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Lee SH, Ko MJ, Lee YS, Park YS. Correlation between GLCM-based texture features of the lateral pterygoid muscle and cognitive function in patients with idiopathic normal pressure hydrocephalus: a preliminary report. Acta Neurochir (Wien) 2024; 166:324. [PMID: 39098926 DOI: 10.1007/s00701-024-06215-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 07/23/2024] [Indexed: 08/06/2024]
Abstract
PURPOSE The potential relationship between mastication ability and cognitive function in idiopathic normal pressure hydrocephalus (iNPH) patients is unclear. This report investigated the association between mastication and cognitive function in iNPH patients using the gray level of the co-occurrence matrix on the lateral pterygoid muscle. METHODS We analyzed data from 96 unoperated iNPH patients who underwent magnetic resonance imaging (MRI) between December 2016 and February 2023. Radiomic features were extracted from T2 MRI scans of the lateral pterygoid muscle, and muscle texture parameters were correlated with the iNPH grading scale. Subgroup analysis compared the texture parameters of patients with normal cognitive function with those of patients with cognitive impairment. RESULTS The mini-mental state examination score correlated positively with the angular second moment (P < 0.05) and negatively with entropy (P < 0.05). The dementia scale (Eide's classification) correlated negatively with gray values (P < 0.05). Gray values were higher in the cognitive impairment group (64.7 ± 16.6) when compared with the non-cognitive impairment group (57.4 ± 13.3) (P = 0.005). Entropy was higher in the cognitive impairment group (8.2 ± 0.3) than in the non-cognitive impairment group (8.0 ± 0.3) (P < 0.001). The area under the receiver operating characteristic curve was 0.681 (P = 0.003) and 0.701 (P < 0.001) for gray value and entropy, respectively. CONCLUSION Our findings suggest an association between heterogeneity of mastication and impaired cognitive function in iNPH patients and highlight muscle texture analysis as a potential tool for predicting cognitive impairment in these patients.
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Affiliation(s)
- Shin Heon Lee
- Department of Neurosurgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102 Heukseok-ro, Dongjak-gu, Seoul, 06973, Republic of Korea
| | - Myeong Jin Ko
- Department of Neurosurgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102 Heukseok-ro, Dongjak-gu, Seoul, 06973, Republic of Korea
| | - Young-Seok Lee
- Department of Neurosurgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102 Heukseok-ro, Dongjak-gu, Seoul, 06973, Republic of Korea
| | - Yong-Sook Park
- Department of Neurosurgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, 102 Heukseok-ro, Dongjak-gu, Seoul, 06973, Republic of Korea.
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Piancino MG, De Biase C, Di Benedetto L, Chaurasia A, Vallelonga T, Tortarolo A. Reverse chewing patterns in patients with bilateral posterior crossbite are related to the occlusal features of the malocclusion. J Oral Rehabil 2024. [PMID: 39095962 DOI: 10.1111/joor.13822] [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: 08/21/2023] [Revised: 07/13/2024] [Accepted: 07/17/2024] [Indexed: 08/04/2024]
Abstract
BACKGROUND Bilateral posterior crossbite (BPXB) is a severe malocclusion associated with maxillary hypoplasia. BPXB may involve the same or a different number of teeth between the sides. OBJECTIVES To evaluate the masticatory function in BPXB and the association between the masticatory alterations and the occlusal features of BPXB. METHODS This observational study included 170 participants: 130 patients with BPXB (65 occlusally symmetric BPXB, i.e. same number and type of posterior teeth in crossbite between the sides, F = 33, M = 32, median age 9.6 (8.2-13) [years.months]; 65 patients occlusally asymmetric BPXB, F = 30, M = 35, median age 9.9 (8.3-13.6)) and 40 controls (F = 25, M = 15, median age 10.2 (9.4-11.6)). The masticatory function was evaluated by the detection of the Reverse Chewing Cycles (RCCs) recorded with a kinesiograph using standardised soft and hard boluses. RESULTS The frequency of RCCs was significantly increased in all BPXB patients compared to controls (p < .000). In symmetric BPXB patients, there were no significant differences in the frequency of RCCs during chewing on the left or the right side. In asymmetric BPXB patients, the frequency of RCCs was significantly increased during chewing on the side with relatively more teeth in crossbite (p < .000). CONCLUSIONS The masticatory function was significantly altered in all BPXB patients and it was differently affected by symmetric or asymmetric occlusal features of the malocclusion.
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Affiliation(s)
| | | | - Laura Di Benedetto
- Department of Surgical Sciences, Dental School, University of Turin, Turin, Italy
| | | | | | - Alessandro Tortarolo
- Department of Surgical Sciences, Dental School, University of Turin, Turin, Italy
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Kang Y, Toyoda H, Saito M. Search for unknown neural link between the masticatory and cognitive brain systems to clarify the involvement of its impairment in the pathogenesis of Alzheimer's disease. Front Cell Neurosci 2024; 18:1425645. [PMID: 38994328 PMCID: PMC11236757 DOI: 10.3389/fncel.2024.1425645] [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: 04/30/2024] [Accepted: 06/12/2024] [Indexed: 07/13/2024] Open
Abstract
Brain degenerations in sporadic Alzheimer's disease (AD) are observed earliest in the locus coeruleus (LC), a population of noradrenergic neurons, in which hyperphosphorylated tau protein expression and β-amyloid (Aβ) accumulation begin. Along with this, similar changes occur in the basal forebrain cholinergic neurons, such as the nucleus basalis of Meynert. Neuronal degeneration of the two neuronal nuclei leads to a decrease in neurotrophic factors such as brain-derived neurotrophic factor (BDNF) in the hippocampus and cerebral cortex, which results in the accumulation of Aβ and hyperphosphorylated tau protein and ultimately causes neuronal cell death in those cortices. On the other hand, a large number of epidemiological studies have shown that tooth loss or masticatory dysfunction is a risk factor for dementia including AD, and numerous studies using experimental animals have also shown that masticatory dysfunction causes brain degeneration in the basal forebrain, hippocampus, and cerebral cortex similar to those observed in human AD, and that learning and memory functions are impaired accordingly. However, it remains unclear how masticatory dysfunction can induce such brain degeneration similar to AD, and the neural mechanism linking the trigeminal nervous system responsible for mastication and the cognitive and memory brain system remains unknown. In this review paper, we provide clues to the search for such "missing link" by discussing the embryological, anatomical, and physiological relationship between LC and its laterally adjoining mesencephalic trigeminal nucleus which plays a central role in the masticatory functions.
