Extracellular-signal regulated kinases expression is altered in brainstem nuclei during neuropathic pain and antidepressants treatment

Abstract

Event Abstract Back to Event Extracellular-signal regulated kinases expression is altered in brainstem nuclei during neuropathic pain and antidepressants treatment Gisela Borges1, Esther Berrocoso2, Antonio Ortega-Alvaro2, Juan Antonio-Mico2 and Fani L. Neto1* 1 Universidade do Porto, Instituto de Histologia e Embriologia, Faculdade de Medicina do Porto e Instituto de Biologia Molecular e Celular (IBMC), Portugal 2 Universitad de Cadiz, Departamento de Neurociencias,Facultad de Medicina, Spain Antidepressants are prescribed for neuropathic pain relief but the underlying mechanisms are not understood. Extracellular-signal regulated kinases (ERKs) have been implicated both in antidepressants effects and in pain processing. Here, we evaluated the effect of noxious stimulation or antidepressants administration on ERKs’ activation in the chronic constriction injury (CCI) model of neuropathic pain in rats.CCI was surgically induced by loose ligation of the sciatic nerve. Control rats were sham-operated. To evaluate the effect of noxious stimulation on ERKs activation, SHAM and CCI anaesthetised rats received mechanical stimulation in the ipsilateral hindpaw (SHAM or CCI stimulated, SS and CCI-S, respectively). Other rats did not receive stimulation (SHAM or CCI not stimulated, SNS and CCI-NS, respectively). To study the influence of two antidepressants, separate groups of CCI or SHAM rats were treated for 21 days with saline (SA), amitrityline (AMI, a tricyclic antidepressant) or duloxetine (DLX, a serotonin and norepinephrine reuptake inhibitor). The amount of antidepressant diluted in water/day was evaluated for each rat. Hyperalgesia was analysed by the plantar and the paw pinch nociceptive tests. Immunoreactive cells against pERKs1/2 were counted in monoaminergic brainstem nuclei.Baseline ERKs1/2 activation was observed in monoaminergic brainstem areas of SNS and SHAM-SA animals, like the A5, Locus Coeruleus (LC), Lateral Paragigantocellular (LPGi) and Lateral Reticular (LRt) nuclei. CCI-S or CCI-NS rats showed increased pERKs expression in the A5, LPGi and LRt, but in LC labelling intensity decreased. No changes were detected between stimulated and non-stimulated either in SHAM or CCI groups of rats. AMI and either AMI or DLX induced increases in pERKs expression in A5 and LPGI, respectively, of SHAM rats. Contrarily, among CCI rats antidepressants had no effect on ERKs activation in any region studied, but significant decreases were detected in CCI-AMI when compared to SHAM-AMI rats, in A5 and in Dorsal Raphe. No differences were detected for DLX.Neuropathic pain changed ERKs1/2 activation pattern on some brainstem regions while noxious stimulation had no effects. Additionally antidepressants seem to act on ERKs pathway in serotonergic and/or noradrenergic regions under normal conditions. However, under chronic painful input these mechanisms seem altered.Grant: PI070687, HP2006-0062, Spain; E-42/07, CRUP, Portugal. Conference: 11th Meeting of the Portuguese Society for Neuroscience, Braga, Portugal, 4 Jun - 6 Jun, 2009. Presentation Type: Oral Presentation Topic: Symposium 5 – Pain Citation: Borges G, Berrocoso E, Ortega-Alvaro A, Antonio-Mico J and Neto FL (2009). Extracellular-signal regulated kinases expression is altered in brainstem nuclei during neuropathic pain and antidepressants treatment. Front. Neurosci. Conference Abstract: 11th Meeting of the Portuguese Society for Neuroscience. doi: 10.3389/conf.neuro.01.2009.11.024 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. 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Received: 05 Aug 2009; Published Online: 05 Aug 2009. * Correspondence: Fani L Neto, Universidade do Porto, Instituto de Histologia e Embriologia, Faculdade de Medicina do Porto e Instituto de Biologia Molecular e Celular (IBMC), Porto, Portugal, fanineto@med.up.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Gisela Borges Esther Berrocoso Antonio Ortega-Alvaro Juan Antonio-Mico Fani L Neto Google Gisela Borges Esther Berrocoso Antonio Ortega-Alvaro Juan Antonio-Mico Fani L Neto Google Scholar Gisela Borges Esther Berrocoso Antonio Ortega-Alvaro Juan Antonio-Mico Fani L Neto PubMed Gisela Borges Esther Berrocoso Antonio Ortega-Alvaro Juan Antonio-Mico Fani L Neto Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.