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Scheuber MI, Guidolin C, Martins S, Sartori AM, Hofer AS, Schwab ME. Electrical stimulation of the cuneiform nucleus enhances the effects of rehabilitative training on locomotor recovery after incomplete spinal cord injury. Front Neurosci 2024; 18:1352742. [PMID: 38595973 PMCID: PMC11002271 DOI: 10.3389/fnins.2024.1352742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/13/2024] [Indexed: 04/11/2024] Open
Abstract
Most human spinal cord injuries are anatomically incomplete, leaving some fibers still connecting the brain with the sublesional spinal cord. Spared descending fibers of the brainstem motor control system can be activated by deep brain stimulation (DBS) of the cuneiform nucleus (CnF), a subnucleus of the mesencephalic locomotor region (MLR). The MLR is an evolutionarily highly conserved structure which initiates and controls locomotion in all vertebrates. Acute electrical stimulation experiments in female adult rats with incomplete spinal cord injury conducted in our lab showed that CnF-DBS was able to re-establish a high degree of locomotion five weeks after injury, even in animals with initially very severe functional deficits and white matter lesions up to 80-95%. Here, we analyzed whether CnF-DBS can be used to support medium-intensity locomotor training and long-term recovery in rats with large but incomplete spinal cord injuries. Rats underwent rehabilitative training sessions three times per week in an enriched environment, either with or without CnF-DBS supported hindlimb stepping. After 4 weeks, animals that trained under CnF-DBS showed a higher level of locomotor performance than rats that trained comparable distances under non-stimulated conditions. The MLR does not project to the spinal cord directly; one of its main output targets is the gigantocellular reticular nucleus in the medulla oblongata. Long-term electrical stimulation of spared reticulospinal fibers after incomplete spinal cord injury via the CnF could enhance reticulospinal anatomical rearrangement and in this way lead to persistent improvement of motor function. By analyzing the spared, BDA-labeled giganto-spinal fibers we found that their gray matter arborization density after discontinuation of CnF-DBS enhanced training was lower in the lumbar L2 and L5 spinal cord in stimulated as compared to unstimulated animals, suggesting improved pruning with stimulation-enhanced training. An on-going clinical study in chronic paraplegic patients investigates the effects of CnF-DBS on locomotor capacity.
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Affiliation(s)
- Myriam I. Scheuber
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Carolina Guidolin
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Suzi Martins
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Andrea M. Sartori
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
| | - Anna-Sophie Hofer
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Martin E. Schwab
- Institute for Regenerative Medicine, University of Zurich, Schlieren, Switzerland
- ETH Phenomics Center, ETH Zurich, Zurich, Switzerland
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2
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van de Poll Y, Cras Y, Ellender TJ. The neurophysiological basis of stress and anxiety - comparing neuronal diversity in the bed nucleus of the stria terminalis (BNST) across species. Front Cell Neurosci 2023; 17:1225758. [PMID: 37711509 PMCID: PMC10499361 DOI: 10.3389/fncel.2023.1225758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/03/2023] [Indexed: 09/16/2023] Open
Abstract
The bed nucleus of the stria terminalis (BNST), as part of the extended amygdala, has become a region of increasing interest regarding its role in numerous human stress-related psychiatric diseases, including post-traumatic stress disorder and generalized anxiety disorder amongst others. The BNST is a sexually dimorphic and highly complex structure as already evident by its anatomy consisting of 11 to 18 distinct sub-nuclei in rodents. Located in the ventral forebrain, the BNST is anatomically and functionally connected to many other limbic structures, including the amygdala, hypothalamic nuclei, basal ganglia, and hippocampus. Given this extensive connectivity, the BNST is thought to play a central and critical role in the integration of information on hedonic-valence, mood, arousal states, processing emotional information, and in general shape motivated and stress/anxiety-related behavior. Regarding its role in regulating stress and anxiety behavior the anterolateral group of the BNST (BNSTALG) has been extensively studied and contains a wide variety of neurons that differ in their electrophysiological properties, morphology, spatial organization, neuropeptidergic content and input and output synaptic organization which shape their activity and function. In addition to this great diversity, further species-specific differences are evident on multiple levels. For example, classic studies performed in adult rat brain identified three distinct neuron types (Type I-III) based on their electrophysiological properties and ion channel expression. Whilst similar neurons have been identified in other animal species, such as mice and non-human primates such as macaques, cross-species comparisons have revealed intriguing differences such as their comparative prevalence in the BNSTALG as well as their electrophysiological and morphological properties, amongst other differences. Given this tremendous complexity on multiple levels, the comprehensive elucidation of the BNSTALG circuitry and its role in regulating stress/anxiety-related behavior is a major challenge. In the present Review we bring together and highlight the key differences in BNSTALG structure, functional connectivity, the electrophysiological and morphological properties, and neuropeptidergic profiles of BNSTALG neurons between species with the aim to facilitate future studies of this important nucleus in relation to human disease.
