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1.
Gut-brain axis: A matter of concern in neuropsychiatric disorders…!
Naveed, M, Zhou, QG, Xu, C, Taleb, A, Meng, F, Ahmed, B, Zhang, Y, Fukunaga, K, Han, F
Progress in neuro-psychopharmacology & biological psychiatry. 2021;:110051
Abstract
The gut microbiota is composed of a large number of microbes, usually regarded as commensal bacteria. It has become gradually clear that gastrointestinal microbiota affects gut pathophysiology and the central nervous system (CNS) function by modulating the signaling pathways of the microbiota-gut-brain (MGB) axis. This bidirectional MGB axis communication primarily acts through neuroendocrine, neuroimmune, and autonomic nervous systems (ANS) mechanisms. Accumulating evidence reveals that gut microbiota interacts with the host brain, and its modulation may play a critical role in the pathology of neuropsychiatric disorders. Recently, neuroscience research has established the significance of gut microbiota in the development of brain systems that are essential to stress-related behaviors, including depression and anxiety. Application of modulators of the MGB, such as psychobiotics (e.g., probiotics), prebiotics, and specific diets, may be a promising therapeutic approach for neuropsychiatric disorders. The present review article primarily focuses on the relevant features of the disturbances of the MGB axis in the pathophysiology of neuropsychiatric disorders and its potential mechanisms.
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2.
Sex-Specific Differences in Cognitive Abilities Associated with Childhood Cadmium and Manganese Exposures in School-Age Children: a Prospective Cohort Study.
Zhou, T, Guo, J, Zhang, J, Xiao, H, Qi, X, Wu, C, Chang, X, Zhang, Y, Liu, Q, Zhou, Z
Biological trace element research. 2020;(1):89-99
Abstract
To examine sex-specific associations of neonatal and childhood exposure to eight trace elements with cognitive abilities of school-age children. The association between exposure and effects was assessed among 296 school-age children from a population-based birth cohort study, who had manganese (Mn), cadmium (Cd), and lead (Pb) exposure measured in cord blood and chromium (Cr), manganese, cobalt (Co), copper (Cu), arsenic (As), selenium (Se), cadmium, and lead exposure quantified in spot urine. Cognitive abilities were assessed using the Wechsler Intelligence Scale for Children-Chinese Revised (WISC-CR). Generalized linear models were performed to analyze associations of intelligence quotient (IQ) with trace element concentrations in cord blood and urinary trace element levels. General linear models were used to evaluate association between exposure fluctuation and children's IQ. Urinary Cd concentrations were negatively associated with full-scale IQ (β = - 3.469, 95% confidence interval (CI) - 6.291, - 0.647; p = 0.016) and performance IQ (β = - 4.012, 95% CI - 7.088, - 0.936; p = 0.011) in girls; however, neonatal Cd exposure expressed as Cd concentrations in cord blood was in inverse associations with verbal IQ (β = - 2.590, 95% CI - 4.570, - 0.609; p = 0.010) only in boys. Positive association between urinary Mn concentrations and performance IQ (β = 1.305, 95% CI 0.035, 2.575; p = 0.044) of children was observed, especially in girls. In addition, inverse association of urinary Cu concentrations with verbal IQ (β = - 2.200, 95% CI - 4.360, - 0.039; p = 0.046) was only found in boys. Childhood Cd exposure may adversely affect cognitive abilities, while Mn exposure may beneficially modify cognitive abilities of school-age children, particularly in girls.
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3.
Effects of vitamin D supplementation on cognitive function and blood Aβ-related biomarkers in older adults with Alzheimer's disease: a randomised, double-blind, placebo-controlled trial.
Jia, J, Hu, J, Huo, X, Miao, R, Zhang, Y, Ma, F
Journal of neurology, neurosurgery, and psychiatry. 2019;(12):1347-1352
Abstract
OBJECTIVE Our study aimed to assess the effect of a 12-month vitamin D supplementation on cognitive function and amyloid beta (Aβ)-related biomarkers in subjects with Alzheimer's disease (AD). METHODS : This was a randomised, double-blind, placebo-controlled trial. 210 AD patients were randomly divided into intervention and control groups. Participants received 12-month 800 IU/day of vitamin D or starch granules as placebo. Tests of cognitive performance and Aβ-related biomarkers were measured at baseline, 6 months and 12 months. RESULTS : Repeated-measures analysis of variance showed significant improvements in plasma Aβ42, APP, BACE1, APPmRNA, BACE1mRNA (p<0.001) levels and information, arithmetic, digit span, vocabulary, block design and picture arrange scores (p<0.05) in the intervention group over the control group. According to mixed-model analysis, vitamin D group had significant increase in full scale IQ during follow-up period (p<0.001). CONCLUSIONS Daily oral vitamin D supplementation (800 IU/day) for 12 months may improve cognitive function and decrease Aβ-related biomarkers in elderly patients with AD. Larger scale longer term randomised trials of vitamin D are needed. TRIAL REGISTRATION NUMBER ChiCTR-IIR-16009549.
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4.
Can Slow-Wave Sleep Enhancement Improve Memory? A Review of Current Approaches and Cognitive Outcomes.
Zhang, Y, Gruber, R
The Yale journal of biology and medicine. 2019;(1):63-80
Abstract
Slow-wave sleep (SWS) is involved in the overnight consolidation of declarative memories. Recent efforts using auditory stimulation, slow-oscillatory transcranial direct current stimulation (so-tDCS), and pharmacological agents have targeted sleep slow-waves as a method for enhancing cognitive performance. However, no studies thus far have integrated current evidence to provide a preliminary review of the effects of SWS enhancement on memory and other cognitive outcomes. The objective of this review was to synthesize the results of recent experimental studies that have used auditory stimulation, electrical, and pharmacological methods to boost both SWS and cognitive performance. A systematic review was done to identify and consolidate all currently existing empirical studies in this area. We found that each stimulation method could enhance slow-wave power and/or SWS duration in human subjects. Closed-loop, in-phase auditory stimulation enhanced verbal declarative memory in healthy adults. Electrical stimulation using so-tDCS showed some efficacy in promoting verbal declarative memory, picture recognition memory, and location memory. Interleukin-6 and sodium oxybate enhanced declarative verbal memory, while tiagabine and sodium oxybate improved some non-memory measures of cognitive performance. There is some evidence that so-tDCS can also improve certain cognitive outcomes in clinical populations. Overall, future studies should recruit larger sample sizes drawn from more diverse populations, and determine clinical significance and effect sizes of each enhancement methodology.
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5.
Effects of 12-month, double-blind N-acetyl cysteine on symptoms, cognition and brain morphology in early phase schizophrenia spectrum disorders.
Breier, A, Liffick, E, Hummer, TA, Vohs, JL, Yang, Z, Mehdiyoun, NF, Visco, AC, Metzler, E, Zhang, Y, Francis, MM
Schizophrenia research. 2018;:395-402
Abstract
BACKGROUND Currently approved medications for schizophrenia are relatively ineffective for negative symptoms and cognitive impairment. N-Acetyl Cysteine (NAC) is a neuroprotective agent that improved general symptoms, cognitive impairment and negative symptoms in some but not all studies, but failed to improve positive symptoms in patients with schizophrenia. Progressive brain mass loss (PBML) has been consistently observed in early phase schizophrenia. NAC mitigates the deleterious effects oxidative stress, inflammation and glutamatergic excitotoxicity and these three pathological processes are hypothesized to contribute to PBML. METHODS In this study, we assessed the effects NAC (3600mg/day) in a 52-week, double-blind, placebo controlled trial on symptoms, and cognition in early phase schizophrenia spectrum disorders (N=60). In the context of the clinical trial, we explored the effects of NAC on brain morphology. RESULTS NAC significantly improved (time×group) PANSS total (F=14.7, p<0.001), negative (F=5.1, p=0.024) and disorganized thought (F=13.7, p<0.001) symptom scores. NAC failed to improve PANSS positive symptoms and BACS cognitive scores. In preliminary analyses, baseline right (r=-0.48, p=0.041) and left (r=-0.45, p=0.018) total cortical thickness, and thickness in other cortical regions, were associated with NAC related improvement in PANSS total scores, but NAC, as compared to placebo, did not significantly impact brain morphology over the study treatment period. CONCLUSIONS These results replicate some but not all previous findings of NAC efficacy. Preliminary results suggest that NAC's symptom effects may be related to structural integrity, but NAC failed to demonstrate treatment effects on longitudinal measures of brain morphology. ClinicalTrials.gov Identifier: NCT01339858.
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6.
Association of ideal cardiovascular health metrics and cognitive functioning: the APAC study.
Zhang, N, Yang, Y, Wang, A, Cao, Y, Li, J, Yang, Y, Zhang, K, Zhang, W, Wu, S, Wang, Z, et al
European journal of neurology. 2016;(9):1447-54
Abstract
BACKGROUND AND PURPOSE Previous studies have demonstrated that the components of ideal cardiovascular health (CVH) metrics are related to dementia. This study aimed to investigate the overall effects of ideal CVH metrics on cognitive functioning. METHODS Information was collected on the seven ideal CVH metrics (smoking, body mass index, dietary intake, physical activity, blood pressure, total cholesterol and fasting blood glucose) from the Asymptomatic Polyvascular Abnormalities Community study, and cognitive functioning was assessed by the score of the Mini-Mental State Examination (MMSE). Multivariate logistic regression and linear regression models were used to assess the relationships between ideal CVH metrics and cognitive functioning. RESULTS A total of 3260 (56.7% men) patients were included in this study. After adjusting for potential confounding factors, the associations between the number or score of ideal CVH metrics and cognitive impairment remained significant [odds ratio (OR) (95% confidence interval) 0.773 (0.664-0.928) and 0.904 (0.831-0.983), respectively]. In addition, there were significant linear relationships between the number or score of CVH metrics and the score of the MMSE (β = 0.211 and 0.134 respectively, P < 0.001). CONCLUSIONS A clear inverse association was observed between the number or score of ideal CVH metrics and cognitive impairment in a Chinese population, supporting the importance of ideal CVH metrics in prevention of dementia.
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7.
The effect of creatine and coenzyme q10 combination therapy on mild cognitive impairment in Parkinson's disease.
Li, Z, Wang, P, Yu, Z, Cong, Y, Sun, H, Zhang, J, Zhang, J, Sun, C, Zhang, Y, Ju, X
European neurology. 2015;(3-4):205-211
Abstract
BACKGROUND To investigate the effect of creatine and coenzyme Q10 (CoQ10) combination therapy on mild cognitive impairment (MCI) in Parkinson's disease (PD; PD-MCI) and its influences on plasma phospholipid (PL) levels in PD-MCI. METHODS The demographic data of 75 PD-MCI patients who enrolled in this collaborative PD study were collected. These patients were evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) III and the Montreal Cognitive Assessment (MoCA). These 75 PD-MCI patients were randomly treated with creatine monohydrate 5 g b.i.d. and CoQ10 100 mg t.i.d. orally or placebo. MoCA evaluation and PL level measurements were performed after 12 and 18 months of treatment. RESULTS After 12 and 18 months of treatment, the differences in the MoCA scores of the combination therapy and control groups were statistically significant (p < 0.05 at 12 months and p < 0.01 at 18 months), and the plasma PL levels of the combination therapy group were significantly lower than those of the control group (p < 0.01 at 12 months and p < 0.001 at 18 months). CONCLUSIONS Combination therapy with creatine and CoQ10 could delay the decline of cognitive function in PD-MCI patients and could lower their plasma PL levels; therefore, this combination therapy may have a neuroprotective function.
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8.
Effects of caffeine and menthol on cognition and mood during simulated firefighting in the heat.
Zhang, Y, Balilionis, G, Casaru, C, Geary, C, Schumacker, RE, Neggers, YH, Curtner-Smith, MD, Richardson, MT, Bishop, PA, Green, JM
Applied ergonomics. 2014;(3):510-4
Abstract
This study examined the separate effects of caffeine and menthol on cognition and mood during simulated firefighting in the heat. Participants (N = 10) performed three trials in a counterbalanced order, either with 400 mg caffeine, menthol lozenges, or placebo. The simulated firefighting consisted of 2 bouts of 20-min treadmill exercise and one bout of 20-min stepping exercise in the heat with two brief 15-min rest periods between each exercise phase. Exercise induced significant dehydration (>3%) and elevated rectal temperature (>38.9 °C), for all three conditions. Neither caffeine nor menthol reduced perceived exertion compared to placebo (p > 0.05). Mood ratings (i.e., alertness, hedonic tone, tension) significantly deteriorated over time (p < 0.05), but there was no difference among the three conditions. Simple reaction time, short-term memory, and retrieval memory did not alter with treatments or repeated evaluations. Reaction accuracy from a math test remained unchanged throughout the experimental period; reaction time from the math test was significantly faster after exposure to the heat (p < 0.05). It is concluded that, exhaustive exercise in the heat severely impacted mood, but minimally impacted cognition. These treatments failed to show ergogenic benefits in a simulated firefighting paradigm in a hot environment.