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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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Sirichoat A, Anosri T, Kaewngam S, Aranarochana A, Pannangrong W, Wigmore P, Welbat JU. Neuroprotective properties of chrysin on decreases of cell proliferation, immature neurons and neuronal cell survival in the hippocampal dentate gyrus associated with cognition induced by methotrexate. Neurotoxicology 2022; 92:15-24. [PMID: 35779630 DOI: 10.1016/j.neuro.2022.06.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 05/03/2022] [Accepted: 06/27/2022] [Indexed: 01/21/2023]
Abstract
Methotrexate (MTX) is a drug widely used for chemotherapy and can reduce cancer cell production by inhibiting dihydrofolate reductase and decreasing cancer cell growth. MTX has a neurotoxic effect on neural stem and glial cells, leading to memory deficits. Chrysin is a natural flavonoid that contains essential biological activities, such as neuroprotective and cognitive-improving properties. Therefore, the aim of the present study was to investigate the protective effect of chrysin against MTX-induced memory impairments related to hippocampal neurogenesis. Seventy-two male Sprague Dawley rats were divided into six groups: control, MTX, chrysin (10 and 30 mg/kg), and MTX+ chrysin (10 and 30 mg/kg) groups. Chrysin (10 and 30 mg/kg) was administered by oral gavage for 15 days. MTX (75 mg/kg) was administered by intravenous injection on days 8 and 15. Spatial and recognition memories were evaluated using the novel object location (NOL) and novel object recognition (NOR) tests, respectively. Moreover, cell proliferation, neuronal cell survival, and immature neurons in the subgranular zone of the hippocampal dentate gyrus were quantified by Ki-67, bromodeoxyuridine/neuronal nuclear protein (BrdU/NeuN), and doublecortin (DCX) immunohistochemistry staining. The results of the MTX group demonstrated that spatial and recognition memories were both impaired. Furthermore, cell division reduction, neuronal cell survival reduction, and immature neuron decreases were detected in the MTX group and not observed in the co-administration groups. Therefore, these results revealed that chrysin could alleviate memory and neurogenesis impairments in MTX-treated rats.
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Affiliation(s)
- Apiwat Sirichoat
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Neurogenesis Research Group, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Tanaporn Anosri
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Neurogenesis Research Group, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Soraya Kaewngam
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Neurogenesis Research Group, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Anusara Aranarochana
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Neurogenesis Research Group, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Wanassanun Pannangrong
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Peter Wigmore
- School of Life Sciences, Medical School, Queen's Medical Centre, The University of Nottingham, Nottingham, United Kingdom
| | - Jariya Umka Welbat
- Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Neurogenesis Research Group, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
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An assessment of the existence of adult neurogenesis in humans and value of its rodent models for neuropsychiatric diseases. Mol Psychiatry 2022; 27:377-382. [PMID: 34667259 PMCID: PMC8967762 DOI: 10.1038/s41380-021-01314-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/08/2021] [Accepted: 09/22/2021] [Indexed: 12/14/2022]
Abstract
In sub-mammalian vertebrates like fishes, amphibians, and reptiles, new neurons are produced during the entire lifespan. This capacity diminishes considerably in birds and even more in mammals where it persists only in the olfactory system and hippocampal dentate gyrus. Adult neurogenesis declines even more drastically in nonhuman primates and recent evidence shows that this is basically extinct in humans. Why should such seemingly useful capacity diminish during primate evolution? It has been proposed that this occurs because of the need to retain acquired complex knowledge in stable populations of neurons and their synaptic connections during many decades of human life. In this review, we will assess critically the claim of significant adult neurogenesis in humans and show how current evidence strongly indicates that humans lack this trait. In addition, we will discuss the allegation of many rodent studies that adult neurogenesis is involved in psychiatric diseases and that it is a potential mechanism for human neuron replacement and regeneration. We argue that these reports, which usually neglect significant structural and functional species-specific differences, mislead the general population into believing that there might be a cure for a variety of neuropsychiatric diseases as well as stroke and brain trauma by genesis of new neurons and their incorporation into existing synaptic circuitry.
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Hedberg L, Ekman U, Nordin LE, Smedberg JI, Skott P, Seiger Å, Sandborgh-Englund G, Westman E, Kumar A, Trulsson M. Cognitive changes and neural correlates after oral rehabilitation procedures in older adults: a protocol for an interventional study. BMC Oral Health 2021; 21:297. [PMID: 34107933 PMCID: PMC8191046 DOI: 10.1186/s12903-021-01654-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 06/03/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Epidemiological studies show an association between masticatory function and cognitive impairment. This has further strengthened the notion that tooth loss and impaired masticatory function may be risk factors for dementia and cognitive decline. Animal experiments have indicated a causal relationship and several possible mechanisms have been discussed. This evidence is, however, lacking in humans. Therefore, in the current interventional study, we aim to investigate the effect of rehabilitation of masticatory function on cognition in older adults. METHODS Eighty patients indicated for prosthodontic rehabilitation will be randomly assigned to an experimental or a control group. Participants will conduct neuropsychological assessments, masticatory performance tests, saliva tests, optional magnetic resonance imaging, and answer questionnaires on oral health impact profiles and hospital anxiety and depression scale before, 3 months, and 1 year after oral rehabilitation. The difference between the two groups is that the control group will be tested an additional time, (at an interval of about 3 months) before the onset of the oral rehabilitation procedure. The primary outcome is a change in measures of episodic memory performance. DISCUSSION Although tooth loss and masticatory function are widespread in older people, it is still an underexplored modifiable risk factor potentially contributing to the development of cognitive impairment. If rehabilitation of masticatory function shows positive effects on the neurocognitive function, this will have great implications on future health care for patients with impaired masticatory status. The present project may provide a new avenue for the prevention of cognitive decline in older individuals. TRIAL REGISTRATION The protocol for the study was retrospectively registered in ClinicalTrials.gov Identifier: NCT04458207, dated 02-07-2020.
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Affiliation(s)
- Linn Hedberg
- Folktandvården Eastmaninstitutet, Stockholm, Sweden
- Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Alfred Nobels Allé 8, Box 4064, 141 04, Huddinge, Sweden
| | - Urban Ekman
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden
| | - Love Engström Nordin
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden
- Department of Diagnostic Medical Physics, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Jan-Ivan Smedberg
- Folktandvården Eastmaninstitutet, Stockholm, Sweden
- Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Alfred Nobels Allé 8, Box 4064, 141 04, Huddinge, Sweden
| | - Pia Skott
- Folktandvården Eastmaninstitutet, Stockholm, Sweden
- Academic Centre for Geriatric Dentistry, Stockholm, Sweden
| | - Åke Seiger
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden
- Academic Centre for Geriatric Dentistry, Stockholm, Sweden
| | - Gunilla Sandborgh-Englund
- Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Alfred Nobels Allé 8, Box 4064, 141 04, Huddinge, Sweden
- Academic Centre for Geriatric Dentistry, Stockholm, Sweden
| | - Eric Westman
- Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet, Huddinge, Sweden
| | - Abhishek Kumar
- Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Alfred Nobels Allé 8, Box 4064, 141 04, Huddinge, Sweden.
