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1.
Int J Radiat Biol ; 97(3): 421-430, 2021.
Article En | MEDLINE | ID: mdl-33264581

PURPOSE: The effects of the electromagnetic (EM) radiation emitted by a mobile phone on the central auditory system of rabbits are investigated in this paper. Auditory brainstem response (ABR) measurements were performed before and after short-term exposure to EM radiation. MATERIALS AND METHODS: Excitation was provided by a GSM-1800 emitter placed in contact with the (randomly selected) ear of the anesthetized rabbit/subject. The latency of waves I, II, III, IV, V and the interpeak latencies I-III, I-V, III-V were recorded, for both ears, before (baseline recordings) and after 1, 15, 30, 45 and 60 minutes of exposure to the EM radiation. The repeated measures one-way analysis of variance (ANOVA) followed by the post hoc Tukey test for pairwise comparisons was performed in order to decide about the significance of the results. RESULTS: The statistical tests indicated that, as regards the ear ipsilateral to the radiating module, the mean latencies of waves I, II, III, IV, V, I-III, I-IV after 60 min exposure, the mean latencies of waves I, III, IV, V, I-III, I-IV after 45 min exposure and the mean latencies of waves I, III, IV, V, I-IV after 30 min exposure, were significantly prolonged compared to the corresponding baseline values. Statistically significant differences were also found for certain peak and interpeak latencies for 60 min exposure as compared with the corresponding results for 1 min and 15 min exposure. No statistically significant delay was observed for the latencies before and after the exposure, for the ear contralateral to the radiation source. CONCLUSIONS: Although we found that more than 30 min exposure to GSM-1800 radiation resulted in prolongation of certain ABR components of rabbits, further investigation may be needed into the potential adverse effects on the auditory pathways.


Electromagnetic Fields/adverse effects , Evoked Potentials, Auditory, Brain Stem/radiation effects , Animals , Rabbits , Reaction Time/radiation effects
2.
PLoS One ; 15(11): e0242941, 2020.
Article En | MEDLINE | ID: mdl-33253319

Word-production theories argue that during language production, a concept activates multiple lexical candidates in left temporal cortex, and the intended word is selected from this set. Evidence for theories on spoken-word production comes, for example, from the picture-word interference task, where participants name pictures superimposed by congruent (e.g., picture: rabbit, distractor "rabbit"), categorically related (e.g., distractor "sheep"), or unrelated (e.g., distractor "fork") words. Typically, whereas congruent distractors facilitate naming, related distractors slow down picture naming relative to unrelated distractors, resulting in semantic interference. However, the neural correlates of semantic interference are debated. Previous neuroimaging studies have shown that the left mid-to-posterior STG (pSTG) is involved in the interference associated with semantically related distractors. To probe the functional relevance of this area, we targeted the left pSTG with focal repetitive transcranial magnetic stimulation (rTMS) while subjects performed a picture-word interference task. Unexpectedly, pSTG stimulation did not affect the semantic interference effect but selectively increased the congruency effect (i.e., faster naming with congruent distractors). The facilitatory TMS effect selectively occurred in the more difficult list with an overall lower name agreement. Our study adds new evidence to the causal role of the left pSTG in the interaction between picture and distractor representations or processing streams, only partly supporting previous neuroimaging studies. Moreover, the observed unexpected condition-specific facilitatory rTMS effect argues for an interaction of the task- or stimulus-induced brain state with the modulatory TMS effect. These issues should be systematically addressed in future rTMS studies on language production.


Pattern Recognition, Visual/physiology , Temporal Lobe/radiation effects , Transcranial Magnetic Stimulation/methods , Wernicke Area/physiology , Adult , Animals , Attention/radiation effects , Female , Humans , Language , Pattern Recognition, Visual/radiation effects , Rabbits , Reaction Time/radiation effects , Speech/radiation effects , Wernicke Area/radiation effects
3.
J Safety Res ; 74: 169-177, 2020 09.
Article En | MEDLINE | ID: mdl-32951780

