Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study
In mammals, glucosensing markers reside in brain areas known to play an important role in the control of food intake. The best characterized glucosensing mechanism is that dependent on glucokinase (GK) whose activation by increased levels of glucose leads in specific hypothalamic neurons to decrease...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2019-04-01
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| Series: | Frontiers in Endocrinology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fendo.2019.00254/full |
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| author | Cristina Otero-Rodiño Ana Rocha Elisa Sánchez Rosa Álvarez-Otero José L. Soengas José M. Cerdá-Reverter |
| author_facet | Cristina Otero-Rodiño Ana Rocha Elisa Sánchez Rosa Álvarez-Otero José L. Soengas José M. Cerdá-Reverter |
| author_sort | Cristina Otero-Rodiño |
| collection | DOAJ |
| description | In mammals, glucosensing markers reside in brain areas known to play an important role in the control of food intake. The best characterized glucosensing mechanism is that dependent on glucokinase (GK) whose activation by increased levels of glucose leads in specific hypothalamic neurons to decreased or increased activity, ultimately leading to decreased food intake. In fish, evidence obtained in recent years suggested the presence of GK-like immunoreactive cells in different brain areas related to food intake control. However, it has not been established yet whether or not those neuronal populations having glucosensing capacity are the same that express the neuropeptides involved in the metabolic control of food intake. Therefore, we assessed through dual fluorescent in situ hybridization the possible expression of GK in the melanocortinergic neurons expressing proopiomelanocortin (POMC) or agouti-related protein (AGRP). POMC and AGRP expression localized exclusively in the rostral hypothalamus, in the ventral pole of the lateral tuberal nucleus, the homolog of the mammalian arcuate nucleus. Hypothalamic GK expression confined to the ependymal cells coating the ventral pole of the third ventricle but some expression level occurred in the AGRP neurons. GK expression seems to be absent in the hypothalamic POMC neurons. These results suggest that AGRP neurons might sense glucose directly through a mechanism involving GK. In contrast, POMC neurons would not directly respond to glucose through GK and would require presynaptic inputs to sense glucose. Ependymal cells could play a critical role relying glucose metabolic information to the central circuitry regulating food intake in fish, especially in POMC neurons. |
| first_indexed | 2024-04-12T01:45:40Z |
| format | Article |
| id | doaj.art-0bb216b7f4db46d3853386c538974238 |
| institution | Directory Open Access Journal |
| issn | 1664-2392 |
| language | English |
| last_indexed | 2024-04-12T01:45:40Z |
| publishDate | 2019-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Endocrinology |
| spelling | doaj.art-0bb216b7f4db46d3853386c5389742382022-12-22T03:53:05ZengFrontiers Media S.A.Frontiers in Endocrinology1664-23922019-04-011010.3389/fendo.2019.00254444708Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological StudyCristina Otero-Rodiño0Ana Rocha1Elisa Sánchez2Rosa Álvarez-Otero3José L. Soengas4José M. Cerdá-Reverter5Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Vigo, SpainGrupo Control de Ingesta, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Departamento de Fisiología y Biotecnología de Peces, Instituto de Acuicultura de Torre de la Sal, Castellón, SpainGrupo Control de Ingesta, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Departamento de Fisiología y Biotecnología de Peces, Instituto de Acuicultura de Torre de la Sal, Castellón, SpainLaboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Vigo, SpainLaboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Vigo, SpainGrupo Control de Ingesta, Consejo Superior de Investigaciones Científicas (IATS-CSIC), Departamento de Fisiología y Biotecnología de Peces, Instituto de Acuicultura de Torre de la Sal, Castellón, SpainIn mammals, glucosensing markers reside in brain areas known to play an important role in the control of food intake. The best characterized glucosensing mechanism is that dependent on glucokinase (GK) whose activation by increased levels of glucose leads in specific hypothalamic neurons to decreased or increased activity, ultimately leading to decreased food intake. In fish, evidence obtained in recent years suggested the presence of GK-like immunoreactive cells in different brain areas related to food intake control. However, it has not been established yet whether or not those neuronal populations having glucosensing capacity are the same that express the neuropeptides involved in the metabolic control of food intake. Therefore, we assessed through dual fluorescent in situ hybridization the possible expression of GK in the melanocortinergic neurons expressing proopiomelanocortin (POMC) or agouti-related protein (AGRP). POMC and AGRP expression localized exclusively in the rostral hypothalamus, in the ventral pole of the lateral tuberal nucleus, the homolog of the mammalian arcuate nucleus. Hypothalamic GK expression confined to the ependymal cells coating the ventral pole of the third ventricle but some expression level occurred in the AGRP neurons. GK expression seems to be absent in the hypothalamic POMC neurons. These results suggest that AGRP neurons might sense glucose directly through a mechanism involving GK. In contrast, POMC neurons would not directly respond to glucose through GK and would require presynaptic inputs to sense glucose. Ependymal cells could play a critical role relying glucose metabolic information to the central circuitry regulating food intake in fish, especially in POMC neurons.https://www.frontiersin.org/article/10.3389/fendo.2019.00254/fullglucosensingglucokinase (GK)AGRPPOMCneuronbrain |
| spellingShingle | Cristina Otero-Rodiño Ana Rocha Elisa Sánchez Rosa Álvarez-Otero José L. Soengas José M. Cerdá-Reverter Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study Frontiers in Endocrinology glucosensing glucokinase (GK) AGRP POMC neuron brain |
| title | Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study |
| title_full | Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study |
| title_fullStr | Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study |
| title_full_unstemmed | Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study |
| title_short | Sensing Glucose in the Central Melanocortin Circuits of Rainbow Trout: A Morphological Study |
| title_sort | sensing glucose in the central melanocortin circuits of rainbow trout a morphological study |
| topic | glucosensing glucokinase (GK) AGRP POMC neuron brain |
| url | https://www.frontiersin.org/article/10.3389/fendo.2019.00254/full |
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