| | - Mats Trulsson
- Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Alfred Nobels Allé 8, Box 4064, 141 04, Huddinge, Sweden
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Lopez-Chaichio L, Padial-Molina M, O'Valle F, Gil-Montoya JA, Catena A, Galindo-Moreno P. Oral health and healthy chewing for healthy cognitive ageing: A comprehensive narrative review. Gerodontology 2020; 38:126-135. [PMID: 33179281 DOI: 10.1111/ger.12510] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 09/11/2020] [Accepted: 10/24/2020] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Ageing leads to physiological cognitive decline that it is worsened in people with neurodegenerative diseases such as Alzheimer's disease. Despite the ongoing search for a solution to this cognitive decline, no effective remedies have been established. It has been determined that modifiable external factors, such as oral health and occlusal function, prevent cognitive decline. OBJECTIVE To analyse the primary interactions between occlusal function and cognitive functions. MAIN FINDINGS Masticatory function is related to cognitive functions. In particular, current evidence, from both animal and human studies, suggests that the activation of masticatory muscles and proper mastication, with natural teeth or dental prosthesis, induces the release of several mediators and the activation of specific brain areas. Together, they result in higher neuronal activity, neurotrophic support, blood flow and the prevention of amyloid-beta plaque formation. Thus, all the components of the masticatory system must work together in order to preserve cognitive function. CONCLUSIONS Available evidence suggests that oral and cognitive health are more interconnected than previously thought. Therefore, maintenance and adequate restoration of the whole masticatory system are important for the prevention of cognitive decline. In summary, oral and chewing health lead to healthy cognitive ageing.
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Affiliation(s)
- Lucia Lopez-Chaichio
- Department of Oral Surgery and Implant Dentistry, School of Dentistry, University of Granada, Granada, Spain
| | - Miguel Padial-Molina
- Department of Oral Surgery and Implant Dentistry, School of Dentistry, University of Granada, Granada, Spain
| | - Francisco O'Valle
- Department of Pathology and IBIMER, School of Medicine, University of Granada, Granada, Spain.,Biosanitary Institute of Granada (ibs.Granada), University of Granada, Granada, Spain
| | - Jose Antonio Gil-Montoya
- Biosanitary Institute of Granada (ibs.Granada), University of Granada, Granada, Spain.,Department of Gerodontology, School of Dentistry, University of Granada, Granada, Spain
| | - Andres Catena
- Mind, Brain and Behavior Research Center, University of Granada, Granada, Spain
| | - Pablo Galindo-Moreno
- Department of Oral Surgery and Implant Dentistry, School of Dentistry, University of Granada, Granada, Spain
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Keleş Aİ, Nyengaard JR, Odacı E. Changes in pyramidal and granular neuron numbers in the rat hippocampus 7 days after exposure to a continuous 900-MHz electromagnetic field during early and mid-adolescence. J Chem Neuroanat 2019; 101:101681. [PMID: 31465830 DOI: 10.1016/j.jchemneu.2019.101681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/30/2019] [Accepted: 08/25/2019] [Indexed: 11/19/2022]
Abstract
The aim of this study was to investigate qualitative and quantitative changes in pyramidal and granule neurons in the male rat hippocampus after exposure to a continuous 900-megahertz (MHz) electromagnetic field (EMF) for 25 days during early and mid-adolescence. Three-week-old (21 day) healthy Sprague Dawley male rats were divided equally into control (CON), pseudo-exposed (PEX) and EMF groups. EMF rats were exposed to a 900-MHz EMF in an EMF-application cage, while the PEX rats were placed in the same cage without being exposed to EMF. No procedure was performed in CON. EMF was applied for 1 h/day, every day for 25 days. Following the 900-MHz EMF and pseudo-exposed applications, behavioral tests were performed for seven days. Then, all animals were euthanized and their brains were removed. Following histological tissue procedures, sections were taken from tissues and stained with toluidine blue. The optical fractionation technique was performed to estimate the pyramidal neuron numbers in the CA1, CA2-3 and hilus regions of the hippocampus and granule neuron numbers in the dentate gyrus region. Our findings indicated that the number of pyramidal and granule neurons in the hippocampus of the EMF group was statistically higher than PEX. Furthermore, the histopathological results showed that the cytoplasm of pyramidal (in the hilus, CA1, CA2 and CA3 region) and granular (in the dentate gyrus region) cells at the hippocampus were disrupted, as evident by intensive staining around cytoplasm and some artifacts were detected in the EMF group. In addition, statistical comparisons of the mean body weights and brain weights of the study groups revealed no significant differences. There was no statistically significant difference between the PEX and EMF groups in terms of temperature (p > 0.05) or humidity (p > 0.05) in the cages. In conclusion, higher numbers of both pyramidal and granule neurons were found in the male rat hippocampus after continuous 900-MHz EMF treatment.
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Affiliation(s)
- Ayşe İkinci Keleş
- Department of Histology and Embryology, Faculty of Medicine, Niğde Ömer Halisdemir University, Niğde, Turkey.
| | - Jens Randel Nyengaard
- Department of Clinical Medicine, Core Centre for Molecular Morphology, Section for Stereology and Microscopy, Aarhus University Hospital, Aarhus C, Denmark
| | - Ersan Odacı
- Department of Histology and Embryology, Karadeniz Technical University Medical Faculty, Trabzon, Turkey
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Yaoita F, Tsuchiya M, Arai Y, Tadano T, Tan-No K. Involvement of catecholaminergic and GABAAergic mediations in the anxiety-related behavior in long-term powdered diet-fed mice. Neurochem Int 2018; 124:1-9. [PMID: 30529642 DOI: 10.1016/j.neuint.2018.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/30/2018] [Accepted: 12/04/2018] [Indexed: 11/26/2022]
Abstract
Dietary habits are important factors which affect metabolic homeostasis and the development of emotion. We have previously shown that long-term powdered diet feeding in mice increases spontaneous locomotor activity and social interaction (SI) time. Moreover, that diet causes changes in the dopaminergic system, especially increased dopamine turnover and decreased dopamine D4 receptor signals in the frontal cortex. Although the increased SI time indicates low anxiety, the elevated plus maze (EPM) test shows anxiety-related behavior and impulsive behavior. In this study, we investigated whether the powdered diet feeding causes changes in anxiety-related behavior. Mice fed a powdered diet for 17 weeks from weaning were compared with mice fed a standard diet (control). The percentage (%) of open arm time and total number of arm entries were increased in powdered diet-fed mice in the EPM test. We also examined the effects of diazepam, benzodiazepine anti-anxiety drug, bicuculline, GABA-A receptor antagonist, methylphenidate, dopamine transporter (DAT) and noradrenaline transporter (NAT) inhibitor, atomoxetine, selective NAT inhibitor, GBR12909, selective DAT inhibitor, and PD168077, selective dopamine D4 receptor agonist, on the changes of the EPM in powdered diet-fed mice. Methylphenidate and atomoxetine are clinically used to treat attention deficit/hyperactivity disorder (ADHD) symptoms. The % of open arm time in powdered diet-fed mice was decreased by treatments of atomoxetine, methylphenidate and PD168077. Diazepam increased the % of open arm time in control diet-fed mice, but not in powdered diet-fed mice. The powdered diet feeding induced a decrease in GABA transaminase, GABA metabolic enzymes, in the frontal cortex. Moreover, the powdered diet feeding induced an increase in NAT expression, but not DAT expression, in the frontal cortex. These results suggest that the long-term powdered diet feeding may cause low anxiety or impulsivity, possibly via noradrenergic and/or dopaminergic, and GABAAergic mediations and increase the risk for onset of ADHD-like behaviors.