INTRODUCTION: Night work requires inversion of the natural, diurnal human activity-rest cycle and is associated with decreased alertness and some measures of performance, reduced safety, adverse health effects, and chronic disruption of the melatonin cycle that has been associated with increased risk for several major diseases. Previous studies show that red light exposures at night can promote alertness and improve performance while not negatively affecting melatonin secretion. METHOD: This ongoing crossover, mixed (within- and between-subjects) design field study is testing the efficacy and acceptance of red light delivered to day-shift and night-shift workers using personal light glasses while they are at work. Each participant experienced three lighting interventions at the eyes: red light (50 lx, 630 nm, the treatment intervention), blue light (50 lx, 460 nm, the positive control intervention), and dim white light (10 lx, 3,000 K, the placebo control). During the interventions, participants underwent visual performance testing, submitted salivary melatonin and cortisol samples, and provided subjective reports of sleepiness, sleep disturbance, and general health over the 20-week protocol. Due to the ongoing nature of the study, only the performance and subjective reports are presented here. RESULTS: Preliminary results indicate that response times were improved by the red and blue interventions, but not accuracy and hit rates. Blue light was associated with improvements to self-reported sleep disturbances compared to dim light. CONCLUSIONS: These field results partially support our laboratory results that showed a positive effect of red light for promoting alertness and certain performance outcomes during the day and at night. Practical Applications: Red light may be used to improve response times in shift workers. Continued research will elucidate the lighting interventions' effects on melatonin and objective sleep measures (actigraphy).


Attention , Health Personnel/statistics & numerical data , Light , Lighting/instrumentation , Shift Work Schedule , Adult , Female , Hospitals , Humans , Male , Middle Aged , Reaction Time/radiation effects , Safety , Wakefulness
4.
Sci Rep ; 9(1): 14371, 2019 10 07.
Article En | MEDLINE | ID: mdl-31591426

Prefrontal dysfunction is a common feature of brain diseases such as schizophrenia and contributes to deficits in executive functions, including working memory, attention, flexibility, inhibitory control, and timing of behaviors. Currently, few interventions improve prefrontal function. Here, we tested whether stimulating the axons of prefrontal neurons in the striatum could compensate for deficits in temporal processing related to prefrontal dysfunction. We used an interval-timing task that requires working memory for temporal rules and attention to the passage of time. Our previous work showed that inactivation of the medial frontal cortex (MFC) impairs interval timing and attenuates ramping activity, a key form of temporal processing in the dorsomedial striatum (DMS). We found that 20-Hz optogenetic stimulation of MFC axon terminals increased curvature of time-response histograms and improved interval-timing behavior. Furthermore, optogenetic stimulation of terminals modulated time-related ramping of medium spiny neurons in the striatum. These data suggest that corticostriatal stimulation can compensate for deficits caused by MFC inactivation and they imply that frontostriatal projections are sufficient for controlling responses in time.


Axons/physiology , Brain Diseases/physiopathology , Neurons/radiation effects , Schizophrenia/physiopathology , Action Potentials/physiology , Action Potentials/radiation effects , Animals , Axons/radiation effects , Corpus Striatum/physiopathology , Corpus Striatum/radiation effects , Disease Models, Animal , Electric Stimulation , Executive Function/radiation effects , Frontal Lobe/physiopathology , Frontal Lobe/radiation effects , Humans , Male , Memory, Short-Term/physiology , Memory, Short-Term/radiation effects , Neurons/pathology , Optogenetics/methods , Prefrontal Cortex/physiopathology , Prefrontal Cortex/radiation effects , Rats , Reaction Time/physiology , Reaction Time/radiation effects , Schizophrenia/diagnostic imaging
5.
Sci Rep ; 9(1): 15110, 2019 10 22.
Article En | MEDLINE | ID: mdl-31641196

In the visual system, retinal ganglion cells (RGCs) of various subtypes encode preprocessed photoreceptor signals into a spike output which is then transmitted towards the brain through parallel feature pathways. Spike timing determines how each feature signal contributes to the output of downstream neurons in visual brain centers, thereby influencing efficiency in visual perception. In this study, we demonstrate a marked population-wide variability in RGC response latency that is independent of trial-to-trial variability and recording approach. RGC response latencies to simple visual stimuli vary considerably in a heterogenous cell population but remain reliable when RGCs of a single subtype are compared. This subtype specificity, however, vanishes when the retinal circuitry is bypassed via direct RGC electrical stimulation. This suggests that latency is primarily determined by the signaling speed through retinal pathways that provide subtype specific inputs to RGCs. In addition, response latency is significantly altered when GABA inhibition or gap junction signaling is disturbed, which further supports the key role of retinal microcircuits in latency tuning. Finally, modulation of stimulus parameters affects individual RGC response delays considerably. Based on these findings, we hypothesize that retinal microcircuits fine-tune RGC response latency, which in turn determines the context-dependent weighing of each signal and its contribution to visual perception.