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Affiliation(s)
- Yana van de Poll
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Yasmin Cras
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Tommas J. Ellender
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
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3
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Singhal SM, Zell V, Faget L, Slosky LM, Barak LS, Caron MG, Pinkerton AB, Hnasko TS. Neurotensin receptor 1-biased ligand attenuates neurotensin-mediated excitation of ventral tegmental area dopamine neurons and dopamine release in the nucleus accumbens. Neuropharmacology 2023; 234:109544. [PMID: 37055008 PMCID: PMC10192038 DOI: 10.1016/j.neuropharm.2023.109544] [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: 12/02/2022] [Revised: 03/29/2023] [Accepted: 04/10/2023] [Indexed: 04/15/2023]
Abstract
Strong expression of the G protein-coupled receptor (GPCR) neurotensin receptor 1 (NTR1) in ventral tegmental area (VTA) dopamine (DA) neurons and terminals makes it an attractive target to modulate DA neuron activity and normalize DA-related pathologies. Recent studies have identified a novel class of NTR1 ligand that shows promising effects in preclinical models of addiction. A lead molecule, SBI-0654553 (SBI-553), can act as a positive allosteric modulator of NTR1 β-arrestin recruitment while simultaneously antagonizing NTR1 Gq protein signaling. Using cell-attached recordings from mouse VTA DA neurons we discovered that, unlike neurotensin (NT), SBI-553 did not independently increase spontaneous firing. Instead, SBI-553 blocked the NT-mediated increase in firing. SBI-553 also antagonized the effects of NT on dopamine D2 auto-receptor signaling, potentially through its inhibitory effects on G-protein signaling. We also measured DA release directly, using fast-scan cyclic voltammetry in the nucleus accumbens and observed antagonist effects of SBI-553 on an NT-induced increase in DA release. Further, in vivo administration of SBI-553 did not notably change basal or cocaine-evoked DA release measured in NAc using fiber photometry. Overall, these results indicate that SBI-553 blunts NT's effects on spontaneous DA neuron firing, D2 auto-receptor function, and DA release, without independently affecting these measures. In the presence of NT, SBI-553 has an inhibitory effect on mesolimbic DA activity, which could contribute to its efficacy in animal models of psychostimulant use.
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Affiliation(s)
- Sarthak M Singhal
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Vivien Zell
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Lauren Faget
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Lauren M Slosky
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | | | - Marc G Caron
- Departments of Cell Biology, Neurobiology and Medicine, Duke University, Durham, NC, USA
| | - Anthony B Pinkerton
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Thomas S Hnasko
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA; Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
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4
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Chen L, Liu C, Xue Y, Chen XY. Several neuropeptides involved in parkinsonian neuroprotection modulate the firing properties of nigral dopaminergic neurons. Neuropeptides 2023; 99:102337. [PMID: 37087783 DOI: 10.1016/j.npep.2023.102337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023]
Abstract
Parkinson's disease is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta. The surviving nigral dopaminergic neurons display altered spontaneous firing activity in Parkinson's disease. The firing rate of nigral dopaminergic neurons decreases long before complete neuronal death and the appearance of parkinsonian symptoms. A mild stimulation could rescue dopaminergic neurons from death and in turn play neuroprotective effects. Several neuropeptides, including cholecystokinin (CCK), ghrelin, neurotensin, orexin, tachykinins and apelin, within the substantia nigra pars compacta play important roles in the modulation of spontaneous firing activity of dopaminergic neurons and therefore involve motor control and motor disorders. Here, we review neuropeptide-induced modulation of the firing properties of nigral dopaminergic neurons. This review may provide a background to guide further investigations into the involvement of neuropeptides in movement control by modulating firing activity of nigral dopaminergic neurons in Parkinson's disease.
