1
|
Tolentino L, Iqbal A, Rahman S, Lutfy K. The Role of Beta-Endorphin in Food Deprivation-Mediated Increases in Food Intake and Binge-Eating. Brain Sci 2023; 13:brainsci13020212. [PMID: 36831755 PMCID: PMC9954518 DOI: 10.3390/brainsci13020212] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/17/2023] [Accepted: 01/24/2023] [Indexed: 01/31/2023] Open
Abstract
Food deprivation and binge eating represent significant public health concerns. Previous studies have implicated that hypothalamic opioids are affected following food deprivation. However, the role of each opioid peptide is not fully understood. Therefore, we investigated the role of endogenous beta-endorphin in food deprivation-mediated increases in food intake and binge eating. Male mice lacking beta-endorphin and their respective controls were subjected to 24 h food deprivation and then were randomly assigned to receive a regular diet (RD) or a high-fat diet (HFD). After four to five weeks, animals were re-exposed to an HFD to assess if previous exposure to HFD would enhance binge-eating behavior. We report that food deprivation significantly increases food intake; however, beta-endorphin may not be involved in this process. In addition, our findings suggest that prior exposure to an HFD promotes binge-eating behavior in wildtype mice, and that these effects were modestly decreased in beta-endorphin knockout mice. Overall, our results support that beta-endorphin may play a modest role in mediating palatability-driven feeding, but not hunger-associated feeding. A better understanding of neural mechanisms involved in binge eating and deprivation-induced increases in food intake may inspire new prevention or treatment options to decrease the burden of eating disorders.
Collapse
Affiliation(s)
- Laica Tolentino
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Asif Iqbal
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
- Department of Pharmaceutical Sciences, University of Connecticut, 69 North Eagleville Road, Unit 3092, Storrs, CT 06269, USA
| | - Shafiqur Rahman
- Department of Pharmaceutical Sciences, College of Pharmacy, South Dakota State University, Brookings, SD 57007, USA
| | - Kabirullah Lutfy
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, Pomona, CA 91766, USA
- Correspondence:
| |
Collapse
|
2
|
Levine AS, Jewett DC, Kotz CM, Olszewski PK. Behavioral plasticity: Role of neuropeptides in shaping feeding responses. Appetite 2022; 174:106031. [PMID: 35395362 DOI: 10.1016/j.appet.2022.106031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/12/2022] [Accepted: 03/29/2022] [Indexed: 11/28/2022]
Abstract
Behavioral plasticity refers to changes occurring due to external influences on an organism, including adaptation, learning, memory and enduring influences from early life experience. There are 2 types of behavioral plasticity: "developmental", which refers to gene/environment interactions affecting a phenotype, and "activational" which refers to innate physiology and can involve structural physiological changes of the body. In this review, we focus on feeding behavior, and studies involving neuropeptides that influence behavioral plasticity - primarily opioids, orexin, neuropeptide Y, and oxytocin. In each section of the review, we include examples of behavioral plasticity as it relates to actions of these neuropeptides. It can be concluded from this review that eating behavior is influenced by a number of external factors, including time of day, type of food available, energy balance state, and stressors. The reviewed work underscores that environmental factors play a critical role in feeding behavior and energy balance, but changes in eating behavior also result from a multitude of non-environmental factors, such that there can be no single mechanism or variable that can explain ingestive behavior.
Collapse
Affiliation(s)
- Allen S Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA.
| | - David C Jewett
- Department of Psychology, University of Wisconsin-Eau Claire, Eau Claire, WI, USA
| | - Catherine M Kotz
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Geriatric, Research, Education and Clinical Center, Minneapolis Veterans Affairs Health, Minneapolis, MN, 55417, USA
| | - Pawel K Olszewski
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA; Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Faculty of Science and Engineering, University of Waikato, Hamilton, 3240, New Zealand
| |
Collapse
|
3
|
Head MA, McColl LK, Klockars A, Levine AS, Olszewski PK. Acute Hypophagia and Changes in c-Fos Immunoreactivity in Adolescent Rats Treated with Low Doses of Oxytocin and Naltrexone. J Clin Med 2021; 11:jcm11010059. [PMID: 35011797 PMCID: PMC8745073 DOI: 10.3390/jcm11010059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/14/2021] [Accepted: 12/20/2021] [Indexed: 01/19/2023] Open
Abstract
A recent case report has shown that an adjunctive oxytocin + naltrexone (OT + NTX) treatment promoted more robust hypophagia and body weight reduction than OT alone in an adolescent male with hypothalamic obesity after craniopharyngioma resection. Thus far, there has been no basic research in adolescent laboratory animals that would examine whether the benefit of OT + NTX on appetite extends onto adolescent individuals without surgically induced overeating. Thus, here we examined whether low doses of combined OT + NTX acutely affect post-deprivation intake of energy-dense, standard chow; intake of energy-dense and palatable high-fat high-sugar (HFHS) diet; or calorie-dilute, palaTable 10% sucrose solution without deprivation in adolescent male rats. We assessed whether OT + NTX decreases water intake after water deprivation or produces a conditioned taste aversion (CTA). Finally, by using c-Fos immunoreactivity, we determined changes in activity of feeding-related brain areas after OT + NTX. We found that individual subthreshold doses of OT and NTX decreased feeding induced by energy and by palatability. Significant c-Fos changes were noted in the arcuate and dorsomedial hypothalamic nuclei. The hypophagic doses of OT + NTX did not suppress water intake in thirsty rats and did not cause a CTA, which suggests that feeding reduction is not a secondary effect of gastrointestinal discomfort or changes in thirst processing. We conclude that OT + NTX is an effective drug combination to reduce appetite in adolescent male rats.
