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Hashimoto A, Nozaki A, Inoue H, Kuwano T. High masticatory ability attenuates psychosocial stress: A cross-sectional study. PLoS One 2023; 18:e0279891. [PMID: 36652405 PMCID: PMC9847911 DOI: 10.1371/journal.pone.0279891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 12/16/2022] [Indexed: 01/19/2023] Open
Abstract
Mastication interventions have previously been shown to alleviate acute stress. However, the relationship between masticatory performance and stress response among individuals remains unclear. This study aimed to examine the relationship between masticatory ability and stress response in young women by measuring the autonomic nerve function and salivary α-amylase activity during psychosocial stress. Eighty women (aged 20.0 ± 1.9 years) were divided into either a low or high masticatory performance group, and the Trier Social Stress Test was conducted. Moreover, the autonomic function was measured at rest, immediately before stress, immediately after stress, and 10 min after stress. The salivary α-amylase activity was also measured at rest, 5 min after stress, and 15 min after stress. The visual analog scale (VAS) was used for subjective stress evaluation. There was a significant increase in the autonomic balance of both groups immediately before stress loading, but whilst the high masticatory ability group showed a return to resting-state levels after stress loading, the low masticatory ability group showed elevated levels after stress loading. Salivary α-amylase activity significantly increased 5 min after stress loading in the low, but not high, masticatory ability group. Furthermore, the VAS scores for tension and confusion after stress were significantly higher in the low masticatory ability group than in the high masticatory ability group. Our findings suggest that high masticatory performance may contribute to alleviating psychosocial stress. This is the first study to clarify the relationship between habitual masticatory performance and psychosocial stress suppression in young women.
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Affiliation(s)
- Ayako Hashimoto
- Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women’s University, Kyoto, Japan
| | - Aya Nozaki
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan
| | - Hiroko Inoue
- Department of Nutrition and Health Sciences, Faculty of Food and Nutritional Sciences, Toyo University, Gunma, Japan
| | - Toshiko Kuwano
- Graduate School of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka, Japan
- * E-mail:
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2
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Yao D, Mu Y, Lu Y, Li L, Shao S, Zhou J, Li J, Chen S, Zhang D, Zhang Y, Zhu Z, Li H. Hippocampal AMPA receptors mediate the impairment of spatial learning and memory in prenatally stressed offspring rats. J Psychiatr Res 2022; 151:17-24. [PMID: 35427874 DOI: 10.1016/j.jpsychires.2022.03.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 02/15/2022] [Accepted: 03/21/2022] [Indexed: 11/18/2022]
Abstract
Numerous studies have shown that prenatal stress (PS) induces learning and memory deficits in offspring, yet the specific mechanisms and effective interventions remain limited. Chewing has been known as one of the active coping strategies to suppress stress, but its effects during PS on learning and memory are unknown. The purpose of this study was to investigate the role of hippocampal AMPA receptors in the adverse effects of PS on spatial learning and memory, and whether chewing during PS could prevent these effects in prenatally stressed adult offspring rats. Prenatal restraint stress with or without chewing to dams during the day 11-20 of pregnancy was used to analyze the impact of different treatments for offspring. The spatial learning and memory were tested by the Morris water maze. The mRNA and protein expression of AMPA receptors in the hippocampus were measured by qRT-PCR and Western blot, respectively. The methylation of AMPA receptors was detected by bisulfite sequencing PCR. Our results revealed that PS impaired spatial learning acquisition and memory retrieval in adult offspring rats, but chewing could relieve this effect. Hippocampal GluA1-4 expression was significantly reduced in prenatally stressed offspring, while there were no changes in the methylation level of GluA2 and GluA4 promoters. Moreover, chewing increased PS-induced suppression of AMPA receptors in the hippocampus. In short, hippocampal AMPA receptors mediate the impairment of spatial learning and memory in prenatally stressed offspring, whereas chewing during PS could ameliorate PS-induced memory deficits.