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Affiliation(s)
- Lei Chen
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China.
| | - Cui Liu
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yan Xue
- Department of Physiology and Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Xin-Yi Chen
- Department of International Medicine, Affiliated Hospital of Qingdao University, Qingdao, China.
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5
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Holt MK. The ins and outs of the caudal nucleus of the solitary tract: An overview of cellular populations and anatomical connections. J Neuroendocrinol 2022; 34:e13132. [PMID: 35509189 PMCID: PMC9286632 DOI: 10.1111/jne.13132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 11/29/2022]
Abstract
The body and brain are in constant two-way communication. Driving this communication is a region in the lower brainstem: the dorsal vagal complex. Within the dorsal vagal complex, the caudal nucleus of the solitary tract (cNTS) is a major first stop for incoming information from the body to the brain carried by the vagus nerve. The anatomy of this region makes it ideally positioned to respond to signals of change in both emotional and bodily states. In turn, the cNTS controls the activity of regions throughout the brain that are involved in the control of both behaviour and physiology. This review is intended to help anyone with an interest in the cNTS. First, I provide an overview of the architecture of the cNTS and outline the wide range of neurotransmitters expressed in subsets of neurons in the cNTS. Next, in detail, I discuss the known inputs and outputs of the cNTS and briefly highlight what is known regarding the neurochemical makeup and function of those connections. Then, I discuss one group of cNTS neurons: glucagon-like peptide-1 (GLP-1)-expressing neurons. GLP-1 neurons serve as a good example of a group of cNTS neurons, which receive input from varied sources and have the ability to modulate both behaviour and physiology. Finally, I consider what we might learn about other cNTS neurons from our study of GLP-1 neurons and why it is important to remember that the manipulation of molecularly defined subsets of cNTS neurons is likely to affect physiology and behaviours beyond those monitored in individual experiments.
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Affiliation(s)
- Marie K. Holt
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUK
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6
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Polzin BJ, Heimovics SA, Riters LV. Immunolabeling Provides Evidence for Subregions in the Songbird Nucleus Accumbens and Suggests a Context-Dependent Role in Song in Male European Starlings (Sturnus vulgaris). BRAIN, BEHAVIOR AND EVOLUTION 2022; 96:147-162. [PMID: 34879382 DOI: 10.1159/000521310] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/01/2021] [Indexed: 12/17/2022]
Abstract
Birdsong is well known for its role in mate attraction during the breeding season. However, many birds, including European starlings (Sturnus vulgaris), also sing outside the breeding season as part of large flocks. Song in a breeding context can be extrinsically rewarded by mate attraction; however, song in nonbreeding flocks, referred to here as gregarious song, results in no obvious extrinsic reward and is proposed to be intrinsically rewarded. The nucleus accumbens (NAC) is a brain region well known to mediate reward and motivation, which suggests it is an ideal candidate to regulate reward associated with gregarious song. The goal of this study was to provide new histochemical information on the songbird NAC and its subregions (rostral pole, core, and shell) and to begin to determine subregion-specific contributions to gregarious song in male starlings. We examined immunolabeling for tyrosine hydroxylase (TH), neurotensin, and enkephalin (ENK) in the NAC. We then examined the extent to which gregarious and sexually motivated song differentially correlated with immunolabeling for the immediate early genes FOS and ZENK in each subdivision of the NAC. We found that TH and ENK labeling within subregions of the starling NAC was generally similar to patterns seen in the core and shell of NACs in mammals and birds. Additionally, we found that gregarious song, but not sexually motivated song, positively correlated with FOS in all NAC subregions. Our observations provide further evidence for distinct subregions within the songbird NAC and suggest the NAC may play an important role in regulating gregarious song in songbirds.
