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Aspesi D, Farinetti A, Marraudino M, Morgan GSK, Marzola E, Abbate-Daga G, Gotti S. Maternal separation alters the reward system of activity-based anorexia rats. Psychoneuroendocrinology 2021; 133:105393. [PMID: 34481327 DOI: 10.1016/j.psyneuen.2021.105393] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 08/02/2021] [Accepted: 08/20/2021] [Indexed: 02/07/2023]
Abstract
Maternal separation (MS) is a known chronic stressor in the postnatal period and when associated with another paradigm like the activity-based anorexia (ABA) rat model, causes different effects in the two sexes. In ABA females, the separation leads to increased hyperactivity and anxiety reduction, whereas, in males, the separation induces decreased locomotor activity without similar reduction of anxiety-like behaviors as observed in females. To understand the mechanisms altered by MS in synergy with the induction of the anorexic-like phenotype, we considered the reward system, which involves neurons synthesizing dopamine (DA) in the ventral tegmental area (VTA), substantia nigra pars compacta, and serotoninergic neurons in the dorsal raphe nucleus. Moreover, we analyzed the orexin circuit in the lateral hypothalamic area (LHA), which affects DA synthesis in the VTA and is also known to regulate food consumption and locomotor activity. Rats of both sexes were exposed to the two paradigms (MS and ABA), leading to four experimental groups for each sex: non-separated control (CON), non-separated ABA groups (ABA), MS control (MSCON), and MS plus ABA groups (MSABA). Immunohistochemistry analysis was performed to determine quantitative differences in the number of cells expressing DA, orexin, and serotonin (5-HT) among the experimental groups. The results showed that, in the DA system, the effect of MS was more evident in females than in males, with a substantial increase in DA cells in the VTA of MSABA. However, the analysis of the orexin system revealed a similar cellular increment in the LHA in the non-separated ABA groups of both sexes. Regarding 5-HT, there was an opposite effect in males and females of the MSABA groups, with only females showing a greater density of 5-HT cells. The changes in the reward system could partially explain the behavioral data: the hyperactivity, weight loss, and decreased anxiety levels of the MSABA females could be linked to an increase in DA and 5-HT cells, whereas in males, MS could mitigate the behavioral effects of the ABA protocol affecting the anxiety levels and locomotor activity through a lack of increased activation of the reward system.
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Affiliation(s)
- Dario Aspesi
- Department of Psychology and Neuroscience Program, University of Guelph, Guelph, Ontario, N1G 2W1 Canada.
| | - Alice Farinetti
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
| | - Marilena Marraudino
- NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
| | - Godstime Stephen Kojo Morgan
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
| | - Enrica Marzola
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; Eating Disorders Center of the "Città della Salute e della Scienza" Hospital, University of Turin, Italy.
| | - Giovanni Abbate-Daga
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; Eating Disorders Center of the "Città della Salute e della Scienza" Hospital, University of Turin, Italy.
| | - Stefano Gotti
- Department of Neuroscience "Rita Levi Montalcini", University of Turin, 10126 Turin, Italy; NICO - Neuroscience Institute Cavalieri Ottolenghi, Orbassano, 10043 Turin, Italy.
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D'Addario C, Zaplatic E, Giunti E, Pucci M, Micioni Di Bonaventura MV, Scherma M, Dainese E, Maccarrone M, Nilsson IA, Cifani C, Fadda P. Epigenetic regulation of the cannabinoid receptor CB1 in an activity-based rat model of anorexia nervosa. Int J Eat Disord 2020; 53:432-446. [PMID: 32275093 DOI: 10.1002/eat.23271] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 11/08/2019] [Revised: 03/16/2020] [Accepted: 03/16/2020] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Both environmental and genetic factors are known to contribute to the development of anorexia nervosa (AN), but the exact etiology remains poorly understood. Herein, we studied the transcriptional regulation of the endocannabinoid system, an interesting target for body weight maintenance and the control of food intake and energy balance. METHOD We used two well-characterized animal models of AN: (a) the activity-based anorexia (ABA) model in which rats, housed with running wheels and subjected to daily food restriction, show reductions in body weight and increase in physical activity; (b) the genetic anx/anx mouse displaying the core features of AN: low food intake and emaciation. RESULTS Among the evaluated endocannabinoid system components, we observed a selective and significant down-regulation of the gene encoding for the type 1 cannabinoid receptor (Cnr1) in ABA rats' hypothalamus and nucleus accumbens and, in the latter area, a consistent, significant and correlated increase in DNA methylation at the gene promoter. No changes were evident in the anx/anx mice except for a down-regulation of Cnr1, in the prefrontal cortex. DISCUSSION Our findings support a possible role for Cnr1 in the ABA animal model of AN. In particular, its regulation in the nucleus accumbens appears to be triggered by environmental cues due to the consistent epigenetic modulation of the promoter. These data warrant further studies on Cnr1 regulation as a possible target for treatment of AN.
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Affiliation(s)
- Claudio D'Addario
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Elizabeta Zaplatic
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Elisa Giunti
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - Mariangela Pucci
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | | | - Maria Scherma
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - Enrico Dainese
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy
| | - Mauro Maccarrone
- Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy.,Lipid Neurochemistry Unit, Santa Lucia Foundation IRCCS, Rome, Italy
| | - Ida A Nilsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Center for Molecular Medicine, Karolinska Hospital, Stockholm, Sweden
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Paola Fadda
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy.,CNR Institute of Neuroscience - Cagliari, National Research Council, Cagliari, Italy
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