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Affiliation(s)
- Dan Yao
- Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, Xi'an, Shaanxi, 710061, China
| | - Yingjun Mu
- Central Laboratory, Heze Medical College, 1750 University Road, Heze, Shandong, 274009, China
| | - Yong Lu
- Central Laboratory, Heze Medical College, 1750 University Road, Heze, Shandong, 274009, China
| | - Li Li
- Central Laboratory, Heze Medical College, 1750 University Road, Heze, Shandong, 274009, China
| | - Shuya Shao
- Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, Xi'an, Shaanxi, 710061, China
| | - Jiahao Zhou
- Maternal and Infant Health Research Institute, Northwest University, 229 Taibai North Road, Xi'an, Shaanxi, 710069, China
| | - Jing Li
- Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, Xi'an, Shaanxi, 710061, China
| | - Shengquan Chen
- Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, Xi'an, Shaanxi, 710061, China
| | - Dan Zhang
- Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, Xi'an, Shaanxi, 710061, China
| | - Yifan Zhang
- Central Laboratory, Heze Medical College, 1750 University Road, Heze, Shandong, 274009, China
| | - Zhongliang Zhu
- Maternal and Infant Health Research Institute, Northwest University, 229 Taibai North Road, Xi'an, Shaanxi, 710069, China
| | - Hui Li
- Department of Neonatology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Road, Xi'an, Shaanxi, 710061, China.
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Chewing Behavior Attenuates the Tumor Progression-Enhancing Effects of Psychological Stress in a Breast Cancer Model Mouse. Brain Sci 2021; 11:brainsci11040479. [PMID: 33918787 PMCID: PMC8069186 DOI: 10.3390/brainsci11040479] [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: 02/25/2021] [Revised: 04/03/2021] [Accepted: 04/07/2021] [Indexed: 12/24/2022] Open
Abstract
We examined whether chewing behavior affects the tumor progression-enhancing impact of psychological stress. Human breast cancer cell line (MDA-MB-231) cells were inoculated into the mammary fat pads of athymic nude mice. The mice were assigned randomly to control, stress, and stress+chewing groups. Psychological stress was created by keeping mice in a transparent restraint cylinder for 45 min, three times a day, for 35 days after cell inoculation. Animals in the stress+chewing group were provided with a wooden stick for chewing on during the psychological stress period. Chewing behavior remarkably inhibited the tumor growth accelerated by the psychological stress. Immunohistochemical and Western blot findings revealed that chewing behavior during psychological stress markedly suppressed tumor angiogenesis and cell proliferation. In addition, chewing behavior decreased serum glucocorticoid levels and expressions of glucocorticoid and β2-adrenergic receptors in tumors. Chewing behavior decreased expressions of inducible nitric oxide synthase and 4-hydroxynonenal, and increased expression of superoxide dismutase 2 in tumors. Our findings suggest that chewing behavior could ameliorate the enhancing effects of psychological stress on the progression of breast cancer, at least partially, through modulating stress hormones and their receptors, and the subsequent signaling pathways involving reactive oxygen and nitrogen species.
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Hippocampal Protein Kinase C Gamma Signaling Mediates the Impairment of Spatial Learning and Memory in Prenatally Stressed Offspring Rats. Neuroscience 2019; 414:186-199. [DOI: 10.1016/j.neuroscience.2019.06.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/06/2019] [Accepted: 06/23/2019] [Indexed: 12/13/2022]
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Weijenberg RAF, Delwel S, Ho BV, van der Maarel-Wierink CD, Lobbezoo F. Mind your teeth-The relationship between mastication and cognition. Gerodontology 2018; 36:2-7. [PMID: 30480331 PMCID: PMC7380285 DOI: 10.1111/ger.12380] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 10/08/2018] [Accepted: 10/20/2018] [Indexed: 12/22/2022]
Abstract
This article explores the multifactorial relationship between mastication and cognition, with a focus on dementia. Older persons, especially those with dementia, are at great risk of suffering from oral health problems such as orofacial pain and loss of natural teeth. A possible explanation could be that the cognitive and motor impairments resulting from dementia cause a decrease in self‐care and as such, a worsening of oral health. An alternative explanation is that cognition and oral health influence each other. Animal studies show that a decrease in masticatory activity, for example, due to a soft diet or loss of teeth, causes memory loss and neuronal degeneration. The relationship between mastication and cognition has also been researched in human studies, but a cause‐effect relationship has not been proven. It is likely that multiple factors play a role in this relationship, such as self‐care, nutrition, stress and pain.
