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Neyens DM, Brenner L, Calkins R, Winzenried ET, Ritter RC, Appleyard SM. CCK-sensitive C fibers activate NTS leptin receptor-expressing neurons via NMDA receptors. Am J Physiol Regul Integr Comp Physiol 2024; 326:R383-R400. [PMID: 38105761 DOI: 10.1152/ajpregu.00238.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/07/2023] [Accepted: 12/07/2023] [Indexed: 12/19/2023]
Abstract
The hormone leptin reduces food intake through actions in the peripheral and central nervous systems, including in the hindbrain nucleus of the solitary tract (NTS). The NTS receives viscerosensory information via vagal afferents, including information from the gastrointestinal tract, which is then relayed to other central nervous system (CNS) sites critical for control of food intake. Leptin receptors (lepRs) are expressed by a subpopulation of NTS neurons, and knockdown of these receptors increases both food intake and body weight. Recently, we demonstrated that leptin increases vagal activation of lepR-expressing neurons via increased NMDA receptor (NMDAR) currents, thereby potentiating vagally evoked firing. Furthermore, chemogenetic activation of these neurons was recently shown to inhibit food intake. However, the vagal inputs these neurons receive had not been characterized. Here we performed whole cell recordings in brain slices taken from lepRCre × floxedTdTomato mice and found that lepR neurons of the NTS are directly activated by monosynaptic inputs from C-type afferents sensitive to the transient receptor potential vanilloid type 1 (TRPV1) agonist capsaicin. CCK administered onto NTS slices stimulated spontaneous glutamate release onto lepR neurons and induced action potential firing, an effect mediated by CCKR1. Interestingly, NMDAR activation contributed to the current carried by spontaneous excitatory postsynaptic currents (EPSCs) and enhanced CCK-induced firing. Peripheral CCK also increased c-fos expression in these neurons, suggesting they are activated by CCK-sensitive vagal afferents in vivo. Our results indicate that the majority of NTS lepR neurons receive direct inputs from CCK-sensitive C vagal-type afferents, with both peripheral and central CCK capable of activating these neurons and NMDARs able to potentiate these effects.
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Affiliation(s)
- Drew M Neyens
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Lynne Brenner
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Rowan Calkins
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Eric T Winzenried
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Robert C Ritter
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
| | - Suzanne M Appleyard
- Department of Integrated Physiology and Neuroscience, Washington State University, Pullman, Washington, United States
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Martinez de Morentin PB, Gonzalez JA, Dowsett GKC, Martynova Y, Yeo GSH, Sylantyev S, Heisler LK. A brainstem to hypothalamic arcuate nucleus GABAergic circuit drives feeding. Curr Biol 2024; 34:1646-1656.e4. [PMID: 38518777 DOI: 10.1016/j.cub.2024.02.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 02/05/2024] [Accepted: 02/29/2024] [Indexed: 03/24/2024]
Abstract
The obesity epidemic is principally driven by the consumption of more calories than the body requires. It is therefore essential that the mechanisms underpinning feeding behavior are defined. Neurons within the brainstem dorsal vagal complex (DVC) receive direct information from the digestive system and project to second-order regions in the brain to regulate food intake. Although γ-aminobutyric acid is expressed in the DVC (GABADVC), its function in this region has not been defined. In order to discover the unique gene expression signature of GABADVC cells, we used single-nucleus RNA sequencing (Nuc-seq), and this revealed 19 separate clusters. We next probed the function of GABADVC cells and discovered that the selective activation of GABADVC neurons significantly controls food intake and body weight. Optogenetic interrogation of GABADVC circuitry identified GABADVC → hypothalamic arcuate nucleus (ARC) projections as appetite suppressive without creating aversion. Electrophysiological analysis revealed that GABADVC → ARC stimulation inhibits hunger-promoting neuropeptide Y (NPY) neurons via GABA release. Adopting an intersectional genetics strategy, we clarify that the GABADVC → ARC circuit curbs food intake. These data identify GABADVC as a new modulator of feeding behavior and body weight and a controller of orexigenic NPY neuron activity, thereby providing insight into the neural underpinnings of obesity.
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Affiliation(s)
- Pablo B Martinez de Morentin
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK; School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Woodhouse LS2 9JT, UK.
| | - J Antonio Gonzalez
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK
| | - Georgina K C Dowsett
- MRC Metabolic Diseases Unit, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Yuliia Martynova
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK
| | - Giles S H Yeo
- MRC Metabolic Diseases Unit, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK
| | - Sergiy Sylantyev
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK; Odesa National Mechnikov University, Biological Department, 2 Shampansky Ln., Odesa 65015, Ukraine.
| | - Lora K Heisler
- The Rowett Institute, University of Aberdeen, Ashgrove Road W, Aberdeen AB25 2ZD, UK
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3
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Huo L, Ye Z, Liu M, He Z, Huang M, Li D, Wu Q, Wang Q, Wang X, Cao P, Dong J, Shang C. Brain circuits for retching-like behavior. Natl Sci Rev 2024; 11:nwad256. [PMID: 38288368 PMCID: PMC10824557 DOI: 10.1093/nsr/nwad256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 09/06/2023] [Accepted: 09/24/2023] [Indexed: 01/31/2024] Open
Abstract
Nausea and vomiting are important defensive responses to cope with pathogens and toxins that invade the body. The nucleus of the solitary tract (NTS) is important for initiating these responses. However, the molecular heterogeneities and cellular diversities of the NTS occlude a better understanding of these defensive responses. Here, we constructed the single-nucleus transcriptomic atlas of NTS cells and found multiple populations of NTS neurons that may be involved in these defensive responses. Among these, we identified Calbindin1-positive (Calb1+) NTS neurons that are molecularly distinct from Tac1+ neurons. These Calb1+ neurons are critical for nausea and retching induced by cereulide; an emetic toxin secreted by Bacillus Cereus. Strikingly, we found that cereulide can directly modulate vagal sensory neurons that innervate Calb1+ NTS neurons, a novel mechanism distinct from that for nausea and retching induced by Staphylococcal enterotoxin A. Together, our transcriptomic atlas of NTS neurons and the functional analyses revealed the neural mechanism for cereulide-induced retching-like behavior. These results demonstrate the molecular and cellular complexities in the brain that underlie defensive responses to the diversities of pathogens and toxins.
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Affiliation(s)
- Lifang Huo
- School of Basic Medical Sciences, Guangzhou National Laboratory, The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 510799, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510320, China
| | - Zhimin Ye
- School of Basic Medical Sciences, Guangzhou National Laboratory, The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 510799, China
| | - Meiling Liu
- School of Basic Medical Sciences, Guangzhou National Laboratory, The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 510799, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510320, China
| | - Ziqing He
- School of Basic Medical Sciences, Guangzhou National Laboratory, The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 510799, China
| | - Meizhu Huang
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510320, China
| | - Dapeng Li
- Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Qian Wu
- State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Qian Wang
- Changping Life Science Laboratory, Beijing 102299, China
| | - Xiaoqun Wang
- State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Peng Cao
- National Institute of Biological Sciences, Beijing 102206, China
| | - Ji Dong
- School of Basic Medical Sciences, Guangzhou National Laboratory, The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 510799, China
| | - Congping Shang
- School of Basic Medical Sciences, Guangzhou National Laboratory, The Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou 510799, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510320, China
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Sweetland GD, Eggleston C, Bartz JC, Mathiason CK, Kincaid AE. Expression of the cellular prion protein by mast cells in the human carotid body. Prion 2023; 17:67-74. [PMID: 36943020 PMCID: PMC10038025 DOI: 10.1080/19336896.2023.2193128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Prion diseases are fatal neurologic disorders that can be transmitted by blood transfusion. The route for neuroinvasion following exposure to infected blood is not known. Carotid bodies (CBs) are specialized chemosensitive structures that detect the concentration of blood gasses and provide feedback for the neural control of respiration. Sensory cells of the CB are highly perfused and densely innervated by nerves that are synaptically connected to the brainstem and thoracic spinal cord, known to be areas of early prion deposition following oral infection. Given their direct exposure to blood and neural connections to central nervous system (CNS) areas involved in prion neuroinvasion, we sought to determine if there were cells in the human CB that express the cellular prion protein (PrPC), a characteristic that would support CBs serving as a route for prion neuroinvasion. We collected CBs from cadaver donor bodies and determined that mast cells located in the carotid bodies express PrPC and that these cells are in close proximity to blood vessels, nerves, and nerve terminals that are synaptically connected to the brainstem and spinal cord.
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Affiliation(s)
- Gregory D Sweetland
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA
| | - Connor Eggleston
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA
| | - Jason C Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE, USA
| | - Candace K Mathiason
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Anthony E Kincaid
- Department of Pharmacy Sciences, School of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, NE, USA
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Zlatkovic J, Dalmau Gasull A, Hägg D, Font-Gironès F, Bellman J, Meister B, Palsdottir V, Ruud J, Ohlsson C, Dickson SL, Anesten F, Jansson JO. Reduction of body weight by increased loading is associated with activation of norepinephrine neurones in the medial nucleus of the solitary tract. J Neuroendocrinol 2023; 35:e13352. [PMID: 37885347 DOI: 10.1111/jne.13352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/28/2023]
Abstract
We previously provided evidence supporting the existence of a novel leptin-independent body weight homeostat ("the gravitostat") that senses body weight and then initiates a homeostatic feed-back regulation of body weight. We, herein, hypothesize that this feed-back regulation involves a CNS mechanism. To identify populations of neurones of importance for the putative feed-back signal induced by increased loading, high-fat diet-fed rats or mice were implanted intraperitoneally or subcutaneously with capsules weighing ∼15% (Load) or ∼2.5% (Control) of body weight. At 3-5 days after implantation, neuronal activation was assessed in different parts of the brain/brainstem by immunohistochemical detection of FosB. Implantation of weighted capsules, both subcutaneous and intraperitoneal, induced FosB in specific neurones in the medial nucleus of the solitary tract (mNTS), known to integrate information about the metabolic status of the body. These neurones also expressed tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DbH), a pattern typical of norepinephrine neurones. In functional studies, we specifically ablated norepinephrine neurones in mNTS, which attenuated the feed-back regulation of increased load on body weight and food intake. In conclusion, increased load appears to reduce body weight and food intake via activation of norepinephrine neurones in the mNTS.
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Affiliation(s)
- Jovana Zlatkovic
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | | | - Daniel Hägg
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Ferran Font-Gironès
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Jakob Bellman
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Björn Meister
- Institute of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | - Johan Ruud
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Claes Ohlsson
- Center for Bone and Arthritis Research, University of Gothenburg, Gothenburg, Sweden
| | - Suzanne L Dickson
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Fredrik Anesten
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - John-Olov Jansson
- Departement of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
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6
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Pace SA, Myers B. Hindbrain Adrenergic/Noradrenergic Control of Integrated Endocrine and Autonomic Stress Responses. Endocrinology 2023; 165:bqad178. [PMID: 38015813 DOI: 10.1210/endocr/bqad178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/07/2023] [Accepted: 11/27/2023] [Indexed: 11/30/2023]
Abstract
Hindbrain adrenergic/noradrenergic nuclei facilitate endocrine and autonomic responses to physical and psychological challenges. Neurons that synthesize adrenaline and noradrenaline target hypothalamic structures to modulate endocrine responses while descending spinal projections regulate sympathetic function. Furthermore, these neurons respond to diverse stress-related metabolic, autonomic, and psychosocial challenges. Accordingly, adrenergic and noradrenergic nuclei are integrative hubs that promote physiological adaptation to maintain homeostasis. However, the precise mechanisms through which adrenaline- and noradrenaline-synthesizing neurons sense interoceptive and exteroceptive cues to coordinate physiological responses have yet to be fully elucidated. Additionally, the regulatory role of these cells in the context of chronic stress has received limited attention. This mini-review consolidates reports from preclinical rodent studies on the organization and function of brainstem adrenaline and noradrenaline cells to provide a framework for how these nuclei coordinate endocrine and autonomic physiology. This includes identification of hindbrain adrenaline- and noradrenaline-producing cell groups and their role in stress responding through neurosecretory and autonomic engagement. Although temporally and mechanistically distinct, the endocrine and autonomic stress axes are complementary and interconnected. Therefore, the interplay between brainstem adrenergic/noradrenergic nuclei and peripheral physiological systems is necessary for integrated stress responses and organismal survival.
