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Flores RA, Dos-Santos RC, Rodrigues-Santos I, de Jesus AA, Antunes-Rodrigues J, Elias LLK. Tonic noradrenergic input to neurons in the dorsal raphe nucleus mediates food intake in male mice. Behav Brain Res 2024; 462:114872. [PMID: 38266779 DOI: 10.1016/j.bbr.2024.114872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/08/2024] [Accepted: 01/18/2024] [Indexed: 01/26/2024]
Abstract
The dorsal raphe nucleus (DRN) is essential for the control of food intake. Efferent projections from the DRN extend to several forebrain regions that are involved in the control of food intake. However, the neurotransmitters released in the DRN related to the control of food intake are not known. We have previously demonstrated that a tonic α1 action on DRN neurons contributes to satiety in the fed rats. In this study we investigated the participation of norepinephrine (NE) signaling in the DRN in the satiety response. Intra-DRN administration of NE causes an increase in the 2-hour food intake of sated mice, an effect that was blocked by previous administration of yohimbine, an α2 antagonist. Similarly, Intra-DRN administration of clonidine, an α2 agonist, increases food intake in sated mice. This result indicates that in the satiated mice exogenous NE acts on α2 receptors to increase food intake. Furthermore, administration of phenylephrine, an α1 agonist, decreases food intake in fasted mice and prazosin, an α1 antagonist, increases food intake in the sated mice. Taken together these results indicate that, in a satiated condition, a tonic α1 adrenergic action on the DRN neurons inhibits food intake and that exogenous NE administered to the DRN acts on α2 adrenergic receptors to increase food intake. These data reinforce the intricate neuronal functioning of the DRN and its effects on feeding.
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Affiliation(s)
- Rafael Appel Flores
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, 3900, Bandeirantes Av., Prof. Dr. Zeferino Vaz Building, ZIP Code: 14049-900, Ribeirão Preto, SP, Brazil.
| | - Raoni C Dos-Santos
- Department of Cell and Molecular Biology, Tulane University, 6602 Freret St, New Orleans, Percival Stern Hall, ZIP Code: 70118, New Orleans, Louisiana, USA.
| | - Isabelle Rodrigues-Santos
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, 3900, Bandeirantes Av., Prof. Dr. Zeferino Vaz Building, ZIP Code: 14049-900, Ribeirão Preto, SP, Brazil
| | - Aline Alves de Jesus
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, 3900, Bandeirantes Av., Prof. Dr. Zeferino Vaz Building, ZIP Code: 14049-900, Ribeirão Preto, SP, Brazil
| | - José Antunes-Rodrigues
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, 3900, Bandeirantes Av., Prof. Dr. Zeferino Vaz Building, ZIP Code: 14049-900, Ribeirão Preto, SP, Brazil
| | - Lucila L K Elias
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, 3900, Bandeirantes Av., Prof. Dr. Zeferino Vaz Building, ZIP Code: 14049-900, Ribeirão Preto, SP, Brazil.
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Imig JD. Frontiers in metabolic physiology grand challenges. Front Physiol 2022; 13:879617. [PMID: 36035475 PMCID: PMC9399398 DOI: 10.3389/fphys.2022.879617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
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