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Stamos J, Stalnaker K, Teegala S, Routh VH, Beck KD. Effects of glucose modulation in lateral hypothalamus on motivated behavior to obtain sucrose in an operant task. Appetite 2023; 189:106621. [PMID: 37311483 DOI: 10.1016/j.appet.2023.106621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/02/2023] [Accepted: 06/03/2023] [Indexed: 06/15/2023]
Abstract
Orexin neurons in the Lateral Hypothalamus (LH) play an important role in food seeking behavior. Approximately 60 percent of LH orexin neurons are inhibited by elevated extracellular glucose. It has been shown that elevated LH glucose decreases conditioned place preference for a food associated chamber. However, it has never been shown how modulation of LH extracellular glucose effects a rat's motivation to work for food. In this experiment we used reverse microdialysis to modulate extracellular glucose levels in LH during an operant task. Results from a progressive ratio task demonstrated that 4 mM glucose perfusion significantly decreased the animal's motivation to work for sucrose pellets while not effecting the hedonic value of the pellets. In a second experiment we demonstrated that 4 mM but not 2.5 mM glucose perfusion was sufficient to significantly decrease the number of sucrose pellets earned. Finally, we showed that modulating LH extracellular glucose mid-session from 0.7 mM to 4 mM did not affect behavior. This indicates that once feeding behavior has begun the animal becomes unresponsive to changes in extracellular glucose levels in LH. Taken together these experiments indicate that LH glucose sensing neurons play an important role in motivation to initiate feeding. However, once consumption has begun it is likely that feeding is controlled by brain regions downstream of LH.
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Affiliation(s)
- Joshua Stamos
- Neurobehavioral Research Laboratory, Research Service, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA
| | - Katherine Stalnaker
- School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Suraj Teegala
- School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Vanessa H Routh
- School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA; Department of Pharmacology, Physiology & Neuroscience, Rutgers - New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Kevin D Beck
- Neurobehavioral Research Laboratory, Research Service, Veterans Affairs New Jersey Health Care System, East Orange, NJ, USA; School of Graduate Studies, Rutgers, The State University of New Jersey, Newark, NJ, USA; Department of Pharmacology, Physiology & Neuroscience, Rutgers - New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA.
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2
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Calderon-Garcia AA, Perez-Fernandez M, Curto-Aguilera D, Rodriguez-Martin I, Sánchez-Barba M, Gonzalez-Nunez V. Exposure to Morphine and Cocaine Modify the Transcriptomic Landscape in Zebrafish Embryos. Neuroscience 2022; 507:14-27. [PMID: 36404518 DOI: 10.1016/j.neuroscience.2022.10.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/17/2022] [Accepted: 10/20/2022] [Indexed: 11/19/2022]
Abstract
Morphine and other opioid analgesics are the drugs of election to treat moderate-to-severe pain, and they elicit their actions by binding to the opioid receptors. Cocaine is a potent inhibitor of dopamine, serotonin, and noradrenaline reuptake, as it blocks DAT, the dopamine transporter, causing an increase in the local concentration of these neurotransmitters in the synaptic cleft. The molecular effects of these drugs have been studied in specific brain areas or nuclei, but the systemic effects in the whole organism have not been comprehensively analyzed. This study aims to analyze the transcriptomic changes elicited by morphine (10 uM) and cocaine (15 uM) in zebrafish embryos. An RNAseq assay was performed with tissues extracts from zebrafish embryos treated from 5 hpf (hours post fertilization) to 72 hpf, and the most representative deregulated genes were experimentally validated by qPCR. We have found changes in the expression of genes related to lipid metabolism, chemokine receptor ligands, visual system, hemoglobins, and metabolic detoxification pathways. Besides, morphine and cocaine modified the global DNA methylation pattern in zebrafish embryos, which would explain the changes in gene expression elicited by these two drugs of abuse.
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Affiliation(s)
- Andrés Angel Calderon-Garcia
- Dept. Biochemistry and Molecular Biology, Faculty of Medicine, University of Salamanca, Spain; Instituto de Neurociencias de Castilla y León (INCYL), Faculty of Medicine, University of Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), Spain
| | - Maria Perez-Fernandez
- Instituto de Neurociencias de Castilla y León (INCYL), Faculty of Medicine, University of Salamanca, Spain
| | - Daniel Curto-Aguilera
- Dept. Biochemistry and Molecular Biology, Faculty of Medicine, University of Salamanca, Spain
| | - Ivan Rodriguez-Martin
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, Pozuelo de Alarcón, Madrid, Spain
| | - Mercedes Sánchez-Barba
- Institute of Biomedical Research of Salamanca (IBSAL), Spain; Dept. Statistics. Faculty of Medicine, University of Salamanca, Spain
| | - Veronica Gonzalez-Nunez
- Dept. Biochemistry and Molecular Biology, Faculty of Medicine, University of Salamanca, Spain; Instituto de Neurociencias de Castilla y León (INCYL), Faculty of Medicine, University of Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), Spain.
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Monosov IE, Ogasawara T, Haber SN, Heimel JA, Ahmadlou M. The zona incerta in control of novelty seeking and investigation across species. Curr Opin Neurobiol 2022; 77:102650. [PMID: 36399897 DOI: 10.1016/j.conb.2022.102650] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 10/02/2022] [Accepted: 10/06/2022] [Indexed: 11/17/2022]
Abstract
Many organisms rely on a capacity to rapidly replicate, disperse, and evolve when faced with uncertainty and novelty. But mammals do not evolve and replicate quickly. They rely on a sophisticated nervous system to generate predictions and select responses when confronted with these challenges. An important component of their behavioral repertoire is the adaptive context-dependent seeking or avoiding of perceptually novel objects, even when their values have not yet been learned. Here, we outline recent cross-species breakthroughs that shed light on how the zona incerta (ZI), a relatively evolutionarily conserved brain area, supports novelty-seeking and novelty-related investigations. We then conjecture how the architecture of the ZI's anatomical connectivity - the wide-ranging top-down cortical inputs to the ZI, and its specifically strong outputs to both the brainstem action controllers and to brain areas involved in action value learning - place the ZI in a unique role at the intersection of cognitive control and learning.