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Affiliation(s)
- Sebastian A Pace
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Brent Myers
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
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7
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Zoccal DB. Understanding the hypothalamic-brainstem bridge in the hypoxia puzzle. J Physiol 2023; 601:4243-4244. [PMID: 37698923 DOI: 10.1113/jp285387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023] Open
Affiliation(s)
- Daniel B Zoccal
- Department of Physiology and Pathology, School of Dentistry of Araraquara, São Paulo State University (UNESP), Araraquara, Brazil
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8
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Nakajima Y, Tsujimura T, Tsutsui Y, Chotirungsan T, Kawada S, Dewa N, Magara J, Inoue M. Atropine facilitates water-evoked swallows via central muscarinic receptors in anesthetized rats. Am J Physiol Gastrointest Liver Physiol 2023; 325:G109-G121. [PMID: 37219016 DOI: 10.1152/ajpgi.00039.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 05/01/2023] [Accepted: 05/16/2023] [Indexed: 05/24/2023]
Abstract
Anticholinergic medication causes impaired swallowing with hyposalivation. However, the underlying mechanisms by which these drugs modulate the swallowing reflex remain unclear. This study investigated the effects of the muscarinic acetylcholine receptor (mAChR) nonspecific antagonist atropine on the initiation of swallowing. Experiments were performed on 124 urethane-anesthetized rats. A swallow was evoked by either topical laryngeal application of a small amount of distilled water (DW), saline, citric acid, or capsaicin; upper airway distention with a continuous airflow; electrical stimulation of the superior laryngeal nerve (SLN); or focal microinjection of N-methyl-d-aspartate (NMDA) into the lateral region of the nucleus of the solitary tract (L-nTS). Swallows were identified by electromyographic bursts of the digastric and thyrohyoid muscles. Either atropine, the peripheral mAChR antagonist methylatropine, or antagonists of mAChR subtypes M1-M5 were intravenously delivered. Atropine at a dose of 1 mg/kg increased the number of DW-evoked swallows compared with baseline and did not affect the number of swallows evoked by saline, citric acid, capsaicin, or upper airway distention. Methylatropine and M1-M5 antagonists did not significantly change the number of DW-evoked swallows. Bilateral SLN transection completely abolished DW-evoked swallows, and atropine decreased the swallowing threshold of SLN electrical stimulation. Finally, microinjection of NMDA receptor antagonist AP-5 into the L-nTS inhibited DW-evoked swallows, and atropine facilitated the initiation of swallowing evoked by NMDA microinjection into this region. These results suggest that atropine facilitates DW-evoked swallows via central mAChR actions.NEW & NOTEWORTHY Atropine facilitated the distilled water (DW)-evoked swallows in anesthetized rats. Atropine decreased the swallowing threshold evoked by electrical stimulation of the superior laryngeal nerve, which is a primary sensory nerve for the initiation of DW-evoked swallows. Atropine facilitated the swallows evoked by N-methyl-d-aspartate microinjection into the lateral region of the nucleus of the solitary tract, which is involved in the DW-evoked swallows. We speculate that atropine facilitates the DW-evoked swallows via central muscarinic receptor actions.
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Affiliation(s)
- Yuta Nakajima
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Takanori Tsujimura
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yuhei Tsutsui
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Titi Chotirungsan
- Department of Oral Diagnosis, Faculty of Dentistry, Naresuan University, Muang, Phitsanulok, Thailand
| | - Satomi Kawada
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Nozomi Dewa
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Jin Magara
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Makoto Inoue
- Division of Dysphagia Rehabilitation, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Failor M, Bohler M, Cao C, Gilbert E, Cline M. Elucidating the central anorexigenic mechanism of glucagon-like peptide 1 in Japanese quail (Coturnix japonica). Gen Comp Endocrinol 2023; 339:114292. [PMID: 37088166 DOI: 10.1016/j.ygcen.2023.114292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/04/2023] [Accepted: 04/19/2023] [Indexed: 04/25/2023]
Abstract
Glucagon-like peptide 1 (GLP-1) elicits a potent reduction in food intake, although the central mechanism mediating this appetite-suppressive effect is not fully understood in all species. To begin to elucidate the molecular mechanisms in quail, we administered GLP-1 via intracerebroventricular (ICV) injection to 7-day-old Japanese quail(Coturnix japonica) and determined effects on food and water intake, behavior, and brain nucleus activation. We observed a reduction in food and water intake, with the lowest effective dose being 0.01 nmol. Quail injected with GLP-1 displayed fewer steps, feeding pecks, exploratory pecks, and jumps, while time spent sitting increased. We quantified c-Fos immunoreactivity at 60 minutes post-injection in hypothalamic and brainstem nuclei that mediate food intake and determined that the hypothalamic paraventricular nucleus (PVN), and nucleus of the solitary tract and area postrema of the brainstem were activated in response to GLP-1.In conclusion, these results suggest that GLP-1 induces anorexigenic effects that are likely mediated at the level of the PVN and brainstem.
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Affiliation(s)
- Madison Failor
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Mark Bohler
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Chang Cao
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Elizabeth Gilbert
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Mark Cline
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA.
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Ji Y, Onwukwe C, Smith J, Laub H, Posa L, Keller A, Masri R, Cramer N. Noradrenergic input from nucleus of the solitary tract regulates parabrachial activity in mice. eNeuro 2023; 10:ENEURO.0412-22.2023. [PMID: 37072175 PMCID: PMC10162360 DOI: 10.1523/eneuro.0412-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 03/29/2023] [Accepted: 03/31/2023] [Indexed: 04/20/2023] Open
Abstract
The parabrachial complex (PB) is critically involved in aversive processes, and chronic pain is associated with amplified activity of PB neurons in rodent models of neuropathic pain. Here we demonstrate that catecholaminergic input from the caudal nucleus of the solitary tract (cNTScat)-a stress responsive region that integrates intero- and exteroceptive signals-causes amplification of PB activity and their sensory afferents. We used a virally mediated expression of a norepinephrine (NE) sensor, NE2h, fiber photometry, and extracellular recordings in anesthetized mice to show that noxious mechanical and thermal stimuli activate cNTS neurons. These stimuli also produce prolonged NE transients in PB that far outlast the noxious stimuli. Similar NE transients can be evoked by focal electrical stimulation of cNTS, a region that contains the noradrenergic A2 cell group that projects densely upon PB. In vitro, optical stimulation of cNTScat terminals depolarized PB neurons and caused a prolonged increase the frequency of excitatory synaptic activity. A dual opsin approach showed that sensory afferents from the caudal spinal trigeminal nucleus are potentiated by cNTScat terminal activation. This potentiation was coupled with a decrease in the paired pulse ratio, consistent with an cNTScat -mediated increase in the probability of release at SpVc synapses. Together, these data suggest that A2 neurons of the cNTS generate long lasting NE transients in PB which increase excitability and potentiate responses of PB neurons to sensory inputs. These reveal a mechanism through which stressors from multiple modalities may potentiate the aversiveness of nociceptive stimuli.Significance StatementIncreased excitability of the parabrachial nucleus (PB), a key integrative hub for aversive stimuli, is linked to amplified pain behaviors. We show that prolonged norepinephrine (NE) transients in PB following noxious stimulation in mice. These NE transients potentiate sensory input to PB and arise, at least in part, from catecholaminergic projections from the caudal nucleus of the solitary tract (cNTScat). We propose that activity this cNTScat to PB pathway may potentiate the aversiveness of pain.
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Affiliation(s)
- Yadong Ji
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland 21201, and
| | - Chimdiya Onwukwe
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Jesse Smith
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Hanna Laub
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Luca Posa
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
| | - Asaf Keller
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Center to Advance Chronic Pain Research, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Radi Masri
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland 21201, and
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Center to Advance Chronic Pain Research, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Nathan Cramer
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, and
- Center to Advance Chronic Pain Research, University of Maryland School of Medicine, Baltimore, Maryland 21201
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11
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Kavalali ET. Interrogating synaptic transmission at circadian time scales. J Physiol 2023; 601:1697-1698. [PMID: 36994489 DOI: 10.1113/jp284668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023] Open
Affiliation(s)
- Ege T Kavalali
- Brain Institute, Vanderbilt University, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
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12
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Krohn F, Novello M, van der Giessen RS, De Zeeuw CI, Pel JJM, Bosman LWJ. The integrated brain network that controls respiration. eLife 2023; 12:83654. [PMID: 36884287 PMCID: PMC9995121 DOI: 10.7554/elife.83654] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 01/29/2023] [Indexed: 03/09/2023] Open
Abstract
Respiration is a brain function on which our lives essentially depend. Control of respiration ensures that the frequency and depth of breathing adapt continuously to metabolic needs. In addition, the respiratory control network of the brain has to organize muscular synergies that integrate ventilation with posture and body movement. Finally, respiration is coupled to cardiovascular function and emotion. Here, we argue that the brain can handle this all by integrating a brainstem central pattern generator circuit in a larger network that also comprises the cerebellum. Although currently not generally recognized as a respiratory control center, the cerebellum is well known for its coordinating and modulating role in motor behavior, as well as for its role in the autonomic nervous system. In this review, we discuss the role of brain regions involved in the control of respiration, and their anatomical and functional interactions. We discuss how sensory feedback can result in adaptation of respiration, and how these mechanisms can be compromised by various neurological and psychological disorders. Finally, we demonstrate how the respiratory pattern generators are part of a larger and integrated network of respiratory brain regions.
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Affiliation(s)
- Friedrich Krohn
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | - Manuele Novello
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | | | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands.,Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences, Amsterdam, Netherlands
| | - Johan J M Pel
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
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13
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Colzato LS, Elmers J, Beste C, Hommel B. A Prospect to Ameliorate Affective Symptoms and to Enhance Cognition in Long COVID Using Auricular Transcutaneous Vagus Nerve Stimulation. J Clin Med 2023; 12:jcm12031198. [PMID: 36769845 PMCID: PMC9917620 DOI: 10.3390/jcm12031198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Long COVID, the postviral disorder caused by COVID-19, is expected to become one of the leading causes of disability in Europe. The cognitive consequences of long COVID have been described as "brain fog" and characterized by anxiety and depression, and by cognitive deficits. Long COVID is assumed to be a complex condition arising from multiple causes, including persistent brainstem dysfunction and disrupted vagal signaling. We recommend the potential application of auricular transcutaneous vagus nerve stimulation (atVNS) as an ADD-ON instrument to compensate for the cognitive decline and to ameliorate affective symptoms caused by long COVID. This technique enhances vagal signaling by directly activating the nuclei in the brainstem, which are hypoactive in long COVID to enhance mood and to promote attention, memory, and cognitive control-factors affected by long COVID. Considering that atVNS is a non-pharmacological intervention, its ADD-ON to standard pharmaceutical agents will be useful for non-responders, making of this method a suitable tool. Given that atVNS can be employed as an ecological momentary intervention (EMI), we outline the translational advantages of atVNS in the context of accelerating the cognitive and affective recovery from long COVID.
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Affiliation(s)
- Lorenza S. Colzato
- Cognitive Psychology, Faculty of Psychology, Shandong Normal University, Jinan 250014, China
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Dresden University of Technology, 01307 Dresden, Germany
- Center of Clinical Neuroscience, Department of Neurology, University Hospital Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
| | - Julia Elmers
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Dresden University of Technology, 01307 Dresden, Germany
- Center of Clinical Neuroscience, Department of Neurology, University Hospital Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
| | - Christian Beste
- Cognitive Psychology, Faculty of Psychology, Shandong Normal University, Jinan 250014, China
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Dresden University of Technology, 01307 Dresden, Germany
- Center of Clinical Neuroscience, Department of Neurology, University Hospital Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
| | - Bernhard Hommel
- Cognitive Psychology, Faculty of Psychology, Shandong Normal University, Jinan 250014, China
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, Dresden University of Technology, 01307 Dresden, Germany
- Center of Clinical Neuroscience, Department of Neurology, University Hospital Carl Gustav Carus, Dresden University of Technology, 01307 Dresden, Germany
- Correspondence:
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14
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Rowland NE. Neurobehavioral Mechanisms of Sodium Appetite. Nutrients 2023; 15. [PMID: 36771327 DOI: 10.3390/nu15030620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/05/2023] [Accepted: 01/18/2023] [Indexed: 01/27/2023] Open
Abstract
The objectives of this paper are to first present physiological and ecological aspects of the unique motivational state of sodium appetite, then to focus on systemic physiology and brain mechanisms. I describe how laboratory protocols have been developed to allow the study of sodium appetite under controlled conditions, and focus on two such conditions specifically. The first of these is the presentation a sodium-deficient diet (SDD) for at least one week, and the second is accelerated sodium loss using SDD for 1-2 days coupled with the diuretic furosemide. The modality of consumption is also considered, ranging from a free intake of high concentration of sodium solution, to sodium-rich food or gels, and to operant protocols. I describe the pivotal role of angiotensin and aldosterone in these appetites and discuss whether the intakes or appetite are matched to the physiological need state. Several brain systems have been identified, most recently and microscopically using molecular biological methods. These include clusters in both the hindbrain and the forebrain. Satiation of sodium appetite is often studied using concentrated sodium solutions, but these can be consumed in apparent excess, and I suggest that future studies of satiation might emulate natural conditions in which excess consumption does not occur, using either SDD only as a stimulus, offering a sodium-rich food for the assessment of appetite, or a simple operant task.
