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Mir DA, Cox M, Horrocks J, Ma Z, Rogers A. Roles of progranulin and FRamides in neural versus non-neural tissues on dietary restriction-related longevity and proteostasis in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579250. [PMID: 38370756 PMCID: PMC10871266 DOI: 10.1101/2024.02.06.579250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Dietary restriction (DR) mitigates loss of proteostasis associated with aging that underlies neurodegenerative conditions including Alzheimer's disease and related dementias. Previously, we observed increased translational efficiency of certain FMRFamide-like neuropeptide ( flp ) genes and the neuroprotective growth factor progranulin gene prgn-1 under dietary restriction in C. elegans . Here, we tested the effects of flp-5 , flp-14 , flp-15 and pgrn-1 on lifespan and proteostasis under both standard and dietary restriction conditions. We also tested and distinguished function based on their expression in either neuronal or non-neuronal tissue. Lowering the expression of pgrn-1 and flp genes selectively in neural tissue showed no difference in survival under normal feeding conditions nor under DR in two out of three experiments performed. Reduced expression of flp-14 in non-neuronal tissue showed decreased lifespan that was not specific to DR. With respect to proteostasis, a genetic model of DR from mutation of the eat-2 gene that showed increased thermotolerance compared to fully fed wild type animals demonstrated no change in thermotolerance in response to knockdown of pgrn-1 or flp genes. Finally, we tested effects on motility in a neural-specific model of proteotoxicity and found that neuronal knockdown of pgrn-1 and flp genes improved motility in early life regardless of diet. However, knocking these genes down in non-neuronal tissue had variable results. RNAi targeting flp-14 increased motility by day seven of adulthood regardless of diet. Interestingly, non-neuronal RNAi of pgrn-1 decreased motility under standard feeding conditions while DR increased motility for this gene knockdown by day seven (early mid-life). Results show that pgrn-1 , flp-5 , flp-14 , and flp-15 do not have major roles in diet-related changes in longevity or whole-body proteostasis. However, reduced expression of these genes in neurons increases motility early in life in a neural-specific model of proteotoxicity, whereas knockdown of non-neuronal expression mostly increases motility in mid-life under the same conditions.
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Laule C, Sayar-Atasoy N, Aklan I, Kim H, Ates T, Davis D, Atasoy D. Stress integration by an ascending adrenergic-melanocortin circuit. Neuropsychopharmacology 2024:10.1038/s41386-024-01810-9. [PMID: 38326456 DOI: 10.1038/s41386-024-01810-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/09/2024]
Abstract
Stress is thought to be an important contributing factor for eating disorders; however, neural substrates underlying the complex relationship between stress and appetite are not fully understood. Using in vivo recordings from awake behaving mice, we show that various acute stressors activate catecholaminergic nucleus tractus solitarius (NTSTH) projections in the paraventricular hypothalamus (PVH). Remarkably, the resulting adrenergic tone inhibits MC4R-expressing neurons (PVHMC4R), which are known for their role in feeding suppression. We found that PVHMC4R silencing encodes negative valence in sated mice and is required for avoidance induced by visceral malaise. Collectively, these findings establish PVHMC4R neurons as an effector of stress-activated brainstem adrenergic input in addition to the well-established hypothalamic-pituitary-adrenal axis. Convergent modulation of stress and feeding by PVHMC4R neurons implicates NTSTH → PVHMC4R input in stress-associated appetite disorders.