Reaction Time/physiology , Retina/physiology , Signal Transduction , Animals , Calcium Signaling/radiation effects , Gap Junctions/radiation effects , Light , Mice, Inbred C57BL , Neural Inhibition/radiation effects , Photic Stimulation , Reaction Time/radiation effects , Retina/radiation effects , Retinal Ganglion Cells/physiology , Retinal Ganglion Cells/radiation effects , Signal Transduction/radiation effects
6.
Article En | MEDLINE | ID: mdl-31547412

Human neuropsychological reactions and brain activities when driving electric vehicles (EVs) are considered as an issue for traffic and public safety purposes; this paper examined the effect of the static magnetic field (SMF) derived from EVs. A lane change task was adopted to evaluate the driving performance; and the driving reaction time test and the reaction time test were adopted to evaluate the variation of the neuro-psychological cognitive functions. Both the sham and the real exposure conditions were performed with a 350 µT localized SMF in this study; 17 student subjects were enrolled in this single-blind experiment. Electroencephalographs (EEGs) of the subjects were adopted and recorded during the experiment as an indicator of the brain activity for the variations of the driving performance and of the cognitive functions. Results of this study have indicated that the impact of the given SMF on both the human driving performance and the cognitive functions are not considerable; and that there is a correlation between beta sub-band of the EEGs and the human reaction time in the analysis.


Automobile Driving/statistics & numerical data , Automobiles/classification , Cognition/radiation effects , Magnetic Fields/adverse effects , Reaction Time/radiation effects , Female , Hong Kong , Humans , Male , Single-Blind Method , Young Adult
7.
Radiat Prot Dosimetry ; 187(3): 279-285, 2019 Dec 31.
Article En | MEDLINE | ID: mdl-31251356

This study investigated the effect of short-term exposure to Wi-Fi signals on the cognitive functions of the mind. After obtaining permission from the local Ethics Committee of Shiraz University of Medical Sciences and approval by the Iranian Registry of Clinical Trials (IRCT2017041233398N1), 45 male and female students from Shiraz University of Medical Sciences volunteered to participate in this study. They were exposed to Wi-Fi signals in two sham and exposure sessions, each for 2 hours. After completion, they took part in reaction time, short-term memory, and reasoning ability tests. After scoring, the data were analysed by SPSS software. In addition, the electric field strength and power density were calculated. The results showed no statistically significant differences between the mean scores of reaction time, short-term memory, and reasoning ability in sham and exposure. Also, the obtained values from the electric field strength and power density (E = 4.1 Vm-1, P = 0.446 Wm-2) were lower than that of threshold values by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Our results can greatly reduce concerns regarding the effects of short-term exposure to Wi-Fi waves on cognitive functions.


Cognition/radiation effects , Electromagnetic Fields/adverse effects , Memory, Short-Term/radiation effects , Radio Waves/adverse effects , Reaction Time/radiation effects , Students/psychology , Wireless Technology/statistics & numerical data , Adult , Female , Humans , Male , Visual Perception , Young Adult
8.
Int J Dev Neurosci ; 71: 10-17, 2018 Dec.
Article En | MEDLINE | ID: mdl-30076989

The popularity of using wireless fidelity over the last decades increased apprehensions about impact of high frequency electromagnetic fields (EMF) on health. Most of previous studies mentioned adverse effect of EMF on cognitive processes, but so far, no study has provided a way to control adverse effects of EMF exposure. The purpose of this study was to examine the effect of Wi-Fi EMF and physical activity on spatial learning and motor function in pregnant rat's offspring. Forty Albino-Wistar pregnant rats divided randomly into four groups (EMF, physical activity, combined 2.4GHZ EMF and physical activity and control groups). For assessing spatial learning in 56 post-natal days' old (PND) male offspring, Morris Water Maze (MWM) was used and to examine motor function Open-field test was taken. Although results of MWM test revealed that Wi-Fi modem EMF caused impairment in spatial learning in rats exposed to EMF but physical activity could reduce negative effect of EMF in pregnant rat's offspring who exposed during pregnancy but performed swimming. In addition, results of open-field test showed that litter's motor function in EMF group significantly declined in comparison with physical activity and combined 2.4GHZ EMF and physical activity groups. According to our findings, it can be concluded that execution physical activity individually or along with wave-exposed pregnancy can significantly progressive effect on offspring' cognitive and motor functions.