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15
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Yao Y, Barger Z, Saffari Doost M, Tso CF, Darmohray D, Silverman D, Liu D, Ma C, Cetin A, Yao S, Zeng H, Dan Y. Cardiovascular baroreflex circuit moonlights in sleep control. Neuron 2022; 110:3986-3999.e6. [PMID: 36170850 DOI: 10.1016/j.neuron.2022.08.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/02/2022] [Accepted: 08/29/2022] [Indexed: 01/04/2023]
Abstract
Sleep disturbances are strongly associated with cardiovascular diseases. Baroreflex, a basic cardiovascular regulation mechanism, is modulated by sleep-wake states. Here, we show that neurons at key stages of baroreflex pathways also promote sleep. Using activity-dependent genetic labeling, we tagged neurons in the nucleus of the solitary tract (NST) activated by blood pressure elevation and confirmed their barosensitivity with optrode recording and calcium imaging. Chemogenetic or optogenetic activation of these neurons promoted non-REM sleep in addition to decreasing blood pressure and heart rate. GABAergic neurons in the caudal ventrolateral medulla (CVLM)-a downstream target of the NST for vasomotor baroreflex-also promote non-REM sleep, partly by inhibiting the sympathoexcitatory and wake-promoting adrenergic neurons in the rostral ventrolateral medulla (RVLM). Cholinergic neurons in the nucleus ambiguous-a target of the NST for cardiac baroreflex-promoted non-REM sleep as well. Thus, key components of the cardiovascular baroreflex circuit are also integral to sleep-wake brain-state regulation.
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Affiliation(s)
- Yuanyuan Yao
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Zeke Barger
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Mohammad Saffari Doost
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Chak Foon Tso
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Dana Darmohray
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Daniel Silverman
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Danqian Liu
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Chenyan Ma
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ali Cetin
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Shenqin Yao
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Yang Dan
- Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
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16
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Xie Z, Zhang X, Zhao M, Huo L, Huang M, Li D, Zhang S, Cheng X, Gu H, Zhang C, Zhan C, Wang F, Shang C, Cao P. The gut-to-brain axis for toxin-induced defensive responses. Cell 2022; 185:4298-4316.e21. [PMID: 36323317 DOI: 10.1016/j.cell.2022.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/16/2022] [Accepted: 09/30/2022] [Indexed: 11/11/2022]
Abstract
After ingestion of toxin-contaminated food, the brain initiates a series of defensive responses (e.g., nausea, retching, and vomiting). How the brain detects ingested toxin and coordinates diverse defensive responses remains poorly understood. Here, we developed a mouse-based paradigm to study defensive responses induced by bacterial toxins. Using this paradigm, we identified a set of molecularly defined gut-to-brain and brain circuits that jointly mediate toxin-induced defensive responses. The gut-to-brain circuit consists of a subset of Htr3a+ vagal sensory neurons that transmit toxin-related signals from intestinal enterochromaffin cells to Tac1+ neurons in the dorsal vagal complex (DVC). Tac1+ DVC neurons drive retching-like behavior and conditioned flavor avoidance via divergent projections to the rostral ventral respiratory group and lateral parabrachial nucleus, respectively. Manipulating these circuits also interferes with defensive responses induced by the chemotherapeutic drug doxorubicin. These results suggest that food poisoning and chemotherapy recruit similar circuit modules to initiate defensive responses.
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Affiliation(s)
- Zhiyong Xie
- National Institute of Biological Sciences, Beijing, China; Department of Psychological Medicine, Zhongshan Hospital, State Key Laboratory of Medical Neurobiology, Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China.
| | - Xianying Zhang
- National Institute of Biological Sciences, Beijing, China; College of Life Sciences, Beijing Normal University, Beijing, China
| | - Miao Zhao
- National Institute of Biological Sciences, Beijing, China
| | - Lifang Huo
- Innovation Center for Advanced Interdisciplinary Medicine, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Laboratory, Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| | - Meizhu Huang
- National Institute of Biological Sciences, Beijing, China; Innovation Center for Advanced Interdisciplinary Medicine, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Laboratory, Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| | - Dapeng Li
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | | | - Xinyu Cheng
- National Institute of Biological Sciences, Beijing, China
| | - Huating Gu
- National Institute of Biological Sciences, Beijing, China
| | - Chen Zhang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Cheng Zhan
- School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Fengchao Wang
- National Institute of Biological Sciences, Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China.
| | - Congping Shang
- Innovation Center for Advanced Interdisciplinary Medicine, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Laboratory, Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China.
| | - Peng Cao
- National Institute of Biological Sciences, Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China.
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17
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Escanilla OD, Hajnal A, Czaja K, Di Lorenzo PM. The Neural Code for Taste in the Nucleus of the Solitary Tract of Rats with Obesity Following Roux-En-Y Gastric Bypass Surgery. Nutrients 2022; 14:4129. [PMID: 36235781 DOI: 10.3390/nu14194129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/26/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022] Open
Abstract
Previous work has shown that taste responses in the nucleus tractus solitarius (NTS; the first central relay for gustation) are blunted in rats with diet-induced obesity (DIO). Here, we studied whether these effects could be reversed by Roux-en-Y gastric bypass (RYGB) surgery, an effective treatment for obesity. Rats were fed a high energy diet (60% kcal fat; HED) both before and after undergoing RYGB. Electrophysiological responses from NTS cells in unrestrained rats were recorded as they licked tastants from a lick spout. Sweet, salty, and umami tastes, as well as their naturalistic counterparts, were presented. Results were compared with those of lean rats from a previous study. As with DIO rats, NTS cells in RYGB rats were more narrowly tuned, showed weaker responses, and less lick coherence than those in lean rats. Both DIO and RYGB rats licked at a slower rate than lean rats and paused more often during a lick bout. However, unlike DIO rats, the proportion of taste cells in RYGB rats was similar to that in lean rats. Our data show that, despite being maintained on a HED after surgery, RYGB can induce a partial recovery of the deficits seen in the NTS of DIO rats.
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18
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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19
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Konno D, Sugino S, Shibata TF, Misawa K, Imamura-Kawasawa Y, Suzuki J, Kido K, Nagasaki M, Yamauchi M. Antiemetic effects of baclofen in a shrew model of postoperative nausea and vomiting: Whole-transcriptome analysis in the nucleus of the solitary tract. CNS Neurosci Ther 2022; 28:922-931. [PMID: 35238164 PMCID: PMC9062569 DOI: 10.1111/cns.13823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 11/28/2022] Open
Abstract
Aims The molecular genetic mechanisms underlying postoperative nausea and vomiting (PONV) in the brain have not been fully elucidated. This study aimed to determine the changes in whole transcriptome in the nucleus of the solitary tract (NTS) in an animal model of PONV, to screen a drug candidate and to elucidate the molecular genetic mechanisms of PONV development. Methods Twenty‐one female musk shrews were assigned into three groups: the Surgery group (shrew PONV model, n = 9), the Sham group (n = 6), and the Naïve group (n = 6). In behavioral studies, the main outcome was the number of emetic episodes. In genetic experiments, changes in the transcriptome in the NTS were measured. In a separate study, 12 shrews were used to verify the candidate mechanism underlying PONV. Results A median of six emetic episodes occurred in both the Sham and Surgery groups. Whole‐transcriptome analysis indicated the inhibition of the GABAB receptor‐mediated signaling pathway in the PONV model. Baclofen (GABAB receptor agonist) administration eliminated emetic behaviors in the shrew PONV model. Conclusions Our findings suggest that the GABAB receptor‐mediated signaling pathway is involved in emesis and that baclofen may be a novel therapeutic or prophylactic agent for PONV.
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Affiliation(s)
- Daisuke Konno
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan.,Department of Integrative Genomics, Tohoku University Tohoku Medical Megabank Organization, Sendai, Japan
| | - Shigekazu Sugino
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Tomoko F Shibata
- Department of Integrative Genomics, Tohoku University Tohoku Medical Megabank Organization, Sendai, Japan
| | - Kazuharu Misawa
- Department of Integrative Genomics, Tohoku University Tohoku Medical Megabank Organization, Sendai, Japan.,Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yuka Imamura-Kawasawa
- Department of Pharmacology, Biochemistry and Molecular Biology, Institute for Personalized Medicine, Pennsylvania State University College of Medicine, Hershey, USA
| | - Jun Suzuki
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Kanta Kido
- Department of Anesthesiology, Kanagawa Dental University Graduate School of Dentistry, Yokosuka, Japan
| | - Masao Nagasaki
- Department of Integrative Genomics, Tohoku University Tohoku Medical Megabank Organization, Sendai, Japan.,Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, Japan
| | - Masanori Yamauchi
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
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20
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Bartonjo J, Masterson S, J St John S, Lundy R. Perturbation of amygdala/somatostatin- nucleus of the solitary tract projections reduces sensitivity to quinine in a brief-access test. Brain Res 2022;:147838. [PMID: 35182570 DOI: 10.1016/j.brainres.2022.147838] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 12/21/2022]
Abstract
Neural processing in the nucleus of the solitary tract (NST) is critical for concentration-dependent intake of normally preferred and avoided taste stimuli (e.g. affective responding); and is influenced by descending input from numerous forebrain regions. In one region, the central nucleus of the amygdala (CeA), a subpopulation of neurons that project to the NST express the neuropeptide somatostatin (Sst). The present study investigated whether this CeA/Sst-to-NST pathway contributes to concentration-dependent intake of sucrose and quinine hydrochloride (QHCl) solutions using brief-access lick trials (5s). In both female and male mice, we used virus-based optogenetic tools and laser light illumination to manipulate the activity of CeA/Sst neurons that project to the NST. During light-induced inhibition of CeA/Sst-to-NST neurons, mice licked significantly more to our three highest concentrations of QHCl compared to control mice, while sucrose intake was unaffected. Interestingly, light-induced activation of this descending pathway did not influence licking of either sucrose or QHCl. These findings suggest that the CeA/Sst-to-NST pathway must be active for normal affective responding to an exemplary aversive taste stimulus.
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21
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Janes TA, Ambrozio-Marques D, Fournier S, Joseph V, Soliz J, Kinkead R. Testosterone Supplementation Induces Age-Dependent Augmentation of the Hypoxic Ventilatory Response in Male Rats With Contributions From the Carotid Bodies. Front Physiol 2022; 12:781662. [PMID: 35002764 PMCID: PMC8741195 DOI: 10.3389/fphys.2021.781662] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/03/2021] [Indexed: 12/30/2022] Open
Abstract
Excessive carotid body responsiveness to O2 and/or CO2/H+ stimuli contributes to respiratory instability and apneas during sleep. In hypogonadal men, testosterone supplementation may increase the risk of sleep-disordered breathing; however, the site of action is unknown. The present study tested the hypothesis that testosterone supplementation potentiates carotid body responsiveness to hypoxia in adult male rats. Because testosterone levels decline with age, we also determined whether these effects were age-dependent. In situ hybridization determined that androgen receptor mRNA was present in the carotid bodies and caudal nucleus of the solitary tract of adult (69 days old) and aging (193–206 days old) male rats. In urethane-anesthetized rats injected with testosterone propionate (2 mg/kg; i.p.), peak breathing frequency measured during hypoxia (FiO2 = 0.12) was 11% greater vs. the vehicle treatment group. Interestingly, response intensity following testosterone treatment was positively correlated with animal age. Exposing ex vivo carotid body preparations from young and aging rats to testosterone (5 nM, free testosterone) 90–120 min prior to testing showed that the carotid sinus nerve firing rate during hypoxia (5% CO2 + 95% N2; 15 min) was augmented in both age groups as compared to vehicle (<0.001% DMSO). Ventilatory measurements performed using whole body plethysmography revealed that testosterone supplementation (2 mg/kg; i.p.) 2 h prior reduced apnea frequency during sleep. We conclude that in healthy rats, age-dependent potentiation of the carotid body’s response to hypoxia by acute testosterone supplementation does not favor the occurrence of apneas but rather appears to stabilize breathing during sleep.