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Affiliation(s)
- Roxane A F Weijenberg
- Oral Kinesiology, Academisch Centrum Tandheelkunde Amsterdam, Amsterdam, The Netherlands
| | - Suzanne Delwel
- Oral Kinesiology, Academisch Centrum Tandheelkunde Amsterdam, Amsterdam, The Netherlands.,Clinical Neuropsychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Bach Van Ho
- Oral Kinesiology, Academisch Centrum Tandheelkunde Amsterdam, Amsterdam, The Netherlands
| | | | - Frank Lobbezoo
- Oral Kinesiology, Academisch Centrum Tandheelkunde Amsterdam, Amsterdam, The Netherlands
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Sasaguri K, Yamada K, Yamamoto T. Uncovering the neural circuitry involved in the stress-attenuation effects of chewing. JAPANESE DENTAL SCIENCE REVIEW 2018; 54:118-126. [PMID: 30128059 PMCID: PMC6094491 DOI: 10.1016/j.jdsr.2018.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 12/08/2017] [Accepted: 03/10/2018] [Indexed: 02/02/2023] Open
Abstract
Previous animal studies have indicated that coupling restraint stress load with activation of the masticatory organs (chewing) causes a reduction in the systemic and central nervous system stress response. However, the brain mechanism underlying this effect is unknown. Therefore, in this review, we summarize the literature regarding brain regions involved in the attenuating effects of chewing and the systemic stress response attenuation effects induced by those brain regions. In addition, we also focusing on the amygdala, as the emotional control center, and the hypothalamic-pituitary-adrenal axis, as one of the outputs of the systemic response. In particular, we will report on one of the chewing-related stress attenuation mechanisms within the brain brought about by the activation of the inhibition pathway accompanying the activation of the amygdala's GABAergic function.
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Affiliation(s)
- Kenichi Sasaguri
- Department of Dentistry, Oral and Maxillofacial Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Kentaro Yamada
- Department of Dentistry, Oral and Maxillofacial Surgery, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
- Brain Functions and Neuroscience Division, Department of Oral Science, Kanagawa Dental University Graduate School, Inaoka-cho 82, Yokosuka, Kanagawa 238-8580, Japan
| | - Toshiharu Yamamoto
- Brain Functions and Neuroscience Division, Department of Oral Science, Kanagawa Dental University Graduate School, Inaoka-cho 82, Yokosuka, Kanagawa 238-8580, Japan
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Leon M, Woo C. Environmental Enrichment and Successful Aging. Front Behav Neurosci 2018; 12:155. [PMID: 30083097 PMCID: PMC6065351 DOI: 10.3389/fnbeh.2018.00155] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/04/2018] [Indexed: 12/18/2022] Open
Abstract
The human brain sustains a slow but progressive decline in function as it ages and these changes are particularly profound in cognitive processing. A potential contributor to this deterioration is the gradual decline in the functioning of multiple sensory systems and the effects they have on areas of the brain that mediate cognitive function. In older adults, diminished capacity is typically observed in the visual, auditory, masticatory, olfactory, and motor systems, and these age-related declines are associated with both a decline in cognitive proficiency, and a loss of neurons in regions of the brain. We will review how the loss of hearing, vision, mastication skills, olfactory impairment, and motoric decline accompany cognitive loss, and how improved functioning of these systems may aid in the restoration of the cognitive abilities in older adults. The human brain appears to require a great deal of stimulation to maintain its cognitive efficacy as people age and environmental enrichment may aid in its maintenance and recovery.