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Affiliation(s)
- Youngnam Kang
- Department of Behavioral Physiology, Osaka University Graduate School of Human Sciences, Osaka, Japan
| | - Hiroki Toyoda
- Department of Oral Physiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - Mitsuru Saito
- Department of Oral Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
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Vassal M, Martins F, Monteiro B, Tambaro S, Martinez-Murillo R, Rebelo S. Emerging Pro-neurogenic Therapeutic Strategies for Neurodegenerative Diseases: A Review of Pre-clinical and Clinical Research. Mol Neurobiol 2024:10.1007/s12035-024-04246-w. [PMID: 38816676 DOI: 10.1007/s12035-024-04246-w] [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: 01/03/2024] [Accepted: 05/14/2024] [Indexed: 06/01/2024]
Abstract
The neuroscience community has largely accepted the notion that functional neurons can be generated from neural stem cells in the adult brain, especially in two brain regions: the subventricular zone of the lateral ventricles and the subgranular zone in the dentate gyrus of the hippocampus. However, impaired neurogenesis has been observed in some neurodegenerative diseases, particularly in Alzheimer's, Parkinson's, and Huntington's diseases, and also in Lewy Body dementia. Therefore, restoration of neurogenic function in neurodegenerative diseases emerges as a potential therapeutic strategy to counteract, or at least delay, disease progression. Considering this, the present study summarizes the different neuronal niches, provides a collection of the therapeutic potential of different pro-neurogenic strategies in pre-clinical and clinical research, providing details about their possible modes of action, to guide future research and clinical practice.
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Affiliation(s)
- Mariana Vassal
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
| | - Filipa Martins
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
| | - Bruno Monteiro
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal
| | - Simone Tambaro
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Huddinge, Sweden
| | - Ricardo Martinez-Murillo
- Neurovascular Research Group, Department of Translational Neurobiology, Cajal Institute (CSIC), Madrid, Spain
| | - Sandra Rebelo
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro, Portugal.
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Inamochi Y, Ogino Y, Harada K, Fueki K, Ayukawa Y, Nishimura M, Maekawa K, Kang Y, Hirai T, Kuboki T. DO ORAL CARE AND REHABILITATION IMPROVE COGNITIVE FUNCTION? A SYSTEMATIC REVIEW OF CLINICAL STUDIES. J Evid Based Dent Pract 2024; 24:101948. [PMID: 38448117 DOI: 10.1016/j.jebdp.2023.101948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 09/19/2023] [Accepted: 10/16/2023] [Indexed: 03/08/2024]
Abstract
OBJECTIVES An increasing number of studies have identified an association between oral health status and cognitive function. However, the effect of oral interventions, including oral health care, dental treatment and oral motor exercises, on cognitive function remains unclear. This systematic review examined whether oral interventions contribute to the long-term improvement of cognitive status. METHODS Four databases were searched (MEDLINE, Web of Science, Cochrane Library, and ICHUSHI Web) to identify randomized and nonrandomized controlled trial studies and prospective cohort studies from inception until 1 September 2023, published in English or Japanese. The Cochrane risk of bias tool for randomized controlled trials and the risk of bias assessment tool for nonrandomized studies were used to assess bias risk. RESULTS A total of 20 articles were included in the qualitative analysis; 13 articles were published in English, and 7 were published in Japanese. The implemented interventions were oral care in 8 studies, dental treatment in 8 studies, and oral motor exercise in 4 studies. One study found a significant effect on attention following oral care intervention. Some dental treatments influenced cognitive function, although a clear positive effect was not determined. In 1 study, attention and working memory improved in the chewing exercise group. CONCLUSIONS Several studies verified the improvement effects of oral interventions, such as oral care, dental treatment, and oral motor exercise, on cognitive function or impairment. However, there was still a lack of conclusive evidence that such an intervention clearly improved cognitive function. To clarify the effects of oral interventions on cognitive function, it is necessary to examine participants, interventions, and outcome measures in detail.
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Affiliation(s)
- Yuka Inamochi
- Department of Masticatory Function and Health Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
| | - Yoichiro Ogino
- Division of Oral Rehabilitation, Faculty of Dental Science, Section of Fixed Prosthodontics, Kyushu University, Fukuoka, Japan
| | - Kae Harada
- Department of Oral and Maxillofacial Prosthodontics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kenji Fueki
- Department of Masticatory Function and Health Science, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yasunori Ayukawa
- Division of Oral Rehabilitation, Faculty of Dental Science, Section of Fixed Prosthodontics, Kyushu University, Fukuoka, Japan
| | - Masahiro Nishimura
- Department of Oral and Maxillofacial Prosthodontics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Kenji Maekawa
- Department of Removable Prosthodontics and Occlusion, Osaka Dental University, Osaka, Japan
| | - Youngnam Kang
- Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, Suita, Osaka, Japan
| | - Toshihiro Hirai
- Department of Dentistry, Removable Prosthodontics, School of Dentistry, Health Sciences University of Hokkaido, Hokkaido, Japan
| | - Takuo Kuboki
- Department of Oral Rehabilitation and Regenerative Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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Lin CS, Chen TC, Verhoeff MC, Lobbezoo F, Trulsson M, Fuh JL. An umbrella review on the association between factors of oral health and cognitive dysfunction. Ageing Res Rev 2024; 93:102128. [PMID: 38007045 DOI: 10.1016/j.arr.2023.102128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 11/27/2023]
Abstract
An increasing number of systematic reviews and meta-analyses have been published on the association between oral health and cognitive dysfunction, also known as oral-cognitive links. However, there is great diversity in the oral and cognitive factors included in these studies, with different opinions for clinical practice drawn from the evidence. To understand which oral and cognitive factors are involved in those associations, we conducted an umbrella review of 28 systematic reviews, including 12 meta-analyses, on oral-cognitive links. We found that (a) periodontal diseases, oral microbiome, and dementia were frequently studied, while other factors, such as mastication and mild cognitive impairment, were less commonly investigated, and (b) severe deterioration of oral health, such as severe periodontitis or extensive tooth loss, rather than the presence of oral diseases alone, was strongly associated with cognitive dysfunction. In conclusion, the diversity of oral and cognitive factors included in the review studies reflects the complexity of oral-cognitive links. Clarifying the factors helps to form evidence-based clinical advice for healthcare.