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Affiliation(s)
- Tara A Janes
- Department of Physiology, Women and Children's Health Research Institute, University of Alberta, Edmonton, AB, Canada.,Department of Pediatrics, Québec Heart and Lung Institute, Université Laval, Québec, QC, Canada
| | | | - Sébastien Fournier
- Department of Surgery, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - Vincent Joseph
- Department of Pediatrics, Québec Heart and Lung Institute, Université Laval, Québec, QC, Canada
| | - Jorge Soliz
- Department of Pediatrics, Québec Heart and Lung Institute, Université Laval, Québec, QC, Canada
| | - Richard Kinkead
- Department of Pediatrics, Québec Heart and Lung Institute, Université Laval, Québec, QC, Canada
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22
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Reiner BC, Crist RC, Borner T, Doyle RP, Hayes MR, De Jonghe BC. Single nuclei RNA sequencing of the rat AP and NTS following GDF15 treatment. Mol Metab 2021; 56:101422. [PMID: 34942400 PMCID: PMC8749158 DOI: 10.1016/j.molmet.2021.101422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/30/2021] [Accepted: 12/16/2021] [Indexed: 12/04/2022] Open
Abstract
Objective Growth differentiation factor 15 (GDF15) is known to play a role in feeding, nausea, and body weight, with action through the GFRAL-RET receptor complex in the area postrema (AP) and nucleus tractus solitarius (NTS). To further elucidate the underlying cell type-specific molecular mechanisms downstream of GDF15 signaling, we used a single nuclei RNA sequencing (snRNAseq) approach to profile AP and NTS cellular subtype-specific transcriptomes after systemic GDF15 treatment. Methods AP and NTS micropunches were used for snRNAseq from Sprague Dawley rats 6 h following GDF15 or saline injection, and Seurat was used to identify cellular subtypes and cell type-specific alterations in gene expression that were due to the direct and secondary effects of systemic GDF15 treatment. Results Using the transcriptome profile of ∼35,000 individual AP/NTS nuclei, we identified 19 transcriptomically distinct cellular subtypes, including a single population Gfral and Ret positive excitatory neurons, representing the primary site of action for GDF15. A total of ∼600 cell type-specific differential expression events were identified in neurons and glia, including the identification of transcriptome alterations specific to the direct effects of GDF15 in the Gfral-Ret positive excitatory neurons and shared transcriptome alterations across neuronal and glial cell types. Downstream analyses identified shared and cell type-specific alterations in signaling pathways and upstream regulatory mechanisms of the observed transcriptome alterations. Conclusions These data provide a considerable advance in our understanding of AP and NTS cell type-specific molecular mechanisms associated with GDF15 signaling. The identified cellular subtype-specific regulatory mechanism and signaling pathways likely represent important targets for future pharmacotherapies. GDF15 directly alters transcription in Gfral- and Ret-positive excitatory neurons. GDF15 indirectly alters transcription in other neuronal and glial populations. Cell type-specific expression changes identify regulatory and signaling mechanisms.
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Affiliation(s)
- Benjamin C Reiner
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
| | - Richard C Crist
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Tito Borner
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Department of Biobehavioral Health Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Robert P Doyle
- Syracuse University, Department of Chemistry, 111 College Place, Syracuse, New York 13244
| | - Matthew R Hayes
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Department of Biobehavioral Health Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Bart C De Jonghe
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Department of Biobehavioral Health Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
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McCaughey SA. Variation in the gene Tas1r3 reveals complex temporal properties of mouse brainstem taste responses to sweeteners. Am J Physiol Regul Integr Comp Physiol 2021; 321:R751-R767. [PMID: 34523351 PMCID: PMC8616626 DOI: 10.1152/ajpregu.00001.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 11/22/2022]
Abstract
The gene Tas1r3 codes for the protein T1R3, which dimerizes with T1R2 to form a sweetener-binding receptor in taste cells. Tas1r3 influences sweetener preferences in mice, as shown by work with a 129.B6-Tas1r3 segregating congenic strain on a 129P3/J (129) genetic background; members of this strain vary in whether they do or do not have one copy of a donor fragment with the C57BL/6ByJ (B6) allele for Tas1r3 (B6/129 and 129/129 mice, respectively). Taste-evoked neural responses were measured in the nucleus of the solitary tract (NST), the first central gustatory relay, in B6/129 and 129/129 littermates, to examine how the activity dependent on the T1R2/T1R3 receptor is distributed across neurons and over time. Responses to sucrose were larger in B6/129 than in 129/129 mice, but only during a later, tonic response portion (>600 ms) sent to different cells than the earlier, phasic response. Similar results were found for artificial sweeteners, whose responses were best considered as complex spatiotemporal patterns. There were also group differences in burst firing of NST cells, with a significant positive correlation between bursting prevalence and sucrose response size in only the 129/129 group. The results indicate that sweetener transduction initially occurs through T1R3-independent mechanisms, after which the T1R2/T1R3 receptor initiates a separate, spatially distinct response, with the later period dominating sweet taste perceptions and driving sugar preferences. Furthermore, the current data suggest that burst firing is distributed across NST neurons nonrandomly and in a manner that may amplify weak incoming gustatory signals.
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Affiliation(s)
- Stuart A McCaughey
- Center for Medical Education, Ball State University, Muncie, Indiana
- Monell Chemical Senses Center, Philadelphia, Pennsylvania
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Cooper CM, Farrand AQ, Andresen MC, Beaumont E. Vagus nerve stimulation activates nucleus of solitary tract neurons via supramedullary pathways. J Physiol 2021; 599:5261-5279. [PMID: 34676533 DOI: 10.1113/jp282064] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/12/2021] [Indexed: 01/20/2023] Open
Abstract
Vagus nerve stimulation (VNS) treats patients with drug-resistant epilepsy, depression and heart failure, but the mechanisms responsible are uncertain. The mild stimulus intensities used in chronic VNS suggest activation of myelinated primary visceral afferents projecting to the nucleus of the solitary tract (NTS). Here, we monitored the activity of second and higher order NTS neurons in response to peripheral vagal activation using therapeutic VNS criteria. A bipolar stimulating electrode activated the left cervical vagus nerve, and stereotaxically placed single tungsten electrodes recorded unit activity from the left caudomedial NTS of chloralose-anaesthetized rats. High-intensity single electrical stimuli established vagal afferent conduction velocity (myelinated A-type or unmyelinated C-type) as well as synaptic order (second vs. higher order using paired electrical stimuli) for inputs to single NTS neurons. Then, VNS treatment was applied. A mid-collicular knife cut (KC) divided the brainstem from all supramedullary regions to determine their contribution to NTS activity. Our chief findings indicate that the KC reduced basal spontaneous activity of second-order NTS neurons receiving myelinated vagal input by 85%. In these neurons, acute VNS increased activity similarly in Control and KC animals. Interestingly, the KC interrupted VNS activation of higher order NTS neurons and second-order NTS neurons receiving unmyelinated vagal input, indicating that supramedullary descending projections to NTS are needed to amplify the peripheral neuronal signal from VNS. The present study begins to define the pathways activated during VNS and will help to better identify the central nervous system contributions to the therapeutic benefits of VNS therapy. KEY POINTS: Vagus nerve stimulation is routinely used in the clinic to treat epilepsy and depression, despite our uncertainty about how this treatment works. For this study, the connections between the nucleus of the solitary tract (NTS) and the higher brain regions were severed to learn more about their contribution to activity of these neurons during stimulation. Severing these brain connections reduced baseline activity as well as reducing stimulation-induced activation for NTS neurons receiving myelinated vagal input. Higher brain regions play a significant role in maintaining both normal activity in NTS and indirect mechanisms of enhancing NTS neuronal activity during vagus nerve stimulation.
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Affiliation(s)
- Coty M Cooper
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Ariana Q Farrand
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | | | - Eric Beaumont
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
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Chrobok L, Klich JD, Sanetra AM, Jeczmien-Lazur JS, Pradel K, Palus-Chramiec K, Kepczynski M, Piggins HD, Lewandowski MH. Rhythmic neuronal activities of the rat nucleus of the solitary tract are impaired by high-fat diet - implications for daily control of satiety. J Physiol 2021; 600:751-767. [PMID: 34490628 DOI: 10.1113/jp281838] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Temporal partitioning of daily food intake is crucial for survival and involves the integration of internal circadian states and external influences such as the light-dark cycle and dietary composition. These intrinsic and extrinsic factors are interdependent with misalignment of circadian rhythms promoting body weight gain, while consumption of a calorie-dense diet elevates the risk of obesity and blunts circadian rhythms. Recently, we defined the circadian properties of the dorsal vagal complex of the brainstem, a structure implicated in the control of food intake and autonomic tone, but whether and how 24 h rhythms in this area are influenced by diet remains unresolved. Here we focused on a key structure of this complex, the nucleus of the solitary tract (NTS). We used a combination of immunohistochemical and electrophysiological approaches together with daily monitoring of body weight and food intake to interrogate how the neuronal rhythms of the NTS are affected by a high-fat diet. We report that short-term consumption of a high-fat diet increases food intake during the day and blunts NTS daily rhythms in neuronal discharge. Additionally, we found that a high-fat diet dampens NTS responsiveness to metabolic neuropeptides, and decreases orexin immunoreactive fibres in this structure. These alterations occur without prominent body weight gain, suggesting that a high-fat diet acts initially to reduce activity in the NTS to disinhibit mechanisms that suppress daytime feeding. KEY POINTS: The dorsal vagal complex of the rodent hindbrain possesses intrinsic circadian timekeeping mechanisms In particular, the nucleus of the solitary tract (NTS) is a robust circadian oscillator, independent of the master suprachiasmatic clock Here, we reveal that rat NTS neurons display timed daily rhythms in their neuronal activity and responsiveness to ingestive cues These daily rhythms are blunted or eliminated by a short-term high-fat diet, together with increased consumption of calories during the behaviourally quiescent day Our results help us better understand the circadian control of satiety by the brainstem and its malfunctioning under a high-fat diet.
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Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jasmin D Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Anna M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda S Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Mariusz Kepczynski
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland
| | - Hugh D Piggins
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
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Pirník Z, Kořínková L, Osacká J, Železná B, Kuneš J, Maletínská L. Cholecystokinin system is involved in the anorexigenic effect of peripherally applied palmitoylated prolactin-releasing peptide in fasted mice. Physiol Res 2021; 70:579-590. [PMID: 34062082 PMCID: PMC8820541 DOI: 10.33549/physiolres.934694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/22/2021] [Indexed: 11/25/2022] Open
Abstract
Prolactin-releasing peptide (PrRP) has been proposed to mediate the central satiating effects of cholecystokinin (CCK) through the vagal CCK1 receptor. PrRP acts as an endogenous ligand of G protein-coupled receptor 10 (GPR10), which is expressed at the highest levels in brain areas related to food intake regulation, e.g., the paraventricular hypothalamic nucleus (PVN) and nucleus of the solitary tract (NTS). The NTS and PVN are also significantly activated after peripheral CCK administration. The aim of this study was to determine whether the endogenous PrRP neuronal system in the brain is involved in the central anorexigenic effect of the peripherally administered CCK agonist JMV236 or the CCK1 antagonist devazepide and whether the CCK system is involved in the central anorexigenic effect of the peripherally applied lipidized PrRP analog palm-PrRP31 in fasted lean mice. The effect of devazepide and JMV236 on the anorexigenic effects of palm-PrRP31 as well as devazepide combined with JMV236 and palm-PrRP31 on food intake and Fos cell activation in the PVN and caudal NTS was examined. Our results suggest that the anorexigenic effect of JMV236 is accompanied by activation of PrRP neurons of the NTS in a CCK1 receptor-dependent manner. Moreover, while the anorexigenic effect of palm-PrRP31 was not affected by JMV236, it was partially attenuated by devazepide in fasted mice. The present findings indicate that the exogenously influenced CCK system may be involved in the central anorexigenic effect of peripherally applied palm-PrRP31, which possibly indicates some interaction between the CCK and PrRP neuronal systems.
