Hippocampal subareas arranged in the dorsoventral axis modulate cardiac baroreflex function in a site-dependent manner in rats

Autor(es)

Ferreira-Junior, Nilson Carlos ^[1] ; Lagatta, Davi Campos ^[1] ; Fabri, Denise Resende ^[1] ; Ferrari Alves, Fernando Henrique ^[1] ; Aguiar Correa, Fernando Morgan ^[1] ; Moraes Resstel, Leonardo Barbosa ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Pharmacol, 3900 Bandeirantes Ave, BR-14049900 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Experimental Physiology; v. 102, n. 1, p. 14-24, JAN 1 2017.
• Citações Web of Science: 1

Resumo

New Findings What is the central question of this study? Classically, areas of the brainstem are involved in the cardiac baroreceptor reflex. However, forebrain areas, such as the hippocampus, may also modulate the cardiac baroreflex function. What is the main finding and its importance? According to the hippocampal subarea recruited dorsoventrally, the baroreflex function can be either facilitated or inhibited. These results are according to the new topographical division proposed for the hippocampus, i.e. it can be divided into functionally and anatomically different regions along its dorsoventral axis. From a neuroanatomical point of view, we may split the hippocampal formation into the dorsal (DH) and ventral hippocampus (VH). Although the basic intrinsic circuitry of the hippocampus seems to be maintained throughout its longitudinal axis, dorsal and ventral portions connect differently with cortical and subcortical areas and express different gene patterns, being functionally distinct. Differential stimulation of the DH or VH can evoke either an increase or a decrease in blood pressure, heart rate and sympathetic activity. However, to the best of our knowledge, specific involvement of the hippocampus and its different subareas in the baroreflex function remains to be investigated. In the present work, therefore, we evaluated the involvement of hippocampal subareas arranged on the dorsoventral axis in cardiac baroreflex modulation. Our results suggest that inhibition of hippocampal subareas by CoCl2, a calcium-dependent synaptic neurotransmission blocker, differentially affects baroreflex sensitivity; administration of CoCl2 into the DH increased cardiac baroreflex function, whereas it diminished cardiac baroreflex function when administered into the VH. In contrast, administration of CoCl2 into intermediate portions of the hippocampus did not affect the baroreflex response. Our findings suggest that the hippocampus influences baroreflex function according to the hippocampal subarea recruited dorsoventrally. (AU)

• Processo FAPESP: 11/07332-3 - Estudo do envolvimento do hipocampo dorsal de ratos nas respostas comportamentais e autonômicas associadas a reações de defesa: uma possível via receptores NMDA/óxido nítrico e endocanabinóides
• Beneficiário: Leonardo Resstel Barbosa Moraes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/19494-8 - Envolvimento do hipocampo dorsal na modulação da atividade barorreflexa cardíaca: participação dos receptores NMDA, CB1, TRPV1, muscarínicos e do óxido nítrico.
• Beneficiário: Nilson Carlos Ferreira Junior
• Modalidade de apoio: Bolsas no Brasil - Doutorado