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Affiliation(s)
- Ilya E Monosov
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Takaya Ogasawara
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Suzanne N Haber
- Department of Pharmacology and Physiology, University of Rochester School of Medicine & Dentistry, Rochester, NY, 14642, USA; Department of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, 02478, USA
| | - J Alexander Heimel
- Circuits Structure and Function Group, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA, Amsterdam, the Netherlands
| | - Mehran Ahmadlou
- Circuits Structure and Function Group, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA, Amsterdam, the Netherlands; Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, 25 Howland St., W1T4JG London, UK
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Potter LE, Burgess CR. The melanin-concentrating hormone system as a target for the treatment of sleep disorders. Front Neurosci 2022; 16:952275. [PMID: 36177357 PMCID: PMC9513178 DOI: 10.3389/fnins.2022.952275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Given the widespread prevalence of sleep disorders and their impacts on health, it is critical that researchers continue to identify and evaluate novel avenues of treatment. Recently the melanin-concentrating hormone (MCH) system has attracted commercial and scientific interest as a potential target of pharmacotherapy for sleep disorders. This interest emerges from basic scientific research demonstrating a role for MCH in regulating sleep, and particularly REM sleep. In addition to this role in sleep regulation, the MCH system and the MCH receptor 1 (MCHR1) have been implicated in a wide variety of other physiological functions and behaviors, including feeding/metabolism, reward, anxiety, depression, and learning. The basic research literature on sleep and the MCH system, and the history of MCH drug development, provide cause for both skepticism and cautious optimism about the prospects of MCH-targeting drugs in sleep disorders. Extensive efforts have focused on developing MCHR1 antagonists for use in obesity, however, few of these drugs have advanced to clinical trials, and none have gained regulatory approval. Additional basic research will be needed to fully characterize the MCH system’s role in sleep regulation, for example, to fully differentiate between MCH-neuron and peptide/receptor-mediated functions. Additionally, a number of issues relating to drug design will continue to pose a practical challenge for novel pharmacotherapies targeting the MCH system.
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Affiliation(s)
- Liam E. Potter
- Department of Molecular and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Liam E. Potter,
| | - Christian R. Burgess
- Department of Molecular and Integrative Physiology, Michigan Medicine, Ann Arbor, MI, United States
- Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States
- Christian R. Burgess,
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The role of the nucleus accumbens and ventral pallidum in feeding and obesity. Prog Neuropsychopharmacol Biol Psychiatry 2021; 111:110394. [PMID: 34242717 DOI: 10.1016/j.pnpbp.2021.110394] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 05/31/2021] [Accepted: 06/29/2021] [Indexed: 02/04/2023]
Abstract
Obesity is a growing global epidemic that stems from the increasing availability of highly-palatable foods and the consequent enhanced calorie consumption. Extensive research has shown that brain regions that are central to reward seeking modulate feeding and evidence linking obesity to pathology in such regions have recently started to accumulate. In this review we focus on the contribution of two major interconnected structures central to reward processing, the nucleus accumbens and the ventral pallidum, to obesity. We first review the known literature linking these structures to feeding behavior, then discuss recent advances connecting pathology in the nucleus accumbens and ventral pallidum to obesity, and finally examine the similarities and differences between drug addiction and obesity in the context of these two structures. The understanding of how pathology in brain regions involved in reward seeking and consumption may drive obesity and how mechanistically similar obesity and addiction are, is only now starting to be revealed. We hope that future research will advance knowledge in the field and open new avenues to studying and treating obesity.
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Lord MN, Subramanian K, Kanoski SE, Noble EE. Melanin-concentrating hormone and food intake control: Sites of action, peptide interactions, and appetition. Peptides 2021; 137:170476. [PMID: 33370567 PMCID: PMC8025943 DOI: 10.1016/j.peptides.2020.170476] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022]
Abstract
Given the increased prevalence of obesity and its associated comorbidities, understanding the mechanisms through which the brain regulates energy balance is of critical importance. The neuropeptide melanin-concentrating hormone (MCH) is produced in the lateral hypothalamic area and the adjacent incerto-hypothalamic area and promotes both food intake and energy conservation, overall contributing to body weight gain. Decades of research into this system has provided insight into the neural pathways and mechanisms (behavioral and neurobiological) through which MCH stimulates food intake. Recent technological advancements that allow for selective manipulation of MCH neuron activity have elucidated novel mechanisms of action for the hyperphagic effects of MCH, implicating neural "volume" transmission in the cerebrospinal fluid and sex-specific effects of MCH on food intake control as understudied areas for future investigation. Highlighted here are historical and recent findings that illuminate the neurobiological mechanisms through which MCH promotes food intake, including the identification of various specific neural signaling pathways and interactions with other peptide systems. We conclude with a framework that the hyperphagic effects of MCH signaling are predominantly mediated through enhancement of an "appetition" process in which early postoral prandial signals promote further caloric consumption.
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Affiliation(s)
- Magen N Lord
- Department of Foods and Nutrition, University of Georgia, Athens, GA 30606, USA
| | - Keshav Subramanian
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA; Human and Evolutionary Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
| | - Emily E Noble
- Department of Foods and Nutrition, University of Georgia, Athens, GA 30606, USA.
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