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Affiliation(s)
- Brandon J Polzin
- Department of Integrative Biology, University of Wisconsin - Madison, Madison, Wisconsin, USA
| | - Sarah A Heimovics
- Department of Biology, University of St. Thomas, Saint Paul, Minnesota, USA
| | - Lauren V Riters
- Department of Integrative Biology, University of Wisconsin - Madison, Madison, Wisconsin, USA
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7
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Watts AG, Kanoski SE, Sanchez-Watts G, Langhans W. The physiological control of eating: signals, neurons, and networks. Physiol Rev 2022; 102:689-813. [PMID: 34486393 PMCID: PMC8759974 DOI: 10.1152/physrev.00028.2020] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/30/2021] [Indexed: 02/07/2023] Open
Abstract
During the past 30 yr, investigating the physiology of eating behaviors has generated a truly vast literature. This is fueled in part by a dramatic increase in obesity and its comorbidities that has coincided with an ever increasing sophistication of genetically based manipulations. These techniques have produced results with a remarkable degree of cell specificity, particularly at the cell signaling level, and have played a lead role in advancing the field. However, putting these findings into a brain-wide context that connects physiological signals and neurons to behavior and somatic physiology requires a thorough consideration of neuronal connections: a field that has also seen an extraordinary technological revolution. Our goal is to present a comprehensive and balanced assessment of how physiological signals associated with energy homeostasis interact at many brain levels to control eating behaviors. A major theme is that these signals engage sets of interacting neural networks throughout the brain that are defined by specific neural connections. We begin by discussing some fundamental concepts, including ones that still engender vigorous debate, that provide the necessary frameworks for understanding how the brain controls meal initiation and termination. These include key word definitions, ATP availability as the pivotal regulated variable in energy homeostasis, neuropeptide signaling, homeostatic and hedonic eating, and meal structure. Within this context, we discuss network models of how key regions in the endbrain (or telencephalon), hypothalamus, hindbrain, medulla, vagus nerve, and spinal cord work together with the gastrointestinal tract to enable the complex motor events that permit animals to eat in diverse situations.
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Affiliation(s)
- Alan G Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Scott E Kanoski
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Graciela Sanchez-Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule-Zürich, Schwerzenbach, Switzerland
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8
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Woodward ORM, Gribble FM, Reimann F, Lewis JE. Gut peptide regulation of food intake - evidence for the modulation of hedonic feeding. J Physiol 2022; 600:1053-1078. [PMID: 34152020 DOI: 10.1113/jp280581] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/17/2021] [Indexed: 12/13/2022] Open
Abstract
The number of people living with obesity has tripled worldwide since 1975 with serious implications for public health, as obesity is linked to a significantly higher chance of early death from associated comorbidities (metabolic syndrome, type 2 diabetes, cardiovascular disease and cancer). As obesity is a consequence of food intake exceeding the demands of energy expenditure, efforts are being made to better understand the homeostatic and hedonic mechanisms governing food intake. Gastrointestinal peptides are secreted from enteroendocrine cells in response to nutrient and energy intake, and modulate food intake either via afferent nerves, including the vagus nerve, or directly within the central nervous system, predominantly gaining access at circumventricular organs. Enteroendocrine hormones modulate homeostatic control centres at hypothalamic nuclei and the dorso-vagal complex. Additional roles of these peptides in modulating hedonic food intake and/or preference via the neural systems of reward are starting to be elucidated, with both peripheral and central peptide sources potentially contributing to central receptor activation. Pharmacological interventions and gastric bypass surgery for the treatment of type 2 diabetes and obesity elevate enteroendocrine hormone levels and also alter food preference. Hence, understanding of the hedonic mechanisms mediated by gut peptide action could advance development of potential therapeutic strategies for the treatment of obesity and its comorbidities.
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Affiliation(s)
- Orla R M Woodward
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Fiona M Gribble
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Frank Reimann
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Jo E Lewis
- Wellcome Trust - MRC Institute of Metabolic Science Metabolic Research Laboratories, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
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9
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Lei S, Hu B. Ionic and signaling mechanisms involved in neurotensin-mediated excitation of central amygdala neurons. Neuropharmacology 2021; 196:108714. [PMID: 34271017 DOI: 10.1016/j.neuropharm.2021.108714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/05/2021] [Accepted: 07/09/2021] [Indexed: 10/20/2022]
Abstract
Neurotensin (NT) serves as a neuromodulator in the brain where it regulates a variety of physiological functions. Whereas the central amygdala (CeA) expresses NT peptide and NTS1 receptors and application of NT has been shown to excite CeA neurons, the underlying cellular and molecular mechanisms have not been determined. We found that activation of NTS1 receptors increased the neuronal excitability of the lateral nucleus (CeL) of CeA. Both phospholipase Cβ (PLCβ) and phosphatidylinositol 4,5-bisphosphate (PIP2) depletion were required, whereas intracellular Ca2+ release and PKC were unnecessary for NT-elicited excitation of CeL neurons. NT increased the input resistance and time constants of CeL neurons, suggesting that NT excites CeL neurons by decreasing a membrane conductance. Depressions of the inwardly rectifying K+ (Kir) channels including both the Kir2 subfamily and the GIRK channels were required for NT-elicited excitation of CeL neurons. Activation of NTS1 receptors in the CeL led to GABAergic inhibition of medial nucleus of CeA neurons, suggesting that NT modulates the network activity in the amygdala. Our results may provide a cellular and molecular mechanism to explain the physiological functions of NT in vivo.