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Affiliation(s)
- Z Pirník
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic,
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Holt MK. Mind affects matter: Hindbrain GLP1 neurons link stress, physiology and behaviour. Exp Physiol 2021; 106:1853-1862. [PMID: 34302307 DOI: 10.1113/ep089445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 07/19/2021] [Indexed: 12/12/2022]
Abstract
NEW FINDINGS What is the topic of this review? This Lecture covers the role of caudal brainstem GLP1 neurons in acute and chronic stress responses. What advances does it highlight? This Lecture focuses on the recent advances in our understanding of GLP1 neurons and their physiological role in many aspects of stress. Particular focus is given to the recent elucidation, in part, of the anatomical basis for recruitment of GLP1 neurons in response to acute stress. Finally, the potential, but at this time somewhat speculative, role of GLP1 neurons in chronic stress is discussed. ABSTRACT The brain responds rapidly to stressful stimuli by increasing sympathetic outflow, activating the hypothalamic-pituitary-adrenal axis and eliciting avoidance behaviours to limit risks to safety. Stress responses are adaptive and essential but can become maladaptive when the stress is chronic, causing autonomic imbalance, hypothalamic-pituitary-adrenal axis hyper-reactivity and a state of hypervigilance. Ultimately, this contributes to the development of cardiovascular disease and affective disorders, including major depression and anxiety. Stress responses are often thought to be driven mainly by forebrain areas; however, the brainstem nucleus of the solitary tract (NTS) is ideally located to control both autonomic outflow and behaviour in response to stress. Here, I review the preclinical evidence that the NTS and its resident glucagon-like peptide-1 (GLP1)-expressing neurons are prominent mediators of stress responses. This Lecture introduces the reader to the idea of good and bad stress and outlines the types of stress that engage the NTS and GLP1 neurons. I describe in particular detail the recent studies by myself and others aimed at mapping sources of synaptic inputs to GLP1 neurons and consider the implications for our understanding of the role of GLP1 neurons in stress. This is followed by a discussion of the contribution of brain GLP1 and GLP1 neurons to behavioural and physiological stress responses. The evidence reviewed highlights a potentially prominent role for GLP1 neurons in the response of the brain to acute stress and reveals important unanswered questions regarding their role in chronic stress.
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Affiliation(s)
- Marie K Holt
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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Sugino S, Konno D, Abe J, Imamura-Kawasawa Y, Kido K, Suzuki J, Endo Y, Yamauchi M. Crucial involvement of catecholamine neurotransmission in postoperative nausea and vomiting: Whole-transcriptome profiling in the rat nucleus of the solitary tract. Genes Brain Behav 2021; 20:e12759. [PMID: 34114352 DOI: 10.1111/gbb.12759] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 05/21/2021] [Accepted: 06/09/2021] [Indexed: 11/29/2022]
Abstract
The genetic mechanisms of postoperative nausea and vomiting (PONV) and the involvement of the catecholamine system in the brain have not been elucidated. Eating kaolin clay as a type of pica has been examined as an alternative behavior to emesis. Here, we evaluated changes in whole-transcriptome analysis in the nucleus of the solitary tract (NTS) in a rat pica model as a surrogate behavior of PONV to elucidate the molecular genetic mechanisms of the development of PONV and the involvement of the catecholamine system in the NTS. First, kaolin pica behaviors were investigated in 71 female Wistar rats following isoflurane anesthesia, surgical insult or morphine administration. Multiple linear regression analysis showed that 3 mg/kg morphine increased kaolin intake by 2.8 g (P = 0.0002). Next, total RNA and protein were extracted from the dissected NTS, and whole-transcriptome sequencing (RNA-seq) was performed to identify PONV-associated genes and to verify the involvement of the catecholamine system. The gene expression levels of tyrosine hydroxylase and dopamine beta-hydroxylase in the catecholamine biosynthesis pathway decreased significantly in the PONV model. Release of noradrenaline, a catecholamine pathway end product, may have increased at the synaptic terminal of the NTS neuron after pica behavior. Systematic administration of α2 adrenergic receptor agonists after surgery reduced kaolin intake from 3.2 g (control) to 1.0 g (P = 0.0014). These results indicated that catecholamine neurotransmission was involved in the development of PONV in the NTS.
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Affiliation(s)
- Shigekazu Sugino
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Daisuke Konno
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Junko Abe
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Yuka Imamura-Kawasawa
- Department of Pharmacology, Department of Biochemistry and Molecular Biology, Institute for Personalized Medicine, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
| | - Kanta Kido
- Department of Anesthesiology, Kanagawa Dental University Graduate School of Dentistry, Yokosuka, Japan
| | - Jun Suzuki
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Yasuhiro Endo
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
| | - Masanori Yamauchi
- Department of Anesthesiology and Perioperative Medicine, Tohoku University School of Medicine, Sendai, Japan
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Hinojo CM, Ciarlone GE, D'Agostino DP, Dean JB. Exogenous ketone salts inhibit superoxide production in the rat caudal solitary complex during exposure to normobaric and hyperbaric hyperoxia. J Appl Physiol (1985) 2021; 130:1936-1954. [PMID: 33661724 DOI: 10.1152/japplphysiol.01071.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The use of hyperbaric oxygen (HBO2) in hyperbaric and undersea medicine is limited by the risk of seizures [i.e., central nervous system (CNS) oxygen toxicity, CNS-OT] resulting from increased production of reactive oxygen species (ROS) in the CNS. Importantly, ketone supplementation has been shown to delay onset of CNS-OT in rats by ∼600% in comparison with control groups (D'Agostino DP, Pilla R, Held HE, Landon CS, Puchowicz M, Brunengraber H, Ari C, Arnold P, Dean JB. Am J Physiol Regu Integr Comp Physiol 304: R829-R836, 2013). We have tested the hypothesis that ketone body supplementation inhibits ROS production during exposure to hyperoxygenation in rat brainstem cells. We measured the rate of cellular superoxide ([Formula: see text]) production in the caudal solitary complex (cSC) in rat brain slices using a fluorogenic dye, dihydroethidium (DHE), during exposure to control O2 (0.4 ATA) followed by 1-2 h of normobaric oxygen (NBO2) (0.95 ATA) and HBO2 (1.95, and 4.95 ATA) hyperoxia, with and without a 50:50 mixture of ketone salts (KS) dl-β-hydroxybutyrate + acetoacetate. All levels of hyperoxia tested stimulated [Formula: see text] production similarly in cSC cells and coexposure to 5 mM KS during hyperoxia significantly blunted the rate of increase in DHE fluorescence intensity during exposure to hyperoxia. Not all cells tested produced [Formula: see text] at the same rate during exposure to control O2 and hyperoxygenation; cells that increased [Formula: see text] production by >25% during hyperoxia in comparison with baseline were inhibited by KS, whereas cells that did not reach that threshold during hyperoxia were unaffected by KS. These findings support the hypothesis that ketone supplementation decreases the steady-state concentrations of superoxide produced during exposure to NBO2 and HBO2 hyperoxia.NEW & NOTEWORTHY Exposure of rat medullary tissue slices to levels of O2 that mimic those that cause seizures in rats stimulates cellular superoxide ([Formula: see text]) production to varying degrees. Cellular [Formula: see text] generation in the caudal solitary complex is variable during exposure to control O2 and hyperoxia and significantly decreases during ketone supplementation. Our findings support the theory that ketone supplementation delays onset of central nervous system oxygen toxicity in mammals, in part, by decreasing [Formula: see text] production in O2-sensitive neurons.
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Affiliation(s)
- Christopher M Hinojo
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida
| | - Geoffrey E Ciarlone
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida
| | - Dominic P D'Agostino
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida.,Institute of Human and Machine Cognition, Ocala, Florida
| | - Jay B Dean
- Department of Molecular Pharmacology and Physiology, Hyperbaric Biomedical Research Laboratory, Morsani College of Medicine, MDC 8, University of South Florida, Tampa, Florida
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Chrobok L, Wojcik M, Klich JD, Pradel K, Lewandowski MH, Piggins HD. Phasic Neuronal Firing in the Rodent Nucleus of the Solitary Tract ex vivo. Front Physiol 2021; 12:638695. [PMID: 33762969 PMCID: PMC7982836 DOI: 10.3389/fphys.2021.638695] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/10/2021] [Indexed: 02/02/2023] Open
Abstract
Phasic pattern of neuronal activity has been previously described in detail for magnocellular vasopressin neurons in the hypothalamic paraventricular and supraoptic nuclei. This characteristic bistable pattern consists of alternating periods of electrical silence and elevated neuronal firing, implicated in neuropeptide release. Here, with the use of multi-electrode array recordings ex vivo, we aimed to study the firing pattern of neurons in the nucleus of the solitary tract (NTS) - the brainstem hub for homeostatic, cardio-vascular, and metabolic processes. Our recordings from the mouse and rat hindbrain slices reveal the phasic activity pattern to be displayed by a subset of neurons in the dorsomedial NTS subjacent to the area postrema (AP), with the inter-spike interval distribution closely resembling that reported for phasic magnocellular vasopressin cells. Additionally, we provide interspecies comparison, showing higher phasic frequency and firing rate of phasic NTS cells in mice compared to rats. Further, we describe daily changes in their firing rate and pattern, peaking at the middle of the night. Last, we reveal these phasic cells to be sensitive to α 2 adrenergic receptors activation and to respond to electrical stimulation of the AP. This study provides a comprehensive description of the phasic neuronal activity in the rodent NTS and identifies it as a potential downstream target of the AP noradrenergic system.
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Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland.,Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Michal Wojcik
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Jasmin Daniela Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Marian Henryk Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Hugh David Piggins
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,School of Physiology, Pharmacology, and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, United Kingdom
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Sammons JD, Bass CE, Victor JD, Di Lorenzo PM. Enhancing GABAergic Tone in the Rostral Nucleus of the Solitary Tract Reconfigures Sensorimotor Neural Activity. J Neurosci 2021; 41:489-501. [PMID: 33234608 DOI: 10.1523/JNEUROSCI.0388-20.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 11/11/2020] [Accepted: 11/15/2020] [Indexed: 11/21/2022] Open
Abstract
Recent work has shown that most cells in the rostral, gustatory portion of the nucleus tractus solitarius (rNTS) in awake, freely licking rats show lick-related firing. However, the relationship between taste-related and lick-related activity in rNTS remains unclear. Here, we tested whether GABA-derived inhibitory activity regulates the balance of lick- and taste-driven neuronal activity. Combinatorial viral tools were used to restrict the expression of channelrhodopsin 2-enhanced yellow fluorescent protein to GAD1+ GABAergic neurons. Viral infusions were bilateral in rNTS. A fiber-optic fiber attached to a bundle of drivable microwires was later implanted into the rNTS. After recovery, water-deprived rats were presented with taste stimuli in an experimental chamber. Trials were five consecutive taste licks [NaCl, KCl, NH4Cl, sucrose, monosodium glutamate/inosine-5'-monophosphate, citric acid, quinine, or artificial saliva (AS)] separated by five AS rinse licks on a variable ratio 5 schedule. Each taste lick triggered a 1 s train of laser light (25 Hz; 473 nm; 8-10 mW) in a random half of the trials. In all, 113 cells were recorded in the rNTS, 50 cells responded to one or more taste stimuli without GABA enhancement. Selective changes in response magnitude (spike count) within cells shifted across-unit patterns but preserved interstimulus relationships. Cells where enhanced GABAergic tone increased lick coherence conveyed more information distinguishing basic taste qualities and different salts than other cells. In addition, GABA activation significantly amplified the amount of information that discriminated palatable versus unpalatable tastants. By dynamically regulating lick coherence and remodeling the across-unit response patterns to taste, enhancing GABAergic tone in rNTS reconfigures the neural activity reflecting sensation and movement.
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Abstract
GDF15 is a cell activation and stress response cytokine of the glial cell line-derived neurotrophic factor family within the TGF-β superfamily. It acts through a recently identified orphan member of the GFRα family called GFRAL and signals through the Ret coreceptor. Cell stress and disease lead to elevated GDF15 serum levels, causing anorexia, weight loss, and alterations to metabolism, largely by actions on regions of the hindbrain. These changes restore homeostasis and, in the case of obesity, cause a reduction in adiposity. In some diseases, such as advanced cancer, serum GDF15 levels can rise by as much as 10-100-fold, leading to an anorexia-cachexia syndrome, which is often fatal. This review discusses how GDF15 regulates appetite and metabolism, the role it plays in resistance to obesity, and how this impacts diseases such as diabetes, nonalcoholic fatty liver disease, and anorexia-cachexia syndrome. It also discusses potential therapeutic applications of targeting the GDF15-GFRAL pathway and lastly suggests some potential unifying hypotheses for its biological role.
