Citation

Bravo L, Mico JA, Rey Brea R, Pérez Nievas B, Leza JC, Berrocoso E. Anesthesiology 2012; 117(3): 613-625.

Affiliation

Department of Neuroscience (Pharmacology and Psychiatry), University of Cádiz, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Cádiz, Spain. † Professor and Head, Department of Neuroscience (Pharmacology and Psychiatry), University of Cádiz, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). ‡ Research Technician, Department of Neuroscience (Pharmacology and Psychiatry), University of Cádiz, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). § Postdoctoral Researcher, Faculty Medicine, University Complutense, Centro de Investigación Biomédica en red de Salud Mental (CIBERSAM), Madrid, Spain. ∥ Professor, Department of Pharmacology, Faculty Medicine, University Complutense, Centro de Investigación Biomédica en red de Salud Mental (CIBERSAM). # Professor of Psychobiology Area, Department of Psychology, University of Cádiz, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM).

Copyright

(Copyright © 2012, American Society of Anesthesiologists, Publisher Lippincott Williams and Wilkins)

DOI

10.1097/ALN.0b013e3182657b3e

PMID

22846678

Abstract

BACKGROUND:: Chronic pain and depression are two complex states with sensory/somatic and emotional components, and they may mutually exacerbate one another in conditions of comorbidity, leading to a poorer prognosis. METHODS:: The authors have evaluated the sensory and emotional components in a rat model combining chronic constriction injury (CCI, a model of chronic neuropathic pain) with unpredictable chronic mild stress (CMS, an experimental model of depression). In addition, the phosphorylation/activation of the extracellular signal-regulated kinases 1 and 2 and neuronal density was also evaluated in the anterior cingulate cortex. Four groups were tested: sham-control, sham-CMS, CCI-control, and CCI-CMS. RESULTS:: CMS selectively heightens aversion to painful experiences in animals subjected to CCI, as measured in the place escape/avoidance test at 20, 25, and 30 min (CCI-CMS (mean ± SEM): 75.68 ± 3.32, 66.75 ± 4.70, 77.54 ± 3.60 vs. CCI-control: 44.66 ± 6.07, 43.17 ± 6.92, 52.83 ± 5.92, respectively), in conjunction with an increase in the accumulation of phosphorylation/activation of the extracellular signal-regulated kinases (CCI-CMS: 4.17 ± 0.52 vs. sham-control: 0.96 ± 0.05) and a decrease in neuronal density in the anterior cingulate cortex. In contrast, chronic pain did not exacerbate the characteristic profile of depression (anhedonia and behavioral despair) in rats subjected to CMS. Furthermore, depression enhances the perception of some specific modalities of sensorial pain such as cold allodynia but has no influence on mechanical threshold. CONCLUSIONS:: These findings support the theory that depression leads to emotional dysfunction in the interpretation of pain in patients suffering chronic pain. In addition, combined animal models of pain-depression may provide a valuable tool to study the comorbidity of pain and depression.

Language: en