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Affiliation(s)
- Connor Laule
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Nilufer Sayar-Atasoy
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Iltan Aklan
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Hyojin Kim
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Tayfun Ates
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Debbie Davis
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Deniz Atasoy
- Department of Neuroscience and Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
- Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
- Fraternal Order of Eagles Diabetes Research Center (FOEDRC), Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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Jiang J, Liu Y, Wang A, Zhuo Z, Shi H, Zhang X, Li W, Sun M, Jiang S, Wang Y, Zou X, Zhang Y, Jia Z, Xu J. Development and validation of a nutrition-related genetic-clinical-radiological nomogram associated with behavioral and psychological symptoms in Alzheimer's disease. Chin Med J (Engl) 2023:00029330-990000000-00878. [PMID: 38031345 DOI: 10.1097/cm9.0000000000002914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND Few evidence is available in the early prediction models of behavioral and psychological symptoms of dementia (BPSD) in Alzheimer's disease (AD). This study aimed to develop and validate a novel genetic-clinical-radiological nomogram for evaluating BPSD in patients with AD and explore its underlying nutritional mechanism. METHODS This retrospective study included 165 patients with AD from the Chinese Imaging, Biomarkers, and Lifestyle (CIBL) cohort between June 1, 2021, and March 31, 2022. Data on demoimagedatas, neuropsychological assessments, single-nucleotide polymorphisms of AD risk genes, and regional brain volumes were collected. A multivariate logistic regression model identified BPSD-associated factors, for subsequently constructing a diagnostic nomogram. This nomogram was internally validated through 1000-bootstrap resampling and externally validated using a time-series split based on the CIBL cohort data between June 1, 2022, and February 1, 2023. Area under receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA) were used to assess the discrimination, calibration, and clinical applicability of the nomogram. RESULTS Factors independently associated with BPSD were: CETP rs1800775 (odds ratio [OR] = 4.137, 95% confidence interval [CI]: 1.276-13.415, P = 0.018), decreased Mini Nutritional Assessment score (OR = 0.187, 95% CI: 0.086-0.405, P <0.001), increased caregiver burden inventory score (OR = 8.993, 95% CI: 3.830-21.119, P <0.001), and decreased brain stem volume (OR = 0.006, 95% CI: 0.001-0.191, P = 0.004). These variables were incorporated into the nomogram. The area under the ROC curve was 0.925 (95% CI: 0.884-0.967, P <0.001) in the internal validation and 0.791 (95% CI: 0.686-0.895, P <0.001) in the external validation. The calibration plots showed favorable consistency between the prediction of nomogram and actual observations, and the DCA showed that the model was clinically useful in both validations. CONCLUSION A novel nomogram was established and validated based on lipid metabolism-related genes, nutritional status, and brain stem volumes, which may allow patients with AD to benefit from early triage and more intensive monitoring of BPSD. REGISTRATION Chictr.org.cn, ChiCTR2100049131.
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Affiliation(s)
- Jiwei Jiang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Yaou Liu
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
- Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Anxin Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Zhizheng Zhuo
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
- Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
| | - Hanping Shi
- Department of Gastrointestinal Surgery, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, China
- Department of Clinical Nutrition, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, China
- Beijing International Science and Technology Cooperation Base for Cancer Metabolism and Nutrition, Beijing 100081, China
| | - Xiaoli Zhang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Wenyi Li
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Mengfan Sun
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Shirui Jiang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Yanli Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Xinying Zou
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Yuan Zhang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Ziyan Jia
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
| | - Jun Xu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Diseases, Beijing 100070, China
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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: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [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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Fortin SM, Chen JC, Petticord MC, Ragozzino FJ, Peters JH, Hayes MR. The locus coeruleus contributes to the anorectic, nausea, and autonomic physiological effects of glucagon-like peptide-1. SCIENCE ADVANCES 2023; 9:eadh0980. [PMID: 37729419 PMCID: PMC10511187 DOI: 10.1126/sciadv.adh0980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/21/2023] [Indexed: 09/22/2023]
Abstract
Increasing the therapeutic potential and reducing the side effects of U.S. Food and Drug Administration-approved glucagon-like peptide-1 receptor (GLP-1R) agonists used to treat obesity require complete characterization of the central mechanisms that mediate both the food intake-suppressive and illness-like effects of GLP-1R signaling. Our studies, in the rat, demonstrate that GLP-1Rs in the locus coeruleus (LC) are pharmacologically and physiologically relevant for food intake control. Furthermore, agonism of LC GLP-1Rs induces illness-like behaviors, and antagonism of LC GLP-1Rs can attenuate GLP-1R-mediated nausea. Electrophysiological and behavioral pharmacology data support a role for LC GLP-1Rs expressed on presynaptic glutamatergic terminals in the control of feeding and malaise. Collectively, our work establishes the LC as a site of action for GLP-1 signaling and extends our understanding of the GLP-1 signaling mechanism necessary for the development of improved obesity pharmacotherapies.