Collapse
Affiliation(s)
- Mitchell A. Head
- Faculty of Science and Engineering, University of Waikato, Hamilton 3214, New Zealand; (M.A.H.); (L.K.M.); (A.K.)
| | - Laura K. McColl
- Faculty of Science and Engineering, University of Waikato, Hamilton 3214, New Zealand; (M.A.H.); (L.K.M.); (A.K.)
| | - Anica Klockars
- Faculty of Science and Engineering, University of Waikato, Hamilton 3214, New Zealand; (M.A.H.); (L.K.M.); (A.K.)
| | - Allen S. Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55113, USA;
| | - Pawel K. Olszewski
- Faculty of Science and Engineering, University of Waikato, Hamilton 3214, New Zealand; (M.A.H.); (L.K.M.); (A.K.)
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55113, USA;
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN 55416, USA
- Correspondence:
| |
Collapse
|
4
|
Hypothalamic control of interoceptive hunger. Curr Biol 2021; 31:3797-3809.e5. [PMID: 34273280 DOI: 10.1016/j.cub.2021.06.048] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/06/2021] [Accepted: 06/16/2021] [Indexed: 01/08/2023]
Abstract
While energy balance is critical to survival, many factors influence food intake beyond caloric need or "hunger." Despite this, some neurons that drive feeding in mice are routinely referred to as "hunger neurons," whereas others are not. To understand how specific hypothalamic circuits control interoceptive hunger, we trained mice to discriminate fasted from sated periods. We then manipulated three hypothalamic neuronal populations with well-known effects on feeding while mice performed this task. While activation of ARCAGRP neurons in sated mice caused mice to report being food-restricted, LHVGAT neuron activation or LHVGLUT2 neuron inhibition did not. In contrast, LHVGAT neuron inhibition or LHVGLUT2 neuron activation in fasted mice attenuated natural hunger, whereas ARCAGRP neuron inhibition did not. Each neuronal population evoked distinct effects on food consumption and reward. After satiety- or sickness-induced devaluation, ARCAGRP neurons drove calorie-specific feeding, while LHVGAT neurons drove calorie-indiscriminate food intake. Our data support a role for ARCAGRP neurons in homeostatic feeding and implicate them in driving a hunger-like internal state that directs behavior toward caloric food sources. Moreover, manipulations of LH circuits did not evoke hunger-like effects in sated mice, suggesting that they may govern feeding more related to reward, compulsion, or generalized consumption than to energy balance, but also that these LH circuits can be powerful negative appetite modulators in fasted mice. This study highlights the complexity of hypothalamic feeding regulation and can be used as a framework to characterize how other neuronal circuits affect hunger and identify potential therapeutic targets for eating disorders.
Collapse
|
5
|
Head MA, Levine AS, Christian DG, Klockars A, Olszewski PK. Effect of combination of peripheral oxytocin and naltrexone at subthreshold doses on food intake, body weight and feeding-related brain gene expression in male rats. Physiol Behav 2021; 238:113464. [PMID: 34022256 DOI: 10.1016/j.physbeh.2021.113464] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 01/17/2023]
Abstract
In a recent case report involving a male with hypothalamic obesity, concurrent administration of oxytocin (OT) and an opioid receptor antagonist, naltrexone (NTX), synergistically affected energy balance. Here, by using laboratory rats, we examined whether the reported synergy between OT and NTX in the context of food intake extends beyond that one unique case. We found that intravenous OT+NTX combination, at doses subthreshold for each of the drugs individually, decreased episodic consumption of a 10% sucrose solution in non-deprived animals. Daily administration of OT and NTX just before a scheduled, 2-hour, high-fat high-sugar (HFHS) meal over 24 days, decreased cumulative HFHS diet intake, but without a change in body weight due to compensatory standard chow intake during the remainder of the day. The NTX-OT treatment affected expression of several feeding-related genes in the hypothalamus, brain stem and nucleus accumbens, brain regions essential for the regulation of energy- and reward-driven consumption. We conclude that OT and NTX act synergistically to decrease food consumption in rats and that this transient effect is accompanied by changes in brain processes relevant to feeding.
Collapse
Affiliation(s)
- Mitchell A Head
- School of Science, Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
| | - Allen S Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113 United States.
| | - David G Christian
- School of Science, Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
| | - Anica Klockars
- School of Science, Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
| | - Pawel K Olszewski
- School of Science, Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113 United States; Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, United States
| |
Collapse
|