Electromagnetic Fields/adverse effects , Motor Activity/radiation effects , Physical Conditioning, Animal/methods , Pregnancy/radiation effects , Prenatal Exposure Delayed Effects/prevention & control , Spatial Learning/radiation effects , Analysis of Variance , Animals , Avoidance Learning/physiology , Avoidance Learning/radiation effects , Exploratory Behavior/physiology , Exploratory Behavior/radiation effects , Female , Male , Maze Learning/physiology , Maze Learning/radiation effects , Mental Recall/physiology , Mental Recall/radiation effects , Physical Conditioning, Animal/physiology , Prenatal Exposure Delayed Effects/etiology , Prenatal Exposure Delayed Effects/physiopathology , Rats , Rats, Wistar , Reaction Time/radiation effects , Swimming/physiology
9.
Proc Biol Sci ; 285(1883)2018 07 18.
Article En | MEDLINE | ID: mdl-30051840

Environmental light can exert potent effects on physiology and behaviour, including pupil size, vigilance and sleep. Previous work showed that these non-image forming effects can last long beyond discontinuation of short-wavelength light exposure. The possible functional effects after switching off long-wavelength light, however, have been insufficiently characterized. In a series of controlled experiments in healthy adult volunteers, we evaluated the effects of five minutes of intense red light on physiology and performance during subsequent darkness. As compared to prior darkness, prior red light induced a subsequent sustained pupil dilation. Prior red light also increased subsequent heart rate and heart rate variability when subjects were asked to perform a sustained vigilance task during the dark exposure. While these changes suggest an increase in the mental effort required for the task, it could not prevent a post-red slowing of response speed. The suggestion that exposure to intense red light affects vigilance during subsequent darkness, was confirmed in a controlled polysomnographic study that indeed showed a post-red facilitation of sleep onset. Our findings suggest the possibility of using red light as a nightcap.


Light , Pupil/physiology , Reaction Time/physiology , Sleep/physiology , Adult , Arousal/physiology , Arousal/radiation effects , Darkness , Female , Humans , Male , Photic Stimulation , Pupil/radiation effects , Reaction Time/radiation effects , Sleep/radiation effects , Young Adult
10.
Intern Med J ; 48(11): 1331-1336, 2018 Nov.
Article En | MEDLINE | ID: mdl-29923282

BACKGROUND: Cognitive function and physical function are important predictors of mortality. AIM: To investigate whether or not reaction time (RT) as a cognitive function and grip strength (GS) as a physical function were associated, alone or in combination, with mortality from heart disease or stroke. METHODS: The subjects included 4901 Adult Health Study participants in Hiroshima who had undergone RT and GS measurements, were 35-74 years old at baseline (1970-1972) and were followed until the end of 2007. RESULTS: After adjustment for other potential risk factors, RT was positively and GS was negatively associated with mortality from both heart disease and stroke. These associations were persistent in the model when adjusting simultaneously for RT, GS and other factors, but hazard ratios were attenuated. When we evaluated the associations by baseline age and gender, we found the greater hazard ratios for RT in the younger cohort, but no clear modification by age for GS. The interaction between RT and GS was statistically significant (P = 0.012) for stroke mortality. In the stratified analyses divided using the age-specific median value of RT or GS, the estimated hazard ratio of stroke mortality for RT was significant in participants with weak or strong GS but greater in the former, and for GS, it was only significant in participants with slow RT. CONCLUSION: RT and GS, alone and in combination, predicted heart disease and stroke mortalities. Interventions for both cognitive function and physical function may be beneficial for the prevention of cardiovascular disease mortality.


Cardiovascular Diseases/mortality , Cognition/physiology , Hand Strength/physiology , Reaction Time/physiology , Stroke/mortality , Adult , Aged , Cognition/radiation effects , Female , Humans , Japan/epidemiology , Longitudinal Studies , Male , Middle Aged , Proportional Hazards Models , Reaction Time/radiation effects
11.
Chronobiol Int ; 35(8): 1095-1103, 2018 08.
Article En | MEDLINE | ID: mdl-29658807

This study investigated the effect of using an artificial bright light on the entrainment of the sleep/wake cycle as well as the reaction times of athletes before the Rio 2016 Olympic Games. A total of 22 athletes from the Brazilian Olympic Swimming Team were evaluated, with the aim of preparing them to compete at a time when they would normally be about to go to bed for the night. During the 8-day acclimatization period, their sleep/wake cycles were assessed by actigraphy, with all the athletes being treated with artificial light therapy for between 30 and 45 min (starting at day 3). In addition, other recommendations to improve sleep hygiene were made to the athletes. In order to assess reaction times, the Psychomotor Vigilance Test was performed before (day 1) and after (day 8) the bright light therapy. As a result of the intervention, the athletes slept later on the third (p = 0.01), seventh (p = 0.01) and eighth (p = 0.01) days after starting bright light therapy. Regarding reaction times, when tested in the morning the athletes showed improved average (p = 0.01) and minimum reaction time (p = 0.03) when comparing day 8 to day 1. When tested in the evening, they showed improved average (p = 0.04), minimum (p = 0.03) and maximum reaction time (p = 0.02) when comparing day 8 to day 1. Light therapy treatment delayed the sleep/wake cycles and improved reaction times of members of the swimming team. The use of bright light therapy was shown to be effective in modulating the sleep/wake cycles of athletes who had to perform in competitions that took place late at night.


