Rostral ventromedial medulla connections in Cavia porcellus and their relation with tonic immobility defensive behavior: A biotinylated dextran amine neurotracing study

Autor(es)

Souza da Silva, Luis Felipe ^[1] ; Coimbra, Norberto Cysne ^{[2, 3]} ; Menescal-de-Oliveira, Leda ^{[4, 3]}

Afiliação do(s) autor(es)

^[1] Univ Paraiba, Ctr Agr Sci, Dept Vet Sci, BR-58397000 Areia, Paraiba - Brazil

^[2] Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Pharmacol, BR-14049900 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo FMRP USP, Ribeirao Preto Med Sch, NAP USP Neurobiol Emot NuPNE, Dept Pharmacol, BR-14049900 Ribeirao Preto, SP - Brazil

^[4] Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Neuroscience Letters; v. 535, p. 116-121, FEB 22 2013.
• Citações Web of Science: 5

Resumo

The rostroventromedial medulla (RVM), together with the periaqueductal gray matter (PAG), constitutes the descendent antinociceptive system. Additionally, these structures mutually regulate defensive behaviors, including tonic immobility (TI) in guinea pigs. The current study was undertaken to evaluate the connections of the RVM with the PAG and the spinal cord in guinea pigs in order to provide an anatomical basis for the role played by RVM in the modulation of TI. To address this goal, five guinea pigs were treated with non-fluorescent biotinylated dextran amine (BDA) neurotracer by injection into the RVM. After four days of survival, the encephalon and spinal cord were removed from each rodent, and BDA labeling was visualized with a standard avidin-biotinylated horseradish peroxidase method through reaction with nickel-intensified peroxidase 3,3'-diaminobenzidine dihydrochloride. The microinjection of BDA into the RVM stained fibers in the ventral horn, dorsal horn and intermediate gray matter of the spinal cord. BDA-labeled fibers, terminal buttons suggesting synaptic contacts, and perikarya were found in the dorsomedial, dorsolateral, lateral and ventrolateral PAG, and neuronal somata were identified in the cuneiform nucleus. Together, the current data demonstrate neuroanatomical evidence that supports the role of the RVM in the modulation of TI defensive behavior. (C) 2012 Elsevier Ireland Ltd. All rights reserved. (AU)

• Processo FAPESP: 07/01174-1 - Estudo do envolvimento do sistema opióide, serotoninérgico e noradrenérgico do sistema endógeno de inibição de dor em processos antinociceptivos induzidos por reações de fuga orientada evocada pela estimulação química do hipotálamo medial
• Beneficiário: Norberto Cysne Coimbra
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 03/05038-4 - Envolvimento de circuitos do nucleo magno da rafe na modulacao do comportamento de imobilidade tonica e nocicepcao em cobaias e a participacao de conexao funcional e neuroanatonica com o locus...
• Beneficiário: Luis Felipe Souza da Silva
• Modalidade de apoio: Bolsas no Brasil - Doutorado