Implications of environmental nanoparticles on neurodegeneration.

The ubiquity of nanoparticles, sourced from both natural environments and human activities, presents critical challenges for public health. While offering significant potential for innovative biomedical applications-especially in enhancing drug transport across the blood-brain barrier-these particles also introduce possible hazards due to inadvertent exposure. This concise review explores the paradoxical nature of nanoparticles, emphasizing their promising applications in healthcare juxtaposed with their potential neurotoxic consequences. Through a detailed examination, we delineate the pathways through which nanoparticles can reach the brain and the subsequent health implications. There is growing evidence of a disturbing association between nanoparticle exposure and the onset of neurodegenerative conditions, highlighting the imperative for comprehensive research and strategic interventions. Gaining a deep understanding of these mechanisms and enacting protective policies are crucial steps toward reducing the health threats of nanoparticles, thereby maximizing their therapeutic advantages.

Hypocholesterolemia is an independent risk factor for depression disorder and suicide attempt in Northern Mexican population.

BACKGROUND: Cholesterol has been associated as a risk factor for cardiovascular disease. Recently, however, there is growing evidence about crucial requirement of neuron membrane cholesterol in the organization and function of the 5-HT1A serotonin receptor. For this, low cholesterol level has been reported to be associated with depression and suicidality. However there have been inconsistent reports about this finding and the exact relationship between these factors remains controversial. Therefore, we investigated the link between serum cholesterol and its fractions with depression disorder and suicide attempt in 467 adult subjects in Mexican mestizo population. METHODS: Plasma levels of total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-c) and low density lipoprotein cholesterol (LDL-c) were determined in 261 MDD patients meeting the DSM-5 criteria for major depressive disorder (MDD), 59 of whom had undergone an episode of suicide attempt, and 206 healthy controls. RESULTS: A significant decrease in total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglyceride serum levels was observed in the groups of MDD patients and suicide attempt compared to those without suicidal behavior (p < 0.05). After adjusting for covariates, lower cholesterol levels were significantly associated with MDD (OR 4.229 CI 95% 2.555 - 7.000, p<.001) and suicide attempt (OR 5.540 CI 95% 2.825 - 10.866, p<.001) CONCLUSIONS: These results support the hypothesis that lower levels of cholesterol are associated with mood disorders like MDD and suicidal behavior. More mechanistic studies are needed to further explain this association.

A 6-Year Posttreatment Follow-up of Panic Disorder Patients: Treatment With Clonazepam Predicts Lower Recurrence Than Treatment With Paroxetine.

BACKGROUND: The aim of this study was to identify factors associated with relapse in panic disorder (PD). METHODS: This was an observational study conducted in the outpatient clinic of a psychiatric hospital in Rio de Janeiro, Brazil. In a previous study, 120 patients diagnosed as having PD according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria were randomized to receive clonazepam or paroxetine. After 3 years, treatment was discontinued in patients who had achieved remission. These subjects were included in the current study and were followed up for 6 years. The follow-up assessments were made at 1, 2, 3, 5, and 6 years after treatment discontinuation. Assessment included the number of panic attacks per month, Clinical Global Impression-Severity, and other measures. Patients who had initiated psychotherapy or pharmacological treatment because of PD symptoms or who had Clinical Global Impression-Severity scores greater than 1 or panic attacks in the month preceding the assessment were considered relapse cases. Data were collected from January 2003 to August 2012. RESULTS: Eighty-five patients completed the follow-up. Cumulative relapse rates were 50% (n = 33) at 1 year and 89.4% (n = 76) at 6 years. One-year relapse rates were lower in patients previously treated with clonazepam (P = 0.001) compared with those treated with paroxetine. Low 6-year relapse rates were associated with high Hamilton Anxiety Rating Scale scores before treatment (P = 0.016) and previous treatment with clonazepam. CONCLUSIONS: Relapse is a frequent problem in PD, and long-term treatment does not protect these patients in the long run. Treatment with clonazepam predicts lower relapse when compared with paroxetine.