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Affiliation(s)
- Samuel N Breit
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia; ,
| | - David A Brown
- Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; .,New South Wales Health Pathology, Institute of Clinical Pathology Research, and Westmead Institute for Medical Research, Westmead Hospital, Westmead, NSW 2145, Australia
| | - Vicky Wang-Wei Tsai
- St. Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia; ,
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33
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Biddinger JE, Lazarenko RM, Scott MM, Simerly R. Leptin suppresses development of GLP-1 inputs to the paraventricular nucleus of the hypothalamus. eLife 2020; 9:59857. [PMID: 33206596 PMCID: PMC7673779 DOI: 10.7554/elife.59857] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 11/06/2020] [Indexed: 02/06/2023] Open
Abstract
The nucleus of the solitary tract (NTS) is critical for the central integration of signals from visceral organs and contains preproglucagon (PPG) neurons, which express leptin receptors in the mouse and send direct projections to the paraventricular nucleus of the hypothalamus (PVH). Here, we visualized projections of PPG neurons in leptin-deficient Lepob/ob mice and found that projections from PPG neurons are elevated compared with controls, and PPG projections were normalized by targeted rescue of leptin receptors in LepRbTB/TB mice, which lack functional neuronal leptin receptors. Moreover, Lepob/ob and LepRbTB/TB mice displayed increased levels of neuronal activation in the PVH following vagal stimulation, and whole-cell patch recordings of GLP-1 receptor-expressing PVH neurons revealed enhanced excitatory neurotransmission, suggesting that leptin acts cell autonomously to suppress representation of excitatory afferents from PPG neurons, thereby diminishing the impact of visceral sensory information on GLP-1 receptor-expressing neurons in the PVH.
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Affiliation(s)
- Jessica E Biddinger
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, United States
| | - Roman M Lazarenko
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, United States
| | - Michael M Scott
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, United States
| | - Richard Simerly
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, United States
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Do J, Chang Z, Sekerková G, McCrimmon DR, Martina M. A Leptin-Mediated Neural Mechanism Linking Breathing to Metabolism. Cell Rep 2020; 33:108358. [PMID: 33176139 DOI: 10.1016/j.celrep.2020.108358] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/27/2020] [Accepted: 10/16/2020] [Indexed: 01/10/2023] Open
Abstract
Breathing is coupled to metabolism. Leptin, a peptide mainly secreted in proportion to adipose tissue mass, increases energy expenditure with a parallel increase in breathing. We demonstrate that optogenetic activation of LepRb neurons in the nucleus of the solitary tract (NTS) mimics the respiratory stimulation after systemic leptin administration. We show that leptin activates the sodium leak channel (NALCN), thereby depolarizing a subset of glutamatergic (VGluT2) LepRb NTS neurons expressing galanin. Mice with selective deletion of NALCN in LepRb neurons have increased breathing irregularity and central apneas. On a high-fat diet, these mice gain weight with an associated depression of minute ventilation and tidal volume, which are not detected in control littermates. Anatomical mapping reveals LepRb NTS-originating glutamatergic axon terminals in a brainstem inspiratory premotor region (rVRG) and dorsomedial hypothalamus. These findings directly link a defined subset of NTS LepRb cells to the matching of ventilation to energy balance.
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Psilopanagioti A, Makrygianni M, Nikou S, Logotheti S, Papadaki H. Nucleobindin 2/nesfatin-1 expression and colocalisation with neuropeptide Y and cocaine- and amphetamine-regulated transcript in the human brainstem. J Neuroendocrinol 2020; 32:e12899. [PMID: 32902020 DOI: 10.1111/jne.12899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 11/26/2022]
Abstract
Feeding is a complex behaviour entailing elaborate interactions between forebrain, hypothalamic and brainstem neuronal circuits via multiple orexigenic and anorexigenic neuropeptides. Nucleobindin-2 (NUCB2)/nesfatin-1 is a negative regulator of food intake and body weight with a widespread distribution in rodent brainstem nuclei. However, its localisation pattern in the human brainstem is unknown. The present study aimed to explore NUCB2/nesfatin-1 immunoexpression in human brainstem nuclei and its possible correlation with body weight. Sections of human brainstem from 20 autopsy cases (13 males, seven females; eight normal weight, six overweight, six obese) were examined using immunohistochemistry and double immunofluorescence labelling. Strong immunoreactivity for NUCB2/nesfatin-1 was displayed in various brainstem areas, including the locus coeruleus, medial and lateral parabrachial nuclei, pontine nuclei, raphe nuclei, nucleus of the solitary tract, dorsal motor nucleus of vagus (10N), area postrema, hypoglossal nucleus, reticular formation, inferior olive, cuneate nucleus, and spinal trigeminal nucleus. NUCB2/nesfatin-1 was shown to extensively colocalise with neuropeptide Y and cocaine- and amphetamine-regulated transcript in the locus coeruleus, dorsal raphe nucleus and solitary tract. Interestingly, in the examined cases, NUCB2/nesfatin-1 protein expression was lower in obese than normal weight subjects in the solitary tract (P = 0.020). The findings of the present study provide neuroanatomical support for a role for NUCB2/nesfatin-1 in feeding behaviour and energy balance. The widespread distribution of NUCB2/nesfatin-1 in the human brainstem nuclei may be indicative of its pleiotropic effects on autonomic, neuroendocrine and behavioural processes. In the solitary tract, a key integrator of energy status, altered neurochemistry may contribute to obesity. Further research is necessary to decipher human brainstem energy homeostasis circuitry, which, despite its importance, remains inadequately characterised.
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Affiliation(s)
- Aristea Psilopanagioti
- Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, Patras, Greece
| | - Maria Makrygianni
- Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, Patras, Greece
| | - Sofia Nikou
- Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, Patras, Greece
| | - Souzana Logotheti
- Department of Pathology, School of Medicine, University of Patras, Patras, Greece
| | - Helen Papadaki
- Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, Patras, Greece
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Skyberg R, Sun C, Hill DL. Selective Removal of Sodium Salt Taste Disrupts the Maintenance of Dendritic Architecture of Gustatory Relay Neurons in the Mouse Nucleus of the Solitary Tract. eNeuro 2020; 7:ENEURO. [PMID: 32817119 DOI: 10.1523/ENEURO.0140-20.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 11/21/2022] Open
Abstract
Neuronal activity plays critical roles in the development of sensory circuits in the mammalian brain. Experimental procedures are now available to alter the function of specific taste transduction pathways and have been especially useful in studying how stimulus-specific taste activity influences the development of central gustatory circuits. We previously used a mouse knock-out (KO) model in which the transduction channel necessary for sodium taste is removed from taste bud cells throughout life. In these KO mice, the terminal fields that carry taste information from taste buds into the nucleus of the solitary tract (NST) fail to mature, suggesting that sodium-elicited taste activity is important for the proper development of central gustatory circuits. Here, we tested the hypothesis that the development and maintenance of the dendritic architecture of NST relay cells, the primary postsynaptic partner of gustatory nerve terminal fields, are similarly dependent on sodium-elicited taste activity. The dendritic fields of NST relay cells, from adult male and female mice in which the α-subunit of the epithelial sodium channel (αENaC) was conditionally deleted in taste bud cells throughout life, were up to 2.4× larger and more complex than that of age-matched control mice. Interestingly, these differences in dendritic architecture did not appear until after the age when terminal fields begin “pruning,” after postnatal day (P)20. Overall, our results suggest that ENaC-mediated sodium taste activity is necessary for the maintenance of dendritic fields of relay cells in the gustatory NST.
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Chen J, Cheng M, Wang L, Zhang L, Xu D, Cao P, Wang F, Herzog H, Song S, Zhan C. A Vagal-NTS Neural Pathway that Stimulates Feeding. Curr Biol 2020; 30:3986-3998.e5. [PMID: 32822608 DOI: 10.1016/j.cub.2020.07.084] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/01/2020] [Accepted: 07/28/2020] [Indexed: 10/23/2022]
Abstract
A fundamental question of physiology is how gut-brain signaling stimulates appetite. While many studies have emphasized the importance of vagal afferents to the brain in inducing satiation, little is known about whether and how the vagal-mediated gut-brain pathway senses orexigenic signals and stimulates feeding. Here, we identified a previously uncharacterized population of fasting-activated catecholaminergic neurons in the nucleus of the solitary tract (NTS). After characterizing the anatomical complexity among NTS catecholaminergic neurons, we surprisingly found that activation of NTS epinephrine (ENTS) neurons co-expressing neuropeptide Y (NPY) stimulated feeding, whereas activation of NTS norepinephrine (NENTS) neurons suppressed feeding. Monosynaptic tracing/activation experiments then showed that these NTS neurons receive direct vagal afferents from nodose neurons. Moreover, activation of the vagal→NPY/ENTS neural circuit stimulated feeding. Our study reveals an orexigenic role of the vagal→NTS pathway in controlling feeding, thereby providing important insights about how gut-brain signaling regulates feeding behavior.
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Affiliation(s)
- Jing Chen
- Department of Biomedical Engineering and Laboratory for Brain and Intelligence, IDG/McGovern Institute for Brain Research, Center for Brain-Inspired Computing Research, Tsinghua University, Beijing 100084, China; National Institute of Biological Sciences, Beijing 102206, China
| | - Mingxiu Cheng
- National Institute of Biological Sciences, Beijing 102206, China; TIMBR Graduate Program, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Liang Wang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Lei Zhang
- Neuroscience Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Dan Xu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Peng Cao
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
| | - Fengchao Wang
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
| | - Herbert Herzog
- Neuroscience Division, Garvan Institute of Medical Research, Sydney, NSW 2010, Australia
| | - Sen Song
- Department of Biomedical Engineering and Laboratory for Brain and Intelligence, IDG/McGovern Institute for Brain Research, Center for Brain-Inspired Computing Research, Tsinghua University, Beijing 100084, China
| | - Cheng Zhan
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China.
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38
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Gasparini S, Howland JM, Thatcher AJ, Geerling JC. Central afferents to the nucleus of the solitary tract in rats and mice. J Comp Neurol 2020; 528:2708-2728. [PMID: 32307700 DOI: 10.1002/cne.24927] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 12/13/2022]
Abstract
The nucleus of the solitary tract (NTS) regulates life-sustaining functions ranging from appetite and digestion to heart rate and breathing. It is also the brain's primary sensory nucleus for visceral sensations relevant to symptoms in medical and psychiatric disorders. To better understand which neurons may exert top-down control over the NTS, here we provide a brain-wide map of all neurons that project axons directly to the caudal, viscerosensory NTS, focusing on a medial subregion with aldosterone-sensitive HSD2 neurons. Injecting an axonal tracer (cholera toxin b) into the NTS produces a similar pattern of retrograde labeling in rats and mice. The paraventricular hypothalamic nucleus (PVH), lateral hypothalamic area, and central nucleus of the amygdala (CeA) contain the densest concentrations of NTS-projecting neurons. PVH afferents are glutamatergic (express Slc17a6/Vglut2) and are distinct from neuroendocrine PVH neurons. CeA afferents are GABAergic (express Slc32a1/Vgat) and are distributed largely in the medial CeA subdivision. Other retrogradely labeled neurons are located in a variety of brain regions, including the cerebral cortex (insular and infralimbic areas), bed nucleus of the stria terminalis, periaqueductal gray, Barrington's nucleus, Kölliker-Fuse nucleus, hindbrain reticular formation, and rostral NTS. Similar patterns of retrograde labeling result from tracer injections into different NTS subdivisions, with dual retrograde tracing revealing that many afferent neurons project axon collaterals to both the lateral and medial NTS subdivisions. This information provides a roadmap for studying descending axonal projections that may influence visceromotor systems and visceral "mind-body" symptoms.
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Affiliation(s)
- Silvia Gasparini
- Department of Neurology, Iowa Neuroscience Institute, University of Iowa, Iowa city, Iowa, USA
| | - Jacob M Howland
- Department of Neurology, Iowa Neuroscience Institute, University of Iowa, Iowa city, Iowa, USA
| | - Andrew J Thatcher
- Department of Neurology, Iowa Neuroscience Institute, University of Iowa, Iowa city, Iowa, USA
| | - Joel C Geerling
- Department of Neurology, Iowa Neuroscience Institute, University of Iowa, Iowa city, Iowa, USA
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Rogers RC, Hasser EM, Hermann GE. Thrombin action on astrocytes in the hindbrain of the rat disrupts glycemic and respiratory control. Am J Physiol Regul Integr Comp Physiol 2020; 318:R1068-R1077. [PMID: 32320636 PMCID: PMC7311679 DOI: 10.1152/ajpregu.00033.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 03/30/2020] [Accepted: 04/21/2020] [Indexed: 02/06/2023]
Abstract
Severe trauma can produce a postinjury "metabolic self-destruction" characterized by catabolic metabolism and hyperglycemia. The severity of the hyperglycemia is highly correlated with posttrauma morbidity and mortality. Although no mechanism has been posited to connect severe trauma with a loss of autonomic control over metabolism, traumatic injury causes other failures of autonomic function, notably, gastric stasis and ulceration ("Cushing's ulcer"), which has been connected with the generation of thrombin. Our previous studies established that proteinase-activated receptors (PAR1; "thrombin receptors") located on astrocytes in the autonomically critical nucleus of the solitary tract (NST) can modulate gastric control circuit neurons to cause gastric stasis. Hindbrain astrocytes have also been implicated as important detectors of low glucose or glucose utilization. When activated, these astrocytes communicate with hindbrain catecholamine neurons that, in turn, trigger counterregulatory responses (CRR). There may be a convergence between the effects of thrombin to derange hindbrain gastrointestinal control and the hindbrain circuitry that initiates CRR to increase glycemia in reaction to critical hypoglycemia. Our results suggest that thrombin acts within the NST to increase glycemia through an astrocyte-dependent mechanism. Blockade of purinergic gliotransmission pathways interrupted the effect of thrombin to increase glycemia. Our studies also revealed that thrombin, acting in the NST, produced a rapid, dramatic, and potentially lethal suppression of respiratory rhythm that was also a function of purinergic gliotransmission. These results suggest that the critical connection between traumatic injury and a general collapse of autonomic regulation involves thrombin action on astrocytes.