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Affiliation(s)
- Fukie Yaoita
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan.
| | - Masahiro Tsuchiya
- Department of Nursing, Tohoku Fukushi University, 1-8-1 Kunimi, Aoba-ku, Sendai, 981-8522, Japan
| | - Yuichiro Arai
- Tokyo Ariake University of Medical and Health Science, 2-9-1 Ariake, Koto-Ku, Tokyo, 135-0063, Japan
| | - Takeshi Tadano
- Complementary and Alternative Medicine Clinical Research and Development, Graduate School of Medicine Sciences, Kanazawa University, Kakumamachi, Kanazawa, 920-1192, Japan
| | - Koichi Tan-No
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, 981-8558, Japan
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Tsai CY, Lee HP, Chang HM, Wu FC. Masticatory hypofunction effects induced by BTXA injection of hippocampal neurons in developing rats. Arch Oral Biol 2018; 96:122-129. [PMID: 30227358 DOI: 10.1016/j.archoralbio.2018.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/07/2018] [Accepted: 09/09/2018] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE In clinical practice, malocclusion is often encountered during the period of growth and development of individuals. In addition to nutritional imbalance, some studies have found that mastication affects learning and memory ability. Tooth loss and masticatory hypofunction have been suggested as risk factors of Alzheimer disease. However, relatively little research has been done in developing animals. The present study evaluated the relationship between masticatory hypofunction and neuropathological changes of the hippocampus in developing rats. DESIGN Four-week-old Wistar rats were randomly divided into saline-injected and botulinum toxin type A (BTXA)-injected groups. After an experiment period of 4 weeks, the rats were sacrificed for evaluation of neuropathological changes in the hippocampus through Nissl staining and phosphorylated cyclic AMP (cAMP) response element binding protein (CREB) immunohistochemistry. RESULTS Nissl staining revealed a significant reduction in the density of neurons in the BTXA-injected rats. The BTXA-injected rats exhibited a decreased level of CREB phosphorylation. The degree of p-CREB immunoreactivity differed significantly between the two groups. CONCLUSION The BTXA-injected rats exhibited a reduction in neuron density and phosphorylated CREB, indicating that mastication might influence the learning and memory ability during the growth period. Therefore, it is strongly suggested that malocclusion be corrected as soon as possible during growth and development.
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Affiliation(s)
- Chi-Yang Tsai
- Department of Orthodontics, Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan; Graduate Institute of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Hsin-Ping Lee
- Department of Orthodontics, Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan; Graduate Institute of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Hung-Ming Chang
- Department of Anatomy, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Fang-Chun Wu
- Department of Orthodontics, Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan; Graduate Institute of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
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Kiriishi K, Doi H, Magata N, Torisu T, Tanaka M, Ohkubo M, Haneda M, Okatomi M, Shinohara K, Ayuse T. Occlusal force predicts global motion coherence threshold in adolescent boys. BMC Pediatr 2018; 18:331. [PMID: 30336772 PMCID: PMC6194662 DOI: 10.1186/s12887-018-1309-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 10/10/2018] [Indexed: 11/24/2022] Open
Abstract
Background Beneficial effects of mastication on cognitive abilities in the elderly have been shown in human studies. However, little is currently known about the effect of masticatory stimulation on cognitive and perceptual ability in younger populations. The purpose of the present study is to investigate the influences of masticatory stimulation on perceptual ability in adolescent boys. Methods The present study examined the relationship between occlusal force (i.e., masticatory stimulation) and visual perception ability in adolescent boys. Visual perception ability was quantified by measuring global motion coherence threshold using psychophysical method. As an index of masticatory stimulation, occlusal force was measured by pressure sensitive film. We also measured participants’ athletic ability, e.g. aerobic capacity and grip strength, as potential confounding factor. Results The multiple regression analysis revealed a significant negative correlation between global motion coherence threshold and occlusal force, which persisted after controlling for confounding factors such as age and aerobic capacity. Conclusions This finding indicates that masticatory stimulation enhances visual perception in adolescent boys, indicating the possibility that beneficial effects of masticatory stimulation are observed not only in the elderly but in developing population consistently with the findings of the previous animal studies.
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Affiliation(s)
- Kensuke Kiriishi
- Department of Clinical Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,Department of Prosthetic Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, Japan
| | - Hirokazu Doi
- Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Nobuaki Magata
- Department of Clinical Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,Department of Prosthetic Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, Japan
| | - Tetsuro Torisu
- Department of Clinical Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,Department of Prosthetic Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, Japan
| | - Mihoko Tanaka
- Department of Clinical Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.,Department of Prosthetic Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, Japan
| | | | | | | | - Kazuyuki Shinohara
- Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Takao Ayuse
- Department of Clinical Physiology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. .,Department of Prosthetic Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki, Japan.
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Krishnamoorthy G, Narayana AI, Balkrishanan D. Mastication as a tool to prevent cognitive dysfunctions. JAPANESE DENTAL SCIENCE REVIEW 2018; 54:169-173. [PMID: 30302135 PMCID: PMC6175965 DOI: 10.1016/j.jdsr.2018.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 05/14/2018] [Accepted: 06/22/2018] [Indexed: 10/28/2022] Open
Abstract
Mastication as we all know has always been related to its primary function of digestion, but little do we know that it produces an enhancing effect on general health, especially the cognitive performance related aspects of memory. Recent studies have shown its association with activation of various brain regions, however little is known about its effects on neuronal activity in these specified regions. According to the enormous evidences collected so far, mastication has proved to be effective in conducting huge amount of sensory information to the brain, and maintaining learning and memory functions of hippocampus. Therefore it is essential that we maintain normal occlusion and preserve the masticatory function as long as possible to prevent the attenuation of hippocampus, caused by occlusal disharmony and reduced mastication. We provide an overview on how mastication activates various cortical areas of the brain and how an increase in the cerebral blood oxygen level of hippocampus and prefrontal cortex (PFC) accentuates the learning and memory process. We also justify why maintaining and establishing a normal occlusion is important from neurological point of view.
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Affiliation(s)
- Gayathri Krishnamoorthy
- Department of Prosthodontics and Crown & Bridge, Manipal College of Dental Sciences, Manipal University, Manipal, 576104 India
| | - Aparna I Narayana
- Department of Prosthodontics and Crown & Bridge, Manipal College of Dental Sciences, Manipal University, Manipal, 576104 India
| | - Dhanasekar Balkrishanan
- Department of Prosthodontics and Crown & Bridge, Manipal College of Dental Sciences, Manipal University, Manipal, 576104 India
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Flores KP, Blohowiak SE, Winzerling JJ, Georgieff MK, Kling PJ. The impact of erythropoietin and iron status on brain myelination in the newborn rat. J Neurosci Res 2018; 96:1586-1599. [DOI: 10.1002/jnr.24243] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 03/16/2018] [Accepted: 03/20/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Karen P. Flores
- Department of Pediatrics; University of Wisconsin-Madison, Madison, WI, 53792, and UnityPoint Health Meriter Madison; Wisconsin
- Department of Internal Medicine; University of Texas-Southwestern; Dallas Texas
| | - Sharon E. Blohowiak
- Department of Pediatrics; University of Wisconsin-Madison, Madison, WI, 53792, and UnityPoint Health Meriter Madison; Wisconsin
| | - Joy J. Winzerling
- Department of Nutritional Sciences; University of Arizona; Tucson Arizona
| | - Michael K. Georgieff
- Department of Pediatrics and Center for Neurobehavioral Development; University of Minnesota; Minneapolis Minnesota
| | - Pamela J. Kling
- Department of Pediatrics; University of Wisconsin-Madison, Madison, WI, 53792, and UnityPoint Health Meriter Madison; Wisconsin
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Jou YT. Dental deafferentation and brain damage: A review and a hypothesis. Kaohsiung J Med Sci 2018; 34:231-237. [PMID: 29655412 DOI: 10.1016/j.kjms.2018.01.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/07/2017] [Accepted: 01/12/2018] [Indexed: 01/04/2023] Open
Abstract
In the last few decades, neurobiological and human brain imaging research have greatly advanced our understanding of brain mechanisms that support perception and memory, as well as their function in daily activities. Knowledge of the neurobiological mechanisms behind the deafferentation of stomatognathic systems has also expanded greatly in recent decades. In particular, current studies reveal that the peripheral deafferentations of stomatognathic systems may be projected globally into the central nervous system (CNS) and become an associated critical factor in triggering and aggravating neurodegenerative diseases. This review explores basic neurobiological mechanisms associated with the deafferentation of stomatognathic systems. Further included is a discussion on tooth loss and other dental deafferentation (DD) mechanisms, with a focus on dental and masticatory apparatuses associated with brain functions and which may underlie the changes observed in the aging brain. A new hypothesis is presented where DD and changes in the functionality of teeth and the masticatory apparatus may cause brain damage as a result of altered cerebral circulation and dysfunctional homeostasis. Furthermore, multiple recurrent reorganizations of the brain may be a triggering or contributing risk factor in the onset and progression of neurodegenerative conditions such as Alzheimer's disease (AD). A growing understanding of the association between DD and brain aging may lead to solutions in treating and preventing cognitive decline and neurodegenerative diseases.
