Melanin-concentrating hormone and orexin A neuropeptidergic systems in the dorsal motor nucleus of the vagus nerve in rat / Sistema neuropeptidergico do hormonio concentrador de melanina e da orexina A no nucleo motor dorsal do nervo vago em rato

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Melanin-concentrating hormone (MCH) and orexin-A (OXA) are neuromediators expressed in neurons distributed in the diencephalum, mainly in the lateral hypothalamic area, projecting nerve fibers to several parts of the central nervous system. These neuropeptides exert potent orexigenic activity, increasing feeding and controlling the energetic balance. Consequently, these neuropeptidergic systems were evaluated in the dorsal motor nucleus of the vagus nerve, a fundamental premotor parasympathetic nucleus that modulates the motility and secretion of the gastrointestinal tract, indirectly collaborating in the feeding behaviour. For these purposes retrograde neuronal tracing and immunohistochemistry methods were used. The main results from this neuroanatomical study showed that the dorsal motor nucleus of the vagus nerve exhibits a heterogeneous rostro-caudal MCH- or OXA-innervation patterns, being the latter more significant. Parasympathetic neurons that send nerve fibers to subdiafragmatic esophagus, stomach and proximal duodenum receive MCH- or OXA-immunoreactive nerve endings like synapses. Finally, the MCH or OXA-immunoreactive diencephalic afferents to dorsal motor nucleus of the vagus nerve were elucidated. These afferents are mainly from dorsal and lateral parts of the lateral hypothalamic area.

ASSUNTO(S)

neuropeptideos rat vagus nerve hypothalamus sistema digestivo neuropeptides digestive system nervo vago hipotalamo rato

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