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Suzuki T, Aoki K, Shimokobe K, Omiya S, Funayama C, Takahashi T, Kato M. Age-related morphological and functional changes in the small intestine of senescence-accelerated mouse. Exp Gerontol 2022; 163:111795. [DOI: 10.1016/j.exger.2022.111795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 11/04/2022]
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Improvement of Learning and Memory in Senescence-Accelerated Mice by S-Allylcysteine in Mature Garlic Extract. Nutrients 2020; 12:nu12061834. [PMID: 32575593 PMCID: PMC7353456 DOI: 10.3390/nu12061834] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/13/2020] [Accepted: 06/17/2020] [Indexed: 11/16/2022] Open
Abstract
S-allylcysteine (SAC), a major thioallyl compound contained in mature garlic extract (MGE), is known to be a neuroactive compound. This study was designed to investigate the effects of SAC on primary cultured hippocampal neurons and cognitively impaired senescence-accelerated mice prone 10 (SAMP10). Treatment of these neurons with MGE or SAC significantly increased the total neurite length and number of dendrites. SAMP10 mice fed MGE or SAC showed a significant improvement in memory dysfunction in pharmacological behavioral analyses. The decrease of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, N-methyl-d-aspartate (NMDA) receptor, and phosphorylated α-calcium/calmodulin-dependent protein kinase II (CaMKII) in the hippocampal tissue of SAMP10 mice fed MGE or SAC was significantly suppressed, especially in the MGE-fed group. These findings suggest that SAC positively contributes to learning and memory formation, having a beneficial effect on brain function. In addition, multiple components (aside from SAC) contained in MGE could be useful for improving cognitive function by acting as neurotrophic factors.
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Li M, Guo K, Adachi Y, Ikehara S. Immune Dysfunction Associated with Abnormal Bone Marrow-Derived Mesenchymal Stroma Cells in Senescence Accelerated Mice. Int J Mol Sci 2016; 17:ijms17020183. [PMID: 26840301 PMCID: PMC4783917 DOI: 10.3390/ijms17020183] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/20/2016] [Accepted: 01/26/2016] [Indexed: 01/14/2023] Open
Abstract
Senescence accelerated mice (SAM) are a group of mice that show aging-related diseases, and SAM prone 10 (SAMP10) show spontaneous brain atrophy and defects in learning and memory. Our previous report showed that the thymus and the percentage of T lymphocytes are abnormal in the SAMP10, but it was unclear whether the bone marrow-derived mesenchymal stroma cells (BMMSCs) were abnormal, and whether they played an important role in regenerative medicine. We thus compared BMMSCs from SAMP10 and their control, SAM-resistant (SAMR1), in terms of cell cycle, oxidative stress, and the expression of PI3K and mitogen-activated protein kinase (MAPK). Our cell cycle analysis showed that cell cycle arrest occurred in the G0/G1 phase in the SAMP10. We also found increased reactive oxygen stress and decreased PI3K and MAPK on the BMMSCs. These results suggested the BMMSCs were abnormal in SAMP10, and that this might be related to the immune system dysfunction in these mice.
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Affiliation(s)
- Ming Li
- Department of Stem Cell Disorders, Kansai Medical University, Hirakata City, Osaka 573-1010, Japan.
| | - Kequan Guo
- Department of Cardiac Surgery, Beijing Institute of Heart, Lung and Blood Vessel Disease, Beijing Anzhen Hospital Affiliated to Capital Medical University, Beijing 100029, China.
| | - Yasushi Adachi
- Department of Stem Cell Disorders, Kansai Medical University, Hirakata City, Osaka 573-1010, Japan.
- Division of Surgical Pathology, Toyooka Hospital, Hyogo 668-8501, Japan.
| | - Susumu Ikehara
- Department of Stem Cell Disorders, Kansai Medical University, Hirakata City, Osaka 573-1010, Japan.