Psychiatric comorbidities in movement disorders.

Psychiatric comorbidities are common in movement disorders. This review provides a practical approach to help clinicians to recognize psychiatric disorders in the most frequent movement disorders. However, the extent of neurodegeneration, as well as the impact of medications with considerable CNS effects, influences the diverse psychiatric presentations that, in turn, are influenced by the stress of living with a movement disorder. Depression, anxiety, and psychosis are the most common psychiatric comorbidities in movement disorders and of the medications used to treat the motor disturbances. These psychiatric problems impair patients' functioning throughout the course of the chronic neurodegenerative diseases. Due to the direct connection between brain dysfunction and psychiatric symptoms, there is hope that understanding the psychiatric comorbidities in movement disorders will lead to a better quality-of-life.

Can Transcranial Direct Current Stimulation Improve the Resistance Strength and Decrease the Rating Perceived Scale in Recreational Weight-Training Experience?

Lattari, E, Andrade, ML, Filho, AS, Moura, AM, Neto, GM, Silva, JG, Rocha, NB, Yuan, T-F, Arias-Carrión, O, and Machado, S. Can transcranial direct current stimulation improve the resistance strength and decrease the rating perceived scale in recreational weight-training experience? J Strength Cond Res 30(12): 3381-3387, 2016-The goal of this study was to evaluate the acute efficacy of anodic transcranial direct current stimulation on the total volume of repetitions and perceived exertion in recreationally trained individuals in strength. The sample consisted of 10 participants trained in exercise against resistance for at least 3 months. Participants underwent elbow flexion exercise at barbell with a specific load of 10 repetition maximum (10RM), responded immediately after the OMNI-RES scale, and were stimulated for 20 minutes with a tDSC protocol (2 mA), depending on randomization. After applying the tDSC, subjects were again subjected to perform elbow flexion with 10RM load and, soon after, again responded to OMNI-RES scale. All subjects underwent the 3 experimental conditions of the study, c-tDSC, a-tDSC, and sham-tDSC, which were randomized. A range of 48-72 hours was allowed between each assessment visit. An interaction to condition and time (F = 52.395; p ≤ 0.001) has shown that repetitions completed after anodic condition were higher compared with the other conditions in the postsession. In relation to perceived exertion, verified by OMNI-RES scale, 2-way analysis of variance for repeated measures showed an interaction between condition and time (F = 28.445; p ≤ 0.001), where the perceived exertion was decreased after the a-tDSC condition and increased after the c-tDSC condition. In strict terms of performance, it seems to be beneficial to attend a session of 20 minutes a-tDSC, when strength training practitioners can no longer support high-volume training and have increased responses in the perceived exertion.

Prior Acute Mental Exertion in Exercise and Sport.

INTRODUCTION: Mental exertion is a psychophysiological state caused by sustained and prolonged cognitive activity. The understanding of the possible effects of acute mental exertion on physical performance, and their physiological and psychological responses are of great importance for the performance of different occupations, such as military, construction workers, athletes (professional or recreational) or simply practicing regular exercise, since these occupations often combine physical and mental tasks while performing their activities. However, the effects of implementation of a cognitive task on responses to aerobic exercise and sports are poorly understood. Our narrative review aims to provide information on the current research related to the effects of prior acute mental fatigue on physical performance and their physiological and psychological responses associated with exercise and sports. METHODS: The literature search was conducted using the databases PubMed, ISI Web of Knowledge and PsycInfo using the following terms and their combinations: "mental exertion", "mental fatigue", "mental fatigue and performance", "mental exertion and sports" "mental exertion and exercise". RESULTS: We concluded that prior acute mental exertion affects effectively the physiological and psychophysiological responses during the cognitive task, and performance in exercise. CONCLUSION: Additional studies involving prior acute mental exertion, exercise/sports and physical performance still need to be carried out in order to analyze the physiological, psychophysiological and neurophysiological responses subsequently to acute mental exertion in order to identify cardiovascular factors, psychological, neuropsychological associates.

