Tooth loss early in life suppresses neurogenesis and synaptophysin expression in the hippocampus and impairs learning in mice

Kubo, Kin‐ya; Murabayashi, Chika; Kotachi, Mika; Suzuki, Ayumi; Mori, Daisuke; Sato, Yuichi; Onozuka, Minoru; Chen, Huayue; Iinuma, Mitsuo

doi:10.1016/j.archoralbio.2016.11.005

Cited by 31 publications

(50 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present study examined the effects of tooth loss early in life on the hippocampal ultrastructure in senescence-accelerated mouse strain P8 (SAMP8) mice. SAMP8 mice exhibit age-related behavioral and morphologic alterations, as well as spatial learning deficits [12,17] . The SAMP8 mouse is a murine model of senile dementia [18].…”

Section: Ivyspringmentioning

confidence: 99%

“…Previous studies revealed that long-term tooth loss, representing a chronic psychologic stressor, induces stress reactions, activates the hypothalamic-pituitaryadrenal axis, and stimulates the adrenal cortex to secrete excess glucocorticoids, corticosterone in rodents and cortisol in humans [7][8][9][10]. Animal experiments demonstrate that the blood corticosterone concentration in animals with long-term tooth loss is significantly higher than that in controls [11,12]. The lipophilic nature of glucocorticoids facilitates their rapid entry into the brain.…”

Section: Introductionmentioning

confidence: 99%

“…The hippocampus contains the highest level of glucocorticoid receptors, making it a target of stress hormone effects [5,13]. Mice and rats with tooth loss exhibit impaired hippocampal neurogenesis as well as impaired spatial learning and memory in the Morris water maze test [12,[14][15][16]. The…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Tooth loss early in life induces hippocampal morphology remodeling in senescence-accelerated mouse prone 8 (SAMP8) mice

et al. 2020

Self Cite

View full text Add to dashboard Cite

Long-term tooth loss is associated with the suppression of hippocampal neurogenesis and impairment of hippocampus-dependent cognition with aging. The morphologic basis of the hippocampal alterations, however, remains unclear. In the present study, we investigated whether tooth loss early in life affects the hippocampal ultrastructure in senescence-accelerated mouse prone 8 (SAMP8) mice, using transmission electron microscopy. Male SAMP8 mice were randomized into control or tooth-loss groups. All maxillary molar teeth were removed at 1 month of age. Hippocampal morphologic alterations were evaluated at 9 months of age. Tooth loss early in life induced mitochondrial damage and lipofuscin accumulation in the hippocampal neurons. A thinner myelin sheath and decreased postsynaptic density length were also observed. Our results revealed that tooth loss early in life may lead to hippocampal ultrastructure remodeling and subsequent hippocampus-dependent cognitive impairment in SAMP8 mice with aging.

show abstract

Section: Ivyspringmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tooth loss early in life induces hippocampal morphology remodeling in senescence-accelerated mouse prone 8 (SAMP8) mice

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Over the past few years there has been an evidence base building up indicating a relationship between masticatory ability, influenced by edentulism and food texture, and AHN in rodents. Forced edentulism, via the removal of molars, in adult mice has been shown by multiple groups to give rise to reduced cell proliferation and new-born neuron density in the dentate gyrus resulting in impaired structure and spatial memory [24,25]. Mice fed on powdered or liquid diets have shown to have reduced survival of new-born cells and reduced cell proliferation in the dentate gyrus [26,27].…”

Section: Discussionmentioning

confidence: 99%

A 3-month mastication intervention improves recognition memory

Kim

Miquel²,

Thuret

2019

NHA

View full text Add to dashboard Cite

BACKGROUND: Decreased mastication due to edentulism in both humans and animals have a negative impact on brain function and cognition. Human populations have shown a close association between masticatory function, cognitive status and age-related neurodegeneration in the elderly. Evidence shows that mastication during tasks may have an acute positive impact on normal cognitive function, such as sustained attention. However, there is a lack of evidence showing the long-term effects of changes in habitual masticatory behaviour on cognition. OBJECTIVE: To investigate the impact of a 3-month mastication intervention on cognitive function in healthy older adults. METHODS: 53 participants aged 45-70 years old were required to chew mint-flavoured sugar free chewing gum for 10 minutes, 3 times a day over 3 months. Pattern separation and recognition memory was measured using the Mnemonic Similarity Task. Questionnaires were administered to measure changes in mood, anxiety, and sleep quality. RESULTS: Extended periods of mastication gave rise to a significant improvement in recognition memory compared to a non-chewing control group. CONCLUSION: With an ageing population, non-medical interventions are imperative to delay age-related cognitive decline. Further work needs to be carried out in larger populations to validate the findings in this study and elucidate potential mechanisms.

show abstract

“…However, nerve damage inflicted in 8-month-old adult SAMP8 mice caused deficits in learning and memory in 11-month-old mice coincident with cholinergic neuron loss in the hippocampus and basal forebrain (He et al, 2014). Interestingly, tooth extraction in very young SAMP8 mice, (1-month-old, an age immediately following tooth eruption) (Kubo et al, 2017) produced learning and memory deficits similar to that observed in the 8-month-old nerve-damaged mice (He et al, 2014;Kondo et al, 2016). In both cohorts, the oral stress negatively impacted structure and function of the hippocampus via neuronal loss or damage.…”

Section: Or Al He Alth and Cog Nitive Impairment-mechanis Tic Ins Imentioning

confidence: 99%

Can oral health and oral‐derived biospecimens predict progression of dementia?

et al. 2020

View full text Add to dashboard Cite

Growing evidence indicates that oral health and brain health are interconnected. Declining cognition and dementia coincide with lack of self‐preservation, including oral hygiene. The oral microbiota plays an important role in maintaining oral health. Emerging evidence suggests a link between oral dysbiosis and cognitive decline in patients with Alzheimer's disease. This review showcases the recent advances connecting oral health and cognitive function during aging and the potential utility of oral‐derived biospecimens to inform on brain health. Collectively, experimental findings indicate that the connection between oral health and cognition cannot be underestimated; moreover, oral biospecimens are abundant and readily obtainable without invasive procedures, which may help inform on cognitive health.

show abstract

Tooth loss early in life suppresses neurogenesis and synaptophysin expression in the hippocampus and impairs learning in mice

Cited by 31 publications

References 48 publications

Tooth loss early in life induces hippocampal morphology remodeling in senescence-accelerated mouse prone 8 (SAMP8) mice

Tooth loss early in life induces hippocampal morphology remodeling in senescence-accelerated mouse prone 8 (SAMP8) mice

A 3-month mastication intervention improves recognition memory

Can oral health and oral‐derived biospecimens predict progression of dementia?

Contact Info

Product

Resources

About