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Ito K. Frontiers of model animals for neuroscience: two prosperous aging model animals for promoting neuroscience research. Exp Anim 2014; 62:275-80. [PMID: 24172191 PMCID: PMC4160957 DOI: 10.1538/expanim.62.275] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A model animal showing spontaneous onset is a useful tool for investigating the mechanism
of disease. Here, I would like to introduce two aging model animals expected to be useful
for neuroscience research: the senescence-accelerated mouse (SAM) and the klotho mouse.
The SAM was developed as a mouse showing a senescence-related phenotype such as a short
lifespan or rapid advancement of senescence. In particular, SAMP8 and SAMP10 show
age-related impairment of learning and memory. SAMP8 has spontaneous spongy degeneration
in the brain stem and spinal cord with aging, and immunohistochemical studies reveal
excess protein expression of amyloid precursor protein and amyloid β in the brain,
indicating that SAMP8 is a model for Alzheimer’s disease. SAMP10 also shows age-related
impairment of learning and memory, but it does not seem to correspond to Alzheimer’s
disease because senile plaques primarily composed of amyloid β or neurofibrillary tangles
primarily composed of phosphorylated tau were not observed. However, severe atrophy in the
frontal cortex, entorhinal cortex, amygdala, and nucleus accumbens can be seen in this
strain in an age-dependent manner, indicating that SAMP10 is a model for normal aging. The
klotho mouse shows a phenotype, regulated by only one gene named α-klotho, similar to
human progeria. The α-klotho gene is mainly expressed in the kidney and brain, and
oxidative stress is involved in the deterioration of cognitive function of the klotho
mouse. These animal models are potentially useful for neuroscience research now and in the
near future.
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Affiliation(s)
- Koichi Ito
- Department of Comparative Pathophysiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Depression-like behavior is dependent on age in male SAMP8 mice. Biogerontology 2013; 14:165-76. [PMID: 23559311 DOI: 10.1007/s10522-013-9420-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Accepted: 03/23/2013] [Indexed: 12/29/2022]
Abstract
Aging is associated with an increased risk of depression in humans. To elucidate the underlying mechanisms of depression and its dependence on aging, here we study signs of depression in male SAMP8 mice. For this purpose, we used the forced swimming test (FST). The total floating time in the FST was greater in SAMP8 than in SAMR1 mice at 9 months of age; however, this difference was not observed in 12-month-old mice, when both strains are considered elderly. Of the two strains, only the SAMP8 animals responded to imipramine treatment. We also applied the dexamethasone suppression test (DST) and studied changes in the dopamine and serotonin (5-HT) uptake systems, the 5-HT2a/2c receptor density in the cortex, and levels of TPH2. The DST showed a significant difference between SAMR1 and SAMP8 mice at old age. SAMP8 exhibits an increase in 5-HT transporter density, with slight changes in 5-HT2a/2c receptor density. In conclusion, SAMP8 mice presented depression-like behavior that is dependent on senescence process, because it differs from SAMR1, senescence resistant strain.