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Affiliation(s)
- Saobo Lei
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND58203, USA.
| | - Binqi Hu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND58203, USA
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10
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Perez-Bonilla P, Santiago-Colon K, Matasovsky J, Ramirez-Virella J, Khan R, Garver H, Fink G, Dorrance AM, Leinninger GM. Activation of ventral tegmental area neurotensin Receptor-1 neurons promotes weight loss. Neuropharmacology 2021; 195:108639. [PMID: 34116109 DOI: 10.1016/j.neuropharm.2021.108639] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 05/17/2021] [Accepted: 06/03/2021] [Indexed: 01/31/2023]
Abstract
Dopamine (DA) neurons in the ventral tegmental area (VTA) modulate physical activity and feeding behaviors that are disrupted in obesity. Yet, the heterogeneity of VTA DA neurons has hindered determination of which ones might be leveraged to support weight loss. We hypothesized that increased activity in the subset of VTA DA neurons expressing neurotensin receptor-1 (NtsR1) might promote weight loss behaviors. To test this, we used Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) to activate VTA NtsR1 neurons in normal weight and diet-induced obese mice. Acute activation of VTA NtsR1 neurons (24hr) significantly decreased body weight in normal weight and obese mice by reducing food intake and increasing physical activity. Moreover, daily activation of VTA NtsR1 neurons in obese mice sustained weight loss over 7 days. Activating VTA NtsR1 neurons also suppressed how much mice worked to obtain sucrose rewards, even when there was high motivation to consume. However, VTA NtsR1 neural activation was not reinforcing, nor did it invoke liabilities associated with whole-body NtsR1 agonism such as anxiety, vasodepressor response or hypothermia. Activating VTA NtsR1 neurons therefore promotes dual behaviors that support weight loss without causing adverse effects, and is worth further exploration for managing obesity.
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Affiliation(s)
- Patricia Perez-Bonilla
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, 48114, USA; Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA
| | | | - Jillian Matasovsky
- Department of Physiology and College of Natural Science, Michigan State University, East Lansing, MI, 48114, USA
| | - Jariel Ramirez-Virella
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, 48114, USA; Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA
| | - Rabail Khan
- Neuroscience Graduate Program, Michigan State University, East Lansing, MI, 48114, USA
| | - Hannah Garver
- Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA
| | - Gregory Fink
- Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA; College of Osteopathic Medicine, East Lansing, MI, 48114, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, East Lansing, MI, 48114, USA; College of Osteopathic Medicine, East Lansing, MI, 48114, USA
| | - Gina M Leinninger
- Department of Physiology and College of Natural Science, Michigan State University, East Lansing, MI, 48114, USA.