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Affiliation(s)
- Yi-Tai Jou
- Department of Endodontics School of Dental Medicine University of Pennsylvania Philadelphia, Pennsylvania, USA.
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13
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Shohayeb B, Diab M, Ahmed M, Ng DCH. Factors that influence adult neurogenesis as potential therapy. Transl Neurodegener 2018; 7:4. [PMID: 29484176 PMCID: PMC5822640 DOI: 10.1186/s40035-018-0109-9] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/16/2018] [Indexed: 12/21/2022] Open
Abstract
Adult neurogenesis involves persistent proliferative neuroprogenitor populations that reside within distinct regions of the brain. This phenomenon was first described over 50 years ago and it is now firmly established that new neurons are continually generated in distinct regions of the adult brain. The potential of enhancing the neurogenic process lies in improved brain cognition and neuronal plasticity particularly in the context of neuronal injury and neurodegenerative disorders. In addition, adult neurogenesis might also play a role in mood and affective disorders. The factors that regulate adult neurogenesis have been broadly studied. However, the underlying molecular mechanisms of regulating neurogenesis are still not fully defined. In this review, we will provide critical analysis of our current understanding of the factors and molecular mechanisms that determine neurogenesis. We will further discuss pre-clinical and clinical studies that have investigated the potential of modulating neurogenesis as therapeutic intervention in neurodegeneration.
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Affiliation(s)
- Belal Shohayeb
- 1School of Biomedical Science, Faculty of Medicine, University of Queensland, St Lucia, QLD 4067 Australia
| | - Mohamed Diab
- 2Faculty of Pharmacy, Pharos University in Alexandria, P.O. Box Sidi Gaber, Alexandria, 21311 Egypt
| | - Mazen Ahmed
- 2Faculty of Pharmacy, Pharos University in Alexandria, P.O. Box Sidi Gaber, Alexandria, 21311 Egypt
| | - Dominic Chi Hiung Ng
- 1School of Biomedical Science, Faculty of Medicine, University of Queensland, St Lucia, QLD 4067 Australia
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The ratio of 1/3 linoleic acid to alpha linolenic acid is optimal for oligodendrogenesis of embryonic neural stem cells. Neurosci Lett 2017; 651:216-225. [PMID: 28504119 DOI: 10.1016/j.neulet.2017.05.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/09/2017] [Accepted: 05/09/2017] [Indexed: 11/22/2022]
Abstract
During neural development, embryonic neural stem cells (eNSCs) differentiate toward glial, oligodendrocytic, and neuronal cells. Dysregulation of polyunsaturated fatty acids (PUFAs) induce a wide range of neurological and developmental disorders. In this study, we investigated the effect of various concentrations and ratios of linoleic acid (LA) and alpha linolenic acid (ALA), which belong respectively to omega-6 and omega-3 PUFAs, on the proliferation and differentiation of eNSCs.Results showed that low (25 and 50μM) or high (100 and 200μM) concentrations of ALA, but not LA, and the ratio of 1:3 of LA/ALA significantly increased neurospheres size, frequency and cell numbers, in comparison to controls. Moreover, low or high concentrations of ALA, but not LA, and different ratios of LA/ALA resulted in a significant increase in mRNA expression levels of Notch1, Hes1 and Ki-67, and the differentiation of eNSCs toward astrocytes (GFAP) and oligodendrocytes (MBP), but not neurons (β-III Tubulin), with the highest increase being for LA/ALA ratio of 1:3, in comparison to controls. These results demonstrate the importance of higher concentrations of ALA in enhancing proliferation and differentiation of eNSCs, which could be used in diet to help preventing neurodevelopmental syndromes, cognitive decline during aging, and various psychiatric disorders.
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Kim EK, Lee SK, Choi YH, Tanaka M, Hirotsu K, Kim HC, Lee HK, Jung YS, Amano A. Relationship between chewing ability and cognitive impairment in the rural elderly. Arch Gerontol Geriatr 2017; 70:209-213. [DOI: 10.1016/j.archger.2017.02.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 11/27/2022]
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Abstract
AbstractThree areas in the brain continuously generate new neurons throughout life: the subventricular zone lining the lateral ventricles, the dentate gyrus in the hippocampus and the median eminence in the hypothalamus. These areas harbour neural stem cells, which contribute to neural repair by generating daughter cells that then become functional neurons or glia. Impaired neurogenesis leads to detrimental consequences, such as depression, decline of cognitive abilities and obesity. Adult neurogenesis is a versatile process that can be modulated either positively or negatively by many effectors, external or endogenous. Diet can modify neurogenesis both ways, either directly by ways of food-borne molecules, or possibly by the modifications induced on gut microbiota composition. It is therefore critical to define dietary strategies optimal for the maintenance of the stem cell pools.
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Smith N, Miquel-Kergoat S, Thuret S. The impact of mastication on cognition: Evidence for intervention and the role of adult hippocampal neurogenesis. ACTA ACUST UNITED AC 2016. [DOI: 10.3233/nua-150054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Natalie Smith
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, The James Black Centre, London, UK
| | | | - Sandrine Thuret
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, The James Black Centre, London, UK
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Chronic Powder Diet After Weaning Induces Sleep, Behavioral, Neuroanatomical, and Neurophysiological Changes in Mice. PLoS One 2015; 10:e0143909. [PMID: 26630494 PMCID: PMC4668096 DOI: 10.1371/journal.pone.0143909] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 11/11/2015] [Indexed: 12/23/2022] Open
Abstract
The purpose of this study is to clarify the effects of chronic powder diet feeding on sleep patterns and other physiological/anatomical changes in mice. C57BL/6 male mice were divided into two groups from weaning: a group fed with solid food (SD) and a group fed with powder food (PD), and sleep and physiological and anatomical changes were compared between the groups. PD exhibited less cranial bone structure development and a significant weight gain. Furthermore, these PD mice showed reduced number of neurogenesis in the hippocampus. Sleep analysis showed that PD induced attenuated diurnal sleep/wake rhythm, characterized by increased sleep during active period and decreased sleep during rest period. With food deprivation (FD), PD showed less enhancement of wake/locomotor activity compared to SD, indicating reduced food-seeking behavior during FD. These results suggest that powder feeding in mice results in a cluster of detrimental symptoms caused by abnormal energy metabolism and anatomical/neurological changes.