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Affiliation(s)
- Richard C Rogers
- Autonomic Neurosciences Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
| | - Eileen M Hasser
- Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Gerlinda E Hermann
- Autonomic Neurosciences Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana
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Hsieh YH, Litvin DG, Zaylor AR, Nethery DE, Dick TE, Jacono FJ. Brainstem inflammation modulates the ventilatory pattern and its variability after acute lung injury in rodents. J Physiol 2020; 598:2791-2811. [PMID: 32378188 DOI: 10.1113/jp279177] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 04/21/2020] [Indexed: 01/20/2023] Open
Abstract
KEY POINTS Compared with sham rats, rats a week after acute lung injury (ALI) express more pro-inflammatory cytokines in their brainstem respiratory control nuclei, exhibit a higher respiratory frequency (fR) and breathe with a more predictable pattern. These characteristics of the respiratory pattern persist in in situ preparations even after minimizing pulmonary and chemo-afferent inputs. Interleukin (IL)-1β microinjected in the nucleus tractus solitarii increases fR and the predictability of the ventilatory pattern similar to rats with ALI. Intracerebroventricular infusion of indomethacin, an anti-inflammatory drug, mitigates the effect of ALI on fR and ventilatory pattern variability. We conclude that changes in the ventilatory pattern after ALI result not only from sensory input due to pulmonary damage and dysfunction but also from neuro-inflammation. ABSTRACT Acute lung injury (ALI) increases respiratory rate (fR) and ventilatory pattern variability (VPV), but also evokes peripheral and central inflammation. We hypothesized that central inflammation has a role in determining the ventilatory pattern after ALI. In rat pups, we intratracheally injected either bleomycin to induce ALI or saline as a sham control. One week later, we recorded the ventilatory pattern of the rat pups using flow-through plethysmography, then formed in situ preparations from these pups and recorded their 'fictive' patterns from respiratory motor nerves. Compared with the ventilatory pattern of the sham rat pups, injured rat pups had increased fR and predictability. Surprisingly, the fictive patterns of the in situ preparations from ALI pups retained these characteristics despite removing their lungs to eliminate pulmonary sensory inputs and perfusing them with hyperoxic artificial cerebral spinal fluid to minimize peripheral chemoreceptor input. Histological processing revealed increased immunoreactivity of the pro-inflammatory cytokine Interleukin-1β (IL-1β) in the nucleus tractus solitarii (nTS) from ALI but not sham rats. In subsequent experiments, we microinjected IL-1β in the nTS bilaterally in anaesthetized naïve adult rats, which increased fR and predictability of ventilatory pattern variability (VPV) after 2 h. Finally, we infused indomethacin intracerebroventricularly during the week of survival after ALI. This did not affect sham rats, but mitigated changes in fR and VPV in ALI rats. We conclude that neuro-inflammation has an essential role in determining the ventilatory pattern of ALI rats.
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Affiliation(s)
- Yee-Hsee Hsieh
- Division of Pulmonary, Critical Care and Sleep Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - David G Litvin
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States.,Department of Fundamental Neuroscience, University of Lausanne, Lausanne, 1005, Switzerland
| | - Abigail R Zaylor
- Division of Pulmonary, Critical Care and Sleep Medicine, Case Western Reserve University, Cleveland, Ohio, United States.,Division of Pulmonary, Critical Care and Sleep Medicine, Louis Stokes VA Medical Center, Cleveland, Ohio, United States
| | - David E Nethery
- Division of Pulmonary, Critical Care and Sleep Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Thomas E Dick
- Division of Pulmonary, Critical Care and Sleep Medicine, Case Western Reserve University, Cleveland, Ohio, United States.,Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio, United States
| | - Frank J Jacono
- Division of Pulmonary, Critical Care and Sleep Medicine, Case Western Reserve University, Cleveland, Ohio, United States.,Division of Pulmonary, Critical Care and Sleep Medicine, Louis Stokes VA Medical Center, Cleveland, Ohio, United States
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Abstract
Previous studies indicate that inhibition of food intake by leptin is mediated by an integrated response to activation of hypothalamic and hindbrain receptors. This study tested whether loss of hindbrain leptin receptor signaling changed sensitivity to forebrain leptin. Injections of leptin-conjugated saporin (Lep-Sap) into the medial nucleus of the solitary tract (NTS) were used to destroy hindbrain leptin receptor-expressing neurons of male Sprague-Dawley rats. Controls were injected with saporin conjugated with a nonsense peptide (Blk-Sap). Lep-Sap had no effect on daily food intake or body weight, but expression of phosphorylated signal transducer and activator of transcription 3 (pSTAT3) in the NTS following a peripheral injection of leptin was abolished 26 days after Lep-Sap injections. To test forebrain leptin sensitivity, Lep-Sap and Blk-Sap rats received third-ventricle injections of 0, 0.05, 0.1, 0.25, or 0.5 μg leptin. Food intake was inhibited by 0.25 and 0.5 μg leptin in Blk-Sap rats, but there was no significant effect of leptin on food intake of Lep-Sap rats. There was no difference in hypothalamic pSTAT3 in unstimulated conditions, but pSTAT3 was lower in the dorsomedial region of the ventromedial nucleus of the hypothalamus (VMH) of Lep-Sap rats compared with Blk-Sap rats following a third-ventricle injection of 0.25 μg leptin. These results are consistent with previous data showing that loss of VMH leptin receptor-expressing cells prevents weight loss caused by fourth-ventricle leptin infusion and show that the integrated response between the hindbrain and forebrain is heavily dependent on leptin activity in the VMH.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
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Kim J, Yamanaka K, Tsukioka K, Waki H. Potential Role of the Amygdala and Posterior Claustrum in Exercise Intensity-dependent Cardiovascular Regulation in Rats. Neuroscience 2020; 432:150-9. [PMID: 32109531 DOI: 10.1016/j.neuroscience.2020.02.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 02/14/2020] [Accepted: 02/17/2020] [Indexed: 11/21/2022]
Abstract
Tuning of the cardiovascular response is crucial to maintain performance during high-intensity exercise. It is well known that the nucleus of the solitary tract (NTS) in the brainstem medulla plays a central role in cardiovascular regulation; however, where and how upper brain regions form circuits with NTS and coordinately control cardiovascular responses during high-intensity exercise remain unclear. Here focusing on the amygdala and claustrum, we investigated part of the mechanism for regulation of the cardiovascular system during exercise. In rats, c-Fos immunostaining was used to examine whether the amygdala and claustrum were activated during treadmill exercise. Further, we examined arterial pressure responses to electrical and chemical stimulation of the claustrum region. We also confirmed the anatomical connections between the amygdala, claustrum, and NTS by retrograde tracer injections. Finally, we performed simultaneous electrical stimulation of the claustrum and amygdala to examine their functional connectivity. c-Fos expression was observed in the amygdala and the posterior part of the claustrum (pCL), but not in the anterior part, in an exercise intensity-dependent manner. pCL stimulation induced a depressor response. Using a retrograde tracer, we confirmed direct projections from the amygdala to the pCL and NTS. Simultaneous stimulation of the central nucleus of the amygdala and pCL showed a greater pressor response compared with the stimulation of the amygdala alone. These results suggest the amygdala and pCL are involved in different phases of exercise. More speculatively, these areas might coordinately tune cardiovascular responses that help maintain performance during high-intensity exercise.
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Mastitskaya S, Turovsky E, Marina N, Theparambil SM, Hadjihambi A, Kasparov S, Teschemacher AG, Ramage AG, Gourine AV, Hosford PS. Astrocytes Modulate Baroreflex Sensitivity at the Level of the Nucleus of the Solitary Tract. J Neurosci 2020; 40:3052-3062. [PMID: 32132265 PMCID: PMC7141885 DOI: 10.1523/jneurosci.1438-19.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 12/16/2019] [Accepted: 01/12/2020] [Indexed: 11/21/2022] Open
Abstract
Maintenance of cardiorespiratory homeostasis depends on autonomic reflexes controlled by neuronal circuits of the brainstem. The neurophysiology and neuroanatomy of these reflex pathways are well understood, however, the mechanisms and functional significance of autonomic circuit modulation by glial cells remain largely unknown. In the experiments conducted in male laboratory rats we show that astrocytes of the nucleus of the solitary tract (NTS), the brain area that receives and integrates sensory information from the heart and blood vessels, respond to incoming afferent inputs with [Ca2+]i elevations. Astroglial [Ca2+]i responses are triggered by transmitters released by vagal afferents, glutamate acting at AMPA receptors and 5-HT acting at 5-HT2A receptors. In conscious freely behaving animals blockade of Ca2+-dependent vesicular release mechanisms in NTS astrocytes by virally driven expression of a dominant-negative SNARE protein (dnSNARE) increased baroreflex sensitivity by 70% (p < 0.001). This effect of compromised astroglial function was specific to the NTS as expression of dnSNARE in astrocytes of the ventrolateral brainstem had no effect. ATP is considered the principle gliotransmitter and is released by vesicular mechanisms blocked by dnSNARE expression. Consistent with this hypothesis, in anesthetized rats, pharmacological activation of P2Y1 purinoceptors in the NTS decreased baroreflex gain by 40% (p = 0.031), whereas blockade of P2Y1 receptors increased baroreflex gain by 57% (p = 0.018). These results suggest that glutamate and 5-HT, released by NTS afferent terminals, trigger Ca2+-dependent astroglial release of ATP to modulate baroreflex sensitivity via P2Y1 receptors. These data add to the growing body of evidence supporting an active role of astrocytes in brain information processing.SIGNIFICANCE STATEMENT Cardiorespiratory reflexes maintain autonomic balance and ensure cardiovascular health. Impaired baroreflex may contribute to the development of cardiovascular disease and serves as a robust predictor of cardiovascular and all-cause mortality. The data obtained in this study suggest that astrocytes are integral components of the brainstem mechanisms that process afferent information and modulate baroreflex sensitivity via the release of ATP. Any condition associated with higher levels of "ambient" ATP in the NTS would be expected to decrease baroreflex gain by the mechanism described here. As ATP is the primary signaling molecule of glial cells (astrocytes, microglia), responding to metabolic stress and inflammatory stimuli, our study suggests a plausible mechanism of how the central component of the baroreflex is affected in pathological conditions.
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Affiliation(s)
- Svetlana Mastitskaya
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Egor Turovsky
- Institute of Cell Biophysics, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino 142290, Russian Federation
| | - Nephtali Marina
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Shefeeq M Theparambil
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Anna Hadjihambi
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Sergey Kasparov
- Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol BS8 1TD, United Kingdom
- Baltic Federal University, Kaliningrad 236041, Russian Federation, and
| | - Anja G Teschemacher
- Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Andrew G Ramage
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom,
| | - Patrick S Hosford
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom,
- William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ, United Kingdom
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44
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Colzato L, Beste C. A literature review on the neurophysiological underpinnings and cognitive effects of transcutaneous vagus nerve stimulation: challenges and future directions. J Neurophysiol 2020; 123:1739-1755. [PMID: 32208895 DOI: 10.1152/jn.00057.2020] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Brain stimulation approaches are important to gain causal mechanistic insights into the relevance of functional brain regions and/or neurophysiological systems for human cognitive functions. In recent years, transcutaneous vagus nerve stimulation (tVNS) has attracted considerable popularity. It is a noninvasive brain stimulation technique based on the stimulation of the vagus nerve. The stimulation of this nerve activates subcortical nuclei, such as the locus coeruleus and the nucleus of the solitary tract, and from there, the activation propagates to the cortex. Since tVNS is a novel stimulation technique, this literature review outlines a brief historical background of tVNS, before detailing underlying neurophysiological mechanisms of action, stimulation parameters, cognitive effects of tVNS on healthy humans, and, lastly, current challenges and future directions of tVNS research in cognitive functions. Although more research is needed, we conclude that tVNS, by increasing norepineprine (NE) and gamma-aminobutyric acid (GABA) levels, affects NE- and GABA-related cognitive performance. The review provides detailed background information how to use tVNS as a neuromodulatory tool in cognitive neuroscience and outlines important future leads of research on tVNS.