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Affiliation(s)
- Samantha M. Fortin
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jack C. Chen
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marisa C. Petticord
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Forrest J. Ragozzino
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - James H. Peters
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Matthew R. Hayes
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
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Scott KA, Tan Y, Johnson DN, Elsaafien K, Baumer-Harrison C, Eikenberry SA, Sa JM, de Lartigue G, de Kloet AD, Krause EG. Mechanosensation of the heart and gut elicits hypometabolism and vigilance in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.29.547073. [PMID: 37425814 PMCID: PMC10327188 DOI: 10.1101/2023.06.29.547073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Interoception broadly refers to awareness of one's internal milieu. Vagal sensory afferents monitor the internal milieu and maintain homeostasis by engaging brain circuits that alter physiology and behavior. While the importance of the body-to-brain communication that underlies interoception is implicit, the vagal afferents and corresponding brain circuits that shape perception of the viscera are largely unknown. Here, we use mice to parse neural circuits subserving interoception of the heart and gut. We determine vagal sensory afferents expressing the oxytocin receptor, hereafter referred to as NDGOxtr, send projections to the aortic arch or stomach and duodenum with molecular and structural features indicative of mechanosensation. Chemogenetic excitation of NDGOxtr significantly decreases food and water consumption, and remarkably, produces a torpor-like phenotype characterized by reductions in cardiac output, body temperature, and energy expenditure. Chemogenetic excitation of NDGOxtr also creates patterns of brain activity associated with augmented hypothalamic-pituitary-adrenal axis activity and behavioral indices of vigilance. Recurrent excitation of NDGOxtr suppresses food intake and lowers body mass, indicating that mechanosensation of the heart and gut can exert enduring effects on energy balance. These findings suggest that the sensation of vascular stretch and gastrointestinal distention may have profound effects on whole body metabolism and mental health.
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Affiliation(s)
- Karen A. Scott
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Yalun Tan
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Dominique N. Johnson
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Khalid Elsaafien
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Caitlin Baumer-Harrison
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Sophia A. Eikenberry
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Jessica M. Sa
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
| | | | - Annette D. de Kloet
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
- McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
| | - Eric G. Krause
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32611, USA
- Center for Integrative Cardiovascular and Metabolic Diseases, University of Florida, Gainesville, FL 32611, USA
- McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
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Dong Y, Weng J, Zhu Y, Sun D, He W, Chen Q, Cheng J, Zhu Y, Jiang Y. Transcriptomic profiling of the developing brain revealed cell-type and brain-region specificity in a mouse model of prenatal stress. BMC Genomics 2023; 24:86. [PMID: 36829105 PMCID: PMC9951484 DOI: 10.1186/s12864-023-09186-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 02/14/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND Prenatal stress (PS) is considered as a risk factor for many mental disorders. PS-induced transcriptomic alterations may contribute to the functional dysregulation during brain development. Here, we used RNA-seq to explore changes of gene expression in the mouse fetal brain after prenatal exposure to chronic unpredictable mild stress (CUMS). RESULTS We compared the stressed brains to the controls and identified groups of significantly differentially expressed genes (DEGs). GO analysis on up-regulated DEGs revealed enrichment for the cell cycle pathways, while down-regulated DEGs were mostly enriched in the neuronal pathways related to synaptic transmission. We further performed cell-type enrichment analysis using published scRNA-seq data from the fetal mouse brain and revealed cell-type-specificity for up- and down-regulated DEGs, respectively. The up-regulated DEGs were highly enriched in the radial glia, while down-regulated DEGs were enriched in different types of neurons. Cell deconvolution analysis further showed altered cell fractions in the stressed brain, indicating accumulation of neuroblast and impaired neurogenesis. Moreover, we also observed distinct brain-region expression pattern when mapping DEGs onto the developing Allen brain atlas. The up-regulated DEGs were primarily enriched in the dorsal forebrain regions including the cortical plate and hippocampal formation. Surprisingly, down-regulated DEGs were found excluded from the cortical region, but highly expressed on various regions in the ventral forebrain, midbrain and hindbrain. CONCLUSION Taken together, we provided an unbiased data source for transcriptomic alterations of the whole fetal brain after chronic PS, and reported differential cell-type and brain-region vulnerability of the developing brain in response to environmental insults during the pregnancy.
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Affiliation(s)
- Yuhao Dong
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Jie Weng
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Yueyan Zhu
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Daijing Sun
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Wei He
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Qi Chen
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Jin Cheng
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Ying Zhu
- grid.8547.e0000 0001 0125 2443Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032 Shanghai, China
| | - Yan Jiang
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, 200032, Shanghai, China.
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Edwards CM, Guerrero IE, Zheng H, Dolezel T, Rinaman L. Blockade of Ghrelin Receptor Signaling Enhances Conditioned Passive Avoidance and Context-Associated cFos Activation in Fasted Male Rats. Neuroendocrinology 2022; 113:535-548. [PMID: 36566746 PMCID: PMC10133005 DOI: 10.1159/000528828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Interoceptive feedback to the brain regarding the body's physiological state plays an important role in guiding motivated behaviors. For example, a state of negative energy balance tends to increase exploratory/food-seeking behaviors while reducing avoidance behaviors. We recently reported that overnight food deprivation reduces conditioned passive avoidance behavior in male (but not female) rats. Since fasting increases circulating levels of ghrelin, we hypothesized that ghrelin signaling contributes to the ability of fasting to reduce conditioned avoidance. METHODS Ad libitum-fed male rats were trained in a passive avoidance procedure using mild footshock. Later, following overnight food deprivation, the same rats were pretreated with ghrelin receptor antagonist (GRA) or saline vehicle 30 min before avoidance testing. RESULTS GRA restored passive avoidance in fasted rats as measured by both latency to enter and time spent in the shock-paired context. In addition, compared to vehicle-injected fasted rats, fasted rats that received GRA before reexposure to the shock-paired context displayed more cFos activation of prolactin-releasing peptide (PrRP)-positive noradrenergic (NA) neurons in the caudal nucleus of the solitary tract, accompanied by more cFos activation in downstream target sites of PrRP neurons (i.e., bed nucleus of the stria terminalis and paraventricular nucleus of the hypothalamus). DISCUSSION These results support the view that ghrelin signaling contributes to the inhibitory effect of fasting on learned passive avoidance behavior, perhaps by suppressing recruitment of PrRP-positive NA neurons and their downstream hypothalamic and limbic forebrain targets.
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Affiliation(s)
- Caitlyn M Edwards
- Department of Psychology, Florida State University, Tallahassee, Florida, USA
| | | | - Huiyuan Zheng
- Department of Psychology, Florida State University, Tallahassee, Florida, USA
| | - Tyla Dolezel
- Department of Psychology, Florida State University, Tallahassee, Florida, USA
| | - Linda Rinaman
- Department of Psychology, Florida State University, Tallahassee, Florida, USA
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Zheng H, López-Ferreras L, Krieger JP, Fasul S, Cea Salazar V, Valderrama Pena N, Skibicka KP, Rinaman L. A Cre-driver rat model for anatomical and functional analysis of glucagon (Gcg)-expressing cells in the brain and periphery. Mol Metab 2022; 66:101631. [PMID: 36368622 PMCID: PMC9677222 DOI: 10.1016/j.molmet.2022.101631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
OBJECTIVE The glucagon gene (Gcg) encodes preproglucagon, which is cleaved to form glucagon-like peptide 1 (GLP1) and other mature signaling molecules implicated in metabolic functions. To date there are no transgenic rat models available for precise manipulation of GLP1-expressing cells in the brain and periphery. METHODS To visualize and manipulate Gcg-expressing cells in rats, CRISPR/Cas9 was used to express iCre under control of the Gcg promoter. Gcg-Cre rats were bred with tdTomato reporter rats to tag Gcg-expressing cells. Cre-dependent AAVs and RNAscope in situ hybridization were used to evaluate the specificity of iCre expression by GLP1 neurons in the caudal nucleus of the solitary tract (cNTS) and intermediate reticular nucleus (IRt), and by intestinal and pancreatic secretory cells. Food intake was assessed in heterozygous (Het) Gcg-Cre rats after chemogenetic stimulation of cNTS GLP1 neurons expressing an excitatory DREADD. RESULTS While genotype has minimal effect on body weight or composition in chow-fed Gcg-Cre rats, homozygous (Homo) rats have lower plasma glucose levels. In neonatal and adult Gcg-Cre/tdTom rats, reporter-labeled cells are present in the cNTS and IRt, and in additional brain regions (e.g., basolateral amygdala, piriform cortex) that lack detectable Gcg mRNA in adults but display transient developmental or persistently low Gcg expression. Compared to wildtype (WT) rats, hindbrain Gcg mRNA and GLP1 protein in brain and plasma are markedly reduced in Homo Gcg-Cre rats. Chemogenetic stimulation of cNTS GLP1 neurons reduced overnight chow intake in males but not females, the effect in males was blocked by antagonism of central GLP1 receptors, and hypophagia was enhanced when combined with a subthreshold dose of cholecystokinin-8 to stimulate gastrointestinal vagal afferents. CONCLUSIONS Gcg-Cre rats are a novel and valuable experimental tool for analyzing the development, anatomy, and function of Gcg-expressing cells in the brain and periphery. In addition, Homo Gcg-Cre rats are a unique model for assessing the role of Gcg-encoded proteins in glucose homeostasis and energy metabolism.
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Affiliation(s)
- Huiyuan Zheng
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Lorena López-Ferreras
- Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Jean-Phillipe Krieger
- Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden
| | - Stephen Fasul
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Valentina Cea Salazar
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Natalia Valderrama Pena
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA
| | - Karolina P. Skibicka
- Department of Nutritional Sciences, College of Health and Human Development, Huck Institute, The Pennsylvania State University, University Park, PA, USA,Institute of Neuroscience and Physiology, Department of Physiology/Metabolic Physiology, The Sahlgrenska Academy at University of Gothenburg, Sweden,Corresponding author. Department of Nutritional Sciences, Pennsylvania State University, 204 Chandlee Lab, University Park, PA 16802, USA
| | - Linda Rinaman
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA,Corresponding author. Department of Psychology, Program in Neuroscience, Florida State University, 1107 W. Call Street, Tallahassee, FL 32306, USA.
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Neuhuber WL, Berthoud HR. Functional anatomy of the vagus system: How does the polyvagal theory comply? Biol Psychol 2022; 174:108425. [PMID: 36100134 DOI: 10.1016/j.biopsycho.2022.108425] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/07/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022]
Abstract
Due to its pivotal role in autonomic networks and interoception, the vagus attracts continued interest from both basic scientists and therapists of various clinical disciplines. In particular, the widespread use of heart rate variability as an index of autonomic cardiac control and a proposed central role of the vagus in biopsychological concepts, e.g., the polyvagal theory, provide a good opportunity to recall basic features of vagal anatomy. In addition to the "classical" vagal brainstem nuclei, i.e., dorsal motor nucleus, nucleus ambiguus and nucleus tractus solitarii, the spinal trigeminal and paratrigeminal nuclei come into play as targets of vagal afferents. On the other hand, the nucleus of the solitary tract receives and integrates not only visceral but also somatic afferents.
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Affiliation(s)
- Winfried L Neuhuber
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität, Krankenhausstrasse 9, Erlangen, Germany.
| | - Hans-Rudolf Berthoud
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
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Holt MK. The ins and outs of the caudal nucleus of the solitary tract: An overview of cellular populations and anatomical connections. J Neuroendocrinol 2022; 34:e13132. [PMID: 35509189 PMCID: PMC9286632 DOI: 10.1111/jne.13132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 11/29/2022]
Abstract
The body and brain are in constant two-way communication. Driving this communication is a region in the lower brainstem: the dorsal vagal complex. Within the dorsal vagal complex, the caudal nucleus of the solitary tract (cNTS) is a major first stop for incoming information from the body to the brain carried by the vagus nerve. The anatomy of this region makes it ideally positioned to respond to signals of change in both emotional and bodily states. In turn, the cNTS controls the activity of regions throughout the brain that are involved in the control of both behaviour and physiology. This review is intended to help anyone with an interest in the cNTS. First, I provide an overview of the architecture of the cNTS and outline the wide range of neurotransmitters expressed in subsets of neurons in the cNTS. Next, in detail, I discuss the known inputs and outputs of the cNTS and briefly highlight what is known regarding the neurochemical makeup and function of those connections. Then, I discuss one group of cNTS neurons: glucagon-like peptide-1 (GLP-1)-expressing neurons. GLP-1 neurons serve as a good example of a group of cNTS neurons, which receive input from varied sources and have the ability to modulate both behaviour and physiology. Finally, I consider what we might learn about other cNTS neurons from our study of GLP-1 neurons and why it is important to remember that the manipulation of molecularly defined subsets of cNTS neurons is likely to affect physiology and behaviours beyond those monitored in individual experiments.
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Affiliation(s)
- Marie K. Holt
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and PharmacologyUniversity College LondonLondonUK
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Trapp S, Stanford SC. New developments in the prospects for GLP-1 therapy. Br J Pharmacol 2022; 179:489-491. [PMID: 35107170 DOI: 10.1111/bph.15788] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Stefan Trapp
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - S Clare Stanford
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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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] [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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Sex and metabolic state interact to influence expression of passive avoidance memory in rats: Potential contribution of A2 noradrenergic neurons. Physiol Behav 2021; 239:113511. [PMID: 34181929 DOI: 10.1016/j.physbeh.2021.113511] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 02/05/2023]
Abstract
Competing motivational drives coordinate behaviors essential for survival. For example, interoceptive feedback from the body during a state of negative energy balance serves to suppress anxiety-like behaviors and promote exploratory behaviors in rats. Results from past research suggest that this shift in motivated behavior is linked to reduced activation of specific neural populations within the caudal nucleus of the solitary tract (cNTS). However, the potential impact of metabolic state and the potential role of cNTS neurons on conditioned avoidance behaviors has not been examined. The present study investigated these questions in male and female rats, using a task in which rats learn to avoid a context (i.e., a darkened chamber) after it is paired with a single mild footshock. When rats later were tested for passive avoidance of the shock-paired chamber, male rats tested in an overnight food-deprived state and female rats (regardless of feeding status) displayed significantly less avoidance compared to male rats that were fed ad libitum prior to testing. Based on prior evidence that prolactin-releasing peptide (PrRP)-positive noradrenergic neurons and glucagon-like peptide 1 (GLP1)-positive neurons within the cNTS are particularly sensitive to metabolic state, we examined whether these neural populations are activated in conditioned rats after re-exposure to the shock-paired chamber, and whether neural activation is modulated by metabolic state. Compared to the control condition, chamber re-exposure activated PrRP+ noradrenergic neurons and also activated neurons within the anterior ventrolateral bed nucleus of the stria terminalis (vlBNST), which receives dense input from PrRP+ terminals, in both male and female rats when fed ad libitum. In parallel with sex differences in passive avoidance behavior, PrRP+ neurons were less activated in female vs. male rats after chamber exposure. GLP1+ neurons were not activated in either sex. In both sexes, overnight food deprivation before chamber re-exposure reduced activation of PrRP+ neurons, and also reduced vlBNST activation. Our results support the view that PrRP+ noradrenergic neurons and their inputs to the vlBNST contribute to the expression of passive avoidance memory, and that this contribution is modulated by metabolic state.
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