Mental Practice Combined with Motor Rehabilitation to Treat Upper Limb Hemiparesis of Post-Stroke Patients: Clinical and Experimental Evidence.

Stroke is one of the major causes of disability in the world. Due to the extended lifetime of the world's population, the number of people affected by stroke has increased substantially over the last years. Stroke may lead to sensorimotor deficits, usually causing hemiplegia or hemiparesia. In order to reduce motor deficits and accelerate functional recovery, MP combined with motor rehabilitation was introduced to the rehabilitation process of post-stroke patients. Evidence has shown that MP combining with motor rehabilitation based on activities of daily living was more effective than conventional motor rehabilitation used per se. This combination proved very useful and effective, with significant results in improvement of motor deficits in post-stroke patients. However, further studies must be conducted to determine specific parameters, such as type of imagery, frequency or duration.

Acute Affective Responses and Frontal Electroencephalographic Asymmetry to Prescribed and Self-selected Exercise.

OBJECTIVE: Our goal was to compare affective responses and frontal electroencephalographic alpha asymmetry induced by prescribed exercise (PE) and self-selected exercise (SS). METHOD: Twenty active participants underwent a submaximal exercise test to estimate maximal oxygen consumption (VO2max). Participants enrolled a cross-over randomized study where each participant completed three conditions: PE (50%PVO2max), SS and Control. The electroencephalography was performed before and after exercise. The feeling scale, felt arousal scale and heart rate were recorded before, during and after each condition. The ratings of perceived exertion were recorded during and after each condition. RESULTS: The heart rate and ratings of perceived exertion showed higher values in the PE and SS conditions compared to controls, with no differences between the PE and SS conditions. For the feeling scale, the SS presented higher values compared to the PE and Control conditions. The felt arousal scale presented higher values in the PE and SS conditions compared to control. There was no interaction between condition and moment, or main effect for condition and moment for frontal alpha asymmetry (InF4-InF3). CONCLUSION: The SS provided better affective responses compared to PE, thus can consider self-selected intensity as an appropriate option. In general, no frontal alpha asymmetry was seen due to an exercise intervention.

Relationship Among Body Image, Anthropometric Parameters and Mental Health in Physical Education Students.

BACKGROUND: The prevalence of body image dissatisfaction (BID) is currently high. Given that psychological well-being is associated with the body measurements imposed by esthetic standards, BID is an important risk factor for mental disorders. OBJECTIVE: Identify the prevalence of BID, and compare anthropometric and mental health parameters between individuals satisfied and dissatisfied with their body image. METHOD: A total of 140 university students completed the silhouette scale to screen for BID. Anthropometric measures, body mass index (BMI), waist circumference (WC) and body fat percentage (BFP) were used. To investigate mental health, The State-Trait Anxiety Inventories (STAI-S and STAI-T), Profile of Mood States (POMS) scale and Quality of Life (QOL-36) questionnaire were used to investigate mental health. The Student's t-test was applied to compare anthropometric and mental health parameters. RESULTS: 67.1% of university students exhibited BID. There was a significant difference (p = 0.041) in BF and WC (p = 0.048) between dissatisfied and satisfied individuals. With respect to mood states, significant differences were observed for anger (p = 0.014), depression (p = 0.011), hostility (p = 0.006), fatigue (p = 0.013), mental confusion (p = 0.021) and total mood disturbance (TMD) (p = 0.001). The mental aspect of QOL was significantly higher (p = 0.001) in satisfied university students compared to their dissatisfied counterparts. CONCLUSION: BID was high and it seems to be influenced by anthropometric measures related to the amount and distribution of body fat. This dissatisfaction may have a negative effect on the quality of life and mood state of young adults.

Treatment of Cognitive Deficits in Alzheimer's disease: A psychopharmacological review.