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Affiliation(s)
- Chia-Shu Lin
- Department of Dentistry, National Yang Ming Chiao Tung University, Taiwan; Institute of Brain Science, National Yang Ming Chiao Tung University, Taiwan; Brain Research Center, National Yang Ming Chiao Tung University, Taiwan; Oral Medicine Innovation Center, National Yang Ming Chiao Tung University, Taiwan.
| | - Ta-Chung Chen
- Division of Prosthodontics, Department of Stomatology, Taipei Veterans General Hospital, Taiwan
| | - Merel Charlotte Verhoeff
- Department of Orofacial Pain and Dysfunction, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Frank Lobbezoo
- Department of Orofacial Pain and Dysfunction, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Mats Trulsson
- Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden; Academic Center for Geriatric Dentistry, Karolinska Institutet, Stockholm, Sweden
| | - Jong-Ling Fuh
- Institute of Brain Science, National Yang Ming Chiao Tung University, Taiwan; Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; School of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Lee S, Tochinai R, Yasuoka A, Nagai T, Saito Y, Kuwahara M, Abe K, Asakura T. Mastication stimuli regulate the heartbeat rate through rhythmic regulation by the hypothalamic-autonomic system; molecular and telemetric studies in weaning-stage rats. Front Neurosci 2023; 17:1260655. [PMID: 37781249 PMCID: PMC10536135 DOI: 10.3389/fnins.2023.1260655] [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: 07/19/2023] [Accepted: 09/01/2023] [Indexed: 10/03/2023] Open
Abstract
Mastication stimuli have been demonstrated to affect memory function and autonomic nerve activity; however, this process has not been well studied during weaning compared to old age. Previously, we conducted molecular analyses of the thalamus and hippocampus to elucidate the mechanisms underlying this memory-enhancing effect in weaning-stage rats. In this study, we aimed to evaluate the effect of masticatory stimuli on the regulation of heartbeat rate (HR) through the hypothalamic-autonomic system. Three-week-old male rats were administered a powdered diet (P group) or chow-diet (C group) for 10 days. Thereafter, transcriptome analysis was performed. Vasopressin, cocaine-amphetamine-regulated transcript prepropeptide, corticotropin-releasing hormone, and thyrotropin-releasing hormone, which are involved in sympathetic activation of heart rate, were downregulated in the C group. Electrocardiograms were recorded continuously for 12 days under the same condition. Interestingly, rats in the C group had a significantly lower HR than those in the P group on day 11. We checked several parameters representing the autonomic regulation of HR. The C group had higher values for the high-frequency band integration of the HR power spectrum (parasympathetic marker) and root mean square successive difference of R-wave intervals (parasympathetic marker) relative to the P group. Such findings provide a molecular and physiological basis for understanding the regulation of cardiovascular function in response to masticatory stimuli in the autonomic nervous system.
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Affiliation(s)
- Seonmi Lee
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ryota Tochinai
- Department of Veterinary Pathophysiology and Animal Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Akihito Yasuoka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Department of Human Nutrition, Seitoku University, Chiba, Japan
| | - Toshitada Nagai
- Department of Applied Biological Science, Faculty of Agriculture, Takasaki University of Health and Welfare, Gunma, Japan
| | - Yoshikazu Saito
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Toyo Institute of Food Technology, Hyogo, Japan
| | - Masayoshi Kuwahara
- Department of Veterinary Pathophysiology and Animal Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Keiko Abe
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Project on Health and Anti-Aging, Kanagawa Academy of Science and Technology, Life Science and Environment Research Center (LiSE), Kawasaki, Japan
| | - Tomiko Asakura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Toyoda H, Fujinami Y, Saito M, Maeda Y, Kang Y. Increased vertical dimension of occlusion for varying periods differentially impairs learning and memory in guinea pigs. Behav Brain Res 2023; 452:114547. [PMID: 37331607 DOI: 10.1016/j.bbr.2023.114547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/07/2023] [Accepted: 06/15/2023] [Indexed: 06/20/2023]
Abstract
There is an increasing number of studies showing that occlusal dysfunction impairs learning and memory. We previously demonstrated that the brain has a mechanism to calibrate between the activities of spindle afferents and periodontal-mechanoreceptor afferents for controlling the chewing movement, and the accurate calibration can be done only at the proper vertical dimension of occlusion (VDO). Then, the chewing at an inappropriate VDO may induce a severe mental stress due to a mal-calibration. However, it is not clear how the impairment of learning/memory progresses over the period of stress induced by occlusal dysfunction. We investigated by passive avoidance test how the behavior and learning/memory are altered in guinea pigs in which the VDO was raised by 2-3 mm over the period up to 8 weeks. We found that the guinea pigs reared under the raised occlusal-condition (ROC) for 1 week showed a very high sensitivity to electrical stimulation whereas this did not cause the memory consolidation in the 1st-day retention trial, suggesting that such hypersensitivity rather hampered the fear learning. In the guinea pigs reared under the ROC for 2 and 8 weeks, the learning ability was not largely affected and memory consolidation occurred similarly whereas the memory retention deteriorated more severely in the latter guinea pigs than in the former ones. In the guinea pigs reared under the ROC for 3 and 4 weeks, learning was severely impaired, and memory consolidation did not occur. These results suggest that the occlusal dysfunction for varying periods differentially impairs learning and memory.
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Affiliation(s)
- Hiroki Toyoda
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan.
| | - Yozo Fujinami
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan; Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Mitsuru Saito
- Department of Oral Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544, Japan
| | - Yoshinobu Maeda
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Youngnam Kang
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan; Department of Behavioral Sciences, Graduate School of Human Sciences, Osaka University, Suita, Osaka 565-0871, Japan.
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Sun W, Okihara H, Ogawa T, Ishidori H, Misawa E, Kato C, Ono T. Pre-Adolescent Diet Normalization Restores Cognitive Function in Young Mice. J Clin Med 2023; 12:jcm12113642. [PMID: 37297836 DOI: 10.3390/jcm12113642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Mastication is a fundamental function critical for human health. Controlled by the central nervous system (CNS), it influences CNS development and function. A poor masticatory performance causes cognitive dysfunction in both older adults and children. Improving mastication may prevent cognitive decline. However, no study has determined the period of masticatory dysfunction that impairs children's later acquisition of cognitive function. Herein, we developed an animal model wherein a soft diet was switched to a normal diet at early and late time points in young mice. We aimed to investigate the impact of restored mastication on learning and memory function. Behavioral studies were conducted to evaluate learning and memory. Micro-CT was used to evaluate orofacial structural differences, while histological and biochemical approaches were employed to assess differences in the hippocampal morphology and function. Correction to a hard-textured diet before adolescence restored mastication and cognitive function through the stimulation of neurogenesis, extracellular signal-regulated kinases, the cyclic adenosine monophosphate-response element-binding protein pathway, and the brain-derived neurotrophic factor, tyrosine receptor B. In contrast, post-adolescent diet normalization failed to rescue full mastication and led to impaired cognitive function, neuronal loss, and decreased hippocampal neurogenesis. These findings revealed a functional linkage between the masticatory and cognitive function in mice during the juvenile to adolescent period, highlighting the need for adequate food texture and early intervention for mastication-related cognitive impairment in children.
