Displaying publications 81 - 100 of 275 in total

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  1. Chronic cerebral hypoperfusion-induced memory impairment and hippocampal long-term potentiation deficits are improved by cholinergic stimulation in rats
    Damodaran T, Müller CP, Hassan Z
    Pharmacol Rep, 2019 Jun;71(3):443-448.
    PMID: 31003155 DOI: 10.1016/j.pharep.2019.01.012
    BACKGROUND: Chronic cerebral hypoperfusion (CCH) can induce the accumulation of reactive oxygen species, which leads to oxidative damage, neuronal injury, and central cholinergic dysfunction in vulnerable regions of the brain, such as the hippocampus and cerebral cortex. These effects can lead to significant cognitive impairments in clinical populations of vascular dementia (VaD). The present studies aimed to investigate the role of the cholinergic system in memory functions and hippocampal long-term potentiation (LTP) impairments induced by CCH in rats.

    METHODS: Male Sprague Dawley rats were subjected to permanent bilateral occlusion of common carotid arteries (PBOCCA) or sham surgery. Then, PBOCCA rats received ip injections with, either vehicle (control group), the muscarinic receptor agonist oxotremorine (0.1 mg/kg), or the acetylcholinesterase inhibitor physostigmine (0.1 mg/kg). Cognitive functions were evaluated using a passive avoidance task and the Morris water maze test. In addition, hippocampal LTP was recorded in vivo under anaesthesia.

    RESULTS: The PBOCCA rats exhibited significant deficits in passive avoidance retention and spatial learning and memory tests. They also showed a suppression of LTP formation in the hippocampus. Oxotremorine and physostigmine significantly improved the learning and memory deficits as well as the suppression of LTP in PBOCCA rats.

    CONCLUSIONS: The present data suggest that the cholinergic system plays an important role in CCH-induced cognitive deficits and could be an effective therapeutic target for the treatment of VaD.

    Matched MeSH terms: Memory/drug effects*; Memory Disorders/drug therapy*; Memory Disorders/etiology
  2. Fulltext Enhanced memory in Wistar rats by virgin coconut oil is associated with increased antioxidative, cholinergic activities and reduced oxidative stress
    Rahim NS, Lim SM, Mani V, Abdul Majeed AB, Ramasamy K
    Pharm Biol, 2017 Dec;55(1):825-832.
    PMID: 28118770 DOI: 10.1080/13880209.2017.1280688
    CONTEXT: Virgin coconut oil (VCO) has been reported to possess antioxidative, anti-inflammatory and anti-stress properties.

    OBJECTIVE: Capitalizing on these therapeutic effects, this study investigated for the first time the potential of VCO on memory improvement in vivo.

    MATERIALS AND METHODS: Thirty male Wistar rats (7-8 weeks old) were randomly assigned to five groups (n = six per group). Treatment groups were administered with 1, 5 and 10 g/kg VCO for 31 days by oral gavages. The cognitive function of treated-rats were assessed using the Morris Water Maze Test. Brains were removed, homogenized and subjected to biochemical analyses of acetylcholine (ACh) and acetylcholinesterase (AChE), antioxidants [superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx) and glutathione reductase (GRx)], lipid peroxidase [malondialdehyde (MDA)] as well as nitric oxide (NO). α-Tocopherol (αT; 150 mg/kg) was also included for comparison purposes.

    RESULTS: VCO-fed Wistar rats exhibited significant (p  33%) and NO (≥ 34%). Overall, memory improvement by VCO was comparable to αT.

    DISCUSSION AND CONCLUSION: VCO has the potential to be used as a memory enhancer, the effect of which was mediated, at least in part, through enhanced cholinergic activity, increased antioxidants level and reduced oxidative stress.

