Acetylcholine-mediated neurotransmission within the nucleus raphe magnus exerts a key role in the organization of both interictal and postictal antinociception

Autor(es)

de Oliveira, Rithiele Cristina ^[1] ; de Oliveira, Ricardo ^[1] ; Zanandrea, Priscila Cabrera ^[1] ; Paschoalin-Maurin, Tatiana ^[1] ; Coimbra, Norberto Cysne ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, FMRP, Lab Neuroanat & Neuropsicobiol, Ribeirao Preto Med Sch, Dept Farmacol, BR-14049900 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Epilepsy & Behavior; v. 22, n. 2, p. 178-185, OCT 2011.
• Citações Web of Science: 9

Resumo

The role of the acetylcholine-mediated system in the organization of postictal antinociception was investigated. For this purpose, nicotinic and muscarinic cholinergic receptor antagonists were microinjected into the nucleus raphe magnus (NRM), a key structure of the endogenous pain inhibitory system. After the tail-flick test baseline recording, male Wistar rats (N = 8 per group) were submitted to stereotaxic surgery for the introduction of a guide cannula aiming at the NRM. Five days after surgery, atropine or mecamylamine (1 mu g/0.2 mu L, 3 mu g/0.2 mu L or 5 mu g/0.2 mu L) was microinjected into the NRM. The tail-flick withdrawal latency was recorded immediately after peripheral treatment with pentylenetetrazole (PTZ) (64 mg/kg), in two different interictal time windows, and for 130 minutes after the last seizure evoked by intraperitoneal injection of PTZ. The blockade of GABA-mediated Cl(-) influx caused tonic clonic convulsions in all animals followed by sustained postictal antinociception lasting 110 minutes after seizures; the nociceptive threshold was also found to be high in interictal periods. Pretreatment of the NRM with either atropine or mecamylamine antagonized both interictal and postictal antinociception, suggesting the involvement of cholinergic mechanisms recruiting muscarinic and nicotinic cholinergic receptors of the NRM in the organization of tonic clonic seizure-induced antinociception. (C) 2011 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 04/10237-9 - Estudo do envolvimento do núcleo pré-tectal anterior e de receptores opióides u1, e serotoninérgico 5-HT2A/2C na analgesia pós-ictal
• Beneficiário: Priscila Cabrera Zanandrea
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 05/02989-3 - Estudo do envolvimento de vias colinérgicas que conectam o núcleo pedúnculo pontino tegmentar a núcleos monoaminérgicos do sistema endógeno de inibição de dor na analgesia pós-ictal
• Beneficiário: Rithiele Cristina de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 08/09897-5 - Estudo psicofarmacológico do duplo elo inibitório opióide e gabaérgico entre o complexo amigdalóide, a substância negra, lateral, e o teto mesencefálico e sua influência no medo eliciado por estimulação elétrica e química do colículo inferior
• Beneficiário: Ricardo de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 09/00668-6 - Estudo do envolvimento de vias colinérgicas que conectam o núcleo tegmentar pedúnculo-pontino a núcleos monoaminérgicos do sistema endógeno de inibição de dor na analgesia pós-ictal
• Beneficiário: Norberto Cysne Coimbra
• Modalidade de apoio: Auxílio à Pesquisa - Regular