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11
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Ramirez-Virella J, Leinninger GM. The Role of Central Neurotensin in Regulating Feeding and Body Weight. Endocrinology 2021; 162:6144574. [PMID: 33599716 PMCID: PMC7951050 DOI: 10.1210/endocr/bqab038] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Indexed: 12/16/2022]
Abstract
The small peptide neurotensin (Nts) is implicated in myriad processes including analgesia, thermoregulation, reward, arousal, blood pressure, and modulation of feeding and body weight. Alterations in Nts have recently been described in individuals with obesity or eating disorders, suggesting that disrupted Nts signaling may contribute to body weight disturbance. Curiously, Nts mediates seemingly opposing regulation of body weight via different tissues. Peripherally acting Nts promotes fat absorption and weight gain, whereas central Nts signaling suppresses feeding and weight gain. Thus, because Nts is pleiotropic, a location-based approach must be used to understand its contributions to disordered body weight and whether the Nts system might be leveraged to improve metabolic health. Here we review the role of Nts signaling in the brain to understand the sites, receptors, and mechanisms by which Nts can promote behaviors that modify body weight. New techniques permitting site-specific modulation of Nts and Nts receptor-expressing cells suggest that, even in the brain, not all Nts circuitry exerts the same function. Intriguingly, there may be dedicated brain regions and circuits via which Nts specifically suppresses feeding behavior and weight gain vs other Nts-attributed physiology. Defining the central mechanisms by which Nts signaling modifies body weight may suggest strategies to correct disrupted energy balance, as needed to address overweight, obesity, and eating disorders.
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Affiliation(s)
- Jariel Ramirez-Virella
- Neuroscience Program, Michigan State University, East Lansing, Michigan, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Gina M Leinninger
- Neuroscience Program, Michigan State University, East Lansing, Michigan, USA
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
- Correspondence: Gina M. Leinninger, PhD, Department of Physiology, Michigan State University, 5400 ISTB, 766 Service Rd, East Lansing, MI 48824, USA.
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12
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Azevedo EP, Tan B, Pomeranz LE, Ivan V, Fetcho R, Schneeberger M, Doerig KR, Liston C, Friedman JM, Stern SA. A limbic circuit selectively links active escape to food suppression. eLife 2020; 9:58894. [PMID: 32894221 PMCID: PMC7476759 DOI: 10.7554/elife.58894] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023] Open
Abstract
Stress has pleiotropic physiologic effects, but the neural circuits linking stress to these responses are not well understood. Here, we describe a novel population of lateral septum neurons expressing neurotensin (LSNts) in mice that are selectively tuned to specific types of stress. LSNts neurons increase their activity during active escape, responding to stress when flight is a viable option, but not when associated with freezing or immobility. Chemogenetic activation of LSNts neurons decreases food intake and body weight, without altering locomotion and anxiety. LSNts neurons co-express several molecules including Glp1r (glucagon-like peptide one receptor) and manipulations of Glp1r signaling in the LS recapitulates the behavioral effects of LSNts activation. Activation of LSNts terminals in the lateral hypothalamus (LH) also decreases food intake. These results show that LSNts neurons are selectively tuned to active escape stress and can reduce food consumption via effects on hypothalamic pathways.
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Affiliation(s)
- Estefania P Azevedo
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States
| | - Bowen Tan
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States
| | - Lisa E Pomeranz
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States
| | - Violet Ivan
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States
| | - Robert Fetcho
- Department of Psychiatry, Weill Cornell Medical College-New York Presbyterian Hospital, New York, United States
| | - Marc Schneeberger
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States
| | - Katherine R Doerig
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States
| | - Conor Liston
- Department of Psychiatry, Weill Cornell Medical College-New York Presbyterian Hospital, New York, United States
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States.,Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Sarah A Stern
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States
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13
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Widely Distributed Neurotensinergic Neurons in the Brainstem Regulate NREM Sleep in Mice. Curr Biol 2020; 30:1002-1010.e4. [DOI: 10.1016/j.cub.2020.01.047] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/30/2019] [Accepted: 01/14/2020] [Indexed: 12/13/2022]
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14
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Neurotensin in reward processes. Neuropharmacology 2020; 167:108005. [PMID: 32057800 DOI: 10.1016/j.neuropharm.2020.108005] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/06/2020] [Accepted: 02/09/2020] [Indexed: 12/18/2022]
Abstract
Neurotensin (NTS) is a neuropeptide neurotransmitter expressed in the central and peripheral nervous systems. Many studies over the years have revealed a number of roles for this neuropeptide in body temperature regulation, feeding, analgesia, ethanol sensitivity, psychosis, substance use, and pain. This review provides a general survey of the role of neurotensin with a focus on modalities that we believe to be particularly relevant to the study of reward. We focus on NTS signaling in the ventral tegmental area, nucleus accumbens, lateral hypothalamus, bed nucleus of the stria terminalis, and central amygdala. Studies on the role of NTS outside of the ventral tegmental area are still in their relative infancy, yet they reveal a complex role for neurotensinergic signaling in reward-related behaviors that merits further study. This article is part of the special issue on 'Neuropeptides'.