Activity Cycles/radiation effects , Athletes/psychology , Circadian Rhythm/radiation effects , Competitive Behavior , Phototherapy/methods , Reaction Time/radiation effects , Sleep/radiation effects , Swimming , Wakefulness/radiation effects , Adult , Female , Humans , Male , Time Factors , Treatment Outcome , Young Adult
12.
Chronobiol Int ; 35(8): 1035-1044, 2018 08.
Article En | MEDLINE | ID: mdl-29580072

INTRODUCTION: Bright light exposure in the late evening can affect cognitive function the following morning either by changing the biological clock and/or disturbing sleep, but the evidence for this effect is scarce, and the underlying mechanism remains unknown. In this study, we first aimed to evaluate the effect of bright light exposure before bedtime on frontal lobe activity the following morning using near-infrared spectroscopy (NIRS) during a Go/NoGo task. Second, we aimed to evaluate the effects of bright light exposure before bedtime on polysomnographic measures and on a frontal lobe function test the following morning. METHODS: Twenty healthy, young males (mean age, 25.5 years) were recruited between September 2013 and August 2014. They were first exposed to control light (150 lux) before bedtime (from 20:00 h to 24:00 h) for 2 days and then to bright light (1,000 lux) before bedtime for an additional 5 days. We performed polysomnography (PSG) on the final night of each light exposure period (on nights 2 and night 7) and performed NIRS, which measures the concentrations of oxygenated and deoxygenated hemoglobin (OxyHb and DeoxyHb, respectively), coupled with a Go/NoGo task the following morning (between 09:30 h and 11:30 h). The participants also completed frontal lobe function tests the following morning. RESULTS: NIRS showed decreased hemodynamic activity (lower OxyHb and a tendency toward higher DeoxyHb concentration) in the right frontal lobe during the NoGo block after 1000-lux light exposure compared with that during the NoGo block after 150-lux light exposure. The commission error rate (ER) during the Go/NoGo task was higher after 1000-lux light exposure than that during the Go/NoGo task after 150-lux light exposure (1.24 ± 1.09 vs. 0.6 ± 0.69, P = 0.002), suggesting a reduced inhibitory response. CONCLUSION: This study shows that exposure to bright light before bedtime for 5 days impairs right frontal lobe activation and response inhibition the following morning.


Activity Cycles/radiation effects , Cerebrovascular Circulation/radiation effects , Circadian Rhythm/radiation effects , Executive Function/radiation effects , Frontal Lobe/blood supply , Frontal Lobe/radiation effects , Light/adverse effects , Sleep/radiation effects , Adult , Biomarkers/blood , Cross-Over Studies , Hemoglobins/metabolism , Humans , Male , Neuropsychological Tests , Oxyhemoglobins/metabolism , Polysomnography , Reaction Time/radiation effects , Spectroscopy, Near-Infrared , Time Factors , Young Adult
13.
Article En | MEDLINE | ID: mdl-29543731

Exposure to bright light is typically intermittent in our daily life. However, the acute effects of intermittent light on alertness and sleep have seldom been explored. To investigate this issue, we employed within-subject design and compared the effects of three light conditions: intermittent bright light (30-min pulse of blue-enriched bright light (~1000 lux, ~6000 K) alternating with 30-min dim normal light (~5 lux, ~3600 K) three times); continuous bright light; and continuous dim light on subjective and objective alertness and subsequent sleep structure. Each light exposure was conducted during the three hours before bedtime. Fifteen healthy volunteers (20 ± 3.4 years; seven males) were scheduled to stay in the sleep laboratory for four separated nights (one for adaptation and the others for the light exposures) with a period of at least one week between nights. The results showed that when compared with dim light, both intermittent light and continuous bright light significantly increased subjective alertness and decreased sleep efficiency (SE) and total sleep time (TST). Intermittent light significantly increased objective alertness than dim light did during the second half of the light-exposure period. Our results suggested that intermittent light was as effective as continuous bright light in their acute effects in enhancing subjective and objective alertness and in negatively impacting subsequent sleep.