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Affiliation(s)
- Michael Leon
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Cynthia Woo
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
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Kubo KY, Kotachi M, Suzuki A, Iinuma M, Azuma K. Chewing during prenatal stress prevents prenatal stress-induced suppression of neurogenesis, anxiety-like behavior and learning deficits in mouse offspring. Int J Med Sci 2018; 15:849-858. [PMID: 30008596 PMCID: PMC6036092 DOI: 10.7150/ijms.25281] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/30/2018] [Indexed: 01/08/2023] Open
Abstract
Prenatal stress (PS) induces learning deficits and anxiety-like behavior in mouse pups by increasing corticosterone levels in the dam. We examined the effects of maternal chewing during PS on arginine vasopressin (AVP) mRNA expression in the dams and on neurogenesis, brain-derived neurotrophic factor (BDNF) mRNA expression, learning deficits and anxiety-like behavior in the offspring. Mice were divided into control, stress and stress/chewing groups. Pregnant mice were exposed to restraint stress beginning on day 12 of pregnancy and continuing until delivery. Mice in the stress/chewing group were given a wooden stick to chew during restraint stress. PS significantly increased AVP mRNA expression in the paraventricular nucleus (PVN) of the hypothalamus in the dams. PS also impaired learning ability, suppressed neurogenesis and BDNF mRNA expression in the hippocampus, and induced anxiety-like behavior in the offspring. Chewing during PS prevented the PS-induced increase in AVP mRNA expression of the PVN in the dams. Chewing during PS significantly attenuated the PS-induced learning deficits, anxiety-like behavior, and suppression of neurogenesis and BDNF mRNA expression in the hippocampus of the offspring. Chewing during PS prevented the increase in plasma corticosterone in the dam by inhibiting the hypothalamic-pituitary-adrenal axis activity, and attenuated the attenuated the PS-induced suppression of neurogenesis and BDNF expression in the hippocampus of the pups, thereby ameliorating the PS-induced learning deficits and anxiety-like behavior. Chewing during PS is an effective stress-coping method for the dam to prevent PS-induced deficits in learning ability and anxiety-like behavior in the offspring.
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Affiliation(s)
- Kin-ya Kubo
- Graduate School of Human Life Science, Nagoya Women's University, 3-40 Shioji-cho, Mizuho-ku, Nagoya, Aichi, 467-8610, Japan
| | - Mika Kotachi
- Departments of 2 Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu, 501-0296, Japan
| | - Ayumi Suzuki
- Departments of 2 Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu, 501-0296, Japan
| | - Mitsuo Iinuma
- Departments of 2 Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu, 501-0296, Japan
| | - Kagaku Azuma
- Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyusyu, 807-8555, Japan
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Association between Mastication, the Hippocampus, and the HPA Axis: A Comprehensive Review. Int J Mol Sci 2017; 18:ijms18081687. [PMID: 28771175 PMCID: PMC5578077 DOI: 10.3390/ijms18081687] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 07/31/2017] [Accepted: 08/01/2017] [Indexed: 12/29/2022] Open
Abstract
Mastication is mainly involved in food intake and nutrient digestion with the aid of teeth. Mastication is also important for preserving and promoting general health, including hippocampus-dependent cognition. Both animal and human studies indicate that mastication influences hippocampal functions through the end product of the hypothalamic-pituitary-adrenal (HPA) axis, glucocorticoid (GC). Epidemiologic studies suggest that masticatory dysfunction in aged individuals, such as that resulting from tooth loss and periodontitis, acting as a source of chronic stress, activates the HPA axis, leading to increases in circulating GCs and eventually inducing various physical and psychological diseases, such as cognitive impairment, cardiovascular disorders, and osteoporosis. Recent studies demonstrated that masticatory stimulation or chewing during stressful conditions suppresses the hyperactivity of the HPA axis via GCs and GC receptors within the hippocampus, and ameliorates chronic stress-induced hippocampus-dependent cognitive deficits. Here, we provide a comprehensive overview of current research regarding the association between mastication, the hippocampus, and HPA axis activity. We also discuss several potential molecular mechanisms involved in the interactions between mastication, hippocampal function, and HPA axis activity.
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Suzuki A, Iinuma M, Hayashi S, Sato Y, Azuma K, Kubo KY. Maternal chewing during prenatal stress ameliorates stress-induced hypomyelination, synaptic alterations, and learning impairment in mouse offspring. Brain Res 2016; 1651:36-43. [PMID: 27613358 DOI: 10.1016/j.brainres.2016.09.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/12/2016] [Accepted: 09/05/2016] [Indexed: 01/24/2023]
Abstract
Maternal chewing during prenatal stress attenuates both the development of stress-induced learning deficits and decreased cell proliferation in mouse hippocampal dentate gyrus. Hippocampal myelination affects spatial memory and the synaptic structure is a key mediator of neuronal communication. We investigated whether maternal chewing during prenatal stress ameliorates stress-induced alterations of hippocampal myelin and synapses, and impaired development of spatial memory in adult offspring. Pregnant mice were divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube, and was initiated on day 12 of pregnancy and continued until delivery. Mice in the stress/chewing group were given a wooden stick to chew during restraint. In 1-month-old pups, spatial memory was assessed in the Morris water maze, and hippocampal oligodendrocytes and synapses in CA1 were assayed by immunohistochemistry and electron microscopy. Prenatal stress led to impaired learning ability, and decreased immunoreactivity of myelin basic protein (MBP) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in the hippocampal CA1 in adult offspring. Numerous myelin sheath abnormalities were observed. The G-ratio [axonal diameter to axonal fiber diameter (axon plus myelin sheath)] was increased and postsynaptic density length was decreased in the hippocampal CA1 region. Maternal chewing during stress attenuated the prenatal stress-induced impairment of spatial memory, and the decreased MBP and CNPase immunoreactivity, increased G-ratios, and decreased postsynaptic-density length in the hippocampal CA1 region. These findings suggest that chewing during prenatal stress in dams could be an effective coping strategy to prevent hippocampal behavioral and morphologic impairments in their offspring.