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Affiliation(s)
- Wenqian Sun
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138510, Japan
| | - Hidemasa Okihara
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138510, Japan
| | - Takuya Ogawa
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138510, Japan
| | - Hideyuki Ishidori
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138510, Japan
- Department of Oral and Maxillofacial Surgery/Orthodontics, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama 2320024, Japan
| | - Eri Misawa
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138510, Japan
| | - Chiho Kato
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138510, Japan
| | - Takashi Ono
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima, Bunkyo-ku, Tokyo 1138510, Japan
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Lin CS, Liu LK, Chen LK, Fuh JL. Association between masseter muscle volume, nutritional status, and cognitive status in older people. Arch Gerontol Geriatr 2023; 113:105038. [PMID: 37116259 DOI: 10.1016/j.archger.2023.105038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 04/30/2023]
Abstract
OBJECTIVES Clinical evidence has suggested that oral function is associated with cognitive, physical, and nutritional status of older people. A smaller volume of masseter, a crucial muscle for mastication, was associated with frailty. It has remained unknown if smaller masseter is associated with cognitive impairment. The current study investigated the association between masseter muscle volume, nutritional status, and cognitive status in older people. MATERIALS AND METHODS We recruited 19 patients with mild cognitive impairment (MCI), 15 patients with Alzheimer's disease (AD), and 28 sex and age-matched non-cognitive impairment (non-CI) older subjects. The number of missing teeth (NMT), masticatory performance (MP), maximal hand-grip force (MGF), and calf circumference (CC) were assessed. The masseter volume index (MVI) was calculated based on the masseter volume measured using magnetic resonance imaging. RESULTS The MVI was significantly lower in the AD group, compared to the MCI as well as the non-CI group. Multiple regression analyses revealed that the MVI was significantly associated with nutritional status (as indexed by CC) in the analysis of combination of NMT, MP, and the MVI. Moreover, the MVI was a significant predictor of CC only in patients with cognitive impairment (i.e., MCI+AD) but not in the non-CI group. CONCLUSIONS Our findings suggested that in addition to the NMT and MP, masseter volume is a critical oral factor associated with cognitive impairment. CLINICAL RELEVANCE Reduction of MVI should be carefully monitored for patients with dementia and frailty, to whom a lower MVI may indicate worse nutrient intake.
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Affiliation(s)
- Chia-Shu Lin
- Department of Dentistry, College of Dentistry, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan; Institute of Brain Science, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan; Brain Research Center, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan.
| | - Li-Kuo Liu
- Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan; Center for Geriatrics and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Liang-Kung Chen
- Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan; Center for Geriatrics and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan; Taipei Municipal Gan-Dau Hospital (Managed by Taipei Veterans General Hospital), Taipei, Taiwan
| | - Jong-Ling Fuh
- Brain Research Center, National Yang Ming Chiao Tung University, Hsin-Chu, Taiwan; Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; School of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Cunha Feio Leal MD, Amaral Junior FLD, Silva Arruda BFD, Kurosawa JAA, Vieira AA, Maia JCC, Scalfoni VVB, Silveira Junior AMD, Feijó MO, Albuquerque FBAD, Marta MHM, Normando MPN, Silva AGOCD, Trindade FCPD, Siqueira Mendes FDCCD, Sosthenes MCK. The Masticatory Activity Interference in Quantitative Estimation of CA1, CA3 and Dentate Gyrus Hippocampal Astrocytes of Aged Murine Models and under Environmental Stimulation. Int J Mol Sci 2023; 24:ijms24076529. [PMID: 37047502 PMCID: PMC10095286 DOI: 10.3390/ijms24076529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/22/2023] [Accepted: 03/01/2023] [Indexed: 04/03/2023] Open
Abstract
Studies indicating the influence of masticatory dysfunction, due to a soft diet or lack of molars, on impairing spatial memory and learning have led to research about neuronal connections between areas and cell populations possibly affected. In this sense, with scarce detailed data on the subfields of hippocampus in dementia neurodegeneration, there is no information about astrocytic responses in its different layers. Thus, considering this context, the present study evaluated the effects of deprivation and rehabilitation of masticatory activity, aging, and environmental enrichment on the stereological quantification of hippocampal astrocytes from layers CA1, CA3, and DG. For this purpose, we examined mature (6-month-old; 6M), and aged (18-month-old; 18M) mice, subjected to distinct masticatory regimens and environments. Three different regimens of masticatory activity were applied: continuous normal mastication with hard pellets (HD); normal mastication followed by deprived mastication with equal periods of pellets followed by soft powder (HD/SD); or rehabilitated masticatory activity with equal periods of HD, followed by powder, followed by pellets (HD/SD/HD). Under each specific regimen, half of the animals were raised in standard cages (impoverished environment (IE)) and the other half in enriched cages (enriched environment (EE)), mimicking sedentary or active lifestyles. Microscopic stereological, systematic, and random sampling approaches with an optical dissector of GFAP-immunolabeled astrocytes were done, allowing for an astrocyte numerical estimate. Stratum moleculare and hilus, from the dentate gyrus (DG) and Strata Lacunosum-Moleculare, Oriens, and Radiatum, similarly to the dentate gyrus, showed no significant change in any of the investigated variables (age, diet, or environment) in these layers. However, in Stratum radiatum, it was possible to observe significant differences associated with diet regimens and age. Therefore, diet-related differences were found when the HD 18M IE group was compared to the HD/SD/HD 18-month-old group in the same environment (IE) (p = 0.007). In the present study, we present modulatory factors (masticatory function, environmental enrichment, and aging) for the differentiated quantitative laminar response in the hippocampal regions, suggesting other studies to read the plasticity and responsiveness of astrocytes, including the molecular background.
