 24 hr later. IS activates serotonin neurons in the dorsal raphe nucleus (DRN), rendering them hyperexcitable. These studies tested whether IS potentiates the analgesic effect of MOR microinjected in the DRN, as predicted by this hypothesis. To test site specificity, the effect of previous IS was examined on MOR microinjected lateral to the DRN and into 2 other sites that support MOR analgesia, the nucleus raphe magnus (NRM) and spinal cord. Twenty-four hours after IS, potentiated analgesia was observed after 0.5 mu g MOR microinjected into, but not lateral to, the DRN. Potentiated analgesia was also observed after NRM (1.0 mu g) and spinal cord (3.0 mu g) MOR microinjections. These data suggest that IS-induced excitability changes within the DRN synergize with opiates microinjected in other analgesia areas and that this potentiates the responses to opiates 24 hr after IS.
Journal Title
Behavioral Neuroscience
Volume
113
Issue/Number
4
Publication Date
1-1-1999
Document Type
Article
Language
English
First Page
795
Last Page
803
WOS Identifier
ISSN
0735-7044
Recommended Citation
"Inescapable shock-induced potentiation of morphine analgesia in rats: Sites of action" (1999). Faculty Bibliography 1990s. 2664.
https://stars.library.ucf.edu/facultybib1990/2664
Comments
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