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Affiliation(s)
- Ayumi Suzuki
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Mitsuo Iinuma
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Sakurako Hayashi
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Yuichi Sato
- Department of Molecular Diagnostics, Kitasato University School of Allied Health Science, Kitasato 1-15-1, Minamiku, Sagamihara, Kanagawa 252-0373, Japan
| | - Kagaku Azuma
- Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8555, Japan
| | - Kin-Ya Kubo
- Seijoh University Graduate School of Health Care Studies, 2-172, Fukinodai, Tokai, Aichi 476-8588, Japan.
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Mastication as a Stress-Coping Behavior. BIOMED RESEARCH INTERNATIONAL 2015; 2015:876409. [PMID: 26090453 PMCID: PMC4450283 DOI: 10.1155/2015/876409] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/21/2014] [Accepted: 01/05/2015] [Indexed: 11/29/2022]
Abstract
Exposure to chronic stress induces various physical and mental effects that may ultimately lead to disease. Stress-related disease has become a global health problem. Mastication (chewing) is an effective behavior for coping with stress, likely due to the alterations chewing causes in the activity of the hypothalamic-pituitary-adrenal axis and autonomic nervous system. Mastication under stressful conditions attenuates stress-induced increases in plasma corticosterone and catecholamines, as well as the expression of stress-related substances, such as neurotrophic factors and nitric oxide. Further, chewing reduces stress-induced changes in central nervous system morphology, especially in the hippocampus and hypothalamus. In rodents, chewing or biting on wooden sticks during exposure to various stressors reduces stress-induced gastric ulcer formation and attenuates spatial cognitive dysfunction, anxiety-like behavior, and bone loss. In humans, some studies demonstrate that chewing gum during exposure to stress decreases plasma and salivary cortisol levels and reduces mental stress, although other studies report no such effect. Here, we discuss the neuronal mechanisms that underline the interactions between masticatory function and stress-coping behaviors in animals and humans.
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Chewing prevents stress-induced hippocampal LTD formation and anxiety-related behaviors: a possible role of the dopaminergic system. BIOMED RESEARCH INTERNATIONAL 2015; 2015:294068. [PMID: 26075223 PMCID: PMC4449872 DOI: 10.1155/2015/294068] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 01/13/2015] [Indexed: 11/17/2022]
Abstract
The present study examined the effects of chewing on stress-induced long-term depression (LTD) and anxiogenic behavior. Experiments were performed in adult male rats under three conditions: restraint stress condition, voluntary chewing condition during stress, and control condition without any treatments except handling. Chewing ameliorated LTD development in the hippocampal CA1 region. It also counteracted the stress-suppressed number of entries to the center region of the open field when they were tested immediately, 30 min, or 60 min after restraint. At the latter two poststress time periods, chewing during restraint significantly increased the number of times of open arm entries in the elevated plus maze, when compared with those without chewing. The in vivo microdialysis further revealed that extracellular dopamine concentration in the ventral hippocampus, which is involved in anxiety-related behavior, was significantly greater in chewing rats than in those without chewing from 30 to 105 min after stress exposure. Development of LTD and anxiolytic effects ameliorated by chewing were counteracted by administering the D1 dopamine receptor antagonist SCH23390, which suggested that chewing may activate the dopaminergic system in the ventral hippocampus to suppress stress-induced anxiogenic behavior.