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Affiliation(s)
- Marília da Cunha Feio Leal
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | - Fabio Leite do Amaral Junior
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | - Bernardo Freire da Silva Arruda
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | | | - Amanda Almeida Vieira
- Curso de Medicina, Centro Universitário do Estado do Pará, Belém 66613-903, PA, Brazil
| | | | | | - Antonio Morais da Silveira Junior
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | - Matheus Oliveira Feijó
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | - Fernanda Beatriz Araújo de Albuquerque
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | | | | | - Alana Gabriele Oliveira Cabeça da Silva
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | - Fernanda Catharina Pires da Trindade
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
| | - Fabíola de Carvalho Chaves de Siqueira Mendes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
- Curso de Medicina, Centro Universitário do Estado do Pará, Belém 66613-903, PA, Brazil
| | - Marcia Consentino Kronka Sosthenes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil
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12
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Prevalence of malocclusions under conditions of prolonged introduction of systemic fluorides in variable concentrations: Literature review. ACTA BIOMEDICA SCIENTIFICA 2023. [DOI: 10.29413/abs.2023-8.1.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023] Open
Abstract
The pathogenesis of malocclusions, which are common among the population of all countries, is well represented in the professional literature. The occurrence of malocclusions is associated with genetic and various environmental factors. Among the latter, fluorides which affect the prevalence of some dental diseases are of particular interest. However, there are few publications reflecting the frequency of malocclusion among the population in the regions with different levels of fluoride in drinking water. This problem seems to be significant in the context of the increasing impact of fluorine compounds on human health, including dental health.The aim of the study. To analyze the literature on the frequency of malocclusion among the population living in conditions of variable fluoride content in drinking water. A manual search of domestic and foreign literature was performed in the search databases PubMed, Medline and Google Scholar. From the initial list of publications, eighteen articles that met the inclusion criteria for the study were selected for analysis. We revealed significant variability of the research results. Some authors note a higher prevalence of malocclusions among the population under conditions of increased fluoride intake, others note a lower one, and still others did not reveal any differences between the values obtained in both samples. Most of the assessed publications did not methodologically meet modern international standards, and therefore were of little evidence.The literature data do not provide grounds for an unambiguous assessment of fluorine compounds as an environmental factor that indirectly affects the process of occlusion formation in humans and animals.The review did not allow to make a definitive conclusion on the possible impact of systemic fluorides on the prevalence and pattern of malocclusion in humans and animals. It requires the implementation of studies that comply with the principles of evidence-based medicine.
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13
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Tanaka Y, Sato H, Toyoda H, Saito M, Maeda Y, Kang Y. The mechanism for regulating the isometric contraction of masseter muscles is involved in determining the vertical dimension of occlusion. J Neurophysiol 2023; 129:211-219. [PMID: 36541608 DOI: 10.1152/jn.00301.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
We previously demonstrated that accurate regulation of isometric contraction (IC) of jaw-closing muscles to counteract the ramp load applied to the jaw in the jaw-opening direction is achieved through the calibration between the two sensations arising from muscle spindles (MSs) and periodontal mechanoreceptors (PMRs). However, it remains unclear whether this calibration mechanism accurately works at any jaw positions, i.e., any vertical dimensions of occlusion (VDO). In the present study, we examined the effects of altering VDO on the IC of the masseter muscles in complete dentulous and edentulous subjects. At a VDO higher than the original VDO (O-VDO), the root mean square (RMS) of masseter EMG activity increased more steeply with a load increase, resulting in an over-counteraction. The regression coefficient of the load-RMS relationship significantly increased as the VDO was increased, suggesting that the overestimation became more pronounced with the VDO increases. Consistently also in the edentulous subjects, at a higher VDO than the O-VDO, a steeper increase in the RMS emerged with a delay in response to the same ramp load whereas a similar steeper increase was seen surprisingly even at a lower VDO. Thus, the edentulous subjects displayed a delayed overestimation of the ramp load presumably due to less and slowly sensitive mucous membrane mechanoreceptor (MMR) in alveolar ridge compared with the PMR. Taken together, the accurate calibration between the two sensations arising from MSs and PMRs/MMRs can be done only at the O-VDO, suggesting that the O-VDO is the best calibration point for performing accurate IC.NEW & NOTEWORTHY Since 1934, the vertical dimension of occlusion (VDO) in edentulous individuals has been anatomically determined mostly by referring to the resting jaw position. However, such a static method is not always accurate. Considering the dynamic nature of clenching/mastication, it is desirable to determine VDO dynamically. We demonstrate that VDO can be accurately determined by measuring masseter EMG during the voluntary isometric contraction of jaw-closing muscles exerted against the ramp load in the jaw-opening direction.
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Affiliation(s)
- Yuto Tanaka
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Japan.,Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Suita, Japan.,Department of Special Care Dentistry, Osaka Dental University Hospital, Osaka, Japan
| | - Hajime Sato
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Hiroki Toyoda
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Mitsuru Saito
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Japan.,Department of Oral Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yoshinobu Maeda
- Department of Prosthodontics, Gerodontology and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Youngnam Kang
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Suita, Japan.,Division of Behavioral Physiology, Department of Behavioral Sciences, Osaka University Graduate School of Human Sciences, Suita, Japan
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14
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Yang S, Park Y, Choi T. Effects of mastication on antibody production under fasting conditions in mice. Int J Med Sci 2023; 20:232-237. [PMID: 36794156 PMCID: PMC9925987 DOI: 10.7150/ijms.80396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/11/2023] [Indexed: 02/04/2023] Open
Abstract
Chewing is beneficial not only for digestion and absorption of food, but also for various physiological functions, such as cognition and immunity. In this study, the effect of chewing on hormonal changes and the immune response was investigated under fasting conditions in mice. We investigated leptin and corticosterone levels, which are hormones with well-known associations with immune response and large changes during fasting. To study of effects of chewing under fasting conditions, one group of mice was provided with wooden sticks to stimulate chewing, one group was supplemented with 30% glucose solution, and one group received both treatments. We examined changes in serum leptin and corticosterone levels after 1 and 2 d of fasting. Antibody production was measured 2 weeks after subcutaneous immunization with bovine serum albumin on the last day of fasting. Under fasting conditions, serum leptin levels decreased and serum corticosterone levels increased. Supplementation with 30% glucose solution during fasting increased leptin levels above normal, but had little effect on corticosterone levels. In contrast, chewing stimulation inhibited the increase in corticosterone production, but did not affect the decrease in leptin levels. Antibody production significantly increased under separate and combined treatments. Taken together, our results showed that chewing stimulation during fasting inhibited the increase in corticosterone production and improved antibody production after immunization.