The growing and aging population has contributed to the increased prevalence of Alzheimer's disease (AD) and other types of dementia in the world. AD is a progressive and degenerative brain disease with an onset characterized by episodic memory impairments, although progressive deficits can be observed in several domains including language, executive functions, attention and working memory. The relationship between cognitive impairments and the topography and progression of brain neuropathology is well established. The pathophysiologic mechanisms and processes that underline the course of cognitive and clinical decline have been the theoretical support for the development of pharmacological treatments for AD. Cholinesterase inhibitors (ChEIs) and N-methyl-D-aspartate (NMDA) antagonists are the main drugs used in the management of global cognitive impairment and several studies also explore the effects of both in specific cognitive measures. Recent research trends also examine the effects of combination therapy using both compounds. This review aims to update practical recommendations for the treatment of global cognitive functioning and specific neurocognitive deficits in AD using ChEIs, NMDA antagonists and combination therapy with both drugs.

Effect of mechanical tactile noise on amplitude of visual evoked potentials: multisensory stochastic resonance.

The present investigation documents the electrophysiological occurrence of multisensory stochastic resonance in the human visual pathway elicited by tactile noise. We define multisensory stochastic resonance of brain evoked potentials as the phenomenon in which an intermediate level of input noise of one sensory modality enhances the brain evoked response of another sensory modality. Here we examined this phenomenon in visual evoked potentials (VEPs) modulated by the addition of tactile noise. Specifically, we examined whether a particular level of mechanical Gaussian noise applied to the index finger can improve the amplitude of the VEP. We compared the amplitude of the positive P100 VEP component between zero noise (ZN), optimal noise (ON), and high mechanical noise (HN). The data disclosed an inverted U-like graph for all the subjects, thus demonstrating the occurrence of a multisensory stochastic resonance in the P100 VEP.

A new dopaminergic nigro-olfactory projection.

Parkinson disease (PD) is a neurodegenerative disorder characterized by massive loss of midbrain dopaminergic neurons. Whereas onset of motor impairments reflects a rather advanced stage of the disorder, hyposmia often marks the beginning of the disease. Little is known about the role of the nigro-striatal system in olfaction under physiological conditions and the anatomical basis of hyposmia in PD. Yet, the early occurrence of olfactory dysfunction implies that pathogens such as environmental toxins could incite the disease via the olfactory system. In the present study, we demonstrate a dopaminergic innervation from neurons in the substantia nigra to the olfactory bulb by axonal tracing studies. Injection of two dopaminergic neurotoxins-1-methyl-4-phenylpyridinium and 6-hydroxydopamine-into the olfactory bulb induced a decrease in the number of dopaminergic neurons in the substantia nigra. In turn, ablation of the nigral projection led to impaired olfactory perception. Hyposmia following dopaminergic deafferentation was reversed by treatment with the D1/D2/D3 dopamine receptor agonist rotigotine. Hence, we demonstrate for the first time the existence of a direct dopaminergic projection into the olfactory bulb and identify its origin in the substantia nigra in rats. These observations may provide a neuroanatomical basis for invasion of environmental toxins into the basal ganglia and for hyposmia as frequent symptom in PD.

Comparative study of subcortical atrophy in patients with frontotemporal dementia and dementia with extrapyramidal signs.

OBJECTIVES: To investigate the severity of subcortical atrophy in frontotemporal dementia (FTD) without extrapyramidal symptoms (EPS) and dementia with EPS. In addition, we aim to verify if there is correlation between demographic and clinical characteristics and subcortical atrophy in the groups. Methodology : The sample was composed of 21 patients with dementia and EPS as well as 19 patients with FTD without EPS. A linear assessment was conducted in order to identify the degree of subcortical atrophy (i.e., bifrontal index - BFI) using MRI. Moreover, the Mini-Mental State Examination (MMSE), Pfeffer Functional Activities Questionnaire (FAQ) and the Clinical Dementia Rating (CDR) were used to investigate clinical aspects. Results : It was verified that patients with dementia and EPS was older than the patients with FTD (p=0.01). The severity of cognitive deficits was associated with BFI, as well as the dementia severity in the EPS group. Conclusion : FTD group presented mean BFI scores above the cutoff for normal elderly population, indicating the presence of subcortical atrophy in this group. Mean BFI was higher (although not statistically significant) in FTD group than in dementia with EPS, which can suggest at least that subcortical pathology in FTD may be as important as in the dementia with EPS group. Subcortical atrophy is a good biological marker for cognitive deterioration in FTD and in dementia with EPS.