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Harris RBS. Chronic and acute effects of stress on energy balance: are there appropriate animal models? Am J Physiol Regul Integr Comp Physiol 2015; 308:R250-65. [PMID: 25519732 PMCID: PMC4329465 DOI: 10.1152/ajpregu.00361.2014] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 12/12/2014] [Indexed: 11/22/2022]
Abstract
Stress activates multiple neural and endocrine systems to allow an animal to respond to and survive in a threatening environment. The corticotropin-releasing factor system is a primary initiator of this integrated response, which includes activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. The energetic response to acute stress is determined by the nature and severity of the stressor, but a typical response to an acute stressor is inhibition of food intake, increased heat production, and increased activity with sustained changes in body weight, behavior, and HPA reactivity. The effect of chronic psychological stress is more variable. In humans, chronic stress may cause weight gain in restrained eaters who show increased HPA reactivity to acute stress. This phenotype is difficult to replicate in rodent models where chronic psychological stress is more likely to cause weight loss than weight gain. An exception may be hamsters subjected to repeated bouts of social defeat or foot shock, but the data are limited. Recent reports on the food intake and body composition of subordinate members of group-housed female monkeys indicate that these animals have a similar phenotype to human stress-induced eaters, but there are a limited number of investigators with access to the model. Few stress experiments focus on energy balance, but more information on the phenotype of both humans and animal models during and after exposure to acute or chronic stress may provide novel insight into mechanisms that normally control body weight.
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Affiliation(s)
- Ruth B S Harris
- Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia
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Chen H, Iinuma M, Onozuka M, Kubo KY. Chewing Maintains Hippocampus-Dependent Cognitive Function. Int J Med Sci 2015; 12:502-9. [PMID: 26078711 PMCID: PMC4466515 DOI: 10.7150/ijms.11911] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/25/2015] [Indexed: 02/07/2023] Open
Abstract
Mastication (chewing) is important not only for food intake, but also for preserving and promoting the general health. Recent studies have showed that mastication helps to maintain cognitive functions in the hippocampus, a central nervous system region vital for spatial memory and learning. The purpose of this paper is to review the recent progress of the association between mastication and the hippocampus-dependent cognitive function. There are multiple neural circuits connecting the masticatory organs and the hippocampus. Both animal and human studies indicated that cognitive functioning is influenced by mastication. Masticatory dysfunction is associated with the hippocampal morphological impairments and the hippocampus-dependent spatial memory deficits, especially in elderly. Mastication is an effective behavior for maintaining the hippocampus-dependent cognitive performance, which deteriorates with aging. Therefore, chewing may represent a useful approach in preserving and promoting the hippocampus-dependent cognitive function in older people. We also discussed several possible mechanisms involved in the interaction between mastication and the hippocampal neurogenesis and the future directions for this unique fascinating research.
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Affiliation(s)
- Huayue Chen
- 1. Department of Anatomy Gifu University Graduate School of Medicine, Gifu, 501-1194, Gifu, Japan
| | - Mitsuo Iinuma
- 2. Department of Pediatric Dentistry, Division of Oral Structure, Function and Development, Asahi University, School of Dentistry, Mizuho, 501-0296, Gifu, Japan
| | - Minoru Onozuka
- 3. Department of Judo Therapy and Medical Science, Faculty of Medical Science, Nippon Sport Science University, Yokohama 227-0033, Kanagawa, Japan
| | - Kin-Ya Kubo
- 4. Seijoh University Graduate School of Health Care Studies, Tokai, 476-8588, Aichi, Japan
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Azuma K, Furuzawa M, Fujiwara S, Yamada K, Kubo KY. Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice. Int J Med Sci 2015; 12:952-7. [PMID: 26664256 PMCID: PMC4661293 DOI: 10.7150/ijms.13298] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/07/2015] [Indexed: 01/24/2023] Open
Abstract
Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia.