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Miyajima M, Numata T, Minoshima M, Tanaka M, Nishimura R, Hosokawa T, Kurasaki M, Saito T. Deficiency of catecholamine syntheses caused by downregulation of phosphorylation of tyrosine hydroxylase in the cerebral cortex of the senescence-accelerated mouse prone 10 strain with aging. Arch Gerontol Geriatr 2012; 56:68-74. [PMID: 22738763 DOI: 10.1016/j.archger.2012.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 05/30/2012] [Accepted: 05/31/2012] [Indexed: 10/28/2022]
Abstract
The purpose of this study was to elucidate the alteration of catecholamine metabolism and the contribution of catecholamines to the decline of learning and memory in the brain of the senescence-accelerated mouse prone 10 (SAMP10) with aging. Catecholamines and their metabolites in the cerebral cortex were measured by HPLC-ECD. The protein levels of tyrosine hydroxylase (TH) as well as TH phosphorylated at Ser19 or Ser40, dopamine-β-hydroxylase (DβH), and cAMP-dependent protein kinase (PKA) were determined by western blot analysis. Dopamine (DA) and norepinephrine (NE) levels in SAMP10 were significantly lower than those in control animals. However, no significant difference was observed in catecholamine metabolite levels between SAMP10 and control mice. The level of TH phosphorylation at Ser40 in SAMP10 was significantly lower than that in control mice, but no significant difference was observed in the levels of TH, TH phosphorylated at Ser19, or DβH. The amount of PKA, which regulates the phosphorylation of TH at Ser40, was significantly lower in SAMP10 than in control mice. The present study demonstrated that a decline in DA and NE concentrations was observed in the cerebral cortex of SAMP10 with aging, and this decrease of catecholamine levels was caused by impairment of their synthetic pathway. These impairments are considered to be caused by downregulation of TH phosphorylation at Ser40 as a result of PKA deficiency. The present study suggests that the decline of learning and memory abilities of SAMP10 is caused by a decrease in catecholamine synthesis in the cerebral cortex with aging.
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Affiliation(s)
- Miki Miyajima
- Graduate School of Health Sciences, Hokkaido University, Sapporo 060-0812, Japan
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Zhao C, Xie Z, Wang P, Wang Y, Lai C, Zhu Z, Liu Z, Cong Y, Zhao Y, Zheng C, Bi J. Granulocyte-colony stimulating factor protects memory impairment in the senescence-accelerated mouse (SAM)-P10. Neurol Res 2012; 33:354-9. [PMID: 21535933 DOI: 10.1179/016164110x12807570509970] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Alzheimer's disease (AD) is a progressive neurodegenerative disorder with memory impairment in elderly people. At present, AD remains incurable. More and more evidences have suggested that granulocyte-colony stimulating factor (G-CSF) has important non-hematopoietic neuroprotective functions in central nervous system. The present study was designed to investigate the therapeutic potential of G-CSF in the senescence-accelerated mouse prone strain (SAM-P10) mice, a mouse model of senile dementia. METHODS Recombinant human G-CSF was administered subcutaneously in SAM-P10 mice once daily for consecutive 7 days. Morris water maze test was used to evaluate spatial memory of the mice. Immunohistochemistry analysis was done to elucidate the changes of apoptotic neurons in CA1 region of hippocampus of the mice. RESULTS In the present study, we found that administration of recombinant G-CSF significantly protected spatial memory impairment, and decreased the number of apoptotic (caspase-3-positive) and tumor necrosis factor related apoptosis-inducing ligand (TRAIL)-positive neurons in CA1 region of hippocampus of SAM-P10 mice, suggesting that G-CSF may protect spatial memory impairment through suppression of TRAIL-mediated apoptosis in neurons. CONCLUSIONS These findings highlight the therapeutic potential of G-CSF in AD.
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Affiliation(s)
- Cuiping Zhao
- Department of Neurology, The Second Hospital of Shandong University, Jinan, China.
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Takeda T. Senescence-accelerated mouse (SAM) with special references to neurodegeneration models, SAMP8 and SAMP10 mice. Neurochem Res 2009; 34:639-59. [PMID: 19199030 DOI: 10.1007/s11064-009-9922-y] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2008] [Indexed: 12/16/2022]
Abstract
The SAM strains, a group of related inbred strains consisting of senescence-prone inbred strains (SAMP) and senescence-resistant inbred strains (SAMR), have been successfully developed by selective inbreeding of the AKR/J strain of mice donated by the Jackson laboratory in 1968. The characteristic feature of aging common to the SAMP and SAMR is accelerated senescence and normal aging, respectively. Furthermore, SAMP and SAMR strains of mice manifest various pathobiological phenotypes spontaneously. Among SAMP strains, SAMP8 and SAMP10 mice show age-related behavioral deterioration such as deficits in learning and memory, emotional disorders (reduced anxiety-like behavior and depressive behavior) and altered circadian rhythm associated with certain pathological, biochemical and pharmacological changes. Here, the previous and recent literature on SAM mice are reviewed with an emphasis on SAMP8 and SAMP10 mice. A spontaneous model like SAM with distinct advantages over the gene-modified model is hoped by investigators to be used more widely as a biogerontological resource to explore the etiopathogenesis of accelerated senescence and neurodegenerative disorders.