Arousal/radiation effects , Light , Sleep/radiation effects , Adolescent , Adult , Attention , Circadian Rhythm , Female , Humans , Male , Reaction Time/radiation effects , Young Adult
14.
Physiol Behav ; 185: 1-13, 2018 03 01.
Article En | MEDLINE | ID: mdl-29223712

Though several studies have reported human alertness to be affected by the intensity and spectral composition of ambient light, the mechanism behind this effect is still largely unclear, especially for daytime exposure. Alerting effects of nocturnal light exposure are correlated with melatonin suppression, but melatonin levels are generally low during the day. The aim of this study was to explore the alerting effect of light in the morning for different correlated colour temperature (CCT) values, as well as its interaction with ambient temperature. Body temperature and perceived comfort were included in the study as possible mediating factors. In a randomized crossover design, 16 healthy females participated in two sessions, once under 2700K and once under 6500K light (both 55lx). Each session consisted of a baseline, a cool, a neutral and a warm thermal environment. Alertness as measured in a reaction time task was lower for the 6500K exposure, while subjective sleepiness was not affected by CCT. Also, core body temperature was higher under 6500K. Skin temperature parameters and perceived comfort were positively correlated with subjective sleepiness. Reaction time correlated with heat loss, but this association did not explain why the reaction time was improved for 2700K.


Body Temperature/physiology , Body Temperature/radiation effects , Color , Temperature , Wakefulness/physiology , Wakefulness/radiation effects , Adolescent , Adult , Arousal/physiology , Arousal/radiation effects , Cross-Over Studies , Female , Humans , Photoperiod , Reaction Time/physiology , Reaction Time/radiation effects , Regional Blood Flow/radiation effects , Skin/blood supply , Skin/radiation effects , Sleep/physiology , Sleep/radiation effects , Young Adult
15.
Neurotox Res ; 33(4): 824-836, 2018 05.
Article En | MEDLINE | ID: mdl-29101721

Environmental stressors inducing oxidative stress such as ionizing radiation may influence cognitive function and neuronal plasticity. Recent studies have shown that transgenic mice deficient of DNA glycosylases display unexpected cognitive deficiencies related to changes in gene expression in the hippocampus. The main objectives of the present study were to determine learning and memory performance in C57BL/6NTac 8-oxoguanine DNA glycosylase 1 (Ogg1)+/- (heterozygote) and Ogg1+/+ (wild type, WT) mice, to study whether a single acute X-ray challenge (0.5 Gy, dose rate 0.457 Gy/min) influenced the cognitive performance in the Barnes maze, and if such differences were related to changes in gene expression levels in the hippocampus. We found that the Ogg1+/- mice exhibited poorer early-phase learning performance compared to the WT mice. Surprisingly, X-ray exposure of the Ogg1+/- animals improved their early-phase learning performance. No persistent effects on memory in the late-phase (6 weeks after irradiation) were observed. Our results further suggest that expression of 3 (Adrb1, Il1b, Prdx6) out of in total 35 genes investigated in the Ogg1+/- hippocampus is correlated to spatial learning in the Barnes maze.


Cognition Disorders/genetics , Cognition Disorders/therapy , DNA Glycosylases/deficiency , Recovery of Function/radiation effects , X-Ray Therapy , Analysis of Variance , Animals , DNA Glycosylases/genetics , Disease Models, Animal , Dose-Response Relationship, Radiation , G-Protein-Coupled Receptor Kinase 2/genetics , G-Protein-Coupled Receptor Kinase 2/metabolism , Gene Expression/genetics , Gene Expression/radiation effects , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Male , Maze Learning/radiation effects , Mice , Mice, Inbred C57BL , Mice, Transgenic , Peroxiredoxin VI/genetics , Peroxiredoxin VI/metabolism , RNA, Messenger/metabolism , Reaction Time/radiation effects , Recovery of Function/genetics
16.
Acta Radiol ; 59(2): 221-228, 2018 Feb.
Article En | MEDLINE | ID: mdl-28478725

Background The question has been raised whether low dose radiation toward the brain in childhood can affect cognitive functions. Purpose To examine if a head computed tomography (CT) examination in childhood affect later cognitive functions. Material and Methods A total of 147 participants (67 girls/women, 80 boys/men) from a previous randomized controlled trial on management strategies after mild head injury (head CT examination or in-hospital observation) were followed up. Participants were aged 6-16 years (mean age = 11.2 ± 2.8) at first inclusion and 11-24 years (mean age = 17.8 ± 2.9) at follow-up. Computerized neuropsychological measures used for the assessment were motor speed and coordination, reaction time, selective attention, visuospatial ability, verbal and non-verbal short-term and long-term memory, and executive function tests from the neurocognitive test battery EuroCog and the Wechsler Memory Scale III. Results were analyzed with Student's t-tests and multivariate analyses adjusting for sex, age at time of injury/exposure, and age at assessment were performed with Factorial ANOVAs. Results The exposed and unexposed groups did not differ in any of the neuropsychological measures and results did not change when sex, age at time of injury/exposure, and age at assessment were included in the analyses. Conclusion A head CT examination at the age of 6-16 years does not seem to affect later cognitive functions.