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Affiliation(s)
- Lorenza Colzato
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany.,Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany.,Cognitive Psychology, Faculty of Psychology, Shandong Normal University, Jinan, China
| | - Christian Beste
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany.,Cognitive Psychology, Faculty of Psychology, Shandong Normal University, Jinan, China
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MacDonald AJ, Holmes FE, Beall C, Pickering AE, Ellacott KLJ. Regulation of food intake by astrocytes in the brainstem dorsal vagal complex. Glia 2019; 68:1241-1254. [PMID: 31880353 PMCID: PMC7187409 DOI: 10.1002/glia.23774] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 02/06/2023]
Abstract
A role for glial cells in brain circuits controlling feeding has begun to be identified with hypothalamic astrocyte signaling implicated in regulating energy homeostasis. The nucleus of the solitary tract (NTS), within the brainstem dorsal vagal complex (DVC), integrates vagal afferent information from the viscera and plays a role in regulating food intake. We hypothesized that astrocytes in this nucleus respond to, and influence, food intake. Mice fed high‐fat chow for 12 hr during the dark phase showed NTS astrocyte activation, reflected in an increase in the number (65%) and morphological complexity of glial‐fibrillary acidic protein (GFAP)‐immunoreactive cells adjacent to the area postrema (AP), compared to control chow fed mice. To measure the impact of astrocyte activation on food intake, we delivered designer receptors exclusively activated by designer drugs (DREADDs) to DVC astrocytes (encompassing NTS, AP, and dorsal motor nucleus of the vagus) using an adeno‐associated viral (AAV) vector (AAV‐GFAP‐hM3Dq_mCherry). Chemogenetic activation with clozapine‐N‐oxide (0.3 mg/kg) produced in greater morphological complexity in astrocytes and reduced dark‐phase feeding by 84% at 4 hr postinjection compared with vehicle treatment. hM3Dq‐activation of DVC astrocytes also reduced refeeding after an overnight fast (71% lower, 4 hr postinjection) when compared to AAV‐GFAP‐mCherry expressing control mice. DREADD‐mediated astrocyte activation did not impact locomotion. hM3Dq activation of DVC astrocytes induced c‐FOS in neighboring neuronal feeding circuits (including in the parabrachial nucleus). This indicates that NTS astrocytes respond to acute nutritional excess, are involved in the integration of peripheral satiety signals, and can reduce food intake when activated.
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Affiliation(s)
- Alastair J MacDonald
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK.,School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Fiona E Holmes
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Craig Beall
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Anthony E Pickering
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, UK.,Anaesthesia, Pain and Critical Care Sciences, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kate L J Ellacott
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
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Nassenstein C, Krasteva-Christ G, Renz H. New aspects of neuroinflammation and neuroimmune crosstalk in the airways. J Allergy Clin Immunol 2018; 142:1415-22. [PMID: 30409249 DOI: 10.1016/j.jaci.2018.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/26/2018] [Accepted: 09/27/2018] [Indexed: 11/23/2022]
Abstract
Neuroimmune interaction has long been discussed in the pathogenesis of allergic airway diseases, such as allergic asthma. Mediators released during inflammation can alter the function of both sensory and parasympathetic neurons innervating the airways. Evidence has been provided that the inflammatory response can be altered by various mediators that are released by sensory and parasympathetic neurons and vice versa. Our aim is to demonstrate recent developments in the reciprocal neuroimmune interaction and to include, if available, data from in vivo and clinical studies.
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Weiss MS, Hajnal A, Czaja K, Di Lorenzo PM. Taste Responses in the Nucleus of the Solitary Tract of Awake Obese Rats Are Blunted Compared With Those in Lean Rats. Front Integr Neurosci 2019; 13:35. [PMID: 31417373 PMCID: PMC6683675 DOI: 10.3389/fnint.2019.00035] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/11/2019] [Indexed: 12/26/2022] Open
Abstract
Taste perception changes with obesity but the underlying neural changes remain poorly understood. To address this issue, we recorded taste responses from single cells in the nucleus tractus solitarius (NTS, the first synapse in the central gustatory circuit) in awake, diet-induced obese [(DIO; ≥ 8 weeks on a high-energy diet (45%fat, 17% sugar; HED)], and lean rats. Rats were implanted with a bundle of microelectrodes in the NTS and allowed to recover. Water-deprived rats were allowed to freely lick various tastants in an experimental chamber. Taste stimuli included an array of sapid stimuli dissolved in artificial saliva (AS). Each taste trial consisted of five consecutive licks followed by five AS licks presented on a VR5 schedule. Results showed that taste responses (n = 49 for DIO; n = 74 for lean rats) in NTS cells in DIO rats were smaller in magnitude, shorter in duration, and longer in latency that those in lean rats. However, there were proportionately more taste-responsive cells in DIO than in lean rats. Lick coherence in DIO rats was significantly lower than in lean rats, both in taste-responsive, and lick-related cells (n = 172 in lean; n = 65 in DIO). Analyses of temporal coding showed that taste cells in DIO rats conveyed less information about taste quality than cells in lean rats. Collectively, results suggest that a HED produces blunted, but more prevalent, responses to taste in the NTS, and a weakened association of taste responses with ingestive behavior. These neural adaptations may represent both negative effects and compensatory mechanisms of a HED that may underlie deficits in taste-related behavior associated with obesity.
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Affiliation(s)
- Michael S Weiss
- Department of Psychology, Binghamton University, Binghamton, NY, United States
| | - Andras Hajnal
- Department of Neural and Behavioral Sciences, College of Medicine, The Pennsylvania State University, Hershey, PA, United States
| | - Krzysztof Czaja
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, GA, United States
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Peli A, Grandis A, Tassinari M, Famigli Bergamini P, Tagliavia C, Roccaro M, Bombardi C. Environment and Behavior: Neurochemical Effects of Different Diets in the Calf Brain. Animals (Basel) 2019; 9:E358. [PMID: 31207977 PMCID: PMC6617313 DOI: 10.3390/ani9060358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/05/2019] [Accepted: 06/12/2019] [Indexed: 11/16/2022] Open
Abstract
Calves reared for the production of white veal are subjected to stressful events due to the type of liquid diet they receive. Stress responses are mediated by three main stress-responsive cerebral regions: the prefrontal cortex, the paraventricular nucleus of the hypothalamus, and the nucleus of the solitary tract of the brainstem. In the present study, we have investigated the effects of different diets on these brain regions of ruminants using immunohistochemical methods. In this study, 15 calves were used and kept in group housing systems of five calves each. They were fed with three different diets: a control diet, a milk diet, and a weaned diet. Brain sections were immunostained to evaluate the distribution of neuronal nitric oxide synthase and myelin oligodendrocyte glycoprotein immunoreactivity in the prefrontal cortex; the expression of oxytocin in the paraventricular nucleus; and the presence of c-Fos in the A2 group of the nucleus of the solitary tract. The main results obtained indicate that in weaned diet group the oxytocin activity is lower than in control diet and milk diet groups. In addition, weaning appears to stimulate myelination in the prefrontal cortex. In summary, this study supports the importance of maintaining a nutritional lifestyle similar to that occurring in natural conditions.
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Affiliation(s)
- Angelo Peli
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
| | - Annamaria Grandis
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
| | - Marco Tassinari
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
| | - Paolo Famigli Bergamini
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
| | - Claudio Tagliavia
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
| | - Mariana Roccaro
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
| | - Cristiano Bombardi
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 50, 40064, Ozzano dell'Emilia (BO), Italy.
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Abstract
Anterograde and retrograde tract tracing were combined with neurotransmitter and modulator immunolabeling to identify the chemical anatomy of vestibular nuclear neurons with direct projections to the solitary nucleus in rats. Direct, sparsely branched but highly varicose axonal projections from neurons in the caudal vestibular nuclei to the solitary nucleus were observed. The vestibular neurons giving rise to these projections were predominantly located in ipsilateral medial vestibular nucleus. The cell bodies were intensely glutamate immunofluorescent, and their axonal processes contained vesicular glutamate transporter 2, supporting the interpretation that the cells utilize glutamate for neurotransmission. The glutamate-immunofluorescent, retrogradely filled vestibular cells also contained the neuromodulator imidazoleacetic acid ribotide, which is an endogenous CNS ligand that participates in blood pressure regulation. The vestibulo-solitary neurons were encapsulated by axo-somatic GABAergic terminals, suggesting that they are under tight inhibitory control. The results establish a chemoanatomical basis for transient vestibular activation of the output pathways from the caudal and intermediate regions of the solitary nucleus. In this way, changes in static head position and movement of the head in space may directly influence heart rate, blood pressure, respiration, as well as gastrointestinal motility. This would provide one anatomical explanation for the synchronous heart rate and blood pressure responses observed after peripheral vestibular activation, as well as disorders ranging from neurogenic orthostatic hypotension, postural orthostatic tachycardia syndrome, and vasovagal syncope to the nausea and vomiting associated with motion sickness.NEW & NOTEWORTHY Vestibular neurons with direct projections to the solitary nucleus utilize glutamate for neurotransmission, modulated by imidazoleacetic acid ribotide. This is the first direct demonstration of the chemical neuroanatomy of the vestibulo-solitary pathway.
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Affiliation(s)
- Amelia H Gagliuso
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Emily K Chapman
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Giorgio P Martinelli
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Gay R Holstein
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York.,Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York.,Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York
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Hardaway JA, Halladay LR, Mazzone CM, Pati D, Bloodgood DW, Kim M, Jensen J, DiBerto JF, Boyt KM, Shiddapur A, Erfani A, Hon OJ, Neira S, Stanhope CM, Sugam JA, Saddoris MP, Tipton G, McElligott Z, Jhou TC, Stuber GD, Bruchas MR, Bulik CM, Holmes A, Kash TL. Central Amygdala Prepronociceptin-Expressing Neurons Mediate Palatable Food Consumption and Reward. Neuron 2019; 102:1037-1052.e7. [PMID: 31029403 DOI: 10.1016/j.neuron.2019.03.037] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 09/27/2018] [Accepted: 03/27/2019] [Indexed: 01/04/2023]
Abstract
Food palatability is one of many factors that drives food consumption, and the hedonic drive to feed is a key contributor to obesity and binge eating. In this study, we identified a population of prepronociceptin-expressing cells in the central amygdala (PnocCeA) that are activated by palatable food consumption. Ablation or chemogenetic inhibition of these cells reduces palatable food consumption. Additionally, ablation of PnocCeA cells reduces high-fat-diet-driven increases in bodyweight and adiposity. PnocCeA neurons project to the ventral bed nucleus of the stria terminalis (vBNST), parabrachial nucleus (PBN), and nucleus of the solitary tract (NTS), and activation of cell bodies in the central amygdala (CeA) or axons in the vBNST, PBN, and NTS produces reward behavior but did not promote feeding of palatable food. These data suggest that the PnocCeA network is necessary for promoting the reinforcing and rewarding properties of palatable food, but activation of this network itself is not sufficient to promote feeding.
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Affiliation(s)
- J Andrew Hardaway
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
| | - Lindsay R Halladay
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA; Department of Psychology, Santa Clara University, Santa Clara, CA 95053, USA
| | - Christopher M Mazzone
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Neurobiology Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dipanwita Pati
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Daniel W Bloodgood
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Neurobiology Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Michelle Kim
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Jennifer Jensen
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Jeffrey F DiBerto
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Kristen M Boyt
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Ami Shiddapur
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Ava Erfani
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Olivia J Hon
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Neurobiology Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Sofia Neira
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Neurobiology Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Christina M Stanhope
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Jonathan A Sugam
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Michael P Saddoris
- Department of Psychology and Neuroscience, University of Colorado, Boulder, Boulder, CO 80309, USA
| | - Greg Tipton
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Zoe McElligott
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Thomas C Jhou
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Garret D Stuber
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Michael R Bruchas
- Division of Basic Research, Department of Anesthesiology, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA; Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA 98195, USA; Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA 98195, USA; Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Cynthia M Bulik
- Department of Psychiatry, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD, USA
| | - Thomas L Kash
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
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