    Matched MeSH terms: Memory/drug effects*
  3. Fulltext Standardised extracts of Moringa Oleifera and Centella Asiatica enhanced the antioxidant activity, learning and memory effects by inhibiting acetylcholinesterase activity in D-galactose induced ageing rats
    Hisyam Jamari, Mohd Salleh Rofiee, Richard James Johari, Mohd Zaki Salleh, Teh, Lay Kek
    Pertanika Journal of Science & Technology, 2020;28(1):293-310.
    MyJurnal
    The potential of Moringa oleifera Lam. (Moringaceae) and Centella asiatica (L.) Urban (Apiaceae) extracts (TGT-PRIMAAGE) in slowing the decline of memory and learning activity was investigated using D-galactose-induced ageing rat model. The extracts were profiled and standardised based on markers identified using LC/MS-QTOF. Toxicity study of the extract was done, and the rat did not show any sign of toxicity. The extract was orally administered to the rat and dose dependent (100, 500 and 1000 mg/kg) efficacy were investigated. The rats were subjected to Morris Water Maze whereby 3 parameters were studied (number of entry to platform, latency and novel object recognition). Plasma was collected for the determination of catalase (CAT) activity and levels of malondialdehyde (MDA) and advanced glycation end products (AGEs). The activity of acetylcholinesterase (AChE), level of acetylcholine (ACh) and lipid peroxidation (LPO) were measured using the brain lysates. Significant improvement (p < 0.05) was seen in the memory and learning abilities in the aged rats that received medium and high dose of TGT-PRIMAAGE, and tocotrienol. Rats treated with TGT-PRIMAAGE had also shown improved CAT activity and resulted in reduced LPO. The level of ACh was found increased in parallel with the reduced AChE activity. The capabilities of learning and memory of the TGT-PRIMAAGE treated rats were enhanced via inhibition of AChE activity and subsequently increased level of ACh.
    Matched MeSH terms: Memory
  4. Fulltext Diagonal preconditioned conjugate gradient algorithm for unconstrained optimization
    Choong Boon Ng, Wah June Leong, Mansor Monsi
    Pertanika Journal of Science & Technology, 2014;22(1):213-224.
    MyJurnal
    The nonlinear conjugate gradient (CG) methods have widely been used in solving unconstrained optimization problems. They are well-suited for large-scale optimization problems due to their low memory requirements and least computational costs. In this paper, a new diagonal preconditioned conjugate gradient (PRECG) algorithm is designed, and this is motivated by the fact that a pre-conditioner can greatly enhance the performance of the CG method. Under mild conditions, it is shown that the algorithm is globally convergent for strongly convex functions. Numerical results are presented to show that the new diagonal PRECG method works better than the standard CG method.
    Matched MeSH terms: Memory
  5. Aggregated effects of combining daily milk consumption and aerobic exercise on short-term memory and sustained attention among female students
    Leong IT, Moghadam S, Hashim HA
    Percept Mot Skills, 2015 Feb;120(1):57-66.
    PMID: 25621523 DOI: 10.2466/22.06.PMS.120v11x3
    Regular aerobic exercise and milk consumption have been found to have positive effects on certain cognitive functions such as short-term memory and sustained attention. However, aggregated effects of combining these modalities have not been explored. This study examined the combined effects of milk supplementation and aerobic exercise on the short-term memory and sustained attention of female students aged 16 yr. (N = 81). The intervention involved serving of 250 ml of regular milk during school days and/or a 1-hr. aerobic exercise period twice per week for 6 weeks. The Digit Span Test and Digit Vigilance Test were used to measure short-term memory and sustained attention, respectively. The combination group (milk and exercise) and exercise group performed significantly better than did the milk and control groups in terms of short-term memory. No significant interaction or group differences were found for sustained attention. The results suggest benefits of regular exercise for students' short-term memory.