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15
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Cansler HL, Wright KN, Stetzik LA, Wesson DW. Neurochemical organization of the ventral striatum's olfactory tubercle. J Neurochem 2020; 152:425-448. [PMID: 31755104 PMCID: PMC7042089 DOI: 10.1111/jnc.14919] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/08/2019] [Accepted: 11/17/2019] [Indexed: 12/11/2022]
Abstract
The ventral striatum is a collection of brain structures, including the nucleus accumbens, ventral pallidum and the olfactory tubercle (OT). While much attention has been devoted to the nucleus accumbens, a comprehensive understanding of the ventral striatum and its contributions to neurological diseases requires an appreciation for the complex neurochemical makeup of the ventral striatum's other components. This review summarizes the rich neurochemical composition of the OT, including the neurotransmitters, neuromodulators and hormones present. We also address the receptors and transporters involved in each system as well as their putative functional roles. Finally, we end with briefly reviewing select literature regarding neurochemical changes in the OT in the context of neurological disorders, specifically neurodegenerative disorders. By overviewing the vast literature on the neurochemical composition of the OT, this review will serve to aid future research into the neurobiology of the ventral striatum.
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Affiliation(s)
- Hillary L Cansler
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
| | - Katherine N Wright
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Lucas A Stetzik
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
| | - Daniel W Wesson
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- Center for Smell and Taste, University of Florida, Gainesville, FL, USA
- Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
- Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, USA
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16
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Torruella-Suárez ML, Vandenberg JR, Cogan ES, Tipton GJ, Teklezghi A, Dange K, Patel GK, McHenry JA, Hardaway JA, Kantak PA, Crowley NA, DiBerto JF, Faccidomo SP, Hodge CW, Stuber GD, McElligott ZA. Manipulations of Central Amygdala Neurotensin Neurons Alter the Consumption of Ethanol and Sweet Fluids in Mice. J Neurosci 2020; 40:632-647. [PMID: 31744862 PMCID: PMC6961987 DOI: 10.1523/jneurosci.1466-19.2019] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 10/11/2019] [Accepted: 11/04/2019] [Indexed: 12/22/2022] Open
Abstract
The central nucleus of the amygdala plays a significant role in alcohol use and other affective disorders; however, the genetically-defined neuronal subtypes and projections that govern these behaviors are not well known. Here we show that neurotensin neurons in the central nucleus of the amygdala of male mice are activated by in vivo ethanol consumption and that genetic ablation of these neurons decreases ethanol consumption and preference in non-ethanol-dependent animals. This ablation did not impact preference for sucrose, saccharin, or quinine. We found that the most robust projection of the central amygdala neurotensin neurons was to the parabrachial nucleus, a brain region known to be important in feeding behaviors, conditioned taste aversion, and alarm. Optogenetic stimulation of projections from these neurons to the parabrachial nucleus is reinforcing, and increases ethanol drinking as well as consumption of sucrose and saccharin solutions. These data suggest that this central amygdala to parabrachial nucleus projection influences the expression of reward-related phenotypes and is a novel circuit promoting consumption of ethanol and palatable fluids.SIGNIFICANCE STATEMENT Alcohol use disorder (AUD) is a major health burden worldwide. Although ethanol consumption is required for the development of AUD, much remains unknown regarding the underlying neural circuits that govern initial ethanol intake. Here we show that ablation of a population of neurotensin-expressing neurons in the central amygdala decreases intake of and preference for ethanol in non-dependent animals, whereas the projection of these neurons to the parabrachial nucleus promotes consumption of ethanol as well as other palatable fluids.
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Affiliation(s)
| | | | | | | | | | | | | | | | - J Andrew Hardaway
- Bowles Center for Alcohol Studies
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599
| | | | | | - Jeffrey F DiBerto
- Bowles Center for Alcohol Studies
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599
| | | | - Clyde W Hodge
- Bowles Center for Alcohol Studies
- Department of Psychiatry
| | - Garret D Stuber
- Bowles Center for Alcohol Studies
- Department of Psychiatry
- Neuroscience Center, and
| | - Zoé A McElligott
- Bowles Center for Alcohol Studies,
- Department of Psychiatry
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, 27599
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