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19
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How masticatory function and periodontal disease relate to senile dementia. JAPANESE DENTAL SCIENCE REVIEW 2015. [DOI: 10.1016/j.jdsr.2014.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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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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Utsugi C, Miyazono S, Osada K, Matsuda M, Kashiwayanagi M. Impaired mastication reduced newly generated neurons at the accessory olfactory bulb and pheromonal responses in mice. Arch Oral Biol 2014; 59:1272-8. [PMID: 25150532 DOI: 10.1016/j.archoralbio.2014.07.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 07/22/2014] [Indexed: 11/24/2022]
Abstract
OBJECTIVES A large number of neurons are generated at the subventricular zone (SVZ) even during adulthood. In a previous study, we have shown that a reduced mastication impairs both neurogenesis in the SVZ and olfactory functions. Pheromonal signals, which are received by the vomeronasal organ, provide information about reproductive and social states. Vomeronasal sensory neurons project to the accessory olfactory bulb (AOB) located on the dorso-caudal surface of the main olfactory bulb. Newly generated neurons at the SVZ migrate to the AOB and differentiate into granule cells and periglomerular cells. This study aimed to explore the effects of changes in mastication on newly generated neurons and pheromonal responses. DESIGN Bromodeoxyuridine-immunoreactive (BrdU-ir; a marker of DNA synthesis) and Fos-ir (a marker of neurons excited) structures in sagittal sections of the AOB after exposure to urinary odours were compared between the mice fed soft and hard diets. RESULTS The density of BrdU-ir cells in the AOB in the soft-diet-fed mice after 1 month was essentially similar to that of the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 3 or 6 months than in the hard-diet-fed mice. The density of Fos-ir cells in the soft-diet-fed mice after 2 months was essentially similar to that in the hard-diet-fed mice, while that was lower in the soft-diet-fed mice for 4 months than in the hard-diet-fed mice. CONCLUSIONS The present results suggest that impaired mastication reduces newly generated neurons at the AOB, which in turn impairs olfactory function at the AOB.
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Affiliation(s)
- Chizuru Utsugi
- Department of Oral and Maxillofacial Surgery, Asahikawa Medical University, Asahikawa 078-8510, Japan; Department of Sensory Physiology, Asahikawa Medical University, Asahikawa 078-8510, Japan
| | - Sadaharu Miyazono
- Department of Sensory Physiology, Asahikawa Medical University, Asahikawa 078-8510, Japan
| | - Kazumi Osada
- Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Tohbetu 061-0293, Japan
| | - Mitsuyoshi Matsuda
- Department of Oral and Maxillofacial Surgery, Asahikawa Medical University, Asahikawa 078-8510, Japan
| | - Makoto Kashiwayanagi
- Department of Sensory Physiology, Asahikawa Medical University, Asahikawa 078-8510, Japan.
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22
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Paphangkorakit J, Leelayuwat N, Boonyawat N, Parniangtong A, Sripratoom J. Effect of chewing speed on energy expenditure in healthy subjects. Acta Odontol Scand 2014; 72:424-7. [PMID: 24102573 DOI: 10.3109/00016357.2013.847490] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The aim of the study was to investigate the effect of rate of chewing on energy expenditure in human subjects. MATERIALS AND METHODS Fourteen healthy subjects (aged 18-24 years) within the normal range of BMI participated in a cross-over experiment consisting of two 6-min sessions of gum chewing, slow (∼60 cycles/min) and fast (∼120 cycles/min) chewing. The resting energy expenditure (REE) and during gum chewing was measured using a ventilated hood connected to a gas analyzer system. The normality of data was explored using the Shapiro-Wilk test. The energy expenditure rate during chewing and the energy expenditure per chewing cycle were compared between the two chewing speeds using Wilcoxon signed ranks tests. RESULTS The energy expenditure per chewing cycle during slow chewing (median 1.4, range 5.2 cal; mean 2.1±1.6 cal) was significantly higher than that during fast chewing (median 0.9, range 2.2 cal; mean 1.0±0.7 cal) (p < 0.005). However, the energy expenditure rate was not significantly different between the two chewing speeds (p > 0.05). CONCLUSIONS The results of this study suggest that chewing at a slower speed could increase the energy expenditure per cycle and might affect the total daily energy expenditure.
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23
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Sakamoto S, Hara T, Kurozumi A, Oka M, Kuroda-Ishimine C, Araki D, Iida S, Minagi S. Effect of occlusal rehabilitation on spatial memory and hippocampal neurons after long-term loss of molars in rats. J Oral Rehabil 2014; 41:715-22. [PMID: 24909970 DOI: 10.1111/joor.12198] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2014] [Indexed: 11/28/2022]
Abstract
Experimental loss of occlusal support caused by the extraction or grinding of molar teeth has been reported to foment the impairment of learning and memory in laboratory animals. The purpose of this study was to examine the effect of occlusal reconstruction after long-term loss of molars on spatial memory by using 8-arm radial maze and by assessing histopathological changes of neuron density in the hippocampus. Experimental dentures were inserted into the oral cavities of molarless rats to recover the occlusal support. Age-matched groups of control, molarless and denture-wearing rats were trained to perform the maze tasks. The difference of the error incidence in the maze task was evaluated between three groups. The difference of neuron density between three groups was also evaluated at the end of the maze task. Serum corticosterone levels were also measured to estimate the chronic stress, which could be caused by extraction, insertion of the experimental denture or any experimental procedure. The error incidence in the denture-wearing group was significantly higher than that of the control group, but significantly lower than that of the molarless group. Significant differences of neuron density were observed between three groups in each of the hippocampal CA1, CA3 and DG subfields. No significant difference of the serum corticosterone levels between three groups could be observed. From the results of this study, it was suggested that the recovery of occlusal support would bring amelioration of cognitive impairment concomitant with long period loss of molars in rats.
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Affiliation(s)
- S Sakamoto
- Department of Occlusal and Oral Functional Rehabilitation, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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24
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Utsugi C, Miyazono S, Osada K, Sasajima H, Noguchi T, Matsuda M, Kashiwayanagi M. Hard-diet feeding recovers neurogenesis in the subventricular zone and olfactory functions of mice impaired by soft-diet feeding. PLoS One 2014; 9:e97309. [PMID: 24817277 PMCID: PMC4016307 DOI: 10.1371/journal.pone.0097309] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 04/17/2014] [Indexed: 01/24/2023] Open
Abstract
The subventricular zone (SVZ) generates an immense number of neurons even during adulthood. These neurons migrate to the olfactory bulb (OB) and differentiate into granule cells and periglomerular cells. The information broadcast by general odorants is received by the olfactory sensory neurons and transmitted to the OB. Recent studies have shown that a reduction of mastication impairs both neurogenesis in the hippocampus and brain functions. To examine these effects, we first measured the difference in Fos-immunoreactivity (Fos-ir) at the principal sensory trigeminal nucleus (Pr5), which receives intraoral touch information via the trigeminal nerve, when female adult mice ingested a hard or soft diet to explore whether soft-diet feeding could mimic impaired mastication. Ingestion of a hard diet induced greater expression of Fos-ir cells at the Pr5 than did a soft diet or no diet. Bromodeoxyuridine-immunoreactive (BrdU-ir) structures in sagittal sections of the SVZ and in the OB of mice fed a soft or hard diet were studied to explore the effects of changes in mastication on newly generated neurons. After 1 month, the density of BrdU-ir cells in the SVZ and OB was lower in the soft-diet-fed mice than in the hard-diet-fed mice. The odor preferences of individual female mice to butyric acid were tested in a Y-maze apparatus. Avoidance of butyric acid was reduced by the soft-diet feeding. We then explored the effects of the hard-diet feeding on olfactory functions and neurogenesis in the SVZ of mice impaired by soft-diet feeding. At 3 months of hard-diet feeding, avoidance of butyric acid was reversed and responses to odors and neurogenesis were recovered in the SVZ. The present results suggest that feeding with a hard diet improves neurogenesis in the SVZ, which in turn enhances olfactory function at the OB.
