Hypothalamic metabolic compartmentation during appetite regulation as revealed by magnetic resonance imaging and spectroscopy methods
- 1Department of Experimental Models of Human diseases, Laboratory of Imaging and Spectroscopy by Magnetic Resonance, Instituto de Investigaciones Biomédicas “Alberto Sols” CSIC/UAM, Madrid, Spain
- 2Departmento de Informática, Escuela Politécnica Superior, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
- 3Laboratorio de Síntesis Orgánica e Imagen Molecular por Resonancia Magnética, Facultad de Ciencias, Universidad Nacional de Educación a Distancia, Unidad Asociada al CSIC, Madrid, Spain
We review the role of neuroglial compartmentation and transcellular neurotransmitter cycling during hypothalamic appetite regulation as detected by Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) methods. We address first the neurochemical basis of neuroendocrine regulation in the hypothalamus and the orexigenic and anorexigenic feed-back loops that control appetite. Then we examine the main MRI and MRS strategies that have been used to investigate appetite regulation. Manganese-enhanced magnetic resonance imaging (MEMRI), Blood oxygenation level-dependent contrast (BOLD), and Diffusion-weighted magnetic resonance imaging (DWI) have revealed Mn2+ accumulations, augmented oxygen consumptions, and astrocytic swelling in the hypothalamus under fasting conditions, respectively. High field 1H magnetic resonance in vivo, showed increased hypothalamic myo-inositol concentrations as compared to other cerebral structures. 1H and 13C high resolution magic angle spinning (HRMAS) revealed increased neuroglial oxidative and glycolytic metabolism, as well as increased hypothalamic glutamatergic and GABAergic neurotransmissions under orexigenic stimulation. We propose here an integrative interpretation of all these findings suggesting that the neuroendocrine regulation of appetite is supported by important ionic and metabolic transcellular fluxes which begin at the tripartite orexigenic clefts and become extended spatially in the hypothalamus through astrocytic networks becoming eventually MRI and MRS detectable.
Keywords: appetite regulation, hypothalamus, neuroendocrine signaling, neuroglial compartmentation, magnetic resonance imaging, magnetic resonance spectroscopy
Citation: Lizarbe B, Benitez A, Peláez Brioso GA, Sánchez-Montañés M, López-Larrubia P, Ballesteros P and Cerdán S (2013) Hypothalamic metabolic compartmentation during appetite regulation as revealed by magnetic resonance imaging and spectroscopy methods. Front. Neuroenergetics 5:6. doi: 10.3389/fnene.2013.00006
Received: 12 March 2013; Accepted: 28 May 2013;
Published online: 13 June 2013.
Edited by:Mary McKenna, University of Maryland, USA
Reviewed by:Caroline Rae, University of New South Wales, Australia
Brenda Bartnik-Olson, Loma Linda University, USA
Copyright © 2013 Lizarbe, Benitez, Peláez Brioso, Sánchez-Montañés, López-Larrubia, Ballesteros and Cerdán. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Sebastián Cerdán, Department of Experimental Models of Human diseases, Instituto de Investigaciones Biomédicas “Alberto Sols” CSIC/UAM., c/ Arturo Duperier 4, Madrid 28029, Spain e-mail: email@example.com