Cognition/radiation effects , Tomography, X-Ray Computed/adverse effects , Adolescent , Age Factors , Analysis of Variance , Child , Executive Function/radiation effects , Female , Follow-Up Studies , Head/radiation effects , Humans , Male , Memory/radiation effects , Multivariate Analysis , Neuropsychological Tests , Radiation Dosage , Reaction Time/radiation effects , Young Adult
17.
Int J Neurosci ; 128(8): 691-696, 2018 Aug.
Article En | MEDLINE | ID: mdl-29185809

INTRODUCTION: Although studies have shown a potential association between extremely low frequency electromagnetic fields (ELF-EMFs) exposure and Alzheimer's disease (AD), few studies have been conducted to investigate the effects of weak magnetic fields on brain functions such as cognitive functions in animal models. Therefore, this study aimed to investigate the effect of ELF-EMF exposure (50 Hz, 10 mT) on spatial learning and memory changes in AD rats. METHODS: Amyloid-ß (Aß) 1-42 was injected into lateral ventricle to establish an AD rat model. The rats were divided into six groups: Group I (control); Group II (surgical sham); Group III (AD) Alzheimer's rat model; Group IV (MF) rats exposed to ELF-MF for 14 consecutive days; Group V (Aß injection+M) rats exposed to magnetic field for 14 consecutive days from day 0 to 14 days after the Aß peptide injection; Group VI (AD+M) rats exposed to magnetic field for 14 consecutive days after 2 weeks of Aß peptide injection from 14th to 28th day . Morris water maze investigations were performed. RESULTS: AD rats showed a significant impairment in learning and memory compared to control rats. The results showed that ELF-MF improved the learning and memory impairments in Aß injection+M and AD+M groups. CONCLUSION: Our results showed that application of ELF-MF not only has improving effect on different cognitive disorder signs of AD animals, but also disrupts the processes of AD rat model formation.


Alzheimer Disease/complications , Magnetic Field Therapy/methods , Memory Disorders/etiology , Memory Disorders/therapy , Recovery of Function/radiation effects , Amyloid beta-Peptides/toxicity , Analysis of Variance , Animals , Disease Models, Animal , Male , Maze Learning/drug effects , Maze Learning/radiation effects , Peptide Fragments/toxicity , Rats , Rats, Wistar , Reaction Time/drug effects , Reaction Time/radiation effects , Swimming , Time Factors , Treatment Outcome
18.
Pain ; 158(2): 347-360, 2017 02.
Article En | MEDLINE | ID: mdl-28092651

Treatments for chronic pain are inadequate, and new options are needed. Nonpharmaceutical approaches are especially attractive with many potential advantages including safety. Light therapy has been suggested to be beneficial in certain medical conditions such as depression, but this approach remains to be explored for modulation of pain. We investigated the effects of light-emitting diodes (LEDs), in the visible spectrum, on acute sensory thresholds in naive rats as well as in experimental neuropathic pain. Rats receiving green LED light (wavelength 525 nm, 8 h/d) showed significantly increased paw withdrawal latency to a noxious thermal stimulus; this antinociceptive effect persisted for 4 days after termination of last exposure without development of tolerance. No apparent side effects were noted and motor performance was not impaired. Despite LED exposure, opaque contact lenses prevented antinociception. Rats fitted with green contact lenses exposed to room light exhibited antinociception arguing for a role of the visual system. Antinociception was not due to stress/anxiety but likely due to increased enkephalins expression in the spinal cord. Naloxone reversed the antinociception, suggesting involvement of central opioid circuits. Rostral ventromedial medulla inactivation prevented expression of light-induced antinociception suggesting engagement of descending inhibition. Green LED exposure also reversed thermal and mechanical hyperalgesia in rats with spinal nerve ligation. Pharmacological and proteomic profiling of dorsal root ganglion neurons from green LED-exposed rats identified changes in calcium channel activity, including a decrease in the N-type (CaV2.2) channel, a primary analgesic target. Thus, green LED therapy may represent a novel, nonpharmacological approach for managing pain.