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Affiliation(s)
- Chizuru Utsugi
- Department of Oral and Maxillofacial Surgery, Asahikawa Medical University, Asahikawa, Japan
- Department of Sensory Physiology, Asahikawa Medical University, Asahikawa, Japan
| | - Sadaharu Miyazono
- Department of Sensory Physiology, Asahikawa Medical University, Asahikawa, Japan
| | - Kazumi Osada
- Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Tohbetu, Japan
| | - Hitoshi Sasajima
- Department of Sensory Physiology, Asahikawa Medical University, Asahikawa, Japan
| | - Tomohiro Noguchi
- Department of Sensory Physiology, Asahikawa Medical University, Asahikawa, Japan
| | - Mitsuyoshi Matsuda
- Department of Oral and Maxillofacial Surgery, Asahikawa Medical University, Asahikawa, Japan
| | - Makoto Kashiwayanagi
- Department of Sensory Physiology, Asahikawa Medical University, Asahikawa, Japan
- * E-mail:
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25
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Soft-diet feeding after weaning affects behavior in mice: Potential increase in vulnerability to mental disorders. Neuroscience 2014; 263:257-68. [PMID: 24444829 DOI: 10.1016/j.neuroscience.2013.12.065] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 12/28/2013] [Accepted: 12/31/2013] [Indexed: 11/23/2022]
Abstract
Mastication is one of the most important oral functions, and the period during which mastication is acquired overlaps with the term of rapid development and maturation of the neural systems. In particular, the acquisition period after weaning is related to the potential onset of mental disorders. However, the roles of mastication during this period for brain development remain largely unknown. Therefore, we used a series of standard behavioral analyses, assessment of hippocampal cell proliferation, and the expression of brain-derived neurotrophic factor (BDNF), TrkB, and Akt1 in the hippocampus and frontal cortex of mice to investigate the effects of post-weaning mastication on brain function. We fed 21-day-old C57BL6/J male mice either a hard or a soft diet for 4weeks and conducted a series of standard behavioral tests from 7weeks of age. Further, histological analysis with bromodeoxyuridine was performed to compare hippocampal cell proliferation at 7 and 14weeks of age. Real-time polymerase chain reaction was performed to compare BDNF, TrkB, and Akt1 expression in the hippocampus and frontal cortex of 14-week-old mice. Compared to mice fed a hard diet (HDM), soft-diet mice (SDM) showed behavioral impairments, including decreased home cage activity, increased open field test activity, and deficits in prepulse inhibition. These results were similar to those observed in mouse models of schizophrenia. However, no effects were observed on anxiety-like behaviors or memory/learning tests. Compared to HDM, SDM showed significantly decreased hippocampal cell proliferation and hippocampal BDNF and Akt1 gene expression at 14weeks of age. A soft diet after weaning may have resulted in histological and molecular changes in the hippocampus and influenced outcomes of behavioral tests related to mental disorders. Our findings suggest that soft-diet feeding after weaning may affect both physical and mental development of mice, and may increase vulnerability to mental disorders.
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26
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Teixeira FB, Pereira Fernandes LDM, Noronha PAT, dos Santos MAR, Gomes-Leal W, Ferraz Maia CDS, Lima RR. Masticatory deficiency as a risk factor for cognitive dysfunction. Int J Med Sci 2014; 11:209-14. [PMID: 24465167 PMCID: PMC3894406 DOI: 10.7150/ijms.6801] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 11/25/2013] [Indexed: 11/13/2022] Open
Abstract
Several studies have demonstrated that chewing helps to maintain cognitive functions in brain regions including the hippocampus, a central nervous system (CNS) region vital for memory and learning. Epidemiological studies suggest that masticatory deficiency is associated with development of dementia, which is related to spatial memory deficits especially in older animals. The purpose of this paper is to review recent work on the effects of masticatory impairment on cognitive functions both in experimental animals and humans. We show that several mechanisms may be involved in the cognitive deficits associated with masticatory deficiency. The epidemiological data suggest a positive correlation between masticatory deficit and Alzheimer's disease. It may be concluded that chewing has important implications for the mechanisms underlying certain cognitive abilities.
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Affiliation(s)
- Francisco Bruno Teixeira
- 1. Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil
| | - Luanna de Melo Pereira Fernandes
- 1. Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil; ; 2. Laboratory Pharmacology of Inflammation and Behavior, Institute of Health Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil
| | - Patrycy Assis Tavares Noronha
- 3. Laboratory of Experimental Neuroprotection and Neuroregeneration, Institute of Biological Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil
| | - Marcio Antonio Raiol dos Santos
- 1. Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil
| | - Walace Gomes-Leal
- 3. Laboratory of Experimental Neuroprotection and Neuroregeneration, Institute of Biological Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil
| | - Cristiane do Socorro Ferraz Maia
- 2. Laboratory Pharmacology of Inflammation and Behavior, Institute of Health Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil
| | - Rafael Rodrigues Lima
- 1. Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, 66075-900, Belém-Pará, Brazil
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Patten A, Moller D, Graham J, Gil-Mohapel J, Christie B. Liquid diets reduce cell proliferation but not neurogenesis in the adult rat hippocampus. Neuroscience 2013; 254:173-84. [DOI: 10.1016/j.neuroscience.2013.09.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 09/11/2013] [Accepted: 09/11/2013] [Indexed: 12/22/2022]
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28
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Impact of lipid nutrition on neural stem/progenitor cells. Stem Cells Int 2013; 2013:973508. [PMID: 24260036 PMCID: PMC3821937 DOI: 10.1155/2013/973508] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 09/09/2013] [Indexed: 11/17/2022] Open
Abstract
The neural system originates from neural stem/progenitor cells (NSPCs). Embryonic NSPCs first proliferate to increase their numbers and then produce neurons and glial cells that compose the complex neural circuits in the brain. New neurons are continually produced even after birth from adult NSPCs in the inner wall of the lateral ventricle and in the hippocampal dentate gyrus. These adult-born neurons are involved in various brain functions, including olfaction-related functions, learning and memory, pattern separation, and mood control. NSPCs are regulated by various intrinsic and extrinsic factors. Diet is one of such important extrinsic factors. Of dietary nutrients, lipids are important because they constitute the cell membrane, are a source of energy, and function as signaling molecules. Metabolites of some lipids can be strong lipid mediators that also regulate various biological activities. Recent findings have revealed that lipids are important regulators of both embryonic and adult NSPCs. We and other groups have shown that lipid signals including fat, fatty acids, their metabolites and intracellular carriers, cholesterol, and vitamins affect proliferation and differentiation of embryonic and adult NSPCs. A better understanding of the NSPCs regulation by lipids may provide important insight into the neural development and brain function.
