title: Chronic pain causes a persistent anxiety state leading to increased ethanol intake in CD1 mice.
abstract: Mood disorders and chronic pain are closely linked, but limited progress has been made in understanding the role of chronic and neuropathic pain in the aetiopathogenesis of depression. To explore the pathological mechanisms that mediate the association between pain and depressive-like behaviours, we studied the time-dependent effect of neuropathic pain on the development of anxiety-like and despair behaviours in CD1 mice. We analysed behavioural data, neuroinflammation reactions and changes in neurotransmitter (glutamate and serotonin) levels in the mouse prefrontal cortex. Sciatic-operated mice displayed long-lasting anxiety-like and despair behaviours, starting 5 and 20 days after partial sciatic nerve ligation, respectively. Glutamatergic neurotransmission and IL-1β cytokine expression were enhanced in the prefrontal cortex of mice with neuropathic pain. We found no change in serotonin metabolism, cytokine IL-6 or brain-derived neurotrophic factor levels. While sciatic-operated mice exposed to intermittent ethanol intake (20% v/v) using the drinking in the dark procedure consumed higher amounts of ethanol than sham-operated mice, thermal allodynia and despair behaviour were not attenuated by ethanol consumption. Our findings reveal an association between glutamatergic neurotransmission and pain-induced mood disorders, and indicate that moderate ethanol consumption does not relieve nociceptive and depressive behaviours associated with chronic pain in mice.
authors.affiliation: Grup de Recerca en Neurobiologia del Comportament (GReNeC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: González-Sepúlveda
authors.affiliation: Bioanalysis Research Group, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain.
authors.forename: Oscar J
authors.initials: OJ
authors.lastname: Pozo
authors.affiliation: Bioanalysis Research Group, IMIM-Hospital del Mar Medical Research Institute, Barcelona, Spain Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Marcos
authors.affiliation: Grup de Recerca en Neurobiologia del Comportament (GReNeC), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, PRBB, Barcelona, Spain Neuroscience Research Programme, IMIM-Hospital del Mar Research Institute, Barcelona, Spain olga.valverde@upf.edu.
authors.forename: Olga
authors.initials: O
authors.lastname: Valverde
mesh_terms: D000428:Alcohol Drinking / Q000453:epidemiology*; D000818:Animals; D001007:Anxiety / Q000209:etiology* / Q000523:psychology; D001522:Behavior, Animal; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D059350:Chronic Pain / Q000150:complications* / Q000523:psychology; D003863:Depression / Q000209:etiology / Q000523:psychology; D004195:Disease Models, Animal; D000431:Ethanol / Q000008:administration & dosage*; D018698:Glutamic Acid / Q000378:metabolism; D006930:Hyperalgesia / Q000150:complications / Q000523:psychology; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D051379:Mice; D017397:Prefrontal Cortex / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D013997:Time Factors
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D015850:Interleukin-6; D012701:Serotonin; D000431:Ethanol; D018698:Glutamic Acid
keywords: DID test; Neuropathic pain; ethanol intake; glutamate; mood disorders; thermal allodynia