Physical activity interventions in schools for improving lifestyle in European countries.

BACKGROUND: In the last decades, children's and adolescents' obesity and overweight have increased in European Countries. Unhealthy eating habits and sedentary lifestyle have been recognized to determine such an epidemic. Schools represent an ideal setting to modify harmful behaviors, and physical activity could be regarded as a potential way to avoid the metabolic risks related to obesity. Methods : A systematic review of the literature was carried out to summarize the evidence of school-based interventions aimed to promote, enhance and implement physical activity in European schools. Only randomized controlled trials were included, carried out in Europe from January 2000 to April 2014, universally delivered and targeting pupils aged between 3 and 18 years old. Results : Forty-seven studies were retrieved based either on multicomponent interventions or solely physical activity programs. Most aimed to prevent obesity and cardiovascular risks among youths. While few studies showed a decrease in BMI, positive results were achieved on other outcomes, such as metabolic parameters and physical fitness. Conclusion : Physical activity in schools should be regarded as a simple, non-expensive and enjoyable way to reach all the children and adolescents with adequate doses of moderate to vigorous physical activity.

Evidence of adult neurogenesis in non-human primates and human.

Adult neurogenesis in rodents has been extensively studied. Here, we briefly summarize the studies of adult neurogenesis based on non-human primate brains and human postmortem brain samples in recent decades. The differences between rodent, primate and human neurogenesis are discussed. We conclude that these differences may contribute to distinct physiological roles and the self-repair mechanisms in the brain across species.

Potential effects of cannabidiol as a wake-promoting agent.

Over the last decades, the scientific interest in chemistry and pharmacology of cannabinoids has increased. Most attention has focused on ∆(9)-tetrahydrocannabinol (∆(9)-THC) as it is the psychoactive constituent of Cannabis sativa (C. sativa). However, in previous years, the focus of interest in the second plant constituent with non-psychotropic properties, cannabidiol (CBD) has been enhanced. Recently, several groups have investigated the pharmacological properties of CBD with significant findings; furthermore, this compound has raised promising pharmacological properties as a wake-inducing drug. In the current review, we will provide experimental evidence regarding the potential role of CBD as a wake-inducing drug.

Effects of chronic exercise on severity, quality of life and functionality in an elderly Parkinson's disease patient: case report.

Exercise produces potential influences on physical and mental capacity in patients with neuropsychiatric disorders, and can be made a viable form of therapy to treat Parkinson's disease (PD). We report the chronic effects of a regular physical exercise protocol on cognitive and motor functions, functional capacity, and symptoms in an elderly PD patient without dementia. The patient participated of a program composed of proprioceptive, aerobic and flexibility exercises, during 1 hour, three days a week, for nine months. Patient used 600 mg of L-DOPA daily, and 1 hour prior to each exercise session. Assessment was conducted in three stages, 0-3, 3-6 and 6 to 9 months, using percentual variation to the scales Hoehn and Yahr, Mini-Mental State Examination (MMSE), Parkinson Activity Scale (PAS), Beck Depression Inventory (BDI), and Unified Parkinson's Disease Rating Scale (UPDRS-III). Reassessment showed clear changes in clinical parameters for Hoehn and Yahr (4 to 2.5), MMSE (14 to 22), PAS (13 to 29), BDI (9 to 7) and UPDRS-III (39 to 27) at the end of 9 months. According to our data, exercise seems to be effective in promoting the functional capacity and the maintenance of cognitive and motor functions of PD patients. Regular exercise protocols can be implemented as an adjunctive treatment for reducing the severity of PD.