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Niijima-Yaoita F, Tsuchiya M, Saito H, Nagasawa Y, Murai S, Arai Y, Nakagawasai O, Nemoto W, Tadano T, Tan-No K. Influence of a long-term powdered diet on the social interaction test and dopaminergic systems in mice. Neurochem Int 2013; 63:309-15. [PMID: 23871718 DOI: 10.1016/j.neuint.2013.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 06/22/2013] [Accepted: 07/07/2013] [Indexed: 10/26/2022]
Abstract
It is well known that the characteristics of mastication are important for the maintenance of our physical well-being. In this study, to assess the importance of the effects of food hardness during mastication, we investigated whether a long-term powdered diet might cause changes in emotional behavior tests, including spontaneous locomotor activity and social interaction (SI) tests, and the dopaminergic system of the frontal cortex and hippocampus in mice. Mice fed a powdered diet for 17 weeks from weaning were compared with mice fed a standard diet (control). The dopamine turnover and expression of dopamine receptors mRNA in the frontal cortex were also evaluated. Spontaneous locomotor activity, SI time and dopamine turnover of the frontal cortex were increased in powdered diet-fed mice. On the other hand, the expression of dopamine-4 (D4) receptors mRNA in the frontal cortex was decreased in powdered diet-fed mice. Moreover, we examined the effect of PD168077, a selective D4 agonist, on the increased SI time in powdered diet-fed mice. Treatment with PD168077 decreased the SI time. These results suggest that the masticatory dysfunction induced by long-term powdered diet feeding may cause the increased SI time and the changes in the dopaminergic system, especially dopamine D4 receptor subtype in the frontal cortex.
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Affiliation(s)
- Fukie Niijima-Yaoita
- Department of Pharmacology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
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Abstract
INTRODUCTION Over the last 8 years, emerging studies bridging the gap between nutrition and mental health have resolutely established that learning and memory abilities as well as mood can be influenced by diet. However, the mechanisms by which diet modulates mental health are still not well understood. Sources of data In this article, a review of the literature was conducted using PubMed to identify studies that provide functional implications of adult hippocampal neurogenesis (AHN) and its modulation by diet. AREAS OF AGREEMENT One of the brain structures associated with learning and memory as well as mood is the hippocampus. Importantly, the hippocampus is one of the two structures in the adult brain where the formation of newborn neurons, or neurogenesis, persists. AREAS OF CONTROVERSY The exact roles of these newborn neurons in learning, memory formation and mood regulation remain elusive. GROWING POINTS Nevertheless, there has been accumulating evidence linking cognition and mood to neurogenesis occurring in the adult hippocampus. Therefore, modulation of AHN by diet emerges as a possible mechanism by which nutrition impacts on mental health. AREAS TIMELY FOR DEVELOPING RESEARCH This area of investigation is new and needs attention because a better understanding of the neurological mechanisms by which nutrition affect mental health may lead to novel dietary approaches for disease prevention, healthier ageing and discovery of new therapeutic targets for mental illnesses.
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Ohkubo C, Morokuma M, Yoneyama Y, Matsuda R, Lee JS. Interactions between occlusion and human brain function activities. J Oral Rehabil 2012; 40:119-29. [PMID: 22624951 DOI: 10.1111/j.1365-2842.2012.02316.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There are few review articles in the area of human research that focus on the interactions between occlusion and brain function. This systematic review discusses the effect of occlusion on the health of the entire body with a focus on brain function. Available relevant articles in English from 1999 to 2011 were assessed in an online database and as hard copies in libraries. The selected 19 articles were classified into the following five categories: chewing and tongue movements, clenching and grinding, occlusal splints and occlusal interference, prosthetic rehabilitation, and pain and stimulation. The relationships between the brain activity observed in the motor and sensory cortices and movements of the oral and maxillofacial area, such as those produced by gum chewing, tapping and clenching, were investigated. It was found that the sensorimotor cortex was also affected by the placement of the occlusal interference devices, splints and implant prostheses. Brain activity may change depending on the strength of the movements in the oral and maxillofacial area. Therefore, mastication and other movements stimulate the activity in the cerebral cortex and may be helpful in preventing degradation of a brain function. However, these findings must be verified by evidence gathered from more subjects.
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Affiliation(s)
- C Ohkubo
- Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan.
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Ohira A, Ono Y, Yano N, Takagi Y. The effect of chewing exercise in preschool children on maximum bite force and masticatory performance. Int J Paediatr Dent 2012; 22:146-53. [PMID: 21781200 DOI: 10.1111/j.1365-263x.2011.01162.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Mastication is a developing function affected by various factors. There is a need for further research on methods of promoting masticatory function in young children. AIM The aim of this study was to evaluate the effects of gum chewing exercise on the maximum bite force (MBF) and the masticatory performance of preschool children. DESIGN The study population included 98 preschool children age 4-6years. MBF was measured by Occlusal Force-Meter(®) , and masticatory performance values were evaluated by using the colour-changeable chewing gum. The examinations were performed four times with an interval of 4weeks. An exercise group of 70 subjects was instructed to chew the exercise gum twice daily for 5min during a 4-week period. The chewing gum used for this study was specially developed with the physical property of maintaining hardness during chewing. A control group of 28 subjects was instructed not to chew any gum during the study period. RESULTS No significant differences were found between the exercise group and the control group in MBF and a* values at the start of the study. After 4weeks of chewing exercise, MBF and a* values were significantly increased in the exercise group compared with those of the control group. These increases were maintained for 4weeks after exercise had finished. CONCLUSIONS Gum chewing exercise is effective to increase MBF and a* values of preschool children and the effects are maintained after exercise completion.
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Affiliation(s)
- Akira Ohira
- Division of Oral Health Sciences, Developmental Oral Health Science, Department of Orofacial Development and Function, Graduate School of Medical and Dental Sciences, Tokyo, Japan.
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Ohno A, Yoshino F, Yoshida A, Hori N, Ono Y, Kimoto K, Onozuka M, Lee MCI. Soft-food diet induces oxidative stress in the rat brain. Neurosci Lett 2012; 508:42-6. [DOI: 10.1016/j.neulet.2011.12.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/30/2011] [Accepted: 12/12/2011] [Indexed: 10/14/2022]
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Kurata C, Ichihashi Y, Onishi M, Iinuma M, Tamura Y, Mori D, Kubo KY. Early toothless condition suppresses cell proliferation in the hippocampal dentate gyrus of SAMP8 mice. PEDIATRIC DENTAL JOURNAL 2012. [DOI: 10.1016/s0917-2394(12)70261-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Rivera P, Romero-Zerbo Y, Pavón FJ, Serrano A, López-Ávalos MD, Cifuentes M, Grondona JM, Bermúdez-Silva FJ, Fernández-Llebrez P, de Fonseca FR, Suárez J, Pérez-Martín M. Obesity-dependent cannabinoid modulation of proliferation in adult neurogenic regions. Eur J Neurosci 2011; 33:1577-86. [PMID: 21395869 DOI: 10.1111/j.1460-9568.2011.07650.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Endocannabinoid signalling participates in the control of neurogenesis, especially after brain insults. Obesity may explain alterations in physiology affecting neurogenesis, although it is unclear whether cannabinoid signalling may modulate neural proliferation in obese animals. Here we analyse the impact of obesity by using two approaches, a high-fat diet (HFD, 60% fat) and a standard/low-fat diet (STD, 10% fat), and the response to a subchronic treatment with the cannabinoid receptor type 1 (CB1) inverse agonist AM251 (3 mg/kg) on cell proliferation of two relevant neurogenic regions, namely the subventricular zone in the striatal wall of the lateral ventricle (SVZ) and the subgranular zone of the dentate gyrus (SGZ), and also in the hypothalamus given its role in energy metabolism. We found evidence of an interaction between diet-induced obesity and CB1 signalling in the regulation of cell proliferation. AM251 reduced caloric intake and body weight in obese rats, as well as corrected plasma levels of cholesterol and triglycerides. AM251 is shown, for the first time, to modulate cell proliferation in HFD-obese rats only. We observed an increase in the number of 5-bromo-2-deoxyuridine-labelled (BrdU+) cells in the SGZ, but a decrease in the number of BrdU+ cells in the SVZ and the hypothalamus of AM251-treated HFD rats. These BrdU+ cells expressed the neuron-specific βIII-tubulin. These results suggest that obesity may impact cell proliferation in the brain selectively, and provide support for a role of CB1 signalling regulation of neurogenesis in response to obesity.
