Work

Opioidergic and adrenergic modulation of formalin-evoked spinal c-fos mRNA expression and nocifensive behavior in the rat

Year: 1999

Type: article

Abstract: Fos protein expression has been used to reflect neuronal activation in pain processing pathways although analgesics may uncouple behavioral and Fos responses. We determine whether formalin-induced spinal c-fos mRNA expression (Northern blotting) correlates with nocifensive behavior following pretreatment with morphine, the alpha2-adrenoceptor agonist dexmedetomidine, or their respective antagonists naloxone and atipamezole. Both opiate and alpha2-adrenoceptor agonists reduced formalin-induced c-fos gene transcription and nocifensive behavior via their cognate receptors. Unexpectedly, blockade of either the opiate or alpha2-adrenergic receptors, alone, caused an increase in formalin-evoked c-fos mRNA; while blocking the opiate receptor had no effect on formalin-induced behavior, alpha2-adrenoceptor block had an analgesic effect, indicating discordance between c-fos message transcription and nocifensive behavior. We concluded that the formalin-induced spinal c-fos signal was a poor predictor of the behavioral response to pharmacological manipulation of pain processing pathways.

Source: European Journal of Pharmacology

DOI: 10.1016/s0014-2999(99)00463-x

Authors: Shigehito Sawamura, Masahiko Fujinaga, Wade S Kingery, Natasha Belanger, M.Frances Davies, Mervyn Maze

Institutions: VA Palo Alto Health Care System, Stanford Medicine, Stanford University

Language: English

Topic: Pain Mechanisms and Treatments

Subfield: Physiology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,230