    Matched MeSH terms: Memory, Short-Term/physiology*
  6. Associations between self-reported and objective face recognition abilities are only evident in above- and below-average recognisers
    Estudillo AJ, Wong HK
    PeerJ, 2021;9:e10629.
    PMID: 33510971 DOI: 10.7717/peerj.10629
    The 20-Item Prosopagnosia Items (PI-20) was recently introduced as a self-report measure of face recognition abilities and as an instrument to help the diagnosis of prosopagnosia. In general, studies using this questionnaire have shown that observers have moderate to strong insights into their face recognition abilities. However, it remains unknown whether these insights are equivalent for the whole range of face recognition abilities. The present study investigates this issue using the Mandarin version of the PI-20 and the Cambridge Face Memory Test Chinese (CFMT-Chinese). Our results showed a moderate negative association between the PI-20 and the CFMT-Chinese. However, this association was driven by people with low and high face recognition ability, but absent in people within the typical range of face recognition performance. The implications of these results for the study of individual differences and the diagnosis of prosopagnosia are discussed.
    Matched MeSH terms: Memory
  7. Fulltext Edible Bird's Nest Prevents Menopause-Related Memory and Cognitive Decline in Rats via Increased Hippocampal Sirtuin-1 Expression
    Hou Z, He P, Imam MU, Qi J, Tang S, Song C, et al.
    Oxid Med Cell Longev, 2017;2017:7205082.
    PMID: 29104731 DOI: 10.1155/2017/7205082
    Menopause causes cognitive and memory dysfunction due to impaired neuronal plasticity in the hippocampus. Sirtuin-1 (SIRT1) downregulation in the hippocampus is implicated in the underlying molecular mechanism. Edible bird's nest (EBN) is traditionally used to improve general wellbeing, and in this study, we evaluated its effects on SIRT1 expression in the hippocampus and implications on ovariectomy-induced memory and cognitive decline in rats. Ovariectomized female Sprague-Dawley rats were fed with normal pellet alone or normal pellet + EBN (6, 3, or 1.5%), compared with estrogen therapy (0.2 mg/kg/day). After 12 weeks of intervention, Morris water maze (four-day trial and one probe trial) was conducted, and serum estrogen levels, toxicity markers (alanine transaminase, alkaline phosphatase, urea, and creatinine), and hippocampal SIRT1 immunohistochemistry were estimated after sacrifice. The results indicated that EBN and estrogen enhanced spatial learning and memory and increased serum estrogen and hippocampal SIRT1 expression. In addition, the EBN groups did not show as much toxicity to the liver as the estrogen group. The data suggested that EBN treatment for 12 weeks could improve cognition and memory in ovariectomized female rats and may be an effective alternative to estrogen therapy for menopause-induced aging-related memory loss.
    Matched MeSH terms: Memory Disorders/metabolism; Memory Disorders/prevention & control*
  8. Non-polyphenolic compounds of a specific kind of dried grape (Maviz) inhibit memory impairments induced by beta-amyloid peptide
    Bakhtiyari E, Ahmadian-Attari MM, Salehi P, Khallaghi B, Dargahi L, Mohamed Z, et al.
    Nutr Neurosci, 2017 Oct;20(8):469-477.
    PMID: 27219682 DOI: 10.1080/1028415X.2016.1183986
    OBJECTIVES: Although grape has been recently the topic of many investigations, Maviz (a kind of dried one) has remained neglected. The aim of this study was to assess anti-Alzheimer activity of Maviz.