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Affiliation(s)
- Seonbu Yang
- Department of Microbiology, College of Medicine, Dankook University
| | - Yujun Park
- Department of Microbiology, College of Medicine, Dankook University
| | - Taesaeng Choi
- Department of Microbiology, College of Medicine, Dankook University
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15
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Tortarolo A, Rotolo R, Nucci L, Tepedino M, Crincoli V, Piancino MG. Condylar Asymmetry in Children with Unilateral Posterior Crossbite Malocclusion: A Comparative Cross-Sectional Study. CHILDREN (BASEL, SWITZERLAND) 2022; 9:1772. [PMID: 36421221 PMCID: PMC9688623 DOI: 10.3390/children9111772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/12/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022]
Abstract
Unilateral posterior crossbite (UXB) is a common, severely asymmetric malocclusion, characterized by maxillary hypoplasia and masticatory dysfunction. The aim of this research is to evaluate the asymmetry of mandibular condyles and rami in children with UXB. This comparative cross-sectional study included 33 children with UXB (girls = 15, boys = 18; mean age ± SD = 8.0 ± 1.3 years.months]) and 33 age- and gender-matched controls (girls = 15, boys = 18; mean age ± SD = 8.4 ± 1.3 years.months]). Pre-treatment OPGs were analyzed by comparing the height of condyles and rami between the sides using the method by Habets et al. (1988); the result was considered significant if the degree of asymmetry was >6%. Children with UXB showed a significantly increased asymmetry of mandibular condyles (mean ± SD = 10.7% ± 9, p < 0.001), but not of rami (mean ± SD = 1.9% ± 2.3), compared to controls. The rami did not show significant asymmetry in either group. The presence of an increased condylar asymmetry index in a developing patient with unilateral posterior crossbite is a sign of altered skeletal growth and should be considered in the diagnostic process and treatment plan.
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Affiliation(s)
- Alessandro Tortarolo
- Department of Surgical Sciences, Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy
| | - Rossana Rotolo
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, School of Medicine and Surgery, University of Campania Luigi Vanvitelli, Via Luigi De Crecchio 6, 80138 Naples, Italy
| | - Ludovica Nucci
- Multidisciplinary Department of Medical-Surgical and Dental Specialties, School of Medicine and Surgery, University of Campania Luigi Vanvitelli, Via Luigi De Crecchio 6, 80138 Naples, Italy
| | - Michele Tepedino
- Department of Biotechnological and Applied Sciences, University of L’Aquila, Piazzale Salvatore Tommasi 1, Blocco 11, 67010 L’Aquila, Italy
| | - Vito Crincoli
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari, Policlinico, Piazza G. Cesare 11, 70121 Bari, Italy
| | - Maria Grazia Piancino
- Department of Surgical Sciences, Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy
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16
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Yasuoka A, Nagai T, Lee S, Miyaguchi H, Saito Y, Abe K, Asakura T. Mastication stimuli enhance the learning ability of weaning-stage rats, altering the hippocampal neuron transcriptome and micromorphology. Front Behav Neurosci 2022; 16:1006359. [PMID: 36263297 PMCID: PMC9574334 DOI: 10.3389/fnbeh.2022.1006359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
Mastication stimuli are known to relieve senile dementia in human and animal studies. However, few studies have focused on its effect on weaning-stage animals and the underlying molecular processes. In this study, 3-week-old male rats were raised on a powdered (P-group) or chow (C-group) diet for 8 days, and their behavior was examined using the Y-maze and novel object recognition tests. In the Y-maze test, the C-group rats showed a larger alternation ratio than the P-group rats. In the novel object recognition test, the C-group rats exhibited a significantly larger discrimination index for novel objects than for familiar objects, but the P-group rats did not. We then compared the hippocampal neuron morphology and transcriptome between the groups. C-group rats exhibited larger dendrite branch numbers in the apical dendrites of pyramidal cells in the cornu ammonis 1 (CA1) region and a larger spine density in the basal dendrites of CA1 neurons than the P-group rats. Using DNA microarray analysis, we identified 621 (P < C) and 96 (P > C) genes that were differentially expressed between the groups. These genes were enriched in functional terms related to dendrite growth and included the Igf2, RhoA, and Rho GEF genes, most of which were upregulated in the C-group. These results suggest that the mastication stimuli during the weaning period can enhance the learning ability of rats by increasing the dendrite branches of hippocampal CA1 neurons and by regulating genes related to dendrite growth.
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Affiliation(s)
- Akihito Yasuoka
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Department of Human Nutrition, Seitoku University, Chiba, Japan
| | - Toshitada Nagai
- Department of Applied Biological Science, Takasaki University of Health and Welfare, Takasaki, Japan
| | - Seonmi Lee
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hitonari Miyaguchi
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yoshikazu Saito
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Keiko Abe
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Kanagawa Institute of Industrial Science and Technology, Kawasaki, Japan
| | - Tomiko Asakura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- *Correspondence: Tomiko Asakura,
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17
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Sui SX, Balanta-Melo J, Pasco JA, Plotkin LI. Musculoskeletal Deficits and Cognitive Impairment: Epidemiological Evidence and Biological Mechanisms. Curr Osteoporos Rep 2022; 20:260-272. [PMID: 35764750 PMCID: PMC9522710 DOI: 10.1007/s11914-022-00736-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/09/2022] [Indexed: 12/01/2022]
Abstract
PURPOSE OF REVIEW Cognitive impairment is associated with obesity, sarcopenia, and osteoporosis. However, no critical appraisal of the literature on the relationship between musculoskeletal deficits and cognitive impairment, focusing on the epidemiological evidence and biological mechanisms, has been published to date. Herein, we critically evaluate the literature published over the past 3 years, emphasizing interesting and important new findings, and provide an outline of future directions that will improve our understanding of the connections between the brain and the musculoskeletal system. RECENT FINDINGS Recent literature suggests that musculoskeletal deficits and cognitive impairment share pathophysiological pathways and risk factors. Cytokines and hormones affect both the brain and the musculoskeletal system; yet, lack of unified definitions and standards makes it difficult to compare studies. Interventions designed to improve musculoskeletal health are plausible means of preventing or slowing cognitive impairment. We highlight several musculoskeletal health interventions that show potential in this regard.
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Affiliation(s)
- Sophia X Sui
- Epi-Centre for Healthy Ageing, Deakin University, IMPACT - Institute for Mental and Physical Health and Clinical Translation, PO Box 281 (Barwon Health), Geelong, VIC, 3220, Australia.
| | - Julián Balanta-Melo
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, 635 Barnhill Drive, MS5022A, Indianapolis, IN, 46202, USA
- Indiana Center for Musculoskeletal Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA
- Universidad del Valle School of Dentistry, Cali, Colombia
| | - Julie A Pasco
- Epi-Centre for Healthy Ageing, Deakin University, IMPACT - Institute for Mental and Physical Health and Clinical Translation, PO Box 281 (Barwon Health), Geelong, VIC, 3220, Australia
- Department of Medicine-Western Campus, The University of Melbourne, St Albans, VIC, Australia
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia
- University Hospital Geelong, Barwon Health, Geelong, VIC, Australia
| | - Lilian I Plotkin
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, 635 Barnhill Drive, MS5022A, Indianapolis, IN, 46202, USA.
- Indiana Center for Musculoskeletal Research, Indiana University School of Medicine, Indianapolis, IN, USA.
- Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.
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18
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de Siqueira Mendes FDCC, de Almeida MNF, Falsoni M, Andrade MLF, Felício APG, da Paixão LTVB, Júnior FLDA, Anthony DC, Brites D, Diniz CWP, Sosthenes MCK. The Sedentary Lifestyle and Masticatory Dysfunction: Time to Review the Contribution to Age-Associated Cognitive Decline and Astrocyte Morphotypes in the Dentate Gyrus. Int J Mol Sci 2022; 23:ijms23116342. [PMID: 35683023 PMCID: PMC9180988 DOI: 10.3390/ijms23116342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 02/01/2023] Open
Abstract
As aging and cognitive decline progresses, the impact of a sedentary lifestyle on the appearance of environment-dependent cellular morphologies in the brain becomes more apparent. Sedentary living is also associated with poor oral health, which is known to correlate with the rate of cognitive decline. Here, we will review the evidence for the interplay between mastication and environmental enrichment and assess the impact of each on the structure of the brain. In previous studies, we explored the relationship between behavior and the morphological features of dentate gyrus glial fibrillary acidic protein (GFAP)-positive astrocytes during aging in contrasting environments and in the context of induced masticatory dysfunction. Hierarchical cluster and discriminant analysis of GFAP-positive astrocytes from the dentate gyrus molecular layer revealed that the proportion of AST1 (astrocyte arbors with greater complexity phenotype) and AST2 (lower complexity) are differentially affected by environment, aging and masticatory dysfunction, but the relationship is not straightforward. Here we re-evaluated our previous reconstructions by comparing dorsal and ventral astrocyte morphologies in the dentate gyrus, and we found that morphological complexity was the variable that contributed most to cluster formation across the experimental groups. In general, reducing masticatory activity increases astrocyte morphological complexity, and the effect is most marked in the ventral dentate gyrus, whereas the effect of environment was more marked in the dorsal dentate gyrus. All morphotypes retained their basic structural organization in intact tissue, suggesting that they are subtypes with a non-proliferative astrocyte profile. In summary, the increased complexity of astrocytes in situations where neuronal loss and behavioral deficits are present is counterintuitive, but highlights the need to better understand the role of the astrocyte in these conditions.
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Affiliation(s)
- Fabíola de Carvalho Chaves de Siqueira Mendes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
- Curso de Medicina, Centro Universitário do Estado do Pará, Belém 66613-903, PA, Brazil
| | - Marina Negrão Frota de Almeida
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
| | - Manoela Falsoni
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
| | - Marcia Lorena Ferreira Andrade
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
| | - André Pinheiro Gurgel Felício
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
| | - Luisa Taynah Vasconcelos Barbosa da Paixão
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
| | - Fábio Leite do Amaral Júnior
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
| | - Daniel Clive Anthony
- Laboratory of Experimental Neuropathology, Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK;
| | - Dora Brites
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-004 Lisbon, Portugal;
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, 1649-004 Lisbon, Portugal
| | - Cristovam Wanderley Picanço Diniz
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
| | - Marcia Consentino Kronka Sosthenes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém 66073-005, PA, Brazil; (F.d.C.C.d.S.M.); (M.N.F.d.A.); (M.F.); (M.L.F.A.); (A.P.G.F.); (L.T.V.B.d.P.); (F.L.d.A.J.); (C.W.P.D.)
- Correspondence:
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19
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Kajimoto K, Hisada C, Ochi S, Yoshikawa E, Suzuki A, Tsugane H, Zhang J, Iinuma M, Kubo KY, Azuma K. Maternal chewing improves prenatal stress-induced cognitive deficit and anxiety-like behavior associated with alterations of the apoptotic response and serotonin pathway in mouse offspring. Arch Oral Biol 2021; 130:105245. [PMID: 34438320 DOI: 10.1016/j.archoralbio.2021.105245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/15/2021] [Accepted: 08/17/2021] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To examine whether maternal chewing affects prenatal stress-induced behavioral alternations associated with the changes in apoptosis-related proteins and serotonin pathway of the mouse offspring. DESIGN Pregnant mice were assigned to control, stress, and stress/chewing groups. Stress mice were placed in restraint tubes, from gestational day 12 until parturition. Stress/chewing mice were given a wooden stick for chewing during stress period. Morris water maze and hole-board tests were applied for behavioral alterations in one-month-old male pups. Hippocampal mRNA expression of B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X protein (Bax) was analyzed by quantitative real-time PCR. Serotonin and tryptophan hydroxylase expression level in the dorsal raphe nucleus was investigated immunohistochemically. RESULTS Prenatal stress impaired the spatial learning, induced anxiety-like behavior, increased the ratio of hippocampal Bax/Bcl-2 expression, and decreased the expression of serotonin and tryptophan hydroxylase in dorsal raphe nucleus of the offspring. Maternal chewing ameliorated prenatal stress-induced cognitive impairment, anxiety-like behavior, and attenuated the increased ratio of hippocampal Bax/Bcl-2 expression, and the downregulated serotonin signaling in dorsal raphe nucleus of the offspring. CONCLUSIONS Our results indicate that maternal chewing could improve prenatal stress-related anxiety-like behavior and cognitive impairment in mouse offspring, at least in part by affecting hippocampal apoptotic response and central serotonin pathway.
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Affiliation(s)
- Kyoko Kajimoto
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Chie Hisada
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Suzuko Ochi
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Eri Yoshikawa
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Ayumi Suzuki
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Hiroko Tsugane
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Jiahe Zhang
- Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8555, Japan
| | - Mitsuo Iinuma
- Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan
| | - Kin-Ya Kubo
- Faculty of Human Life and Environmental Science, Nagoya Women's Univrsity, 3-40 Shijo-machi, Mizuho-ku, Nagoya 467-8610, 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.