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Affiliation(s)
- Kagaku Azuma
- 1. Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, Fukuoka, 807-8555, Japan
| | - Manabu Furuzawa
- 2. Department of Prosthodontics, Asahi University School of Dentistry, Mizuho, 501-0296, Japan
| | - Shu Fujiwara
- 2. Department of Prosthodontics, Asahi University School of Dentistry, Mizuho, 501-0296, Japan
| | - Kumiko Yamada
- 3. Department of Anatomy and Physiology, Faculty of Domestic economy, Nagoya Women's University, Nagoya, 467-8610, Japan
| | - Kin-ya Kubo
- 4. Seijoh University Graduate School of Health Care Studies, Tokai, 478-8588, Japan
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16
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Henderson YO, Victoria NC, Inoue K, Murphy AZ, Parent MB. Early life inflammatory pain induces long-lasting deficits in hippocampal-dependent spatial memory in male and female rats. Neurobiol Learn Mem 2014; 118:30-41. [PMID: 25451312 DOI: 10.1016/j.nlm.2014.10.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/20/2014] [Accepted: 10/29/2014] [Indexed: 11/17/2022]
Abstract
The present experiment tested the hypothesis that neonatal injury disrupts adult hippocampal functioning and that normal aging or chronic stress during adulthood, which are known to have a negative impact on hippocampal function, exacerbate these effects. Male and female Sprague-Dawley rats were given an intraplantar injection of the inflammatory agent carrageenan (1%) on the day of birth and their memory was tested in the hippocampal-dependent spatial water maze in adulthood and again in middle age. We found that neonatal injury impaired hippocampal-dependent memory in adulthood, that the effects of injury on memory were more pronounced in middle-aged male rats, and that chronic stress accelerated the onset of these memory deficits. Neonatal injury also decreased glucocorticoid receptor mRNA in the dorsal CA1 area of middle-aged rats, a brain region critical for spatial memory. Morphine administration at the time of injury completely reversed injury-induced memory deficits, but neonatal morphine treatments in the absence of injury produced significant memory impairments in adulthood. Collectively, these findings are consistent with our hypothesis that neonatal injury produces long-lasting disruption in adult hippocampal functioning.
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Affiliation(s)
- Yoko O Henderson
- Neuroscience Institute, Georgia State University, P.O. Box 5030, Atlanta, GA 30302-5030, United States.
| | - Nicole C Victoria
- Neuroscience Institute, Georgia State University, P.O. Box 5030, Atlanta, GA 30302-5030, United States.
| | - Kiyoshi Inoue
- Department of Psychiatry and Behavioral Sciences, Yerkes National Primate Center, Emory University School of Medicine, 954 Gatewood Rd., Atlanta, GA 30322, United States; Center for Translational Social Neuroscience, Yerkes National Primate Center, Emory University School of Medicine, 954 Gatewood Rd., Atlanta, GA 30322, United States.
| | - Anne Z Murphy
- Neuroscience Institute, Georgia State University, P.O. Box 5030, Atlanta, GA 30302-5030, United States.
| | - Marise B Parent
- Neuroscience Institute, Georgia State University, P.O. Box 5030, Atlanta, GA 30302-5030, United States; Department of Psychology, Georgia State University, P.O. Box 5010, Atlanta, GA 30302-5010, United States.
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Tsuboi H, Hirai Y, Maezawa H, Notani K, Inoue N, Funahashi M. Effects of treadmill exercise on the LiCl-induced conditioned taste aversion in rats. Physiol Behav 2014; 138:1-5. [PMID: 25447753 DOI: 10.1016/j.physbeh.2014.10.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 10/17/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
Abstract
Studies have shown that exercise can enhance learning and memory. Conditioned taste aversion (CTA) is an avoidance behavior induced by associative memory of the taste sensation for something pleasant or neutral with a negative visceral reaction caused by the coincident action of a toxic substance that is tasteless or administered systemically. We sought to measure the effects of treadmill exercise on CTA in rats by investigating the effects of exercise on acquisition, extinction and spontaneous recovery of CTA. We made two groups of rats: an exercise group that ran on a treadmill, and a control group that did not have structured exercise periods. To condition rats to disfavor a sweet taste, consumption of a 0.1% saccharin solution in place of drinking water was paired with 0.15M LiCl (2% body weight, i.p.) to induce visceral discomfort. We measured changes of saccharin consumption during acquisition and extinction of CTA. The exercise and no-exercise groups both acquired CTA to similar levels and showed maximum extinction of CTA around 6 days after acquisition. This result indicates that exercise affects neither acquisition nor extinction of CTA. However, in testing for preservation of CTA after much longer extinction periods that included exercise or not during the intervening period, exercising animals showed a significantly lower saccharin intake, irrespective of having exercised or not during the conditioning phase of the trial. This result suggests that exercise may help to preserve aversive memory (taste aversion in this example) as evidence by the significant spontaneous recovery of aversion in exercising animals.