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Affiliation(s)
- Toshio Takeda
- The Council for SAM Research, 24 Nishi-ohtake-cho Mibu, Nakagyo-ku, Kyoto, 604-8856, Japan.
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Niimi K, Takahashi E, Itakura C. Improved short-term memory and increased expression of NR2B observed in senescence-accelerated mouse (SAM) P6. Exp Gerontol 2008; 43:847-52. [PMID: 18647646 DOI: 10.1016/j.exger.2008.06.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 06/23/2008] [Accepted: 06/26/2008] [Indexed: 10/21/2022]
Abstract
The increased dopamine and serotonin were suggested [Niimi et al., 2008. Emotional behavior and expression pattern of tyrosine hydroxylase and tryptophan hydroxylase in senescence-accelerated mouse (SAM) P6 mice. Behav. Brain Res. 188, 329-336], and as these monoamines are well known to influence working memory processes, SAMP6 may show improved working memory. We found that spatial Y-maze memory and non-spatial novel object recognition memory of SAMP6 were improved compared with those of senescence-accelerated mouse resistant 1 (SAMR1). Among molecules known to be related with memory processes other than dopamine and serotonin, we focused on N-methyl-D-aspartate (NMDA) receptors. Animals treated with (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), a NMDA receptor antagonist, were subjected to the Y-maze and novel object recognition tests to examine whether NMDA receptors are associated with the improved short-term memory of SAMP6. CPP (10 mg/kg) significantly impaired the spontaneous alternation behavior and the exploratory preference of SAMR1, whereas no significant effect was seen in SAMP6 in either of these behavioral tests. Western blot analyses revealed increased expression of NMDA receptor (NR) subunit 2B in forebrain of SAMP6 compared with SAMR1, while there was no difference in the levels of NR1 and NR2A between SAMR1 and SAMP6. Our results indicate that increased expression of NR2B in forebrain of SAMP6 is one of the causes of the improved short-term memory of SAMP6.
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Affiliation(s)
- Kimie Niimi
- Brain Science and Life Technology Research Foundation, 1-28-12 Narimasu, Itabashi, Tokyo 175-0094, Japan
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Disterhoft JF, Oh MM. Learning, aging and intrinsic neuronal plasticity. Trends Neurosci 2006; 29:587-99. [PMID: 16942805 DOI: 10.1016/j.tins.2006.08.005] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 06/14/2006] [Accepted: 08/17/2006] [Indexed: 11/28/2022]
Abstract
In vitro experiments indicate that intrinsic neuronal excitability, as evidenced by changes in the post-burst afterhyperpolarization (AHP) and spike-frequency accommodation, is altered during learning and normal aging in the brain. Here we review these studies, highlighting two consistent findings: (i) that AHP and accommodation are reduced in pyramidal neurons from animals that have learned a task; and (ii) that AHP and accommodation are enhanced in pyramidal neurons from aging subjects, a cellular change that might contribute to age-related learning impairments. Findings from in vivo single-neuron recording studies complement the in vitro data. From these consistently reproduced findings, we propose that the intrinsic AHP level might determine the degree of synaptic plasticity and learning. Furthermore, it seems that reductions in the AHP must occur before learning if young and aging subjects are to learn a task successfully.
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Affiliation(s)
- John F Disterhoft
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611-3008, USA.
