Melanin-concentrating hormone projections to areas involved in somatomotor responses

Autor(es)

Elias, C. F. ; Sita, L. V. ; Zambon, B. K. ; Oliveira, E. R. ; Vasconcelos, L. A. P. ; Bittencourt, J. C. ^[6]

• Tipo de documento: Artigo Científico
• Fonte: Journal of Chemical Neuroanatomy; v. 35, n. 2, p. 188-201, Mar. 2008.
• Área do conhecimento: Ciências Biológicas - Morfologia
• Assunto(s): Sistema nervoso central Região hipotalâmica lateral Subtálamo Formação reticular GABA Parassonias do sono REM

Resumo

The lateral hypothalamic area (LHA) participates in the integration of sensory information and somatomotor responses associated with hunger and thirst. Although the LHA is neurochemically heterogeneous, a particularly high number of cells express melanin-concentrating hormone (MCH), which has been reported to play a role in energy homeostasis. Treatment with MCH increases food intake, and MCH mRNA is overexpressed in leptin-deficient (ob/ob) mice. Mice lacking both MCH and leptin present reduced body fat, mainly due to increased resting energy expenditure and locomotor activity. Dense MCH innervation of the cerebral motor cortex (MCx) and the pedunculopontine tegmental nucleus (PPT), both related to motor function, has been reported. Therefore, we postulated that a specific group of MCH neurons project to these areas. To investigate our hypothesis, we injected retrograde tracers into the MCx and the PPT of rats, combined with immunohistochemistry. We found that 25% of the LHA neurons projecting to the PPT were immunoreactive for MCH, and that 75% of the LHA neurons projecting to the MCx also contained MCH. Few MCH neurons were found to send collaterals to both areas. We also found that 15% of the incerto-hypothalamic neurons projecting to the PPT expressed MCH immunoreactivity. Those neurons preferentially innervated the rostral PPT. In addition, we observed that the MCH neurons express glutamic acid decarboxylase mRNA, a gamma-aminobutyric acid (GABA) synthesizing enzyme. We postulate that MCH/GABA neurons are involved in the inhibitory modulation of the innervated areas, decreasing motor activity in states of negative energy balance. (AU)

• Processo FAPESP: 05/50951-5 - Caracterizacao neuroquimica e hodologica dos neuronios que expressam o hormonio concentrador de melanina (mch) na area pre-optica durante a amamentacao.
• Beneficiário: Carol Fuzeti Elias
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 04/13850-3 - MCH e busca alimentar: um estudo envolvendo lesões neuroquímicas seletivas e microinfusão de MCH
• Beneficiário: Luciane Valéria Sita
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 04/13849-5 - Circuitos peptidérgicos envolvidos na organização do comportamento alimentar
• Beneficiário: Jackson Cioni Bittencourt
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 04/15866-4 - Estudo da participacao do hormonio concentrador de melanina (mch) no controle do comportamento alimentar atraves da expressao da proteina fos no snc de ratos em modelo experimental de busca alimentar.
• Beneficiário: Luciana Auxiliadora de Paula Vasconcelos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado