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Wald HS, Ghidewon MY, Hayes MR, Grill HJ. Hindbrain ghrelin and liver-expressed antimicrobial peptide 2, ligands for growth hormone secretagogue receptor, bidirectionally control food intake. Am J Physiol Regul Integr Comp Physiol 2023; 324:R547-R555. [PMID: 36847494 PMCID: PMC10069974 DOI: 10.1152/ajpregu.00232.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 01/26/2023] [Accepted: 02/16/2023] [Indexed: 03/01/2023]
Abstract
Hindbrain growth hormone secretagogue receptor (GHSR) agonism increases food intake, yet the underlying neural mechanisms remain unclear. The functional effects of hindbrain GHSR antagonism by its endogenous antagonist liver-expressed antimicrobial peptide 2 (LEAP2) are also yet unexplored. To test the hypothesis that hindbrain GHSR agonism attenuates the food intake inhibitory effect of gastrointestinal (GI) satiation signals, ghrelin (at a feeding subthreshold dose) was administered to the fourth ventricle (4V) or directly to the nucleus tractus solitarius (NTS) before systemic delivery of the GI satiation signal cholecystokinin (CCK). Also examined, was whether hindbrain GHSR agonism attenuated CCK-induced NTS neural activation (c-Fos immunofluorescence). To investigate an alternate hypothesis that hindbrain GHSR agonism enhances feeding motivation and food seeking, intake stimulatory ghrelin doses were administered to the 4V and fixed ratio 5 (FR-5), progressive ratio (PR), and operant reinstatement paradigms for palatable food responding were evaluated. Also assessed were 4V LEAP2 delivery on food intake and body weight (BW) and on ghrelin-stimulated feeding. Both 4V and NTS ghrelin blocked the intake inhibitory effect of CCK and 4V ghrelin blocked CCK-induced NTS neural activation. Although 4V ghrelin increased low-demand FR-5 responding, it did not increase high-demand PR or reinstatement of operant responding. Fourth ventricle LEAP2 reduced chow intake and BW and blocked hindbrain ghrelin-stimulated feeding. Data support a role for hindbrain GHSR in bidirectional control of food intake through mechanisms that include interacting with the NTS neural processing of GI satiation signals but not food motivation and food seeking.
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Affiliation(s)
- Hallie S Wald
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Misgana Y Ghidewon
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Matthew R Hayes
- Department of Psychiatry, Institute of Diabetes Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Harvey J Grill
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Matikainen-Ankney BA, Earnest T, Ali M, Casey E, Wang JG, Sutton AK, Legaria AA, Barclay KM, Murdaugh LB, Norris MR, Chang YH, Nguyen KP, Lin E, Reichenbach A, Clarke RE, Stark R, Conway SM, Carvalho F, Al-Hasani R, McCall JG, Creed MC, Cazares V, Buczynski MW, Krashes MJ, Andrews ZB, Kravitz AV. An open-source device for measuring food intake and operant behavior in rodent home-cages. eLife 2021; 10:66173. [PMID: 33779547 PMCID: PMC8075584 DOI: 10.7554/elife.66173] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 03/26/2021] [Indexed: 01/26/2023] Open
Abstract
Feeding is critical for survival, and disruption in the mechanisms that govern food intake underlies disorders such as obesity and anorexia nervosa. It is important to understand both food intake and food motivation to reveal mechanisms underlying feeding disorders. Operant behavioral testing can be used to measure the motivational component to feeding, but most food intake monitoring systems do not measure operant behavior. Here, we present a new solution for monitoring both food intake and motivation in rodent home-cages: the Feeding Experimentation Device version 3 (FED3). FED3 measures food intake and operant behavior in rodent home-cages, enabling longitudinal studies of feeding behavior with minimal experimenter intervention. It has a programmable output for synchronizing behavior with optogenetic stimulation or neural recordings. Finally, FED3 design files are open-source and freely available, allowing researchers to modify FED3 to suit their needs.
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Affiliation(s)
| | - Thomas Earnest
- Department of Psychiatry, Washington University in St. LouisSt. LouisUnited States
| | - Mohamed Ali
- National Institute of Diabetes and Digestive and Kidney DiseasesBethesdaUnited States,Department of Bioengineering, University of MarylandCollege ParkUnited States
| | - Eric Casey
- Department of Psychiatry, Washington University in St. LouisSt. LouisUnited States
| | - Justin G Wang
- Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States
| | - Amy K Sutton
- National Institute of Diabetes and Digestive and Kidney DiseasesBethesdaUnited States
| | - Alex A Legaria
- Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States
| | - Kia M Barclay
- Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States
| | - Laura B Murdaugh
- Department of Neuroscience, Virginia Polytechnic and State UniversityBlacksburgUnited States
| | - Makenzie R Norris
- Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States,Center for Clinical Pharmacology, University of Health Sciences and PharmacySt. LouisUnited States
| | - Yu-Hsuan Chang
- Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States
| | - Katrina P Nguyen
- National Institute of Diabetes and Digestive and Kidney DiseasesBethesdaUnited States
| | - Eric Lin
- Department of Psychiatry, Washington University in St. LouisSt. LouisUnited States
| | | | | | - Romana Stark
- Department of Physiology, Monash UniversityClaytonAustralia
| | - Sineadh M Conway
- Center for Clinical Pharmacology, University of Health Sciences and PharmacySt. LouisUnited States,Department of Anesthesiology, Washington University in St. LouisSt. LouisUnited States
| | | | - Ream Al-Hasani
- Center for Clinical Pharmacology, University of Health Sciences and PharmacySt. LouisUnited States,Department of Anesthesiology, Washington University in St. LouisSt. LouisUnited States
| | - Jordan G McCall
- Center for Clinical Pharmacology, University of Health Sciences and PharmacySt. LouisUnited States,Department of Anesthesiology, Washington University in St. LouisSt. LouisUnited States
| | - Meaghan C Creed
- Department of Psychiatry, Washington University in St. LouisSt. LouisUnited States,Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States,Department of Anesthesiology, Washington University in St. LouisSt. LouisUnited States
| | - Victor Cazares
- Department of Psychology, Williams CollegeWilliamstownUnited States
| | - Matthew W Buczynski
- Department of Neuroscience, Virginia Polytechnic and State UniversityBlacksburgUnited States
| | - Michael J Krashes
- National Institute of Diabetes and Digestive and Kidney DiseasesBethesdaUnited States
| | - Zane B Andrews
- Department of Physiology, Monash UniversityClaytonAustralia
| | - Alexxai V Kravitz
- Department of Psychiatry, Washington University in St. LouisSt. LouisUnited States,Department of Neuroscience, Washington University in St. LouisSt. LouisUnited States,Department of Anesthesiology, Washington University in St. LouisSt. LouisUnited States
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Ramsay DS, Kaiyala KJ, Woods SC. Individual differences in biological regulation: Predicting vulnerability to drug addiction, obesity, and other dysregulatory disorders. Exp Clin Psychopharmacol 2020; 28:388-403. [PMID: 32338936 PMCID: PMC8389185 DOI: 10.1037/pha0000371] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Physiological regulation is so fundamental to survival that natural selection has greatly favored the evolution of robust regulatory systems that use both reactive and preemptive responses to mitigate the disruptive impact of biological and environmental challenges on physiological function. In good health, robust regulatory systems provide little insight into the typically hidden complex array of sensor-effector interactions that accomplish successful regulation. Numerous health disorders have been traced to defective regulatory mechanisms, and generations of scientists have worked to discover ways to correct these defects and restore normal physiological function. Despite progress, numerous chronic health disorders remain resistant to treatment, and indeed for some disorders the incidence is increasing. We propose that an individual's susceptibility to acquire certain persistent dysregulatory disorders can be traced to interindividual variation in how that individual's regulatory system responds to challenges. Preexisting reliable individual differences among regulatory systems are typically unrecognized until appropriate regulatory challenges (e.g., exposure to a drug of abuse) lead to dysregulation (e.g., drug addiction). Specific characteristics of an individual's regulatory responsiveness may include etiological factors that participate in the acquisition, escalation and maintenance of health disorders characterized by dysregulation. By appropriately challenging a healthy individual's regulatory systems to identify its underlying characteristics, it is possible to ascertain whether an individual has an elevated risk for acquiring a dysregulated health condition and thereby enable strategies designed to prevent, rather than treat, the condition. This model is applied to drug addiction, and in addition we relate this approach to other dysregulated conditions such as obesity. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
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Affiliation(s)
- Douglas S. Ramsay
- Department of Oral Health Sciences, University of Washington
- Department of Orthodontics, University of Washington
- Department of Pediatric Dentistry, University of Washington
| | - Karl J. Kaiyala
- Department of Oral Health Sciences, University of Washington
| | - Stephen C. Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati Medical Center
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