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Shimada A, Tsuzuki M, Keino H, Satoh M, Chiba Y, Saitoh Y, Hosokawa M. Apical vulnerability to dendritic retraction in prefrontal neurones of ageing SAMP10 mouse: a model of cerebral degeneration. Neuropathol Appl Neurobiol 2006; 32:1-14. [PMID: 16409548 DOI: 10.1111/j.1365-2990.2006.00632.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The SAMP10 mouse is a model of accelerated ageing in which senescence is characterized by age-related atrophy of the cerebral cortex and limbic structures, poor learning and memory task performance with depressive behaviour and cholinergic and dopaminergic alterations. Here we studied age-related changes in the dendritic arbors and spine density of pyramidal cells in the medial prefrontal cortex of SAMP10 mice using a quantitative Golgi method. Dendrites of prefrontal neurones gradually retracted with ageing towards the soma with the relative preservation of overall complexity. Apical dendrites were much more severely affected than basal dendrites. The combined length of the apical dendrites and spine density were decreased by 45% and 55%, respectively, in mice at 12 months, compared with mice at 3 months of age. Immunohistochemical and immunoblot analyses indicated that expression of microtubule-associated protein (MAP) 2, a marker of dendrites, decreased in an age-related manner not only in the anterior cortex but also in the posterior cortex and olfactory structures in SAMP10 mice. Decreased expression of MAP2 mRNA caused the decrease in MAP2 protein expression. These results suggest that retraction of apical, but not of basal dendrites, with a loss of spines in prefrontal neurones, appears to be responsible for poor learning and memory performance in aged SAMP10 mice. It is also suggested that age-related dendritic retraction occurs in a wide area including the entire cerebral cortex and olfactory structures.
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Affiliation(s)
- A Shimada
- Department of Pathology, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi 480-0392, Japan.
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Phan VL, Miyamoto Y, Nabeshima T, Maurice T. Age-related expression of ?1 receptors and antidepressant efficacy of a selective agonist in the senescence-accelerated (SAM) mouse. J Neurosci Res 2005; 79:561-72. [PMID: 15635598 DOI: 10.1002/jnr.20390] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The sigma1 receptor is a unique intracellular receptor whose activation results in an efficient modulation of several neurotransmitter responses. Its role as a target for the rapid nongenomic effects of neuro(active)steroids and the age-related diminutions in steroid levels suggested that targeting the sigma1 receptor might allow alleviation of age-related neuronal dysfunctions. We examined here the expression and behavioral efficacy of sigma1 receptors in the senescence-accelerated (SAM) mouse model. The sigma1 receptor mRNA expression was measured by using comparative RT-PCR in the olfactory bulb, hippocampus, hypothalamus, cortex, or cerebellum of senescence-prone SAMP/8 and senescence-resistant SAMR/1 control animals. No difference was observed between substrains in 6-, 9-, and 12-month-old (m.o.) mice. The sigma1 protein expression was analyzed by using immunohistochemical techniques. Labeling was intense in the olfactory bulb, hippocampus, hypothalamus, and midbrain of both SAMR/1 and SAMP/8 mice, and the distribution appeared unchanged in 6-, 9-, and 12-m.o. animals. The receptor's in vivo availability was examined by using in vivo [3H](+)-SKF-10,047 binding. No age-related difference was observed in the olfactory bulb, hippocampus, hypothalamus, cortex, cerebellum, and brainstem of 6- or 12-m.o. SAMR/1 or SAMP/8 mice. The antidepressant efficacy of the selective agonist igmesine was examined in the forced-swimming test. The compound decreased significantly the immobility duration at 60 mg/kg in 6- and 12-m.o. SAMR/1 and in 6-m.o. SAMP/8 mice. In 12-m.o. SAMP/8 mice, the drug efficacy was facilitated; a significant effect was measured at 30 mg/kg. Decreased neurosteroid levels, particularly of progesterone, were seen in 12-m.o. SAMP/8 mice that might explain the enhanced efficacy of igmesine. Preserved sigma1 receptor expression and enhanced behavioral efficacy of sigma1 agonists were measured in SAM animals, confirming the therapeutic opportunities for selective ligands against age-related mood disorders.
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Affiliation(s)
- Vân-Ly Phan
- INSERM U. 336, Behavioral Neuropharmacology Group, Montpellier, France
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Unno K, Takabayashi F, Kishido T, Oku N. Suppressive effect of green tea catechins on morphologic and functional regression of the brain in aged mice with accelerated senescence (SAMP10). Exp Gerontol 2004; 39:1027-34. [PMID: 15236762 DOI: 10.1016/j.exger.2004.03.033] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2004] [Revised: 03/15/2004] [Accepted: 03/17/2004] [Indexed: 11/16/2022]
Abstract
Green tea catechins (GT-catechins) have been reported to have an antioxidative effect. We investigated the effect of long-term GT-catechin intake on aging and oxidative damage using aged mice with accelerated senescence (SAMP10), a model of brain senescence with cerebral atrophy and cognitive dysfunction. Major atrophy was observed in the rhinencephalon, hippocampus and striatum of 12-month-old untreated SAMP10 mice. Similarly, levels of 8-oxodeoxyguanosine (8-oxodG), a marker of oxidative DNA damage, were higher in these parts of the cerebrum than in the cerebral cortex and liver. GT-catechin intake effectively suppressed such atrophy in 12-month-old SAMP10 mice. A preventive effect of GT-catechin intake on oxidative DNA damage was also observed in the rhinencephalon (an area particularly susceptible to atrophy) at 6 months of age, i.e. during the early stages of atrophy. A suppressive effect of GT-catechin intake on cognitive dysfunction, as determined by the learning time needed to acquire an avoidance response and assessments of working memory in a Y-maze, was also found in 12-month-old mice. These results suggest that GT-catechin intake partially improves the morphologic and functional alterations that occur naturally in the brains of aged SAMP10 mice.
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Affiliation(s)
- Keiko Unno
- Department of Medical Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, 422-8526, Japan.
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Christian B, McConnaughey K, Bethea E, Brantley S, Coffey A, Hammond L, Harrell S, Metcalf K, Muehlenbein D, Spruill W, Brinson L, McConnaughey M. Chronic aspartame affects T-maze performance, brain cholinergic receptors and Na+,K+-ATPase in rats. Pharmacol Biochem Behav 2004; 78:121-7. [PMID: 15159141 DOI: 10.1016/j.pbb.2004.02.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 02/24/2004] [Accepted: 02/28/2004] [Indexed: 12/01/2022]
Abstract
This study demonstrated that chronic aspartame consumption in rats can lead to altered T-maze performance and increased muscarinic cholinergic receptor densities in certain brain regions. Control and treated rats were trained in a T-maze to a particular side and then periodically tested to see how well they retained the learned response. Rats that had received aspartame (250 mg/kg/day) in the drinking water for 3 or 4 months showed a significant increase in time to reach the reward in the T-maze, suggesting a possible effect on memory due to the artificial sweetener. Using [(3)H]quinuclidinyl benzilate (QNB) (1 nM) to label muscarinic cholinergic receptors and atropine (10(-6) M) to determine nonspecific binding in whole-brain preparations, aspartame-treated rats showed a 31% increase in receptor numbers when compared to controls. In aspartame-treated rats, there was a significant increase in muscarinic receptor densities in the frontal cortex, midcortex, posterior cortex, hippocampus, hypothalamus and cerebellum of 80%, 60%, 61%, 65%, 66% and 60%, respectively. The midbrain was the only area where preparations from aspartame-treated rats showed a significant increase in Na(+),K(+)-ATPase activity. It can be concluded from these data that long-term consumption of aspartame can affect T-maze performance in rats and alter receptor densities or enzymes in brain.
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Affiliation(s)
- Brandon Christian
- Department of Pharmacology, Brody School of Medicine, East Carolina University, Greenville, NC 27858, USA
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