[Guide to write a scientific article]. / Guía para escribir un artículo científico.

Publishing a scientific article is challenging for early-career researchers and clinicians. Success is not solely determined by robust research methods, but also by clear and logical presentation of results. Without clear communication, disruptive findings can be overlooked. A well-structured manuscript leads the reader logically from the introduction to the conclusion. Maintaining a consistent narrative ensures lasting impact. In this paper, we provide practical guidelines for drafting an effective scientific manuscript. Carefully crafted articles increase the chance of acceptance and improve comprehension among diverse specialists. We emphasize the importance of presenting a clear, relevant, and engaging story within a structured framework, highly valued by editors, reviewers, and readers.

Effect of Propranolol on Motor Cortex Excitability in Essential Tremor: An Exploratory Study.

Background: Essential tremor, the world's most prevalent movement disorder, lacks a clear understanding of its pathophysiology. Propranolol, a non-specific beta-blocker capable of crossing the blood-brain barrier, is a primary choice for essential tremor treatment. While its tremor-reducing effects are generally attributed to peripheral actions, various uses hint at central adrenergic effects. Nevertheless, propranolol's precise impact on the central nervous system in essential tremor subjects remains unexplored. Methods: In this study, we employed transcranial magnetic stimulation to assess the influence of propranolol on the excitability of the primary motor cortex (M1) in patients with essential tremor, compared to an age- and sex-matched control group. Cortical excitability parameters were measured following placebo and propranolol administration, encompassing resting and active motor thresholds, motor evoked potential characteristics, cortical silent period, and the input/output curve. Results: Distinct effects were observed across the two cortical hemispheres. Essential tremor patients displayed inhibition of the left M1 cortex and heightened excitability in the right M1 cortex four hours after propranolol administration, but not following placebo. Conclusions: These findings suggest potential differential noradrenergic excitatory and inhibitory modulation. However, comprehensive understanding necessitates further investigations, including left-handed participants and more diverse essential tremor subpopulations. This study underscores the need for continued exploration to unravel propranolol's complex effects on motor cortex excitability in essential tremor.

Motor, Cognitive, and Behavioral Impairment in TLR3 and TLR9 Deficient Male Mice: Insights into the Non-Immunological Roles of Toll-Like Receptors.

BACKGROUND: Toll-like receptors (TLRs) play a critical role in initiating the innate immune response to infection or injury. Recent studies have uncovered their intriguing functions as moonlighting proteins involved in various biological processes, including development, learning, and memory. However, the specific functions of individual TLRs are still largely unknown. AIMS: We investigated the effects of TLR3 and TLR9 receptor deficiency on motor, cognitive, and behavioral functions during development using genetically modified male mice of different ages. METHODS: We evaluated the motor coordination, anxiety-like behavior, spatial learning, and working memory of male mice lacking the TLR3 and TLR9 genes at different ages (two, four, six, and eight months) using the rotarod, open field, water maze, and T-maze tests. RESULTS: We observed that the deletion of either TLR3 or TLR9 resulted in impaired motor performance. Furthermore, young TLR3-deficient mice exhibited reduced anxiety-like behavior and spatial learning deficits; however, their working memory was unaffected. In contrast, young TLR9-knockout mice showed hyperactivity and a tendency toward decreased working memory. CONCLUSIONS: These findings provide valuable insights into the broader roles of the TLR system beyond the innate immune response, revealing its involvement in pathways associated with the central nervous system. Importantly, our results establish a strong association between the endosomal receptors TLR3 and TLR9 and the performance of motor, cognitive, and behavioral tasks that change over time. This study contributes to the growing body of research on the multifaceted functions of TLRs and enhances our understanding of their participation in non-immune-related processes.