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20
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de Siqueira Mendes FDCC, Paixão LTVB, Diniz DG, Anthony DC, Brites D, Diniz CWP, Sosthenes MCK. Sedentary Life and Reduced Mastication Impair Spatial Learning and Memory and Differentially Affect Dentate Gyrus Astrocyte Subtypes in the Aged Mice. Front Neurosci 2021; 15:632216. [PMID: 33935629 PMCID: PMC8081835 DOI: 10.3389/fnins.2021.632216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/03/2021] [Indexed: 11/13/2022] Open
Abstract
To explore the impact of reduced mastication and a sedentary lifestyle on spatial learning and memory in the aged mice, as well as on the morphology of astrocytes in the molecular layer of dentate gyrus (MolDG), different masticatory regimens were imposed. Control mice received a pellet-type hard diet, while the reduced masticatory activity group received a pellet diet followed by a powdered diet, and the masticatory rehabilitation group received a pellet diet, followed by powder diet and then a pellet again. To mimic sedentary or active lifestyles, mice were housed in an impoverished environment of standard cages or in an enriched environment. The Morris Water Maze (MWM) test showed that masticatory-deprived group, regardless of environment, was not able to learn and remember the hidden platform location, but masticatory rehabilitation combined with enriched environment recovered such disabilities. Microscopic three-dimensional reconstructions of 1,800 glial fibrillary acidic protein (GFAP)-immunolabeled astrocytes from the external third of the MolDG were generated using a stereological systematic and random sampling approach. Hierarchical cluster analysis allowed the characterization into two main groups of astrocytes with greater and lower morphological complexities, respectively, AST1 and AST2. When compared to compared to the hard diet group subjected to impoverished environment, deprived animals maintained in the same environment for 6 months showed remarkable shrinkage of astrocyte branches. However, the long-term environmental enrichment (18-month-old) applied to the deprived group reversed the shrinkage effect, with significant increase in the morphological complexity of AST1 and AST2, when in an impoverished or enriched environment. During housing under enriched environment, complexity of branches of AST1 and AST2 was reduced by the powder diet (pellet followed by powder regimes) in young but not in old mice, where it was reversed by pellet diet (pellet followed by powder and pellet regime again). The same was not true for mice housed under impoverished environment. Interestingly, we were unable to find any correlation between MWM data and astrocyte morphological changes. Our findings indicate that both young and aged mice subjected to environmental enrichment, and under normal or rehabilitated masticatory activity, preserve spatial learning and memory. Nonetheless, data suggest that an impoverished environment and reduced mastication synergize to aggravate age-related cognitive decline; however, the association with morphological diversity of AST1 and AST2 at the MolDG requires further investigation.
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Affiliation(s)
- Fabíola de Carvalho Chaves de Siqueira Mendes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil.,Curso de Medicina, Centro Universitário do Estado do Pará, Belém, Brazil
| | - Luisa Taynah Vasconcelos Barbosa Paixão
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Daniel Guerreiro Diniz
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil.,Laboratório de Microscopia Eletrônica, Instituto Evandro Chagas, Belém, Brazil
| | - Daniel Clive Anthony
- Laboratory of Experimental Neuropathology, Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Dora Brites
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal.,Department of Biochemistry and Human Biology, Faculty of Pharmacy, Universidade de Lisboa, Lisbon, Portugal
| | - Cristovam Wanderley Picanço Diniz
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
| | - Marcia Consentino Kronka Sosthenes
- Laboratório de Investigações em Neurodegeneração e Infecção, Instituto de Ciências Biológicas, Hospital Universitário João de Barros Barreto, Universidade Federal do Pará, Belém, Brazil
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21
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Da Silva JD, Ni SC, Lee C, Elani H, Ho K, Thomas C, Kuwajima Y, Ishida Y, Kobayashi T, Ishikawa-Nagai S. Association between cognitive health and masticatory conditions: a descriptive study of the national database of the universal healthcare system in Japan. Aging (Albany NY) 2021; 13:7943-7952. [PMID: 33739304 PMCID: PMC8034966 DOI: 10.18632/aging.202843] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 03/05/2021] [Indexed: 12/02/2022]
Abstract
Cognitive health is subject to decline with increasing numbers of lost teeth which impacts mastication. This study is a descriptive data analysis of the association between masticatory and cognitive conditions using a large database. We obtained the dental and medical records from Japan's universal healthcare system (UHCS) from the national database in 2017. The data from 94% of the Japanese population aged 65 and over is included. It is inclusive of diagnostic codes for various types of cognitive impairment, as well as dental treatment records from 2012 to 2017. The cognitive impairment group was compared to those without a diagnosis of cognitive impairment. Crude odds ratio between loss of mastication with natural teeth (exposure) and cognitive impairments (outcome) were compared. Patients who have lost masticatory function are likely to have cognitive impairment with an odds ratio of 1.89 (p<0.0001) for early elderly (aged 65-75) and 1.33 (p<0.0001) for advanced elderly (over 75). Patients who are edentulous and function with complete dentures are likely to have cognitive impairment with an odds ratio of 2.38 (p<0.0001) and 1.38 (p<0.0001), respectively. The data shows a convincing and significant result of an association between cognitive health and oral health, related to masticatory conditions.
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Affiliation(s)
- John D Da Silva
- Restorative Dentistry and Biomaterial Sciences, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Shy Chwen Ni
- Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Cliff Lee
- Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Hawazin Elani
- Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Kailing Ho
- DMD Candidate, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Carlos Thomas
- DMD Candidate, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Yukinori Kuwajima
- Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Yoshiki Ishida
- Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | | | - Shigemi Ishikawa-Nagai
- Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA 02115, USA.,Iwate Medical University, School of Dental Medicine, Japan
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22
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Kim HB, Kim D, Kim H, Kim W, Chung S, Lee SH, Kim HR, Oh SB. Aβ Accumulation in Vmo Contributes to Masticatory Dysfunction in 5XFAD Mice. J Dent Res 2021; 100:960-967. [PMID: 33719684 DOI: 10.1177/00220345211000263] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Alzheimer's disease (AD) shows various symptoms that reflect cognitive impairment and loss of neural circuit integrity. Sensory dysfunctions such as olfactory and ocular pathology are also observed and used as indicators for early detection of AD. Although mastication is suggested to correlate with AD progression, changes in the masticatory system have yet to be established in transgenic animal models of AD. In the present study, we have assessed pathologic hallmarks of AD with the masticatory behavior of 5XFAD mice. We found that masticatory efficiency and maximum biting force were decreased in 5XFAD mice, with no significant change in general motor function. Immunohistochemical analysis revealed significant accumulation of Aβ (amyloid β), increased microglia number, and cell death in Vmo (trigeminal motor nucleus) as compared with other cranial motor nuclei that innervate the orofacial region. Masseter muscle weight and muscle fiber size were also decreased in 5XFAD mice. Taken together, our results demonstrate that Aβ accumulation in Vmo contributes to masticatory dysfunction in 5XFAD mice, suggesting a close association between masticatory dysfunction and dementia.
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Affiliation(s)
- H B Kim
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - D Kim
- Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - H Kim
- Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Republic of Korea
| | - W Kim
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - S Chung
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - S H Lee
- Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - H R Kim
- College of Dentistry, Dankook University, Cheonan, Republic of Korea
| | - S B Oh
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea.,Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea.,Interdisciplinary Program in Neuroscience, Seoul National University, Seoul, Republic of Korea
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