    METHODS: To reach this goal, total phenolic content (TPC) of ethanolic (Eth) and aqueous (Aq) extracts were determined and radical scavenging activity was assayed by 2,2-diphenyl-1-picrylhydrazyl. Chemical compositions of each extract were also determined via GC-Mass. Behavioral changes were studied via passive avoidance and Morris water maze in Aβ-induced model of Alzheimer's disease. Catalase (CAT) and superoxide dismutase (SOD) determination were also done on rats' hippocampus.

    RESULTS: The results showed that seed Eth extract has a high level of TPC and radical scavenging activity. However, this extract had surprisingly no effect on memory and CAT and SOD activities. In contrast, fruit Aq and Eth extracts (containing furfurals as major compounds) inhibited memory impairment (P 

    Matched MeSH terms: Memory/drug effects
  9. The effects of polyphenols-rich tropical fruit juice on cognitive function and metabolomics profile - a randomized controlled trial in middle-aged women
    Rosli H, Shahar S, Rajab NF, Che Din N, Haron H
    Nutr Neurosci, 2021 Mar 05.
    PMID: 33666540 DOI: 10.1080/1028415X.2021.1880312
    Objectives: Polyphenols, particularly anthocyanins, have received attention in improving health issues during old age, including decline in cognitive function and other health parameters. We aimed to determine the effects of polyphenols-rich tropical fruit TP 3-in-1™ juice towards improving cognitive function, oxidative stress and metabolomics profiles among middle-aged women.Methods: This clinical trial involved 31 subjects with signs of poor cognitive function, as assessed using the Rey Auditory Verbal Learning Test (RAVLT). They were randomized to receive either TP 3-in-1™ juice (n = 16) or placebo (n = 15). Study subjects consumed 500 ml of beverages for three times per day, three days per week, for a period of ten weeks. Juice supplementation provided 9135 mg GAE of total phenolic content and 194.1 mg cyanidin-3-glucoside of total anthocyanin monomer.Results: There was a significant interaction effects on RAVLT immediate recall (p 
    Matched MeSH terms: Memory, Short-Term
  10. Fulltext A pilot placebo-controlled, double-blind, and randomized study on the cognition-enhancing benefits of a proprietary chicken meat ingredient in healthy subjects
    Azhar ZM, Zubaidah JO, Norjan KO, Zhuang CY, Tsang F
    Nutr J, 2013;12:121.
    PMID: 23945213 DOI: 10.1186/1475-2891-12-121
    It has long been postulated that the relative abundance of specific nutrients can affect cognitive processes and emotions. Newly described influences of dietary factors on neuronal function and synaptic plasticity have revealed some of the vital mechanisms that could be responsible for the action of diet on brain health and cognitive function. Here, through a double-blind, randomized, placebo-controlled trial, we asked if the newly discovered chicken meat ingredient-168 (CMI-168) could be beneficial to the cognitive function in healthy adults.
    Matched MeSH terms: Memory, Short-Term
  11. Fulltext Chicken Essence for Cognitive Function Improvement: A Systematic Review and Meta-Analysis
    Teoh SL, Sudfangsai S, Lumbiganon P, Laopaiboon M, Lai NM, Chaiyakunapruk N
    Nutrients, 2016 Jan;8(1).
    PMID: 26805876 DOI: 10.3390/nu8010057
    Chicken essence (CE) is a popular traditional remedy in Asia, which is believed to improve cognitive functions. CE company claimed that the health benefits were proven with research studies. A systematic review was conducted to determine the cognitive-enhancing effects of CE. We systematically searched a number of databases for randomized controlled trials with human subjects consuming CE and cognitive tests involved. Cochrane's Risk of Bias (ROB) tool was used to assess the quality of trials and meta-analysis was performed. Seven trials were included, where six healthy subjects and one subject with poorer cognitive functions were recruited. One trial had unclear ROB while the rest had high ROB. For executive function tests, there was a significant difference favoring CE (pooled standardized mean difference (SMD) of -0.55 (-1.04, -0.06)) and another with no significant difference (pooled SMD of 0.70 (-0.001, 1.40)). For short-term memory tests, no significant difference was found (pooled SMD of 0.63 (-0.16, 1.42)). Currently, there is a lack of convincing evidence to show a cognitive enhancing effect of CE.
    Matched MeSH terms: Memory, Short-Term
  12. Fulltext A Review on the Relationship between Tocotrienol and Alzheimer Disease
    Chin KY, Tay SS
    Nutrients, 2018 Jul 09;10(7).
    PMID: 29987193 DOI: 10.3390/nu10070881
    Alzheimer’s disease (AD) is plaguing the aging population worldwide due to its tremendous health care and socioeconomic burden. Current treatment of AD only offers symptomatic relief to patients. Development of agents targeting specific pathologies of AD is very slow. Tocotrienol, a member of the vitamin E family, can tackle many aspects of AD, such as oxidative stress, mitochondrial dysfunction and abnormal cholesterol synthesis. This review summarizes the current evidence on the role of tocotrienol as a neuroprotective agent. Preclinical studies showed that tocotrienol could reduce oxidative stress by acting as a free-radical scavenger and promoter of mitochondrial function and cellular repair. It also prevented glutamate-induced neurotoxicity in the cells. Human epidemiological studies showed a significant inverse relationship between tocotrienol levels and the occurrence of AD. However, there is no clinical trial to support the claim that tocotrienol can delay or prevent the onset of AD. As a conclusion, tocotrienol has the potential to be developed as an AD-preventing agent but further studies are required to validate its efficacy in humans.
    Matched MeSH terms: Memory/drug effects
  13. Fulltext Tualang honey improves memory performance and decreases depressive-like behavior in rats exposed to loud noise stress
    Azman KF, Zakaria R, AbdAziz C, Othman Z, Al-Rahbi B
    Noise Health, 2015 Mar-Apr;17(75):83-9.
    PMID: 25774610 DOI: 10.4103/1463-1741.153388
    Recent evidence has exhibited dietary influence on the manifestation of different types of behavior induced by stressor tasks. The present study examined the effects of Tualang honey supplement administered with the goal of preventing or attenuating the occurrence of stress-related behaviors in male rats subjected to noise stress. Forty-eight adult male rats were randomly divided into the following four groups: i) nonstressed with vehicle, ii) nonstressed with Tualang honey, iii) stressed with vehicle, and iv) stressed with honey. The supplement was given once daily via oral gavage at 0.2 g/kg body weight. Two types of behavioral tests were performed, namely, the novel object recognition test to evaluate working memory and the forced swimming test to evaluate depressive-like behavior. Data were analyzed by a two-way analysis of variance (ANOVA) using IBM SPSS 18.0. It was observed that the rats subjected to noise stress expressed higher levels of depressive-like behavior and lower memory functions compared to the unexposed control rats. In addition, our results indicated that the supplementation regimen successfully counteracted the effects of noise stress. The forced swimming test indicated that climbing and swimming times were significantly increased and immobility times significantly decreased in honey-supplemented rats, thereby demonstrating an antidepressant-like effect. Furthermore, cognitive function was shown to be intensely affected by noise stress, but the effects were counteracted by the honey supplement. These findings suggest that subchronic exposure to noise stress induces depressive-like behavior and reduces cognitive functions, and that these effects can be attenuated by Tualang honey supplementation. This warrants further studies to examine the role of Tulang honey in mediating such effects.
    Matched MeSH terms: Memory; Memory, Short-Term*
  14. Fulltext Delta-9-Tetrahydrocannabinol (∆9-THC) Induce Neurogenesis and Improve Cognitive Performances of Male Sprague Dawley Rats
    Suliman NA, Taib CNM, Moklas MAM, Basir R
    Neurotox Res, 2018 02;33(2):402-411.
    PMID: 28933048 DOI: 10.1007/s12640-017-9806-x
    Neurogenesis is influenced by various external factors such as enriched environments. Some researchers had postulated that neurogenesis has contributed to the hippocampal learning and memory. This project was designed to observe the effect of Delta-9-tetrahydrocannabinol (∆9-THC) in cognitive performance that influenced by the neurogenesis. Different doses of ∆9-THC were used for observing the neurogenesis mechanism occurs in the hippocampus of rats. The brains were stained with antibodies, namely BrdU, glial fibrillary acidic protein (GFAP), nestin, doublecortin (DCX) and class III β-tubulin (TuJ-1). The cognitive test was used novel-object discrimination test (NOD) while the proteins involved, DCX and brain-derived neurotrophic factor (BDNF), were measured. Throughout this study, ∆9-THC enhanced the markers involved in all stages of neurogenesis mechanism. Simultaneously, the cognitive behaviour of rat also showed improvement in learning and memory functions observed in behavioural test and molecular perspective. Administration of ∆9-THC was observed to enhance the neurogenesis in the brain, especially in hippocampus thus improved the cognitive function of rats.
    Matched MeSH terms: Memory/drug effects*
  15. Human memory retention and recall processes. A review of EEG and fMRI studies
    Amin H, Malik AS
    Neurosciences (Riyadh), 2013 Oct;18(4):330-44.
    PMID: 24141456
    Human memory is an important concept in cognitive psychology and neuroscience. Our brain is actively engaged in functions of learning and memorization. Generally, human memory has been classified into 2 groups: short-term/working memory, and long-term memory. Using different memory paradigms and brain mapping techniques, psychologists and neuroscientists have identified 3 memory processes: encoding, retention, and recall. These processes have been studied using EEG and functional MRI (fMRI) in cognitive and neuroscience research. This study reviews previous research reported for human memory processes, particularly brain behavior in memory retention and recall processes with the use of EEG and fMRI. We discuss issues and challenges related to memory research with EEG and fMRI techniques.
    Matched MeSH terms: Memory/physiology*
  16. Fulltext The treatment of epileptic seizures: the potential of Malaysian medicinal plants
    Choo, Brandon Kar Meng, Kumari, Yatinesh, Mun, Hue-Seow, Shaikh, Mohd. Farooq
    Neuroscience Research Notes, 2018;1(3):35-53.
    MyJurnal
    Epileptic seizures result from excessive brain activity and may affect sensory, motor and autonomic function; as well as, emotional state, memory, cognition or behaviour. Effective anti-epileptic drugs (AEDs) are available but have tolerability issues due to their side effects. Medicinal plants are potential candidates for novel AEDs, as many are traditional epilepsy remedies. Malaysia is a megadiverse country, with many endemic plants serving as a large pool of potential candidates for the development of local herbal products. The large variety of flora makesMalaysia a prime location for the discovery of medicinal plants with anti-convulsive potential. This review lists 23 Malaysian medicinal plants, of which four are used traditionally to treat epilepsy, without any scientific evidence. A further eight plants have no known traditional anti-epileptic usebut have scientific evidence of its anti-epileptic activity. The remaining 11 plants possess both traditional use and scientific evidence. Thus, this review identified several potential candidates for the development of novel AEDs or enhancing current ones; as well as identified an imbalance between traditional use and scientific evidence. In addition, this review also identified several limitations in the reviewed studies and provided additional information to facilitate the design of future studies.
    Matched MeSH terms: Memory
  17. Fulltext Cognitive impairment and memory dysfunction after a stroke diagnosis: a post-stroke memory assessment
    Al-Qazzaz NK, Ali SH, Ahmad SA, Islam S, Mohamad K
    Neuropsychiatr Dis Treat, 2014;10:1677-91.
    PMID: 25228808 DOI: 10.2147/NDT.S67184
    Cognitive impairment and memory dysfunction following stroke diagnosis are common symptoms that significantly affect the survivors' quality of life. Stroke patients have a high potential to develop dementia within the first year of stroke onset. Currently, efforts are being exerted to assess stroke effects on the brain, particularly in the early stages. Numerous neuropsychological assessments are being used to evaluate and differentiate cognitive impairment and dementia following stroke. This article focuses on the role of available neuropsychological assessments in detection of dementia and memory loss after stroke. This review starts with stroke types and risk factors associated with dementia development, followed by a brief description of stroke diagnosis criteria and the effects of stroke on the brain that lead to cognitive impairment and end with memory loss. This review aims to combine available neuropsychological assessments to develop a post-stroke memory assessment (PSMA) scheme based on the most recognized and available studies. The proposed PSMA is expected to assess different types of memory functionalities that are related to different parts of the brain according to stroke location. An optimal therapeutic program that would help stroke patients enjoy additional years with higher quality of life is presented.
    Matched MeSH terms: Memory; Memory Disorders
  18. Views on Memory and Treatment of Cognitive Impairment in 17th-Century Spain: Juan Gutiérrez de Godoy's Work
    Palma JA, Palma F
    Neurology, 2022 Sep 05;99(10):424-427.
    PMID: 35794022 DOI: 10.1212/WNL.0000000000201025
    Memory and its care were significant sociocultural and scientific topics in early modern Spain. Although a major interest in memory was related to its legal and rhetorical implications, medical treatises discussing memory, cognitive impairment, and its treatment began to appear in the 16th and 17th century. Among these treatises, Disputationes phylosophicæ ac medicæ super libros Aristotelis de memoria, et reminiscentia (Philosophical and medical arguments on Aristotle's "De memoria et reminiscentia"), published in 1629 by the physician Juan Gutiérrez de Godoy, is unique in that it is entirely devoted to the medical aspects of memory. Although many of its concepts are now superseded, the treatise is valuable to understand the views on memory and cognitive impairment in 17th-century Spain and their sources, as Gutiérrez quoted many classical, medieval, and contemporary scholars and physicians. The book, written in Latin, is exclusively devoted to memory from a physiologic and medical point of view, with chapters on the classification of memory loss, a description of its causes (including old age, something not widely recognized before), and several chapters on its prevention and treatment, with a fascinating emphasis on confectio anacardina, or anacardium, an intranasal concoction made with the "marking nut," the fruit of the Semecarpus anacardium tree (also known as Malacca bean), with alleged memory-enhancing properties. We review Gutiérrez's Disputationes phylosophicæ, putting it into the wider intellectual and social context in the Europe of its time, and discuss the relevance and purported neuropharmacologic effects of anacardina.
    Matched MeSH terms: Memory Disorders/therapy
  19. The eyes of the past: larger pupil size for autobiographical memories retrieved from field perspective
    El Haj M, Janssen SMJ, Lenoble Q, Robin F, Gallouj K
    Neurol Sci, 2022 Jan;43(1):661-666.
    PMID: 33959825 DOI: 10.1007/s10072-021-05297-w
    BACKGROUND: Visual perspective during memory retrieval has mainly been evaluated with methodologies based on introspection and subjective reports. The current study investigates whether visual perspective can be evaluated with a physiological measurement: pupil dilation.

    METHODS: While their pupil diameter was measured with an eye-tracker, forty-five participants retrieved one memory from a field perspective (i.e., as viewed through our own eyes) and one memory from an observer perspective (i.e., as viewed from a spectator's standpoint). After retrieval, participants rated the emotional intensity of the memories.

    RESULTS: Analysis demonstrated larger pupils during the retrieval of memories from a field perspective and higher emotional intensity for memories retrieved from a field perspective.

    DISCUSSION: The larger pupils for memories recalled from a field perspective could, however, not be attributed to their higher emotional intensity. These findings suggest that pupil dilation could be used as a physiological assessment of visual perspective during memory retrieval.

    Matched MeSH terms: Memory, Episodic*
  20. Fulltext Immunological history governs human stem cell memory CD4 heterogeneity via the Wnt signaling pathway
    Kared H, Tan SW, Lau MC, Chevrier M, Tan C, How W, et al.
    Nat Commun, 2020 02 10;11(1):821.
    PMID: 32041953 DOI: 10.1038/s41467-020-14442-6
    The diversity of the naïve T cell repertoire drives the replenishment potential and capacity of memory T cells to respond to immune challenges. Attrition of the immune system is associated with an increased prevalence of pathologies in aged individuals, but whether stem cell memory T lymphocytes (TSCM) contribute to such attrition is still unclear. Using single cells RNA sequencing and high-dimensional flow cytometry, we demonstrate that TSCM heterogeneity results from differential engagement of Wnt signaling. In humans, aging is associated with the coupled loss of Wnt/β-catenin signature in CD4 TSCM and systemic increase in the levels of Dickkopf-related protein 1, a natural inhibitor of the Wnt/β-catenin pathway. Functional assays support recent thymic emigrants as the precursors of CD4 TSCM. Our data thus hint that reversing TSCM defects by metabolic targeting of the Wnt/β-catenin pathway may be a viable approach to restore and preserve immune homeostasis in the context of immunological history.
    Matched MeSH terms: Immunologic Memory
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