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Affiliation(s)
- Hisanori Tsuboi
- Department of Gerodontology, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan; Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
| | - Yoshiyuki Hirai
- Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
| | - Hitoshi Maezawa
- Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
| | - Kenji Notani
- Department of Gerodontology, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
| | - Nobuo Inoue
- Department of Gerodontology, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
| | - Makoto Funahashi
- Department of Oral Physiology, Division of Oral Functional Science, Hokkaido University Graduate School of Dental Medicine, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.
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Furuzawa M, Chen H, Fujiwara S, Yamada K, Kubo KY. Chewing ameliorates chronic mild stress-induced bone loss in senescence-accelerated mouse (SAMP8), a murine model of senile osteoporosis. Exp Gerontol 2014; 55:12-8. [PMID: 24607548 DOI: 10.1016/j.exger.2014.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 02/13/2014] [Accepted: 03/02/2014] [Indexed: 01/15/2023]
Abstract
Chronic mild stress is a risk factor for osteoporosis and chewing inhibits the stress response. We examined the effect of chewing on chronic stress-induced bone loss and bone microstructural deterioration in mice. The senescence-accelerated mouse strain P8 (SAMP8) was randomly divided into control, stress, and stress with chewing groups of fifteen animals each. Mice in the stress and stress with chewing groups were placed in a ventilated restraint tube for 60minutes, twice a day for 4weeks. The restrained mice were simultaneously subjected daily to one of the following stressors: water immersion, physical shaking and flashing lights. Mice in the stress with chewing group were allowed to chew a wooden stick during the experimental period. After the experiment, the bone response was evaluated using quantitative micro computed tomography, bone histomorphometry, and biochemical markers. Exposure of SAMP8 mice to chronic stress resulted in significant increase of the blood corticosterone and noradrenaline levels, and adrenal weight. The bone resorption was activated and the bone formation was suppressed. Trabecular bone volume and trabecular number were decreased in both the vertebra and distal femur of the stress group. Chewing under chronic stress prevented the increase in the blood corticosterone and noradrenaline levels, attenuated the reduced bone formation and increased bone resorption, improved the trabecular bone loss and bone microstructural deterioration induced by chronic mild stress. These findings indicate that chewing can ameliorate chronic stress-induced bone loss in SAMP8 mice. Thus, chewing may represent a useful method preventing and/or treating chronic stress-related osteoporosis.
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Affiliation(s)
- Manabu Furuzawa
- Department of Prosthodontics, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu, 501-0296, Japan
| | - Huayue Chen
- Department of Anatomy, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
| | - Shu Fujiwara
- Department of Prosthodontics, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu, 501-0296, Japan
| | - Kumiko Yamada
- Department of Anatomy and Physiology, Faculty of Domesticeconomy, Nagoya Women's University, Nagoya, Aichi, 476-8610, Japan
| | - Kin-ya Kubo
- Seijoh University Graduate School of Health Care Studies, Tokai, Aichi, 476-8588, Japan
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Onishi M, Iinuma M, Tamura Y, Kubo KY. Learning deficits and suppression of the cell proliferation in the hippocampal dentate gyrus of offspring are attenuated by maternal chewing during prenatal stress. Neurosci Lett 2014; 560:77-80. [DOI: 10.1016/j.neulet.2013.12.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 11/13/2013] [Accepted: 12/08/2013] [Indexed: 11/27/2022]
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20
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Kubo KY, Nagao I, Mori D, Fujiwara S, Sasaguri K, Yamamoto T, Ono Y, Onozuka M, Chen H. WITHDRAWN: Chewing during chronic stress ameliorates stress-induced suppression of neurogenesis in the hippocampal dentate gyrus in aged SAMP8 mice. Neurosci Lett 2012:S0304-3940(12)00865-8. [PMID: 22750151 DOI: 10.1016/j.neulet.2012.06.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 06/12/2012] [Accepted: 06/20/2012] [Indexed: 10/28/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Kin-Ya Kubo
- Seijoh University Graduate School of Health Care Studies, 2-172 Fukinodai, Tokai, Aichi 476-8588, Japan
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