Analgesics/therapeutic use , Chronic Pain/therapy , Phototherapy/methods , Animals , Calcium Channels, N-Type/genetics , Calcium Channels, N-Type/metabolism , Color , Disease Models, Animal , Dose-Response Relationship, Radiation , Female , Ganglia, Spinal/cytology , Ganglia, Spinal/drug effects , Male , Medulla Oblongata , Naloxone/pharmacology , Narcotic Antagonists/pharmacology , Pain Threshold/radiation effects , Physical Stimulation/adverse effects , Posterior Horn Cells/drug effects , Posterior Horn Cells/radiation effects , Rats , Rats, Long-Evans , Rats, Sprague-Dawley , Reaction Time/radiation effects
19.
Eye (Lond) ; 31(1): 97-106, 2017 Jan.
Article En | MEDLINE | ID: mdl-27983728

PurposeThe purpose of the study was to study the effect of an organic light-emitting diode sleep mask on daytime alertness, wellbeing, and retinal structure/function in healthy volunteers and in diabetic macular oedema (DMO).Patients and methodsHealthy volunteers in two groups, 18-30 yrs (A), 50-70 yrs (B) and people with DMO (C) wore masks (504 nm wavelength; 80 cd/m2 luminance; ≤8 h) nightly for 3 months followed by a 1-month recovery period. Changes from baseline were measured for (means): psychomotor vigilance task (PVT) (number of lapses (NL), response time (RT)), sleep, depression, psychological wellbeing (PW), visual acuity, contrast sensitivity, colour, electrophysiology, microperimetry, and retinal thickness on OCT.ResultsOf 60 participants, 16 (27%) withdrew, 8 (13%) before month 1, due to sleep disturbances and mask intolerance. About 36/55 (65%) who continued beyond month 1 reported ≥1 adverse event. At month 3 mean PVT worsened in Group A (RT (7.65%, P<0.001), NL (43.3%, P=0.005)) and mean PW worsened in all groups (A 28.0%, P=0.01, B 21.2%, P=0.03, C 12.8%, P<0.05). No other clinically significant safety signal was detected. Cysts reduced/resolved in the OCT subfield of maximal pathology in 67% Group C eyes. Thinning was greater at 3 and 4 months for greater baseline thickness (central subfield P<0.001, maximal P<0.05).ConclusionSleep masks showed no major safety signal apart from a small impairment of daytime alertness and a moderate effect on wellbeing. Masks were acceptable apart from in some healthy participants. Preliminary data suggest a beneficial effect on retinal thickness in DMO. This novel therapeutic approach is ready for large clinical trials.


Diabetic Retinopathy/therapy , Macular Edema/therapy , Phototherapy/methods , Adolescent , Adult , Aged , Color Perception/radiation effects , Contrast Sensitivity/radiation effects , Diabetic Retinopathy/physiopathology , Female , Humans , Macular Edema/physiopathology , Male , Masks , Middle Aged , Patient Satisfaction , Phototherapy/adverse effects , Prospective Studies , Psychomotor Performance/radiation effects , Reaction Time/radiation effects , Retina/physiopathology , Retina/radiation effects , Sleep/radiation effects , Sleep Wake Disorders/etiology , Tomography, Optical Coherence , Visual Acuity/physiology , Visual Fields/physiology , Young Adult
20.
J Neurosci ; 36(46): 11727-11738, 2016 11 16.
Article En | MEDLINE | ID: mdl-27852780

The primary visual cortex exhibits a late, long response with a latency of >300 ms and an immediate early response that occurs ∼100 ms after a visual stimulus. The late response is thought to contribute to visual functions such as sensory perception, iconic memory, working memory, and forming connections between temporally separated stimuli. However, how the visual late response is generated and organized is not completely understood. In the mouse primary visual cortex in vivo, we isolated long-delayed responses by using a brief light-flash stimulus for which the stimulus late response occurred long after the stimulus offset and was not contaminated by the instantaneous response evoked by the stimulus. Using whole-cell patch-clamp recordings, we demonstrated that the late rebound response was shaped by a net-balanced increase in excitatory and inhibitory synaptic conductances, whereas transient imbalances were caused by intermittent inhibitory barrage. In contrast to the common assumption that the neocortical late response reflects a feedback signal from the downstream higher-order cortical areas, our pharmacological and optogenetic analyses demonstrated that the late responses likely have a thalamic origin. Therefore, the late component of a sensory-evoked cortical response should be interpreted with caution. SIGNIFICANCE STATEMENT: The long-delayed responses of neocortical neurons are thought to arise from cortical feedback activity that is related to sensory perception and cognition. The mechanism of neocortical late responses was investigated using multiple electrophysiological techniques and the findings indicate that it actually arises from the thalamus. In addition, during the late response, excitation and inhibition are balanced, but inhibition is dominant in patterning action potentials.


Neural Inhibition/physiology , Photic Stimulation/methods , Reaction Time/physiology , Visual Cortex/physiology , Visual Cortex/radiation effects , Visual Perception/physiology , Adult , Animals , Connectome/methods , Female , Humans , Male , Mice , Mice, Inbred C57BL , Nerve Net/physiology , Nerve Net/radiation effects , Neural Inhibition/radiation effects , Neural Pathways/physiology , Reaction Time/radiation effects , Visual Perception/radiation effects
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