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Affiliation(s)
- Patricia Rivera
- Laboratorio de Medicina Regenerativa, Hospital Carlos Haya, Fundación IMABIS, Avda. Carlos Haya 82, Pabellón de Gobierno, 29010 Málaga, Spain
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Weijenberg R, Scherder E, Lobbezoo F. Mastication for the mind—The relationship between mastication and cognition in ageing and dementia. Neurosci Biobehav Rev 2011; 35:483-97. [DOI: 10.1016/j.neubiorev.2010.06.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 06/05/2010] [Accepted: 06/08/2010] [Indexed: 01/14/2023]
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Kubo KY, Ichihashi Y, Kurata C, Iinuma M, Mori D, Katayama T, Miyake H, Fujiwara S, Tamura Y. Masticatory function and cognitive function. Okajimas Folia Anat Jpn 2010; 87:135-140. [PMID: 21174943 DOI: 10.2535/ofaj.87.135] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Recent studies have suggest that masticatory (chewing) function is useful for maintaining neurocognitive function in the elderly. For example, a reduced ability to masticate, such as that resulting from toothlessness or soft-diet feeding, causes learning and memory deficits in aged animals and pathologic changes in the hippocampus. In addition, occlusal disharmony impairs hippocampal memory processes via chronic stress, and induces similar hippocampal pathology. Chewing, however, rescues stress-induced suppression of long-term potentiation in the hippocampus and the stress-induced impairment of hippocampal-dependent learning. These findings strongly suggest a link between mastication and neurocognitive function.
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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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Ono Y, Yamamoto T, Kubo KY, Onozuka M. Occlusion and brain function: mastication as a prevention of cognitive dysfunction. J Oral Rehabil 2010; 37:624-40. [PMID: 20236235 DOI: 10.1111/j.1365-2842.2010.02079.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Research in animals and humans has shown that mastication maintains cognitive function in the hippocampus, a brain area important for learning and memory. Reduced mastication, an epidemiological risk factor for the development of dementia in humans, attenuates spatial memory and causes hippocampal neurons to deteriorate morphologically and functionally, especially in aged animals. Active mastication rescues the stress-attenuated hippocampal memory process in animals and attenuates the perception of stress in humans by suppressing endocrinological and autonomic stress responses. Active mastication further improves the performance of sustained cognitive tasks by increasing the activation of the hippocampus and the prefrontal cortex, the brain regions that are essential for cognitive processing. Abnormal mastication caused by experimental occlusal disharmony in animals produces chronic stress, which in turn suppresses spatial learning ability. The negative correlation between mastication and corticosteroids has raised the hypothesis that the suppression of the hypothalamic-pituitary-adrenal (HPA) axis by masticatory stimulation contributes, in part, to preserving cognitive functions associated with mastication. In the present review, we examine research pertaining to the mastication-induced amelioration of deficits in cognitive function, its possible relationship with the HPA axis, and the neuronal mechanisms that may be involved in this process in the hippocampus.
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Affiliation(s)
- Y Ono
- Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka, Japan.
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Molarless condition suppresses proliferation but not differentiation rates into neurons in the rat dentate gyrus. Neurosci Lett 2009; 469:44-8. [PMID: 19931591 DOI: 10.1016/j.neulet.2009.11.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 11/03/2009] [Accepted: 11/17/2009] [Indexed: 11/23/2022]
Abstract
The dentate gyrus (DG) of the hippocampal complex is one of the few areas of the rodent brain where neurogenesis continues throughout adulthood. We investigated the effects of the molarless condition on cell proliferation, rate of differentiation into neurons in the subgranular zone of the DG, and plasma corticosterone levels. The molarless condition decreased cell proliferation in the DG and increased plasma corticosterone levels. Approximately 80% of newly generated cells differentiated into neurons and the remaining 20% of the cells differentiated into astrocytes. These ratios were not significantly different between control and molarless rats. In conclusion, the rates of neurogenesis and gliogenesis in the DG are suppressed by the molarless condition, and this suppression might be associated with the increased corticosteroid levels in molarless subjects.
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Stangl D, Thuret S. Impact of diet on adult hippocampal neurogenesis. GENES AND NUTRITION 2009; 4:271-82. [PMID: 19685256 DOI: 10.1007/s12263-009-0134-5] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 07/20/2009] [Indexed: 01/09/2023]
Abstract
Research over the last 5 years has firmly established that learning and memory abilities, as well as mood, can be influenced by diet, although the mechanisms by which diet modulates mental health are not well understood. One of the brain structures associated with learning and memory, as well as mood, is the hippocampus. Interestingly, the hippocampus is one of the two structures in the adult brain where the formation of newborn neurons, or neurogenesis, persists. The level of neurogenesis in the adult hippocampus has been linked directly to cognition and mood. Therefore, modulation of adult hippocampal neurogenesis (AHN) by diet emerges as a possible mechanism by which nutrition impacts on mental health. In this study, we give an overview of the mechanisms and functional implications of AHN and summarize recent findings regarding the modulation of AHN by diet.
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Affiliation(s)
- Doris Stangl
- Centre for the Cellular Basis of Behaviour and MRC Centre for Neurodegeneration Research, The James Black Centre, Institute of Psychiatry, King's College London, 125 Coldharbour Lane, London, SE5 9NU, UK
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Nonlinear Dynamical Analysis of the Effect by Six Stimuli on Electroencephalogram. J Clin Neurophysiol 2009; 26:24-38. [DOI: 10.1097/wnp.0b013e31819862db] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Chewing ameliorates stress-induced suppression of hippocampal long-term potentiation. Neuroscience 2008; 154:1352-9. [DOI: 10.1016/j.neuroscience.2008.04.057] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Revised: 04/09/2008] [Accepted: 04/28/2008] [Indexed: 11/21/2022]
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Kushida S, Kimoto K, Hori N, Toyoda M, Karasawa N, Yamamoto T, Kojo A, Onozuka M. Soft-diet feeding decreases dopamine release and impairs aversion learning in Alzheimer model rats. Neurosci Lett 2008; 439:208-11. [DOI: 10.1016/j.neulet.2008.05.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/05/2008] [Accepted: 05/07/2008] [Indexed: 11/26/2022]
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