The diagonal band of Broca is involved in the pressor pathway activated by noradrenaline microinjected into the periaqueductal gray area of rats

Autor(es)

Pelosi, Gislaine Garcia ^[1] ; Tavares, Rodrigo Fiacadori ^[1] ; Aguiar Correa, Fernando Morgan ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Pharmacol, BR-14040900 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Life Sciences; v. 84, n. 13-14, p. 444-450, MAR 27 2009.
• Citações Web of Science: 2

Resumo

Aims: The dorsal periaqueductal gray area (dPAG) is involved in cardiovascular modulation. Previously, we reported that noradrenaline (NA) microinjection into the dPAG caused a pressor response that was mediated by vasopressin release into the circulation. However, the neuronal pathway that mediates this response is as yet unknown. There is evidence that chemical stimulation of the diagonal band of Broca (dbB) also causes a pressor response mediated by systemic vasopressin release. In the present study, we evaluated the participation of the dbB in the pressor response caused by NA microinjection into the dPAG as well as the existence of neural connections between these areas. Main methods: With the above goal, we verified the effect of the pharmacological ablation of the dbB on the cardiovascular response to NA microinjection into the dPAG of unanesthetized rats. In addition, we microinjected the neuronal tracer biotinylated-dextran-amine (BDA) into the dPAG and looked for efferent projections from the dPAG to the dbB. Key findings: The pharmacologically reversible ablation of the dbB with local microinjection of CoCl(2) significantly reduced the pressor response caused by NA microinjection (15 nmol/50 nL) into the dPAG. In addition, BDA microinjection into the dPAG labeled axons in the dbB, pointing to the existence of direct connections between these areas. Significance: The present results indicate that synapses within the dbB are involved in the pressor pathway activated by NA microinjection into the VAG and direct neural projection from the dPAG to the dbB may constitute the neuroanatomic substrate for this pressor pathway. (C) 2009 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 05/57227-0 - Estudo dos efeitos cardiovasculares e comportamentais da microinjeção de noradrenalina na substância cinzenta periaquedutal de ratos
• Beneficiário: Gislaine Garcia Pelosi Gomes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado