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Effects of a Multi-Ingredient Energy Supplement on Cognitive Performance and Cerebral-Cortical Activation.
Daou, M, Sassi, JM, Miller, MW, Gonzalez, AM
Journal of dietary supplements. 2019;(2):129-140
Abstract
This study assessed whether a multi-ingredient energy supplement (MIES) could enhance cerebral-cortical activation and cognitive performance during an attention-switching task. Cerebral-cortical activation was recorded in 24 young adults (12 males, 12 females; 22.8 ± 3.8 yrs) via electroencephalography (EEG) both at rest and during the attention-switching task before (pretest) and 30 min after (posttest) consumption of a single serving of a MIES (MIES-1), two servings of a MIES (MIES-2), or a placebo (PL) in a double-blinded, randomized crossover experimental design. EEG upper-alpha power was assessed at rest and during the task, wherein d' (Z[hit rate]-Z[false alarm rate]) and median reaction time (RT) for correct responses to targets on attention-hold and attention-switch trials were analyzed. For both d' and RT, the Session (MIES-1, MIES-2, PL) × Time (pretest, posttest) interaction approached statistical significance (p = .07, η2p = 0.106). Exploring these interactions with linear contrasts, a significant linear effect of supplement dose on the linear effect of time was observed (ps ≤.034), suggesting the pretest-to-posttest improvement in sensitivity to task target stimuli (d') and RT increased as a function of supplement dose. With respect to upper-alpha power, the Session × Time interaction was significant (p < .001, η2p = 0.422). Exploring this interaction with linear contrasts, a significant linear effect of supplement dose on the linear effect of time was observed (p < .001), suggesting pretest-to-posttest increases in cerebral-cortical activation were a function of supplement dose. In conclusion, our findings suggest that MIES can increase cerebral-cortical activation and RT during task performance while increasing sensitivity to target stimuli in a dose-dependent manner.
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Brain volumes and cortical thickness on MRI in the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER).
Stephen, R, Liu, Y, Ngandu, T, Antikainen, R, Hulkkonen, J, Koikkalainen, J, Kemppainen, N, Lötjönen, J, Levälahti, E, Parkkola, R, et al
Alzheimer's research & therapy. 2019;(1):53
Abstract
BACKGROUND The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) was a multicenter randomized controlled trial that reported beneficial effects on cognition for a 2-year multimodal intervention (diet, exercise, cognitive training, vascular risk monitoring) versus control (general health advice). This study reports exploratory analyses of brain MRI measures. METHODS FINGER targeted 1260 older individuals from the general Finnish population. Participants were 60-77 years old, at increased risk for dementia but without dementia/substantial cognitive impairment. Brain MRI scans were available for 132 participants (68 intervention, 64 control) at baseline and 112 participants (59 intervention, 53 control) at 2 years. MRI measures included regional brain volumes, cortical thickness, and white matter lesion (WML) volume. Cognition was assessed at baseline and 1- and 2-year visits using a comprehensive neuropsychological test battery. We investigated the (1) differences between the intervention and control groups in change in MRI outcomes (FreeSurfer 5.3) and (2) post hoc sub-group analyses of intervention effects on cognition in participants with more versus less pronounced structural brain changes at baseline (mixed-effects regression models, Stata 12). RESULTS No significant differences between the intervention and control groups were found on the changes in MRI measures. Beneficial intervention effects on processing speed were more pronounced in individuals with higher baseline cortical thickness in Alzheimer's disease signature areas (composite measure of entorhinal, inferior and middle temporal, and fusiform regions). The randomization group × time × cortical thickness interaction coefficient was 0.198 (p = 0.021). A similar trend was observed for higher hippocampal volume (group × time × hippocampus volume interaction coefficient 0.1149, p = 0.085). CONCLUSIONS The FINGER MRI exploratory sub-study did not show significant differences between the intervention and control groups on changes in regional brain volumes, regional cortical thicknesses, or WML volume after 2 years in at-risk elderly without substantial impairment. The cognitive benefits on processing speed of the FINGER intervention may be more pronounced in individuals with fewer structural brain changes on MRI at baseline. This suggests that preventive strategies may be more effective if started early, before the occurrence of more pronounced structural brain changes. TRIAL REGISTRATION ClinicalTrials.gov, NCT01041989 . Registered January 5, 2010.
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Caffeine affects children's ERPs and performance in an equiprobable go/no-go task: Testing a processing schema.
Barry, RJ, De Blasio, FM, Fogarty, JS
Psychophysiology. 2019;(5):e13330
Abstract
Caffeine's stimulant properties were used to test a proposed processing schema for children's processing stages in the equiprobable auditory go/no-go task. Active control-related ERP components were hypothesized to be differentially enhanced by caffeine. Caffeine (80 mg) was administered in a counterbalanced, randomized, double-blind, placebo-controlled, cross-over study of 24 children, aged 8-12 years. Four blocks of an equiprobable auditory go/no-go task were completed on each of two occasions, while on or off caffeine. ERP data sets from each condition (caffeine/go, placebo/go, caffeine/no-go, placebo/no-go) were subjected to separate temporal PCAs with extraction and varimax rotation of all components. Caffeine significantly reduced reaction time and go omission errors, and enhanced go PN, N2c, and P3b, and no-go N1-1 and N2b. This selective enhancement of different go/no-go components by caffeine matched the predicted amplification of biomarkers of children's active control processing in this task. Some unexpected findings also support further refinements in the child processing schema.
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Commentary: Fatty acids and Alzheimer's disease: evidence on cognition and cortical β-amyloid from secondary analyses of the Multidomain Alzheimer Preventive Trial.
Hooper, C, Vellas, B
The journal of prevention of Alzheimer's disease. 2018;(3):168-170
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Effects of acute resistance training modality on corticospinal excitability, intra-cortical and neuromuscular responses.
Latella, C, Teo, WP, Harris, D, Major, B, VanderWesthuizen, D, Hendy, AM
European journal of applied physiology. 2017;(11):2211-2224
Abstract
OBJECTIVE Although neural adaptations from strength training are known to occur, the acute responses associated with heavy-strength (HST) and hypertrophy training (HYT) remain unclear. Therefore, we aimed to compare the acute behaviour of corticospinal responses following a single session of HST vs HYT over a 72-h period. METHODS Fourteen participants completed a random counterbalanced, crossover study that consisted of a single HST session [5 sets × 3 repetition maximum (RM)], a HYT session (3 sets × 12 RM) of the leg extensors and a control session (CON). Single- and paired-pulse transcranial magnetic stimulation (TMS) was used to measure changes in motor-evoked potential (MEP) amplitude, corticospinal silent period (CSP), intra-cortical facilitation (ICF), short-interval intra-cortical inhibition (SICI) and long-interval intra-cortical inhibition (LICI). Additionally, maximal muscle compound wave (M MAX) of the rectus femoris (RF) and maximal voluntary isometric contraction (MVIC) of the leg extensors were taken. All measures were taken at baseline, immediately post and 2, 6, 24, 48 and 72 h post-training. RESULTS A significant condition x time interaction was observed for MVIC (P = 0.001), M MAX (P = 0.003), MEP amplitude (P < 0.001) and CSP (P = 0.002). No differences were observed between HST and HYT for all neurophysiological measures. No changes in SICI, ICF and LICI were observed compared to baseline. CONCLUSION Our results suggest that: (1) the acute behaviour of neurophysiological measures is similar between HST and HYT; and (2) the increase in corticospinal excitability may be a compensatory response to attenuate peripheral fatigue.
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Dynamic susceptibility contrast MRI measures of relative cerebral blood volume as a prognostic marker for overall survival in recurrent glioblastoma: results from the ACRIN 6677/RTOG 0625 multicenter trial.
Schmainda, KM, Zhang, Z, Prah, M, Snyder, BS, Gilbert, MR, Sorensen, AG, Barboriak, DP, Boxerman, JL
Neuro-oncology. 2015;(8):1148-56
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Abstract
BACKGROUND The study goal was to determine whether changes in relative cerebral blood volume (rCBV) derived from dynamic susceptibility contrast (DSC) MRI are predictive of overall survival (OS) in patients with recurrent glioblastoma multiforme (GBM) when measured 2, 8, and 16 weeks after treatment initiation. METHODS Patients with recurrent GBM (37/123) enrolled in ACRIN 6677/RTOG 0625, a multicenter, randomized, phase II trial of bevacizumab with irinotecan or temozolomide, consented to DSC-MRI plus conventional MRI, 21 with DSC-MRI at baseline and at least 1 postbaseline scan. Contrast-enhancing regions of interest were determined semi-automatically using pre- and postcontrast T1-weighted images. Mean tumor rCBV normalized to white matter (nRCBV) and standardized rCBV (sRCBV) were determined for these regions of interest. The OS rates for patients with positive versus negative changes from baseline in nRCBV and sRCBV were compared using Wilcoxon rank-sum and Kaplan-Meier survival estimates with log-rank tests. RESULTS Patients surviving at least 1 year (OS-1) had significantly larger decreases in nRCBV at week 2 (P = .0451) and sRCBV at week 16 (P = .014). Receiver operating characteristic analysis found the percent changes of nRCBV and sRCBV at week 2 and sRCBV at week 16, but not rCBV data at week 8, to be good prognostic markers for OS-1. Patients with positive change from baseline rCBV had significantly shorter OS than those with negative change at both week 2 and week 16 (P = .0015 and P = .0067 for nRCBV and P = .0251 and P = .0004 for sRCBV, respectively). CONCLUSIONS Early decreases in rCBV are predictive of improved survival in patients with recurrent GBM treated with bevacizumab.
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[Correlative study of the metabolic disorder of hippocampus and cerebral cortex and cognitive impairment in moderate to severe OSAHS patients].
Wang, B, Xu, X, Liang, G, Zhang, Y, Liu, L, Zhang, J
Lin chuang er bi yan hou tou jing wai ke za zhi = Journal of clinical otorhinolaryngology, head, and neck surgery. 2015;(7):607-11
Abstract
OBJECTIVE To research the serum levels of BDNF, H2S and S-100β as metabolic product of hippocampus and cerebral cortex in moderate to severe obstructive sleep apnea hypopnea syndrome(OSAHS) patients before and after surgery, and to analyze their correlations with cognitive impairment. METHOD Forty-four randomly selected diagnosed OSAHS patients were divided into two groups according to Montreal Cognitive Assessment (MoCA), 19 cases in cognitively normal group and 25 cases in cognitive dysfunction group. Cases in cognitive dysfunction group underwent UPPP oriented surgery, and received 6 months follow-up, 21 cases were remained as treament group, 4 cases lost. 19 cases of healthy subjects were randomly selected as the normal control group. All groups were detected for the serum BDNF, H2S and S-100β levels to analyze the correlations between the biochemical indexes and sleep disorders indexes, hypoxia levels and cognitive function scores. RESULT (1) In the comparison between the treatment group and the normal control group regarding PSG monitoring results, the AHI, I + II, LA/HT and SLT90% indexes of OSAHS patients increased, and the III + IV phase, REM phase, MSaO2 and LSaO2 decreased. In the comparison between the cognitive dysfunction group and the cognitively normal group, the III + IV, REM and LSaO2 indexes of the cognitive dysfunction group decreased. (2) In the comparison between cognitive dysfunction group and cognitively normal group, and between the treatment group and the normal control group, BDNF and H2S levels increased and S-100β levels decreased, and the MoCA total scores, attention, memory/delayed recall scores decreased. (3) The correlation between biochemical indexes with PSG indexes was as follows. The serum BNDF and H2S levels were negatively correlated with AHI index. The serum BNDF and H2S levels were positively correlated with III + IV stage, REM stage and MSaO2 indexes. The S-100β level was positively correlated with AHI index, and S-100β levels were negatively correlated with III + IV stage, REM stage, MSaO2 and LSaO2 indexes. (4) The correlation between biochemical indexes and MoCA scores was as follows. The serum BNDF and H2S levels were positively correlated with MoCA total scores, attention, and memory/delayed recall scores. The serum S-100β levels were negatively correlated with MoCA total scores, attention and memory/ delayed recall scores. (5) The linear regression equation between MoCA total scores in cognitive dysfunction group of OSAHS patients and the serum BNDF, H2S and S-100β levels was as follows: Y(MoCA) = 40.131 + 0.22 X(BDNF) + 0.012 X(H2S)-0.647X(S-100β) (R2 = 0.461). CONCLUSION OSAHS patients with sleep disorder and nocturnal hypoxemia might suffer from cognitive dysfunction in which attention and memory predominates. Serum BNDF, H2S and S-100β levels, which could indirectly reflect the metabolic abnormalities degree of hippocampus and cerebral cortex, are sensitive indicators of early cognitive dysfunction in OSAHS patients.
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Dietary nitrate modulates cerebral blood flow parameters and cognitive performance in humans: A double-blind, placebo-controlled, crossover investigation.
Wightman, EL, Haskell-Ramsay, CF, Thompson, KG, Blackwell, JR, Winyard, PG, Forster, J, Jones, AM, Kennedy, DO
Physiology & behavior. 2015;:149-58
Abstract
Nitrate derived from vegetables is consumed as part of a normal diet and is reduced endogenously via nitrite to nitric oxide. It has been shown to improve endothelial function, reduce blood pressure and the oxygen cost of sub-maximal exercise, and increase regional perfusion in the brain. The current study assessed the effects of dietary nitrate on cognitive performance and prefrontal cortex cerebral blood-flow (CBF) parameters in healthy adults. In this randomised, double-blind, placebo-controlled, parallel-groups study, 40 healthy adults received either placebo or 450 ml beetroot juice (~5.5 mmol nitrate). Following a 90 minute drink/absorption period, participants performed a selection of cognitive tasks that activate the frontal cortex for 54 min. Near-Infrared Spectroscopy (NIRS) was used to monitor CBF and hemodynamics, as indexed by concentration changes in oxygenated and deoxygenated-haemoglobin, in the frontal cortex throughout. The bioconversion of nitrate to nitrite was confirmed in plasma by ozone-based chemi-luminescence. Dietary nitrate modulated the hemodynamic response to task performance, with an initial increase in CBF at the start of the task period, followed by consistent reductions during the least demanding of the three tasks utilised. Cognitive performance was improved on the serial 3s subtraction task. These results show that single doses of dietary nitrate can modulate the CBF response to task performance and potentially improve cognitive performance, and suggest one possible mechanism by which vegetable consumption may have beneficial effects on brain function.
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Anodal Transcranial Direct Current Stimulation Prolongs the Cross-education of Strength and Corticomotor Plasticity.
Hendy, AM, Teo, WP, Kidgell, DJ
Medicine and science in sports and exercise. 2015;(9):1788-97
Abstract
PURPOSE This study aimed to assess the efficacy of applying anodal transcranial direct-current stimulation (a-tDCS) to the ipsilateral motor cortex (iM1) during unilateral strength training to enhance the neurophysiological and functional effects of cross-education. METHODS Twenty-four healthy volunteers were randomly allocated to perform either of the following: strength training during a-tDCS (ST + a-tDCS), strength training during sham tDCS (ST + sham), or a-tDCS during rest (a-tDCS) across 2 wk. Strength training of the right biceps brachii involved four sets of six repetitions at 80% of one-repetition maximum three times per week. Anodal tDCS was applied to the iM1 at 1.5 mA for 15 min during each strength training session. Outcome measures included one-repetition maximum strength of the untrained biceps brachii, corticomotoneuronal excitability, cross-activation, and short-interval intracortical inhibition (SICI) of the iM1 determined by transcranial magnetic stimulation. RESULTS Immediately after the final training session, there was an increase in strength for both the ST + a-tDCS (12.5%, P < 0.001) and the ST + sham group (9.4%, P = 0.007), which was accompanied by significant increases in corticomotoneuronal excitability and decreases in SICI for both groups. After a 48-h retention period, strength increase was maintained in the ST + a-tDCS (13.0%, P = 0.001) group, which was significantly greater than the ST + sham group (7.6%, P = 0.039). Similarly, increases in corticomotoneuronal excitability and decreases in SICI were maintained in the ST + a-tDCS group but not in the ST + sham group. No main effects were reported for the a-tDCS group (all P > 0.05). CONCLUSIONS The addition of a-tDCS to the iM1 during unilateral strength training prolongs the benefits of cross-education, which may have significant implications to enhancement of rehabilitation outcomes after a single-limb injury or impairment.
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Triptan-induced disruption of trigemino-cortical connectivity.
Kröger, IL, May, A
Neurology. 2015;(21):2124-31
Abstract
OBJECTIVE The 5-HT1B/D agonists (triptans) are specific headache medications that have no effect on pain as such. Although they are routinely used in the treatment of acute migraine attacks, the underlying mechanisms of action are still a matter of debate. METHODS Forty-three healthy participants underwent fMRI while receiving trigemino-nociceptive stimulation and control stimuli in a standardized fMRI paradigm. Using a crossover, double-blind, placebo-controlled design, 21 participants (10 women, mean age 26.9, range 20-37 years) received sumatriptan and 22 participants (11 women, mean age 25.5, range 22-32 years) received acetylsalicylic acid (ASA). Administration of medication and saline was randomized between participants of each group resulting in half of the participants receiving saline and the other half receiving the respective medication during the first fMRI data acquisition. RESULTS While mean pain intensity ratings did not differ significantly between control and medication nor between medications, we found a significant blood oxygen level-dependent signal increase in the trigeminal nuclei and the thalamus after sumatriptan treatment compared with placebo or ASA. In addition, we specifically looked for the pharmacologic modulation of functional coupling between trigeminal nuclei and higher brain areas, i.e., trigemino-cortical pathways, and found a strong coupling during the saline condition, which was altered by sumatriptan but not after ASA administration. CONCLUSION These data suggest that a specific functional inhibition of trigemino-cortical projections is one of the reasons that triptans, unlike pain killers, act highly specifically on headache and migraine but not pain as such.